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#172091 - 07/09/07 05:11 PM hk 3480 modification: science or wishful hearing?
rhinemaiden1 Offline
newbie

Registered: 05/10/07
Posts: 2
Question for Alan. What is your opinion of this article re: a dealer modification of the hk3480 to create a "better quality" receiver. Here is explanation on the dealer's site. http://www.stereodaves.com/modifications. Here is the articlehttp://www.hometheaterhifi.com/volume_14_2/hk-3480-receiver-daves-5-2007-part-2.html. a)is it logical b)w/no direct comparison to the original, is it meaningful. c) if the modification did create a better unit, would a careful listener in an average listening environment hear the difference? Thanks.


Edited by rhinemaiden1 (07/09/07 05:39 PM)

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#172092 - 07/09/07 06:48 PM Re: hk 3480 modification: science or wishful hearing? [Re: rhinemaiden1]
barilkobart Offline
old hand

Registered: 11/19/04
Posts: 87
Loc: Pickering, Ontario, Canada
Posted links don't work for me.

Anyone else?

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#172093 - 07/09/07 07:39 PM Re: hk 3480 modification: science or wishful heari [Re: rhinemaiden1]
tomtuttle Offline
axiomite

Registered: 06/20/03
Posts: 8288
Loc: Tacoma
The links didn't work for me, either.

Although I did search and find that our buddy Dave now advocates performing his magic on the HK 247. For only $300
Quote:

The modification to this unit cleans up the bass, improves the width and depth of the soundfield (along with location), improves the overall clarity of the unit, gives the unit a more spacious, penetrating sound, and improves the transient response of the piece. This highly dynamic and detailed receiver competes and bests amplifiers and receivers that are thousands more in cost.




http://www.stereodaves.com/modifications.php

I'm going to guess that the answers are maybe, no, and no.

Sounds like snake oil to me.

Sorry. I must be grumpy.
_________________________
bibere usque ad hilaritatem

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#172094 - 07/09/07 08:47 PM Re: hk 3480 modification: science or wishful heari [Re: tomtuttle]
Spoiler Offline
aficionado

Registered: 01/03/06
Posts: 680
Loc: South Florida
..and he modifies power conditioners, too!
_________________________
Epic 80 / SVS PB13 Ultra
Denon 3805 / M2200 Outlaw Monos /
Sammy 55" LED

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#172095 - 07/09/07 09:35 PM Re: hk 3480 modification: science or wishful heari [Re: tomtuttle]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
I don't see any measurements to back up the claims.

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#172096 - 07/09/07 09:43 PM Re: hk 3480 modification: science or wishful hearing? [Re: rhinemaiden1]
JohnK Offline
shareholder in the making

Registered: 05/11/02
Posts: 10388
Cam, judging from his website, "Stereo Dave" is a snakeoil merchant. The deficiencies he claims to exist in the stock units don't exist and it would be more than a little naive to believe that the mods he proposes can do something that the engineers at Harman couldn't accomplish.
_________________________
-----------------------------------

Enjoy the music, not the equipment.



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#172097 - 07/09/07 11:49 PM Re: hk 3480 modification: science or wishful hearing? [Re: JohnK]
LT61 Offline
aficionado

Registered: 02/23/04
Posts: 836
Loc: Illinois.
JohnK,

How can you not trust an audio professional, with the moniker: "Stereo Dave"?


Edited by LT61 (07/09/07 11:51 PM)
_________________________
LIFE: "Choices, balance, and timing"

(Larryism)

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#172098 - 07/10/07 12:08 AM Re: hk 3480 modification: science or wishful hearing? [Re: LT61]
St_PatGuy Offline
axiomite

Registered: 03/07/05
Posts: 7403
Loc: Glendale, Arizona
Quote:

JohnK,

How can you not trust an audio professional, with the moniker: "Stereo Dave"?




I guess that whole Van Halen thing didn't work out.

Pity.
_________________________
***********
"Nothin' up my sleeve. . ." --Bullwinkle J. Moose

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#172099 - 07/10/07 12:22 AM Re: hk 3480 modification: science or wishful hearing? [Re: LT61]
JohnK Offline
shareholder in the making

Registered: 05/11/02
Posts: 10388
Well Larry, if we heard something from Dave now, I'd be inclined to trust him, because after digging deeper into the site, it appears that he's passed away. So, I'd modify my "is" in the previous reply to "was".

The site rambles on nonsensically that his thing was to "improve electron flow", and this is accomplished with "quality" capacitors. So, this is another one of the capacitor scam sites which imply that more or better capacitors can work some mysterious magic.
_________________________
-----------------------------------

Enjoy the music, not the equipment.



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#172100 - 07/10/07 02:52 PM Re: hk 3480 modification: science or wishful hearing? [Re: JohnK]
2x6spds Offline
connoisseur

Registered: 03/16/02
Posts: 2726
Loc: CA, USA
I don't know whether stereo dave was the real thing or not, but I have no reason to assume he was a snake oil salesman.

There are outfits which modify and improve stock components. AH! Tjoeb modifies Marantz equipment and greatly improves those source components. There are many audio reviews which confirm this, reviews from sites which led many of us to Axiom products in the first place.

Check out Upscale Audio

The Upgrade Company has a good reputation. The Upgrade Compnay

There was an outfit which speciaiized in modifying Philips SACD 1000s and turned an excellent CDP into a world class player. They won't work on the Philps anymore, but they did great work. PHILIPS SACD 1000 MODS

The idea of tweaking a component of modest cost so it performs on par with much more expensive equipment should not be alien to Axiom fans ... after all, Axiom made its reputation by providing modestly priced speakers which compare favorably to much more expensive products.

There are folks out there who love audio, work at it, spend time in their work shops improving the sound from stock components.
_________________________
Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.

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#172101 - 07/10/07 03:29 PM Re: hk 3480 modification: science or wishful hearing? [Re: 2x6spds]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Do these component changes result in audible or measurable differences?

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#172102 - 07/10/07 07:41 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
pmbuko Offline
shareholder in the making

Registered: 04/02/03
Posts: 16273
Loc: Leesburg, Virginia
Them there's a loaded question. Audible and measurable in the same sentence? Bah!
_________________________
"I wish I had documented more…" said nobody on their death bed, ever.

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#172103 - 07/10/07 07:52 PM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Ok. Let's answer one at a time .

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#172104 - 07/10/07 11:24 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
2x6spds Offline
connoisseur

Registered: 03/16/02
Posts: 2726
Loc: CA, USA
Well, I have an Ah! Njoe Tjoeb CDP from Upscale Audio. I upgraded it with Ediswan tubes, noticeable difference in sound quality. I modified it with an Upsampler. Noticeable difference in sound quality.

I never got a chance to modify my Philips SACD 1000 because Philips stopped supporting the product. I modified many speakers - tweaked the cross-overs, upgraded the caps and resistors, etc. My Frankencenters (thanks PMBKO) are heavily modded and with new Axiom drivers and a Reference 3a de capo tweeter it certainly sounds very different from the original Merak kit. Different and MUCH better.

I modded a few pairs of Michaura M55s, very much like the Axiom M22s (same 5.25" drivers and the 3/4" titanium tweeter from the Mzero, M2Ti speakers) - a gorgeous Rose Wood hex shaped anti standing wave solid as a rock cabinet. I replaced the cap with some Jensen paper oils, the resistor with a Mills, and removed the fuse. How does it sound? Well, I brought a pair over to Big Will and we swapped out his beautiful M60s. I thought the M55s sounded as good as the wonderful M60s did. In my system, I ran these speakers with an Antique Sound Labs MG S1 15DT 5 wpc SET tube amp, the Ah! Njoe Tjoeb. The sound stage was huge, high, wide and deep. Imaging was spot on. I enjoyed a wall-of-sound experience which was spectacular. The stock M55s are wonderful sounding speakers, but it doesn't take long to hear the difference.

Have to go now. There is a world of modified and tweaked components out there. I have a little experience with a few. Hope it helped.
_________________________
Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.

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#172105 - 07/20/07 10:11 PM Re: hk 3480 modification: science or wishful heari [Re: rhinemaiden1]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
When I originally searched for any references to the review of Secrets of Home Theater and Hifi on the Stereo Dave's modification of an HK 3480 stereo receiver,
I had not seen this thread regarding the review. As the person who does these modifications, I felt I should respond to some of the remarks directed at Mr. Johnson's online publication and myself.

1) “Stereo Dave” Herren was my late employer and a friend. He was well respected in the Portland area audio community for his innovative custom made audio products and modifications of audio equipment. He had his own store for 25 years. Dave realized that unlike some people in this forum refuse to acknowledge, different brands and makes of audio equipment will have inherent strengths and weaknesses. If this were not so, we would not have so many brands of audio equipment. I think it is naïve to forget that there are many different makes of cars with their own strengths and weaknesses, despite the many engineers utilized in the manufacture of these various makes of cars. It’s well accepted among “car guys” that modifications can make large or vast difference in the performance of those vehicles, hence, a huge aftermarket industry. Mass market audio pieces, which are mid-fi priced, out of necessity have economic constraints imposed on them by the engineers, which have to do with keeping their price below a certain level, not necessarily to with optimal performance.

2) Regarding lack of comparison in the article, Mr. Johnson has no doubt reviewed thousands of pieces and is well qualified in evaluating the sound of performance of a regular $250 stereo receiver vs a modified unit. In the review, he also compares the measurements of the Modified HK 3480 with the listed measurements of the stock unit. The modified unit is shown to be superior to the manufacturers listed measurements.

3) Many people who have considerable amounts of engineering and electrical knowledge cheat themselves out of enjoying the music, by biasing their perceptions of what they hear based on the technical measurements / aspects of a unit. They fail to take an objective evaluation of a speaker or piece of audio equipment based on simply what they hear. Often the orthodox held beliefs have been proven to be not necessarily true; and we have found this to be true in audio. Often, the most expensive, theoretically highly measured equipment are inferior in sound performance compared to other pieces. And I'm sure a number you have had this experience. In fact, this is the dirty little secret in audio. We and many others have listened to modified equipment vs stock units and have easily heard the difference when the mod is done by a competent person. We are not the only company that does modifications. If there was no difference between modified equipment and stock equipment, modifications would have ceased a long time ago.

4) We have a proprietary modification that is not based on the standard capacitor based mod, but does effect the performance of many capacitors and components of the piece. The proof, however, is when people and reviewers listen to the modified units and discover that they are much better than the stock units, as pointed out in DVD player modifications review and receiver modification reviews and by our customers, who continue to give us feedback on the difference they hear.


Sean and Rick

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#172106 - 07/21/07 12:44 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
pmbuko Offline
shareholder in the making

Registered: 04/02/03
Posts: 16273
Loc: Leesburg, Virginia
1. Combustion and electronics are two completely separate and non-comparable things. It may seem like a good analogy, but it's not. Real-world differences between cars are easily verifiable under scientific scrutiny. The same is absolutely untrue of claimed differences among amplifiers, even those with $1000+ differences in retail price. I'm not trying to say one size fits all -- you should definitely buy an amplifier capable of driving your choice of speakers at the levels you desire without clipping, and that's all you should really worry about.

2. So the modded unit specs better, but do those specs result in a real-world performance gain, verifiable by double-blind listening tests? I don't often say "charts schmarts," but a drop of .02 (to make up a number) on the THD measurement isn't going to be audible.

3. "Many people who have considerable amounts of engineering and electrical knowledge cheat themselves out of enjoying the music." And many people who don't fool themselves into spending money on questionably frivolous "improvements". I enjoy my music quite well from my so-called budget system.

If there was no difference between modified equipment and stock equipment, modifications would have ceased a long time ago." Heard of the placebo effect? There are many many snake oil salesmen in the audio world peddling products that even you would agree are absolutely useless. (Example: wooden knobs) These products exist and people buy them because they don't know any better.

4. Audio memory is short. How can the customer be sure they hear a difference when they can't compare the before/after directly? The human brain is a fascinating organ capable of grand deception. It's wise to verify what it's telling you every once in a while.
_________________________
"I wish I had documented more…" said nobody on their death bed, ever.

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#172107 - 07/21/07 12:55 AM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Peter, well said. But I have to tell you that those wooden knobs have sent my blood pressure sky high.

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#172108 - 07/21/07 11:47 AM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
Ken.C Offline
shareholder in the making

Registered: 05/03/03
Posts: 17775
Loc: NoVA
OK, how's this? We know that most well made and designed amplifiers put out a flat signal, no? Perhaps the modifications roll off or boost the signal in certain spots that people find pleasing. It would be just like using a wire gauge that's too small to make the sound "warmer."
_________________________
I am the Doctor, and THIS... is my SPOON!

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#172109 - 07/21/07 01:12 PM Re: hk 3480 modification: science or wishful heari [Re: Ken.C]
Wid Offline
axiomite

Registered: 06/22/03
Posts: 6720
Loc: The Peoples Republic of Il.
I can see a modified unit sounding different. If the changes are made in the pre amp section it could audible. Whether or not better I have no idea.
_________________________
Rick


"A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud


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#172110 - 07/21/07 02:21 PM Re: hk 3480 modification: science or wishful heari [Re: Wid]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
If it sounds different, it should measure different. Let's see the data please.

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#172111 - 07/22/07 01:21 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
tomtuttle Offline
axiomite

Registered: 06/20/03
Posts: 8288
Loc: Tacoma
Quote:

an objective evaluation of a speaker or piece of audio equipment based on simply what they hear




Well, now you've gone and confused me about the difference between subjective and objective.
_________________________
bibere usque ad hilaritatem

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#172112 - 07/22/07 01:51 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
2x6spds Offline
connoisseur

Registered: 03/16/02
Posts: 2726
Loc: CA, USA
Sean and Rick

Perhaps you weren't aware that you're posting on the Axiom loudspeaker forum, where our members know it all. You can't fool us by even suggesting that different amplifiers with similar specifications have any discernable difference in sound quality. To suggest otherwise is a violation of the canons of collective wisdom here, and our canons of collective wisdom are strictly enforced by our resident geniuses like pmbuko.

We understand that there are snake oil salesmen out there who have dedicated their professional lives to tweaking, modifying, even designing and building audio components believing their efforts would result in an improvement of sound quality.

Now, here on this board, we don't really care about sound quality. We insist on listening to charts. Better men than you have snickered at the idea of audio bliss through frequency response curves, call us 'chart zombies and all, but then again, you're a stranger here, aren't you?

After a while, you'll fit in. Let us know when you start using string instead of fancy speaker wire and interconnects.

Then you'll be one of us.

Until then expect a bit of derisive correction from our enforcers of the one, revealed, audio truth.

Charts rule. Who needs ears.
_________________________
Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.

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#172113 - 07/22/07 02:16 AM Re: hk 3480 modification: science or wishful heari [Re: 2x6spds]
CV Offline
Founder, Axiom Upgrade Club
shareholder in the making

Registered: 07/20/06
Posts: 11200
Loc: Richland, WA, USA
The ears are fine. It's when they're connected to a brain that all of the problems arise.

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#172114 - 07/22/07 07:58 AM Re: hk 3480 modification: science or wishful heari [Re: 2x6spds]
Spoiler Offline
aficionado

Registered: 01/03/06
Posts: 680
Loc: South Florida
Close Your Eyes. Enjoy the Music. Then trust your ears. Respect Others with a Differing Valid Opinion.
_________________________
Epic 80 / SVS PB13 Ultra
Denon 3805 / M2200 Outlaw Monos /
Sammy 55" LED

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#172115 - 07/22/07 09:06 AM Re: hk 3480 modification: science or wishful heari [Re: Spoiler]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Let's get the facts first. Then we can distort them as much as we wish .

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#172116 - 07/22/07 09:08 AM Re: hk 3480 modification: science or wishful heari [Re: 2x6spds]
Ajax Offline
axiomite

Registered: 12/30/03
Posts: 6250
Loc: Cleveland, Ohio
Totally unnecessary and unproductive diatribe, 2x6. You made no argument or point, you just made personal attacks dripping with sarcasm and laced with grossly exaggerated, and false, hyperbole. Sadly, doing so says more about you than it does those whom you insult.

With so much anger, frustration, and hatred for many here, it causes one to wonder why on earth you even come here, let alone post here. The only answer that comes to mind is that your goal is to irritate, upset, and cause trouble. Congratulations, in all probability you've succeeded. Happy? Feeling good about yourself? How sad.
_________________________
Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton

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#172117 - 07/23/07 10:42 AM Re: hk 3480 modification: science or wishful heari [Re: Ajax]
Murph Offline
axiomite

Registered: 10/05/06
Posts: 6820
Loc: PEI, Canada

Not often my signature really applies, but here I think it does.....
_________________________
With great power comes Awesome irresponsibility.

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#172118 - 07/23/07 01:15 PM Re: hk 3480 modification: science or wishful heari [Re: 2x6spds]
zhimbo Offline
veteran

Registered: 02/15/07
Posts: 138
Loc: Hanover, New Hampshire
"Charts rule. Who needs ears. "

I care about ears.

The last time this sort of discussion came up, I practically begged for any and all valid, blind *listening* tests. (You know - listening. Done with ears).

The only ones presented basically fell into the "no detectable differences" column. You presented none, but instead preferred to present caricatures and strawmen: just like now!

So I'll take both ears and charts, and BOTH sources of data seem to point to the same conclusion.

But I'm always open to new info.


Edited by zhimbo (07/23/07 01:17 PM)

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#172119 - 07/23/07 04:05 PM Re: hk 3480 modification: science or wishful heari [Re: zhimbo]
pmbuko Offline
shareholder in the making

Registered: 04/02/03
Posts: 16273
Loc: Leesburg, Virginia
Well said, zhimbo. What 2x6 fails to remember every time this discussion arises is that the people he's railing against -- us scientific types -- wholeheartedly believe that ears are the best measuring instrument when it comes to determining whether amp A sounds better than amp B. The catch is that you need to keep your eyes and brain (which is full of conscious and unconscious bias) out of the equation by listening without seeing or knowing which device you're listening to.
_________________________
"I wish I had documented more…" said nobody on their death bed, ever.

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#172120 - 08/03/07 03:31 AM Re: hk 3480 modification: science or wishful heari [Re: rhinemaiden1]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
Fascinating responses I have been reading. Basically, what I am hearing is that as long as the wattage is appropriate for the speakers you are driving, it doesn’t matter what type of equipment you have. Interesting way of looking at things, considering that all players and receivers, not to mention speakers, have different inherent sound characteristics. Although, from some of your comments, I would assume that some of you just look at the price tag and wattage and as long as the unit plays music, you call that good, and discount any sound difference that you hear between brands as being “wishful hearing.” You can try to convince yourself all you want about how speakers other units that have certain advantageous measurements should all sound great, but the truth of the matter is that not everything that measures out well, will sound great. I’ve listened to many speakers that ficticiously went down to 20-17 hz, but I would say they were lucky to go down to 50 hz maybe. These speakers were from a number of major high-end manufacturers btw. Measurements are good, but unless the unit or speakers sound good when you listen to it, then it is meaningless. Many high-end pieces and speakers measure out great, but then you listen to them and realize that some cheaper pieces of equipment actually sound better to your ears. In all honesty, what your own ears hear is what matters. Will a person buy something that measures out very nicely on paper, but to their own ears sounds terrible? I think not.

I do acknowledge that there are plenty of tweaks out there that may or may not work. Much of it will have to do with a person’s system, as they are often meant to fix certain deficiencies. And some will be downright snake oil. Other tweaks will be too complex and ridiculously elaborate, and yet only offer minimal benefit. And, as I have stated before, many high-end manufacturers produce equipment that may cost quite a bit more, but in reality does not sound a lot better (if at all) than many cheaper manufacturers, which I believe is part of why the high-end audio is shrinking. If you want measurements for my modified HK 3480, they are on that review, but I would hope that some of you would let your ears hear the difference and not fool yourself into thinking that all equipment sounds the same and differences in sound are just an illusion.

Sean and Rick

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#172121 - 08/03/07 08:50 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
MarkSJohnson Online   happy
shareholder in the making

Registered: 09/27/04
Posts: 10886
Loc: Central NH
No on here has EVER claimed that speakers don't have distinct tonal qualities.

As to the rest of your post, well, it's just pretty snotty in tone, isn't it?
_________________________
::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::

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#172122 - 08/03/07 09:01 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Quote:

If you want measurements for my modified HK 3480, they are on that review...




Hi Sean and Rick,

Links to the review were posted by the person who originated this post but they are "broken". I'd appreciate if you can post the review so that I can read it.

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#172123 - 08/03/07 10:30 AM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Sean and Rick,

I am curious to hear your thoughts on this:

Re: AVR What to buy, need help??? [Re: Mojo]
#169929 - 05/18/07 05:41 PM


Some of you will like me for this and others will hate me but in the interest of advancing knowledge on this subject I have decided to post this.

I decided to blind test my wife's plastic, dinky Sony boombox with my Denon. Here are the specs:

Sony CFD-Z130: 2.3W + 2.3W into 3.2 Ohms at 10% harmonic distortion.

Denon AVR-2105: 90W + 90W into 8 Ohms at 0.08% THD from 20 Hz to 20 Khz; 125W + 125W into 4 Ohms at 0.7% THD at 1 KHz; dynamic power of 170W/channel into 4 Ohms.

For the Denon, I used my Sony with optical out as the CD source. The boombox has its own CD player.

I put on some Poncho Sanchez and adjusted the gains for 75 dB SPL. By the way, 75 dB in my room requires less than a watt per side. After I had everything adjusted I called in my wife, son and daughter and let them listen to the Denon for 2 minutes and the Sony for two minutes. Then I sent them back out and covered everything up. To make a long story short, we tested 12 times for a minute each time and I had them write down their answers each time. The test was painful as I had to keep changing the leads. Here is the raw data. The first field indicates the amp under test and the last three fields the selections they made:

1. S, D, D, S
2. S, S, D, S
3. S, D, S, S
4. D, D, D, S
5. D, D, S, D
6. D, D, D, S
7. D, S, S, S
8. S, S, S, D
9. S, S, S, S
10. S, D, S, S
11. D, S, D, D
12. D, S, S, D

Out of 36 possible trials, 21 turned up the correct response. That's not much different than guessing heads or tails.

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#172124 - 08/03/07 12:11 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
Ken.C Offline
shareholder in the making

Registered: 05/03/03
Posts: 17775
Loc: NoVA
Good lord. What speakers were you using for that? Also, I don't think that 2/3 is very equivalent to 50%.
_________________________
I am the Doctor, and THIS... is my SPOON!

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#172125 - 08/03/07 12:52 PM Re: hk 3480 modification: science or wishful heari [Re: Ken.C]
chesseroo Offline
connoisseur

Registered: 05/13/02
Posts: 4829
Loc: western canada
Quote:

Good lord. What speakers were you using for that? Also, I don't think that 2/3 is very equivalent to 50%.




Actually from a statistical perspective, the simplest conclusion is that there is no significant difference.
I would consider accepting a correct result 9 out of 10 times, a confidence level of 90%, which is less than that typically used in most science (alpha of 0.05 or 95% confidence limits). A value 2/3 correct falls well within the average of a normal distribution that could be expected from random guessing.

Anyone who has not done a controlled blind test does not have a clue how hard it really is. Those who never want to destroy their fragile egos by finding out how meaningless their "high end, overpriced electronics" are, have to resort to arguments of faith that can never be proved by their very cyclical nature.
_________________________
"Those who preach the myths of audio are ignorant of truth."

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#172126 - 08/03/07 01:53 PM Re: hk 3480 modification: science or wishful heari [Re: chesseroo]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
I was using the M80s.

My conclusion was that my family could not tell the difference between the Denon and the Sony.

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#172127 - 08/03/07 02:25 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
Ken.C Offline
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You hooked up M80s to a boombox and you couldn't hear the difference?!
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#172128 - 08/03/07 02:42 PM Re: hk 3480 modification: science or wishful heari [Re: Ken.C]
Mojo Offline
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Registered: 01/21/07
Posts: 3292
I never participated in the test.

But I don't know why you find that so surprising. I was putting in less than a quarter watt into each M80. This was well within the Sony's spec.

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#172129 - 08/03/07 02:48 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
Ken.C Offline
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How loud was it? I would expect 10% THD to be very audible.
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#172130 - 08/03/07 03:10 PM Re: hk 3480 modification: science or wishful heari [Re: Ken.C]
Mojo Offline
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Registered: 01/21/07
Posts: 3292
75dBC, slow-weighted with noise from a test CD. Remember that the 10% THD for the Sony is at maximum power. I have no idea what the THD is for the SPL that I calibrated.

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#172131 - 08/03/07 08:45 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
pmbuko Offline
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Were the speaker wires elevated off the floor by at least 2 inches? If not, then your signal was tainted with ground effect, which likely contributed a general muddy sound throughout the test making it more difficult to discern the differences between the amps.



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#172132 - 08/03/07 10:18 PM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
Mojo Offline
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Registered: 01/21/07
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I had both amps elevated about 2 feet above the speakers. The speaker wires thus ran "downhill" to the speakers ensuring that the electrons didn't run out of power by the time they reached the speaker terminals.

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#172133 - 08/03/07 10:24 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
CV Offline
Founder, Axiom Upgrade Club
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Posts: 11200
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Were humans holding the amps up, though? Electrons really need that personal touch, or they don't try as hard.

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#172134 - 08/05/07 10:48 PM Re: hk 3480 modification: science or wishful heari [Re: 2x6spds]
LT61 Offline
aficionado

Registered: 02/23/04
Posts: 836
Loc: Illinois.
2x6spds,

Quote:

Perhaps you weren't aware that you're posting on the Axiom loudspeaker forum, where our members know it all.




Now, THAT'S funny........(AND sardonic).
_________________________
LIFE: "Choices, balance, and timing"

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#172135 - 08/06/07 12:07 AM Re: hk 3480 modification: science or wishful heari [Re: LT61]
Ajax Offline
axiomite

Registered: 12/30/03
Posts: 6250
Loc: Cleveland, Ohio
...and accurate!
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"People generally quarrel because they cannot argue." - G. K. Chesterton

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#172136 - 08/07/07 10:33 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
Mojo,

In response to your request of the original links that were "broken," the links are below.

http://www.stereodaves.com/modifications.php

the review
http://www.hometheaterhifi.com/volume_14_2/hk-3480-receiver-daves-5-2007-part-1.html



In response to the gentleman who did the blind listening tests between speakers powered by a Sony Boombox and a Denon receiver, we have a few comments. Besides the already addressed comments on the speakers that were used, on the possible deficient speakers used in the "experiment;" we think that in a strange way your "experiment" only buttresses our point about stock units, particularly mid-fi mass market audio equipment. The Denon receiver should obviously be better than your Sony boombox, but even if your speakers aren't of the highest audiophile grade, you should be able to hear the difference. So factoring out the quality of your speakers, if there is no difference heard between the Sony boombox and your Denon receiver, to us, this only shows the lack of quality sound performance in the Denon stock receiver, which in our experience is often the case with unmodified stock units, particularly those of mid-fi mass market units, due to economic decisions made the in manufacturing of the components to keep the prices affordable. Our experience with more recent Denon stock components has been disappointing. To our ears, they sound thin and muddy. We have modified Denon's before and they do improve. We do prefer modifying Harman Kardon receivers because of the amount of improvement heard and the simplicity of the machine. More complex is not always better.

Rick and Sean

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#172137 - 08/08/07 01:13 PM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
pmbuko Offline
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Quote:

We have modified Denon's before and they do improve.



We can't simply take your word for it. You must have verifiable and testable evidence -- even evidence gathered using human ears alone -- before you can claim improvements. Doing a before and after comparison without instantaneously switching between the units AND without hiding which unit is playing when is insufficient.
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#172138 - 08/08/07 03:21 PM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Spoiler Offline
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Registered: 01/03/06
Posts: 680
Loc: South Florida
Why is it that true double-blind testing is not in your internet vocabulary? Your responses seem to ignore its existence and validity. If some tests were done and were in your favor, I'm sure we'd all be hearing about it.

It's interesting that the reviewer you linked to admitted not having an ummodded HK to compare to, yet gives the modded unit a glowing review!! Should we believe him 'just cuz'? Makes no sense to me, no matter how many reviews he's done or how 'well respected' he is.


I'm not sure what you were alluding to when you referred to "possible deficient speakers used", but I believe Mojo was using M80's. (Correct me Mojo if you did have an issue)

Link me to something, anything showing a double blind testing where results show that exotically priced amplifiers are sonically superior to moderately priced amps / receivers (at soft to moderate sound levels), and I'll seriously consider your point of view. All I've ever seen, read, and experienced has been the opposite.

Until that time, it's all "Cause I and some others say so"...or "I hear it, you may not."

I respect your right to believe what you choose to, but to me it's clear and makes sense... it's "wishful hearing" until I'm shown plainly otherwise.


_________________________
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Denon 3805 / M2200 Outlaw Monos /
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#172139 - 08/08/07 06:14 PM Re: hk 3480 modification: science or wishful heari [Re: Spoiler]
Mojo Offline
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Registered: 01/21/07
Posts: 3292
Yes sir. It was I who did this "test" and I did indeed use my M80s which I love so much. They are definitely not deficient. Everyone please note that the Sony was operating well within its specified limits.

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#172140 - 08/08/07 10:38 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
JohnK Offline
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Posts: 10388
Mo, prayers and best wishes for your father.

Yes, what was asked was whether there were measurements which showed "differences" from the unmodified unit. The linked review totally fails to meet that requirement; as Joe(spoiler)points out, the reviewer checked only the modified unit, yet alleged that he was "amazed" at the results. He stated that he didn't have "the luxury" of testing the unmodified unit, but surely rather than being a "luxury" this would have to be considered a minimum requirement for a credible comparison.

It can also be noted that the reviewer stated that the mod showed an "improvement" over the "spec" of the unmodified unit on bandwidth(140KHz rather than 110KHz), but failed to note that the actual measurements of similar unmodified HK receivers likewise show bandwidth in the 150KHz area(certainly not of audible significance), compared to the 110KHz spec. His use of "improvement" is therefore somewhat misleading.
_________________________
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#172141 - 08/10/07 09:28 AM Re: hk 3480 modification: science or wishful heari [Re: JohnK]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Quote:

It can also be noted that the reviewer stated that the mod showed an "improvement" over the "spec" of the unmodified unit on bandwidth(140KHz rather than 110KHz), but failed to note that the actual measurements of similar unmodified HK receivers likewise show bandwidth in the 150KHz area(certainly not of audible significance), compared to the 110KHz spec. His use of "improvement" is therefore somewhat misleading.




Thanks for the good wishes, JohnK. Where did you see that unmodified HK receivers show bandwidth in the 150KHz area?

It's very unfortunate (but perhaps very propitious for Stereo Dave's) that an unmodified unit was not available for subjective and objective testing.

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#172142 - 08/10/07 10:23 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
I am curious now as to what M80 brand speakers you are referring to. We have seen the floor standing Millenia M80's to computer speakers (cambridge soundworks). Gosh help us if you are comparing two units with computer speakers that only go down to 62 hz, putting only a quarter watt into each channel. How much volume does that actually give you?

RickSean

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#172143 - 08/10/07 10:43 PM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
pmbuko Offline
shareholder in the making

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Loc: Leesburg, Virginia
Back up a step and take a look at the site you're posting that last question on. Is it really that ambiguous? If you were on a BMW fansite and someone said, "I'm amazed at the performance my M3 gives me!" do you think someone would ask him if he was referring to a BMW M3 or this WWII-era vehicle?
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#172144 - 08/10/07 11:04 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
JohnK Offline
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Registered: 05/11/02
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Mo, although it's not a big deal, for example the HK 7300 which has amplifier sections similar to if not identical with the 3480, including a 110KHz bandwith spec, measured as 166KHz here . My mention of the bandwidth point wasn't because it was of any audible significance, but rather that the reviewer seemed to be using a misleading term, i.e., "improvement", when the measurement was simply better than a conservative spec number.
_________________________
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Enjoy the music, not the equipment.



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#172145 - 08/10/07 11:17 PM Re: hk 3480 modification: science or wishful heari [Re: JohnK]
michael_d Offline
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Registered: 07/23/04
Posts: 3904
Loc: Up yonder
Dammtttt… Dropped my popcorn….

I sure do enjoy being indecisive and non-committal when these topics come up. They’re entertaining as hell when I couldn’t care less who the winner is….
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#172146 - 08/11/07 01:41 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
I used Axiom M80s.

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#172147 - 08/24/07 02:29 AM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
Let me get this this straight.. you are running the Axiom M80's (which say they need a minimum wattage of 10W) with 2.3 watts of power from the Sony Boombox? I would have to think that dynamics, bass frequencies and overall clarity would be greatly diminished.

Also, about the reference to the HK 7300; it is about a $1000 unit right now (was more expensive earlier when it was produced). I do not believe it is being made at this time and has not been made for about 2 yrs. It hasn't been on my dealer list for 2 yrs, nor is it on the HK website. This is a substantially more expensive receiver than my modified piece and I would likely take a guess does not sound as good even a stock unit of the HK 3485. The electronic components inside the HK units have changed in the last few years. For instance, the HK 3480 that was reviewed (which at the time was current) has been replaced by the HK 3485. The HK 3485 is clearer, is more dynamic, with more precise bass, and better location and "airy" highs. It has the same amount of wattage, but defintely seems to have better electronics.

Rick Sean

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#172148 - 08/24/07 09:56 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Murph Offline
axiomite

Registered: 10/05/06
Posts: 6820
Loc: PEI, Canada
Trying to understand both sides of the arguments here.

Exactly which parts of the "better electronics" in these two specific models being compared would create the better sound you mention. I have a fundamental understanding of electronics but not as to how current variations relates to sound depth, soundstage, etc. If you can fill in the gaps to explain your argument, it would be appreciated.

I'll expect the debunking theories too follow but both are required for me to learn and hearing both sides make for a good discussion, if nothing else.

Andrew
_________________________
With great power comes Awesome irresponsibility.

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#172149 - 08/24/07 10:07 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Quote:

Let me get this this straight.. you are running the Axiom M80's (which say they need a minimum wattage of 10W) with 2.3 watts of power from the Sony Boombox? I would have to think that dynamics, bass frequencies and overall clarity would be greatly diminished.




Not even 2.3W actually. More like a quarter watt...so well below the Sony's maximum spec. Members that read these posts regularly, know that I listen to music through my M80s at about a half watt per side (for an SPL of around 80dB) and movies at a few watts.

As I understand it, the minimum power spec of 10W tends to be indicative of the power needed for "good" bass output. If you take a look at the M80 frequency response plot, the SPL at "lower" frequencies is attenuated. Hence, putting in a minimum of 10W will bring the SPL at say 20Hz, up to around 75dB which is a respectable level. It will also blow your ears off at higher frequencies so putting in more power is not a great way to increase low frequency performance.

This is why during normal listening, I also have my EP600 on. For this "test" however, I had the sub off. The point is, the listeners could not tell the difference between the dynamics, bass and clarity of the two systems. BTW, although I did not participate in the test, I can certainly tell you that Poncho sounded great through the M80s at this low level.

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#172150 - 08/28/07 07:27 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
That is really very interesting. I did talk this over with an associate of mine, who has been around audio for many years and who worked for my late boss, and his response was rather the same as mine. We both were perplexed at how a speaker that says its minimum wattage is 10W can be powered very well at all at a quarter of a watt. With that amount of wattage, you would only be listening to the tweeter, as the bass driver would not have enough wattage to hardly move, if move at all. The crossover's capacitors also require a certain amount of wattage to power up as well, and may also not be functioning very optimally. I would have to say, that at this low, barely functional wattage level, it would be near impossible to tell the difference between that denon receiver and the Sony, as the woofers would not be functioning hardly at all at a quarter of a watt. Not that I am a fan of Denon equipment, mind you. You would not be able to hear the difference in either harshness or richness or depth when comparing the units at that low wattage level when only the tweeters are functional. A more fair comparison, if you wanted to prove your point that expensive gear is not always the best in fidelity, would have been to compare a cheaper brand receiver (not a very low wattage boombox that can't drive your woofers) with that denon at equal output levels that drove your woofers of your speakers and the subwoofer coming from the receivers. You would then be able to judge at decent wattage how well the units were doing in terms of harshness, midrange, and bass frequency and then be able to make a very fair and interesting comparison between how the individual units sounded throughout the frequency range, not just at the upperend of the frequency range, which tells you nothing about the bass / midrange levels and their quality. I would suggest using a sub in this comparison, you could judge how clean and deep the units you were comparing went and how solid those frequencies were. I am not saying the Denon, would win out either. In fact, I have a suspicion you may find a receiver that was substantially cheaper that could very well beat it. I am not a fan of how Denon equipment sounds, especially the more recent Denon equipment. But I do not think that conducting a test where you are running less than a quarter watt into each speaker from a Sony boombox and a denon is a very fair test, when a person would only be hearing the tweeters. This of course brings us to a discussion about wattage amounts and more wattage vs less, damping factor etc. I personally have noticed a large amount of difference when comparing modified units that had less or a greater amount of wattage. The cone control and precision of movement is just far better. I do not think, though, that the technology was there for high wattage clean sounding units until recently.

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#172151 - 08/28/07 11:14 PM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
pmbuko Offline
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Quote:

With that amount of wattage, you would only be listening to the tweeter, as the bass driver would not have enough wattage to hardly move, if move at all.



That statement right there shows that you and your associate have a fundamental misunderstanding of how speakers use power. When speakers are tested for efficiency, the most common method is to feed them 1 Watt of power and to measure the resulting decibel level 1 meter away. The M80s measure at 91dB in an anechoic chamber and 95 dB in a typical room. The tweeter alone is not responsible for those levels.
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#172152 - 08/29/07 12:26 AM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
tomtuttle Offline
axiomite

Registered: 06/20/03
Posts: 8288
Loc: Tacoma
Alright, everybody freeze! I've got a keyboard and I'm not afraid to use it!

Now, fly this thread to Austin RIGHT NOW and nobody gets hurt!
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#172153 - 08/29/07 07:45 AM Re: hk 3480 modification: science or wishful heari [Re: tomtuttle]
Spoiler Offline
aficionado

Registered: 01/03/06
Posts: 680
Loc: South Florida
Dam hijackers! How many times have I told you to keep that pilot door locked!!
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Denon 3805 / M2200 Outlaw Monos /
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#172154 - 08/29/07 07:00 PM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Mojo Offline
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Registered: 01/21/07
Posts: 3292
In response to RickSean's last post, I've confirmed that the M80s have no problem producing respectable SPLs with a quarter watt and less right down to 40Hz. See the chart below. The background to the measurements for power is shown here.

RickSean, the arguments therefore that you have posited are null and void. I also want to point out that capacitors don't require any "powering up" as they are passive components. And from what I've witnessed out of my low-cost receiver, Denon is to be commended for their engineering prowess.

So, we are now back to square one.



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#172155 - 08/29/07 08:45 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
pmbuko Offline
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Posts: 16273
Loc: Leesburg, Virginia
The extent to which you're geeking out about this is something to behold. I love it.
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#172156 - 08/29/07 10:29 PM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
Mojo Offline
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Registered: 01/21/07
Posts: 3292
I of course geek out to keep you amused . So here is some more amusement for you.

I have no idea what the minimum power rating for a speaker means. At first I thought it was to ensure adequate dispersion. But my ears told me that couldn't be it and then I checked the off-axis frequency response graphs for the M80 and they were excellent with 1 Watt. If anyone knows, please tell us.

With regard to cone control and precision of movement, I am curious how RickSean confirmed that a higher power amp provides an improvement in this area.

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#172157 - 08/29/07 10:41 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
SirQuack Offline
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As long as I've been researching speakers, most manufacturers websites give a recommended min/max amp rating. I think it is just a recommendation and you might be reading to much into it. Look at the 80's, they say 400w for max power. We all know they can handle amplification that far exceeds 400w. As I've mentioned before, in recent lab tests Axiom when testing the new amp drove a pair of m80's continuous for 2 weeks 24hr/day with 700 watts with peaks exceeding 1100 watts.
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#172158 - 08/29/07 10:47 PM Re: hk 3480 modification: science or wishful heari [Re: SirQuack]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Quote:

I think it is just a recommendation and you might be reading to much into it. Look at the 80's, they say 400w for max power.




Max power I can understand. But why a minimum that is clearly far greater than the minimum that I and others experience. A half watt is a far cry from 10 watts.

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#172159 - 08/29/07 11:02 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
JohnK Offline
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Posts: 10388
Mo, as Randy indicated, those suggestions for amp power aren't very meaningful. I suppose that it could be said that the minimum suggestion is something that the speaker manufacturer believes would be adequate to power his speaker even on peaks in "typical"(whatever that means)situations.
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#172160 - 08/29/07 11:07 PM Re: hk 3480 modification: science or wishful heari [Re: JohnK]
Mojo Offline
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Registered: 01/21/07
Posts: 3292
What you're suggesting makes the most sense...sort of. If you're listening to your M80s at an 1/8 watt average, 10W is more than plenty for most material.

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#172161 - 08/30/07 02:02 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
Spoiler Offline
aficionado

Registered: 01/03/06
Posts: 680
Loc: South Florida
Just a guess, but perhaps the minimum wattage spec refers to a recommended minimum rated power for the receiver/amp driving the speakers?
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#172162 - 08/30/07 02:05 PM Re: hk 3480 modification: science or wishful heari [Re: Spoiler]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
That's what JohnK said above. And I said 10W for the M80s would be a reasonable minimum for most material if you listen to them at 1/8 watt on average.

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#172163 - 09/01/07 01:59 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
bridgman Offline
axiomite

Registered: 08/25/04
Posts: 5408
Loc: Bowmanville, Ontario, Canada
>>With regard to cone control and precision of movement, I am curious how RickSean confirmed that a higher power amp provides an improvement in this area.

I think this is the damping factor argument. Big-ass amplifiers tend to have lower effective resistance in the output stages, which IIRC should result in slightly tighter control of the cone movement. Same idea as braking in a full hybrid car, where placing a heavy load (battery charger) on the motor/generator makes it act as a brake.

Either Alan or Ian mentioned that the damping factor argument had been debunked recently although I didn't have time to get the details. Debunked or not, my understanding is that there is a point of diminishing returns, so that the audible difference between a "pretty good" amplifier and a "really good big-ass amp" is negligible.

A not-so-good amp with high output impedence (low damping factor) could presumably result in looser bass, in the same way as having speaker wires which are MUCH too thin could introduce enough resistance to affect the sound.

Just a note to Randy from another thread -- the "Big-ass Amplifier Club" is for people with high power, high quality amplifiers. The "Big Ass Amplifier Club" is something which you may want to avoid.

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#172164 - 09/01/07 02:44 PM Re: hk 3480 modification: science or wishful heari [Re: bridgman]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
Quote:

>>Debunked or not, my understanding is that there is a point of diminishing returns, so that the audible difference between a "pretty good" amplifier and a "really good big-ass amp" is negligible.

Correct.

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#172165 - 09/01/07 10:39 PM Re: hk 3480 modification: science or wishful heari [Re: bridgman]
JohnK Offline
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Registered: 05/11/02
Posts: 10388
Probably re-debunked recently, John. Gene published this study in Audioholics by speaker designer Dick Pierce a few years ago and more recently in Audioholics Mark Sanfilipo covered the point. It appears that amplifier damping has very little to do with "controlling" the speaker, almost nothing until the low single digits that some tube designs exhibit. Anything much beyond the start of the double digits seems to be mostly hot air and even inexpensive solid state designs run around 50 or more.
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#172166 - 09/05/07 08:15 PM Re: hk 3480 modification: science or wishful heari [Re: Mojo]
RickSean Offline
regular

Registered: 07/20/07
Posts: 7
Well, I have to admit this has been an interesting side discussion. I did end up by writing to Axiom Audio, out of curiosity, and a very nice gentleman, JC, did write me back. I would like to post excerpts of his response to my email. I would still argue that the methods used in Mojo’s experiment to prove a Sony Boombox is as good as Denon are highly flawed. Again, I am not a fan of Denon equipment (particularly newer pieces, as I feel the older equipment was actually better sounding). Below are excerpts of JC answers to my questions with my own comments.


In response to my question as to the efficiency of the M80s being able to play at 91db at 1 meter with 1 watt of power and how the woofers would be powered, JC first explained that the speakers would technically play at 91db at 1 meter away with 1 watt, but this was not a constant, unchanging 1 watt of power for the entire frequency range, as was inferred by Mojo. JC stated: “We tend to talk of speakers and amplifiers in static load terms but this is not how they work. A speaker will have (or at least should have) a constant and equal output at each frequency at each wattage level of input. This being said a speaker load is not static in that it changes with frequency. So when we are talking one watt that will be one watt at one frequency (generally 1 kHz), or if broadband then 1 watt at the lowest point on the impedance curve. So the amplifier is not actually putting out one watt at all frequencies. Generally it will be the lower frequencies that consume the most power (resonance point exce!
pted) so hence the concept you are pointing out that the bass driver will be harder to drive than the tweeter.” This is what I had thought previously, as most people know that the bass frequencies are what consumes the vast amount of power.

JC further comments on something which I had wondered about as well, considering how Mojo says he listens to movies at “a few watts.” JC states: “To add another twist to this is the dynamics of music and movies. There is no such thing as playing music or movies at 1 watt; this number would really just be some sort of average power required. Given, lets say a 12 db dynamic peak occurred from your average of 1 watt this peak would require 16 watts of power. Now if you were sitting 26 feet back from a pair of speakers that had an anechoic output of 91 db per watt at 1 meter. You would add say 3 db for the room gain and another 3 db for the second speaker. Now you have 97 dB of output at one watt per channel and one meter back. At 26 feet back you would have 79 dB due to the inverse square law. So if you wanted to have your 91 dB at 26 feet back you would need to put in an average of 16 watts to achieve this. Now your 12 dB peak would require 256 watts to reproduce. This is why so much power is required, especially in a large space.” This is also about what I had already knew. If Mojo is listening to movies at “a few watts,” they had better be very low in volume and be lacking in dynamics, in a rather small room and in close proximity to the speakers. Dynamic range itself would take more than “a few watts.”

In response to my question of whether a person could play the M80s at adequate enough fidelity to conduct a test between two receivers at only a quarter of a watt, JC’s reply was: “That is partially true and it would applied only under certain conditions: an exceedingly small listening room space – a very low volume level – a source material which contain very limited dynamics.” This is actually about what I suspected. Also, by Mojo not testing what is going on below 40 hz and not running a subwoofer also puts in jeopardy the validity of his “test.” To be able to test out two pieces of equipment, you not only need to compare dynamics, but also most people would want to compare how clean or tight it runs the bass, especially low bass (aka below 40hz). Some receivers may sound fine on the upper frequencies and possibly even midrange, but will tend to sound either “boomy” or light or muddy in the bass, and to be able to tell this, you need to be able to hear it. Mojo can make all the charts he wants, but I think he is missing the point of what he is trying to do in the first place. This isn’t a contest as to “what is the least amount of watts I can get away with?” The question really is about comparing low cost pieces of equipment to the more expensive pieces. I have done the same a number of times and the high-end piece does not necessarily win out. If he wants to compare a low priced piece and compare it to a more expensive piece and say that there is no sound difference, he should find something that puts out a low, but decent amount of wattage, instead of putting out wattage at below 3 watts. I do not think it is a very fair way how to compare two receivers if you are merely playing them at one fourth of a watt, with rather low volume and lacking dynamic range, which requires higher wattage to be reproduced correctly. This tells you nothing about the character of the receivers, how they react to dynamics, and the clarity of their sound (especially how they deal with low bass).

As to the current discussion of minimum watts rating JC responded: “Again, the 10 watt rating is for a very small room but also for people running tube amps. Tube amps have a very soft sort of analog clipping which means you can get away with lower power and not have the harsh attributes of output device clipping.”

I personally, always run my speakers at a much higher wattage than the minimum and, as stated earlier, have found that it helps performance. I can tell my speakers are more under control with more power available, proven by listening (a foreign concept to some people around here it seems). When I added a dedicated line (increasing power capacity available and less interference from other circuits), and when I inserted my modified HK 3485 receiver into the system (150 watts for 4ohm, thereby, allowing my already very efficient speakers and subwoofers to have more power available), I noticed in both occasions tighter bass, clearer highs, which would be accounted for by the amplifier being able to control the cone movement to a greater degree. This is what damping factor describes; the ability of a receiver to control the speakers cone movement. A very interesting online article speaking of this and how you really do need more watts to reproduce realistic sound is found below. It was actually posted by another Axiom Audio gentleman.

http://forum.ecoustics.com/bbs/messages/34579/109138.html

In in it he talks about the relationship between SPL, wattage and live sound and attempts to reproduce live sound. Near the end of his rather lengthy post he states: “From all this you can see the huge power requirements inherent in reproducing real-life acoustic sound levels in average or big rooms…. It's the distortion that makes it sound "loud" in a domestic setting…. The lesson in all this is that you can never have too much power, and that big amplifiers rarely damage speakers. Little amplifiers driven into clipping burn out speakers. In the scheme of high fidelity, that last barrier to realism is having enough power and being able to approximate real-life loudness levels.”

by Alan Lofft, Axiom Audio

The article was very interesting and I think would be a good read for anyone. I have personally found that by having a clean, higher wattage receiver, that my “air,” overall definition and stage have improved. The audio is not audibly “louder” by a great degree. In fact, harshness as noticeably decreased.

RickSean

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#172167 - 09/05/07 09:43 PM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
pmbuko Offline
shareholder in the making

Registered: 04/02/03
Posts: 16273
Loc: Leesburg, Virginia
Now that's the kind of post that elevates a discussion from "roll your eyes while reading" to "hey, this is actually getting interesting and educational." Thanks for contributing and not running away screaming when many of us weren't taking you seriously.

For the most part, I have to agree with what you (and JC) say. It's not the average power consumption that's important, but the peaks. That's where the true tests of equipment are. Randy (sirquack) drove this point home very firmly when he was unable to get his new Emotiva amp to perform up to snuff in his "underground cavern" of a basement.

I must point out a flaw in some of your reasoning, however.
Quote:

Also, by Mojo not testing what is going on below 40 hz and not running a subwoofer also puts in jeopardy the validity of his “test.” To be able to test out two pieces of equipment, you not only need to compare dynamics, but also most people would want to compare how clean or tight it runs the bass, especially low bass (aka below 40hz). Some receivers may sound fine on the upper frequencies and possibly even midrange, but will tend to sound either “boomy” or light or muddy in the bass, and to be able to tell this, you need to be able to hear it.



Most subwoofers have onboard amps. When you enable the sub out on a receiver, it peels off the audio signal below the crossover point and sends it out the line level sub output -- unamplified. This results in a lighter, more easier to drive load going to the high level speaker outputs to which the rest of the speakers are connected.

I believe he got better results by not including the subwoofer in the test.
_________________________
"I wish I had documented more…" said nobody on their death bed, ever.

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#172168 - 09/05/07 09:53 PM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
Wid Offline
axiomite

Registered: 06/22/03
Posts: 6720
Loc: The Peoples Republic of Il.
From Ian

"Over the years I have always found the sound differences between amplifiers to be subtle when compared to the differences found in speakers. Hence if budget is a concern you are probably better to cut a little deeper on the amp side. The main reason for this is that amplifiers (with the exception of some bizarre designs out there) do not colour the tonal balance of the performance nor have any bearing on the off axis response. This does not mean that all amplifiers sound the same but that different factors come into play. Without question the big one is the amount of power available to play dynamic peaks. Wid was commenting earlier about the statement that at normal listening levels you do not need more than a watt or two and I agree with him that this statement is, in practical terms, false; though granted in mathematical terms under certain conditions it can be proved true. The power required to bring home a great performance can get pretty large if you want even just moderate listening levels in a large space without any clipping in the dynamics. The reality is that when most people want to crank up their system they rarely achieve the volume level they truly want; instead they go to the level of clipping distortion in the dynamics that they can put up with (which sounds painfully harsh and loud even if it isn’t)."
_________________________
Rick


"A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud


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#172169 - 09/05/07 09:55 PM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
SirQuack Offline
shareholder in the making

Registered: 01/29/04
Posts: 13333
Loc: Iowa
Thanks Peter, Peter, Peter, Peter, oh sorry I was down in my cavern and it echos a lot, no wonder I have treatments.

I'm starting to believe that it is not ALL about power (watts). I'm starting to believe Klaus from Odyssey Audio more and more about the importance of Capacitance reserve. I can really tell now that when listening to music with lots of dynamics at higher levels my new Odyssey Monoblocks just don't run out of gas or show any signs of stress.

Oh yeah, they have a great damping factor as well.

ps: Rick, we all know that guy Alan very well.
_________________________
M80s-VP180-QS8s-EP600-2xEP350 Denon3808 Outlaw7700
M22-OWM22-VP100-Denon2805
Audio Nirvana

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#172170 - 09/05/07 11:16 PM Re: hk 3480 modification: science or wishful heari [Re: pmbuko]
St_PatGuy Offline
axiomite

Registered: 03/07/05
Posts: 7403
Loc: Glendale, Arizona
Quote:

Now that's the kind of post that elevates a discussion from "roll your eyes while reading" to "hey, this is actually getting interesting and educational." Thanks for contributing and not running away screaming when many of us weren't taking you seriously.




Agreed. Well said, Peter! And, also, well said, RickSean. Thanks for the contribution.
_________________________
***********
"Nothin' up my sleeve. . ." --Bullwinkle J. Moose

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#172171 - 09/07/07 12:09 AM Re: hk 3480 modification: science or wishful heari [Re: RickSean]
Mojo Offline
connoisseur

Registered: 01/21/07
Posts: 3292
I'd like to address Rick and Sean's last post. Although I agree with the spirit of most points, some details require clarification.

Quote:

I would still argue that the methods used in Mojo’s experiment to prove a Sony Boombox is as good as Denon are highly flawed.




The purpose of my original "test" wasn't to compare the Denon against the Sony. Rather, it was to compare the two at the same power level. To that end, I'd say my "test" was designed fairly and nothing that has been posted to date proves otherwise as I will argue below.

Quote:

In response to my question as to the efficiency of the M80s being able to play at 91db at 1 meter with 1 watt of power and how the woofers would be powered, JC first explained that the speakers would technically play at 91db at 1 meter away with 1 watt, but this was not a constant, unchanging 1 watt of power for the entire frequency range, as was inferred by Mojo. JC stated: “We tend to talk of speakers and amplifiers in static load terms but this is not how they work. A speaker will have (or at least should have) a constant and equal output at each frequency at each wattage level of input. This being said a speaker load is not static in that it changes with frequency. So when we are talking one watt that will be one watt at one frequency (generally 1 kHz), or if broadband then 1 watt at the lowest point on the impedance curve. So the amplifier is not actually putting out one watt at all frequencies. Generally it will be the lower frequencies that consume the most power (resonance point exce!
pted) so hence the concept you are pointing out that the bass driver will be harder to drive than the tweeter.” This is what I had thought previously, as most people know that the bass frequencies are what consumes the vast amount of power.




I am not sure what the above is getting at but from the test I conducted, it was obvious that the Sony and Denon could equally provide the power demanded by the M80s. By the way, bass frequencies do not consume the vast amount of power. They do however demand higher current than higher frequencies. Power is not a function of the frequency; current and voltage are however. The source material could demand 50 watts at any frequency.

Quote:

JC further comments on something which I had wondered about as well, considering how Mojo says he listens to movies at “a few watts.” JC states: “To add another twist to this is the dynamics of music and movies. There is no such thing as playing music or movies at 1 watt; this number would really just be some sort of average power required. Given, lets say a 12 db dynamic peak occurred from your average of 1 watt this peak would require 16 watts of power. Now if you were sitting 26 feet back from a pair of speakers that had an anechoic output of 91 db per watt at 1 meter. You would add say 3 db for the room gain and another 3 db for the second speaker. Now you have 97 dB of output at one watt per channel and one meter back. At 26 feet back you would have 79 dB due to the inverse square law. So if you wanted to have your 91 dB at 26 feet back you would need to put in an average of 16 watts to achieve this. Now your 12 dB peak would require 256 watts to reproduce. This is why so much power is required, especially in a large space.” This is also about what I had already knew. If Mojo is listening to movies at “a few watts,” they had better be very low in volume and be lacking in dynamics, in a rather small room and in close proximity to the speakers. Dynamic range itself would take more than “a few watts.”

In response to my question of whether a person could play the M80s at adequate enough fidelity to conduct a test between two receivers at only a quarter of a watt, JC’s reply was: “That is partially true and it would applied only under certain conditions: an exceedingly small listening room space – a very low volume level – a source material which contain very limited dynamics.” This is actually about what I suspected. Also, by Mojo not testing what is going on below 40 hz and not running a subwoofer also puts in jeopardy the validity of his “test.” To be able to test out two pieces of equipment, you not only need to compare dynamics, but also most people would want to compare how clean or tight it runs the bass, especially low bass (aka below 40hz). Some receivers may sound fine on the upper frequencies and possibly even midrange, but will tend to sound either “boomy” or light or muddy in the bass, and to be able to tell this, you need to be able to hear it. Mojo can make all the charts he wants, but I think he is missing the point of what he is trying to do in the first place. This isn’t a contest as to “what is the least amount of watts I can get away with?” The question really is about comparing low cost pieces of equipment to the more expensive pieces. I have done the same a number of times and the high-end piece does not necessarily win out. If he wants to compare a low priced piece and compare it to a more expensive piece and say that there is no sound difference, he should find something that puts out a low, but decent amount of wattage, instead of putting out wattage at below 3 watts. I do not think it is a very fair way how to compare two receivers if you are merely playing them at one fourth of a watt, with rather low volume and lacking dynamic range, which requires higher wattage to be reproduced correctly. This tells you nothing about the character of the receivers, how they react to dynamics, and the clarity of their sound (especially how they deal with low bass).




I agree with the spirit of the above. At no time would I ever encourage anyone to purchase an amplifier of a half watt for music and a few watts for movies. These are of course nominal values and dynamics require much more power than this. And this leads to an omission on my part and I do apologize for any confusion that I may have caused newbies. I should have pointed out that these power levels are nominal values.

As I have posted elsewhere on these boards, if you listen at a nominal level of 1/4 watt to music, a 10W amplifier is adequate giving you about 16dB of headroom. And for movies, if you listen at a nominal level of 2 watts, a 64W amplifier should be fine with about 15dB of headroom. So those of us that buy 90W/channel amps should be quite satisfied. And for those with Denon amps, you can be quite sure that you can hit peaks of twice rated continuous power before square-waving takes place. And for those of you that have been reading my posts, you know that these are the typical power levels in my 4,000 cubic foot home theater and they give rise to nominal sound pressure levels of 85-90 dBC. 4,000 cubic feet is not an "exceedingly small listening room".

As to the argument about low bass, I think pmbuko summed it up. A sub-woofer would have placed less of a load on the amps.

I just want to point out again that I was not comparing the Denon against the Sony in an absolute manner. It was a relative test at the same power levels that I typically experience in my home theater while listening to music. If it was an absolute test, the Denon would win hands down.

Rick & Sean stated that they like to run their speakers at a much higher wattage than the minimum. I assume that they are referring to nominal power levels. If I was to run my M80s at a nominal level of 10 watts (their minimum), I would go deaf in my room. I already enjoy nominal sound pressure levels of 85dB to 90dB with nominal levels of a quarter to a half watt.

So my primitive but nonetheless effective test still shows that two amplifiers, when operated within their spec, sound the same. But we're still back to square one on the effect of after-market component tweaks on sound quality. Rick and Sean, both of you obviously have considerable passion for this subject and are in a perfect position to convince us using a combination of technical tests using measuring instruments as well as properly structured A/B listening tests. Imagine the positive impact that irrefutable proof would have on your business. I and others on this site are anxious to see the results.

BTW, I don't know why some text in the quoted sections is garbled.

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