Axiom Home Page Forums General Discussion Technical Questions From a 1909, how much better SQ to 2809. To 3808.

Alan, are you out there?

If Alan has not already written on this, I would like to see if he or others would try to quantify this.
(I have just re-read Alan's Secrets of Amps. article. Which does not focus on this aspect.)

How does one notice or experience increased sound quality with each small, incremental increase in an AVR's power and it's components upgrades? Many of us with modest 90-100 wpc AVR's who are or might consider upgrading for new features, would also like to know what kind of SQ increase we might expect jumping up a model or two.

I was going to ask about AVR's in general, but to give better info for comparison purposes, I am speaking specifically of three Denon models: (A)1909, 90w {I have} (B)2809, 115w & (C)3808, 130w. [Just for reference, the speakers in use will be M80's, VP150, (4) QS8's, (1) Paradigm Servo 15 and (2) KLH 10" subs (in a large 31'x23' room).]

I do watch mostly (BD) movies, but for purposes of describing nuanced SQ changes between these three amps, If you just want to speak to M80's in stereo, that would answer my question as well. (My music listening would probably be in 7 channel stereo.)

We all know the macro story that at the limits of a 1909, it will start to distort just a few dB's below the 2809. The 3808, would go a few dB louder before distorting.

I have read plenty on the upper dB macro discussion and it has been discussed at length, which I hope to avoid here.

I am looking for the nuanced differences in SQ as you go up from the 1909, to a 2809, then to a 3808. Of course the power supply and and amp sections get larger as well as other upgraded components going up the model line. While knowing the hows and whys would be interesting, what I really want to know is the noticeable affect at normal listening levels.

We already decided to leave out 'loud' (95dB+) listening levels. Please speak to perceived and/or measured SQ differences using as the base the (A) 90w 1909, then up to (B)115w 2809 then (C) 3808 130w. I am not sure what SPL level is best to describe this nuanced difference, but for commonality of comparison, I'll just say throw out a 75dB SPL measured or calculated for the common listening distance of 12'. To me, any anechoic lab spec at shorter than a normal listening distance (12'), would not translate for me. So please translate any SPL dB speak.

Actually Db SPL is only a reference point at which you describe or measure SQ differences between the AVRs.

Please forgive the very specific parameters (and this novelette, though Mark would be proud. ) . My experience is that a lot of back and forth is avoided when as many variables are taken into account in the original question. I am certainly no audiophile... that's why I humbly ask help of those who are much more savvy than I.

I'm hardly an audiophile Dave, at least in my opinion. If I understand what your asking, I really don't think your going to notice any difference in sound quality between these receivers, especially at a modest 75dB listening level if everything is apples to apples. You would hear differences if you turn on special DSP modes or tone controls or Audyssey, however, if speaker setup, calibration, etc., is the same, I doubt there would be any audible difference.

Dave, you wouldn't notice "increased sound quality" with the incremental increases that you describe, because it wouldn't exist. At the specific average listening level that you propose of 75dB(which is in fact a good level for average use without causing hearing damage)and at a listening distance of 12'(in-room sound levels fall at a rate far less than 6dB per doubling of listening distance), I calculate that the M80s will be using about a tenth of a watt. Brief split second peaks(say 20dB) on the most dynamic program material with the widest dynamic range would use about 100 times that, i.e., 10 watts. This is easily within the limits for audibly flawless amplification of any of the typical HT receivers with ratings anywhere in the 100 watt area. Adding incremental increases in maximum power output which amount to about about 1dB or less at each step can provide no benefit if the available max is already more than sufficient. Unused headroom is simply that: unused.

Hello Dave,
There is very little chance that there is any nuance difference between the three Denon AVR’s you are questioning. You can measure the quality of an amplifier, but “sound quality” is subjective.
You may measure the quality of the amp and its circuitry, and then listen for any improvement in sound quality the hardware MAY provide.
Sans any consideration to greater functionality, these three AVR’s, I would guess, are identical in terms of overall sound. (Of course any amp will distort if overdriven)
One might be able to calculate approximately what an amplifier may sound like from its measurements, but measurements can be deceiving when you try to match them to sound quality.

The difference in volume between these AVR’s is slight at best, less than 3dB between the 1909 and the 3808. Further, SPL has no relevance to sound quality, and is mainly used to describe speaker sensitivity in this context.

Enjoy the music

Davekro,

I would agree with all the responses here--that you'd be unlikely to hear any audible differences at modest to fairly loud peaks--say, around 95 dB SPL at your listening seat. It is only when you get into much louder peaks (say 105 dB, which subjectively would sound "twice as loud" as peaks at 95 dB) that differences might be audible.

It would also depend on how critical a listener you are. Many of us of a certain age put up with ghastly distortions from phono cartridges playing highly modulated grooves towards the inner part of vinyl discs, yet it didn't ruin the musical enjoyment (admittedly, my knuckles would turn white if I were listening to a work for orchestra and chorus that had its biggest crescendo in the inner grooves. I'd be thinking, will my
Shure V15 Type V in a custom SME tonearm track these without audibly distorting?)

Plus the power handling of the loudspeaker itself would come into play. On very loud peaks, smaller speakers may start getting edgy sounding as the distortion approaches audibility. (Axiom speakers generally have excellent power handling) but lots of speakers don't like, or can't handle, peak levels very well, including all planar flat-panel designs--electrostatic and planar-magnetic.

I'd also point out that through a particular line of AV receivers, the power supply may NOT change as you step up the model range until the very top of the line. I don't know the exact engineering details of Denon's power supplies, and I won't speculate. In many cases, stepping up to a more elaborate model simply gets you more features, inputs and outputs, and greater versatility, but the basic power supply and internal amplifier modules remain the same.

Regards,

Alan

Dave, I think you short circuited the issue by injecting the 75db level. The above are clearly more informed on the technical side. But as the article you cite explains, the issue comes up when you want to go over 75 (come on guys, that is looooowwwww) into the realm of more realistic volumes to reproduce the original source. If a piano hits 109 live, then I think my room should be at least 100 on a jazz CD to even get close to the feel of watching Ray Brown live with a stand up bass struming away as some kid jammed on the piano. (Didn't appreciate that performance it at the time, as I was there to see Irving Mayfield, a popular Trumpet player. Didn't know a legend was on the bass and would pass away soon after. :( )

Anyway, I think this is at the heart of much of the clash between fact and feel you get on the watts issue. If John K likes to listen at 80db, he is not likely to exceed the headroom in his AVR, and would see no benefit in getting a 300 watt amp. But, as Alan's article explains, when I want to listen at 102db 12 feet from the speaker, I need to multiply the power many times over.

As clipping occurs, the sound quality question comes into play. My Denon 3300 starts clipping at under 78.6 watts (THD .016%) while clearly noticeable THD (1%) arrives at 135.3 watts. [My speakers are 4-ohm so those number are actually 95 to first clip, and 174 to 1% THD]. Thus, when I ask the AVR to reproduce the sound of Ray Brown's stand up bass at the 103db, it can't do it without cutting the frequencies off and clipping to some extent, thus not sounding as "good" as the Axiom 1400 that has the power to get to the live level of 109db without clipping (i.e., degrading the sound quality) at all. [JohnK, does that make sense?]

So, in my "more informed than last year" opinion, I would say the 3000 series, at 130+ watts will give you a few extra dbs over the 1900's 90+, but may clip much higher than the 1900, and thus "technically" sound better - not considering the impact of bigger capacitors, and different power supplies, which I don't understand at this point. Plus Audyessy if that applies here.

But at 75db, stick with the 1900, you won't use the extra headroom. But, if you want to "get there" - that momentary suspension of disbelief that makes your brain think for a second you are hearing the performance in your room - then you need to get louder and cleaner. I have only experienced that feeling of a live performance in the room on a few rare occasions - and never in my home. But I am striving to get that in my home. The system I first got there with (my FIRST!) was Krell Amps, driving Wilson Watt speakers, via B&K sources. That system sold for over $100,000. I'm not there yet. But getting better every year, and am convinced it don't take $100K to get there.

A very helpful and informative discussion so far. Charles, I wanted to avoid the comparison of modest power (90-130w) to huge power separates, A1400, et al, because that is not a path I want to, or can afford to go down.

Many of us want to understand as best we can what choices to make that will give us the biggest bang for the buck in the $500-$1200 AVR range. And to TRY to understand if/how and additional $300 (2809) or $600 (3808) will give us better SQ at 95dB and lower, along with the extra features. I fully understand what is required when you expect clean power well above 100dB. That is a discussion for a different level of audio experience.

I picked 75dB rather arbitrarily. When I finally got around to buying a Radio Shack SPL meter, I learned what 75dB, 85dB, and 95dB sounded like at 12' in my HT. To try to quantify my perception a bit, 75dB felt like a nice comfortable listening level, 85dB felt like about how I like to watch an action BD at, while 95dB sounded very LOUD. 95dB was a level I would not want to listen to for more than a few minutes for a movie. Now, throw back a few beers, pop in ZZ Top Live From Texas Blu-Ray, and 95dB is gonna work! If I turn it up past that, I will be fine with limiting my listening to whatever SPL is produced this side of distortion (prior to serious clipping) for the rare times I do this. The WAF is big for HT. She does not like it as loud as I do. She likes rock and roll louder. But she does not drink, so she may nix much above 100dB!

(I am saving the debut of my new ZZ Top BD until my new Axioms arrive MONDAY ! !! Woo Hoo!

I will definitely keep the SPL meter out on a tripod for SPL monitoring for a while while trying out the new speakers, and how the 1909 works for me with them. If I had not already jumped on the 1909 in Dec, at this point I probably would have gotten a 2809 0r 3808. At THIS point already having the 1909, I am trying to discern if spending $1,100 for a 3808 and selling the 1909, is worth it. I like some of the 3808 features, but don't 'need' them. If there is a SQ increase, that would tip me toward buying a 3808.

It appears from the discussion so far, that I would stick with the 1909 with no real difference in SQ at 95dB or lower, compared to the 2809 and 3808.

I guess my NEXT question is if my ZZ Top + beer test leaves me wishing I had a bit more head room for 1-2dB SPL at my max listening (pre distortion) level, that may tilt me to the 3808 still. I am doing my best to TRY to not succumb to a false idea of actually what more SQ I'd get (or need) from going to a 3808. So there it is. My quandary spelled out.

Dave, I picked up ZZ Top Live From Texas last week...you better get some cheap sunglasses, you're in for a treat!

You know you want Audyssey MultEQ XT.

Randy,
I still do not know what this actually does over regular MultEQ. Can you please 'splain it to me? (you are correct in assuming I may just need an 'excuse or two go there'. )