As promised, here is a new thread just for the EP-600 review. Eventually, there will be some comparisons to the PB12-Ultra. For now, here is the starter graph with no eq applied ...

Picture is here now... You mean I waited all day and night and refreshed your arrival page for this Lets get the ball moving J/K I have been waiting 8 months for my ep 600 80 set... Now where is the comparisons.

Here is a "peak hold" graph of Master and Commander. I left it on peak hold so everyone could see the bass spectaculars, and then I stopped it during dialogue - which is the SPL listed in the upper left - appx. 75 dB...

This sub hits HARD...

To help those interested, some explanation of the Master and Commander graph... the EP-600 was delivering 120 dB peaks in the 25 to 30 Hz band on the cannon shots. This weekend, I will try the same scene on twin Ultras. The room was shaking, yet this bass was never sloppy - just deep, tight and powerful.

It passed this test nicely. This disc also has 45 dB peaks over the normal dialogue. That means a tough disc for a home theater ...

Tonight, I used "The Incredibles" for some more testing. The graph is of the fight scene between Mr. Incredible and the 4 legged robot.

A note - This NOT a frequency response curve, it shows the max SPL's at differing frequencies which are being delivered by the movie. More analysis below ...

The Fight Scene graph :



Note the most potent bass here is from about 25 to 32 Hz. Again, this is what the movie delivers in the soundtrack.

I will hopefully find a movie with some solid 16 Hz bass - which is rare. Suggestions accepted ...

Try I Robot.Not the best of movies but quite a bit of bass.

I will look into I Robot again - I think the really powerful stuff was in the 25 Hz range there, too.

For example, The Incredibles has some pretty potent stuff in the 20 Hz range, but at a signifigantly lower level than at 25 to 35 Hz.

Craig, Put in disc 2 of The Incredibles, and select Jack-Jack Attack. Right at the end where the FBI agent uses the "neuralizer" (sp? - sorry) on Kari, there is a deep rumble that rattles everything in my basement. Not sure how deep it is.......

Real 80's ... I just did. Basically, it was a plateau of bass from 28 to 32 Hz. That may also give you an idea how DEEP 28 to 32 Hz is. By the way, it drops like a cliff below and above that 4 Hz band.

Craig I am awaiting all of your reviews on this and have downloaded all your graphs(hope you dont mind). I think there was talk about the whale in "Finding Nemo" and cannons from "Pirates of the Caribbean" Depth charges in "U-571". These are just some of the movies I have heard of.

They all have, like most movies, STRONG bass in the mid 20's with some lower levels in the 15 to 20 Hz range. When you watch the graph, for example, with "The Incredibles", you can see the 115 dB stuff at 28 Hz with some 95-100 dB stuff in the 15-20 Hz range.

By the way, I am liking this subwoofer a LOT.

Craig,

Great to see ya up to your usual self...torturing another sub :^D

There is some sub 20 Hz stuff in the opening credits (1 minute in) of Day After Tomorrow, as well as when the ship hits the bus underwater and the chopper scene.

Also, in Man On Fire, also during the opening credits, starting at 2 minutes and change, there is a pulse that has some sub 20 Hz undertones.

Great sub. I've had my eye on this one and looking forward to the whole scoop!

Bosso

Dave! Great to have you here! Guys, bossobass is a regular over at av123 (though I don't know, nor do I care, if he owns any Rocket gear). He is one of the most knowledgeable sub guys I've come across. In fact, he created a Subwoofer Setup Guide that any of you who are sub freaks, or those who are merely interested in learning more about using a subwoofer, might find interesting.

If you treat him courteously, you will find him a very helpful font of good information on subs, their setup, and their operation.

I'm so glad you've stopped by, Dave. I hope you'll pop in now and then.

Dave, welcome to the fold!

Hi ya Bosso ! We own DAT and Man on Fire - Thanks for the heads up. I will be watching DAT with my son tonight. My wife and daughter are out of town for a wedding. We are having a Dad and Sons weekend - this should be fun.

Craig, as I recall "HellBoy" had some good stuff, esp. in the opening scene with the portal sucking things into it.

Another one is Spiderman 2, when Doc Oc fires up the reactor thingamabob!

I am unsure of the frequency but the scene in "Pirates of the Caribbean" when Elizabeth falls into the water and the pirate coin necklace floats out of her bodice, there is a (appropriate term?) bass "thrum" that occurs which is also displayed by a ripple in the water that the Royal Navy guys react to..."What was that...?"

The scene in LOTR - Two Towers with Golem, Sam and Frodo in the Dead Marsh when the Nazgul flies over on the dragon...it's wing manipulation has an impressive bass hit to it as well...

Although you probably know about these...

WhatFurrer

I read somewhere that the THX intro with the lighting and exploding ball had some good LFE down to single digits.

It does, but at much lower levels than the appx. 30 Hz frequency. I confirmed this on the Twin SVS Ultras in their 12 Hz setting.

What about the opening of Girl With a Pearl Earring? That's probably already in the disc changer for Father/Son weekend anyway . . .

A girl who what ?

Good point. The artillery blasts and depth charges in Girl with a Pearl Earring are pretty mind-blowing. Then when Scarlett Johansson taps on the tank...

I'd give up my sub if Scarlett Johansson was in the room!

Time to do a search. I never even heard of this disc ... yikes !

Don't bother, it looks like a chick flick

Yes, It does. I will wait for da Missus to return for this one.

You won't be needing the EP600 for it either... probably no content below 80 Hz, just cellos and violins

EDIT -- well, a cello does go down to 65 Hz but you still don't need the sub...

For an update, we are getting SERIOUS about working over the EP-600. Last night, it as "Star Wars", and this morning we watched "The Matrix".

The EP-600 seems to be tuned to the 18 Hz - and from that point and up, it delivers HUGE amounts of bass.

There is a lot of physics going on with this subwoofer, and some really intelligent choices. Take a large enclosure (appx 5.5 cubic feet), put in a high excursion driver, a large port with that 18 Hz tuning frequency and combine it with a sensible DSP set up which makes it bullet proof.

On "The Matrix", it handled everything tossed at it. During the Helicopter scene, the room was TOTALLY pressurized, yet the bass managed to not cause the type of wall vibrations the SVS PB12-Ultra does. The combo of having the sub driver WELL off the floor, and the one inch thick rubber feet give the EP-600 the same benefit we realized by putting the SVS PB12-Ultra on a "sub-Dude", which is $50.

For an EP-600 "deal", if you look at a "B" stock, the price becomes $1575 delivered. ( $1750 less 10%) ...

A wood finished Ultra with sub-dude is $1448 delivered, with "B" stock $50 less - $1398.

They are natural competitors, for sure.

This is shaping up as a GREAT shootout.

What the heck is a sub-dude ? I get the play on words but what is it ?

EDIT -- here's what I know so far :

- Auralex makes an isolation platform a few inches high, sounds like this is what Craig is referring to

- a LOT of people use SubDude as their handle on boards

- there is a chain of sub shops in Charlotte with the same name :

Subdude Inc.
10901 University City Blvd, Charlotte
(704) 595-9990

Subdude Inc.
1620 E 4th Street, Charlotte
(704) 334-9998

I have to thank Al Gore for inventing the Internet and delivering so much wonderful trivia into our lives.

bridgman - I was using "A", the Auralex isolation platform ...

Yeah, I figured "C" would give comparable isolation but would make a mess on your carpet as the EP600 squeezed all the condiments out

Your comments on the improvements from isolating the sub are really interesting. Are you running on a covered concrete floor (ie basement) or a regular interior floor over joists ?

This room has an oak floor over a concrete slab with 2x6's for a "spacer".

I was wondering where he went. Murderer.

And to think I thought 2x6 had disappeared due to a disasterous encounter with "Frankenstein"

Now that I know the truth......

'What the heck is a sub-dude?'

Well I suppose one of these cats may very well be a sub-dude. Great music btw!

Craisub, great assessment on the 600. Just whenever I was thinking about the twin Hsu STF3 MKII setup that Legairre was talking about, you come along and add another twist!

Craig, come on man! We are starving for more comments, impressions, comparisons, and so on! Don't make us beg! Ok, I'll beg! Oh please oh please oh please oh please!!!!!!!!!

Sorry - I have been too jammed with biz stuff the past few days. For movies, we watched "The Wedding Date" and "The Upside of Anger" this week. Not much in the way of bass there ... Maybe a few more things this weekend ...

HaHa! No worries. Completely understandable. Are you able to drive up/fly in for the get together Saturday?

I was hoping too - but there is just too much stuff going on here.

Update time. When we got the EP-600 in, as stated earlier, we had a pair of SVS PB12-Ultra/2's.

We also have been beta-testing the new Velodyne SMS-1, which was hooked up to the SVS. The SMS-1 has been hooked up to the EP-600 for the past two weeks, and we have done a lot of switching between the SVS pair and the EP-600.

Both subwoofers are capable of shaking the room with ease. That being said, the EP-600 is, IMO, a superior reproducer of bass when compared to the SVS. It has a way of responding to bass spectaculars that the SVS misses.

In the past three days, we have watched "The Italian Job", "Constantine", "The Matrix", and "The Fifth Element".

The two subwoofers are equal as far as force on scenes like the explosion which drops the safe into the water early on in "Italian Job", but the EP-600 hits harder in the chest. And when Charlie hits Steve in the restaurant scene, the SVS gives a thud, while the EP-600 give a SMACK that you feel.

This performance repeats itself in other movies, and on music as well.

For now, I will go on record as saying the EP-600 is a better bass machine than is the PB12-Ultra pair, with this caveat: To be REALLY certain, I will be running them both nearfield, to make sure it is not the room which is the deciding factor.

High praise indeed! What are we comparing here? One 12" driver in a large cabinet vs.two big cabinets with two 12" drivers in each?

I know this is asking the impossible, but how do you feel the EP600 compares to the Maestro. For those who don't know, Craig had a Maestro from ACI ($2100 with a monster 15" driver), which he found VERY impressive. What I'm asking him to do is compare a sub he's been listening to for weeks (EP600), to one he hasn't heard in months (Maestro). So, keep in mind that anything he has to say is based on his MEMORY of the Maestro.

Jack, The Maestro had a lot of the same characteristics of the EP-600. They both (as does the Velodyne DD-18) have the ability to react more quickly than does the SVS pair - and yes, the SVS pair means two 12 inch drivers in two big cabinets.

One area which actually helps the Axiom is the designers made what I consider to be intelligent choices. The Axiom is ALWAYS in the same tune, with the amplifier optimized to match. This tuning gives bass down to about 16 Hz in our large room. The SVS, quite frankly, can go even lower.

But, 99.99% of all bass is 16 Hz and up, and the EP-600, right now, is walking away from the SVS PAIR in real world performance.

Later this fall/winter, when I get a new Hsu VTF-3 HO, I will be trying all three nearfield, for confirmation.

Thanks Craig.

Wow, sounds like the 600 is the way to go. Like Jack says, thanks Craig for sharing and updating your findings!

You are welcome. By the way, did you see the date for the GTG is officially set for November 19 ?

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The Axiom is ALWAYS in the same tune, with the amplifier optimized to match

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I find that an interesting comment.With that being said,would a Stf series have an advantage over a VTF series.

Not really ... different design goals. (Good logic, though....). Please allow me to elaborate:

The built in DSP/AMP combo with the EP-600, for lack of better terms, "knows" what the driver is doing at all times. It keeps the driver under control, and also delivers a flat response, even under conditions that cause subwoofers without this type of control to lose audible performance.

The STF-3 and VTF-3 use conventional amps, as does SVS. This is not a knock on either, by the way, for the money, they are both excellent.

It is this "intelligent" amp/dsp set up COMBINED with good physics which works so well for the EP-600.

Gottcha

Wow. If a single EP-600 is noticeably better than a pair of PB12-Ultra/2s, then a pair should be able to kick the pants off pretty much anything else out there -- even subs at ungodly prices. This is very high praise, indeed!

I'm tellin' ya. Dennis, with his two EP600s, is gonna, singlehandedly, cause the big one on the San Andreas fault.

Peter, if I understand Craig correctly, the SVS pair will go deeper, and perhaps even play louder. But, the EP600 is "cleaner," "smoother," "more responsive." I hate trying to subjectify performance. If those terms aren't conveying what your hearing, Craig, feel free to correct me. If I've got it correct, it would all depend upon your personal preferences as to which is "better." I don't know about anyone else, but 16Hz is plenty low enough for me, and I live in an apartment, so I don't need to rattle the windows. BUT, that smooth, clean response sure sounds attractive.

craigsub: Can you speculate if there would a potential loss of performance if the EP600 is horizontal on the floor tucked into a nook into the wall almost emulating a floor level center channel recessed into the wall? Since the sub is front firing I am presuming it should not be an issue.

Saturn - You should be fine - the biggest potential problem will be room nodes - and a good EQ to tame peaks will cure that.

And guys - pending the outcome with the Hsu, and with the EP-600 slated to go into our family room, I am considering getting four EP-600's for the upstairs theater room. Think of it as a $6800 super sub.

He's mad! Mad, I tell you!

OH MY LORD! EARTHQUAKE!

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He's mad! Mad, I tell you!

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Actually, He is pretty happy... And he bets Ian talks him down to two.

Only because Ian doesn't want to go up to 4, as well.

Does he use two ? I did not know that... He would probably be right to advise that 2 is plenty. I just have this pic of 4 in my mind ...

I think he was running a single EP600 until Dennis ordered a second sub... then of course Ian had to upgrade as well.

EDIT -- my mistake; it was the other way round. Ian added a second EP600 at home and his results were a factor in Dennis doubling up the 600s in his system :

"Well after having recommendations Alan, and from Amie since Ian added a second, and they seem to have a similar listening area as to size and surfaces. I figured my thought of adding a second was not all that far off. LOL "

OK, so I'm new to this whole killer-sub thing and am totally intrigued by the idea. Is there a minimum size room that is suggested for utilizing two subs?

There are two reasons for going with multiple subs :

1. Getting more bass capacity than you can get out of a single sub.

2. Room resonances (modes) often give you uneven bass response, and even worse give you different bass response at different points in the room. Having multiple sound sources helps... generally you would have the two subs in different parts of the room for best results.

Reason #1 tends to be related to room size; larger rooms need larger subs and eventually you hit the limits of what a single sub can do.

Reason #2 is largely independent of room size; often small rooms can have worse response curves than large rooms.

The area that I am in the process of developing into my HT is a basement room that is divided with the HT on one side and a wetbar game-table area on the other. Each area is about 15x20 sharing an open border. I don't know if the open area to the left of the HT area matters, but with all of this talk of "moving air" with the speakers, it seems that it would have some impact.

That reminds me of a third reason people buy multiple subs... it's hard to predict exactly what you are going to need, so one good strategy is to buy something less than a big monster sub (but still get something that will go deep into the bass) and add a second one if the first one turns out to be a bit too small but otherwise good.

Note that this only makes sense if you start with a fairly capable sub in the first place. Two cheap subs do not equal one good sub -- even 500 cheap subs will not be able to reproduce the really low notes.

Sounds like good advice... but sometimes it's really difficult to pass on what you really lust for. But then, I'm getting off the subject.

Yeah... I guess we're kinda drifting off the thread topic as well

Craig, thanks very much for organizing this. I only knew enough about the EP600 to be able to say "dang, that's nice" !!

Since I usually hijack my own threads, you guys go ahead and have fun. This IS a hobby, afterall ...

This is a fun process. I wonder if Ian would consider building a QUAD 600 sub ... maybe 72 inches long, 30 inches tall, and 18 inches deep. Four x 12 inch drivers, and porting to match.

Hay - a guy can ASK ... right ?

Not an altogether far fetched idea, that is the quad-sub concept. SVS has a limited edition "B12+4" offering that sounds like may have sparked your challenge for a quad-4 600 from Axiom,eh? Why stop there, Axiom is working on "in-the-wall" hybrid speakers, why not a mega-sub that would be a built-in that would rattle the rafters. I can't imagine more resonance than the whole room. But I digress.

We had a B4 + here last year. Pretty nice sub. But what made me think about a Quad 600 was how good a single 600 sounded ...

What really gets me excited about the integration of a good sub(s) is that it takes music/video and moves it beyond aural/visual/cerebral and integrates physical presence into the experience. Therefore, the more forceful the sub, the more moving the experience. Yea, more is definately better, at least until the cops arrive. Or your wife leaves. Whoa, got way too carried away with that one... A Quad-600 would definately do the job!

Any new developments / thoughts with this Craig? I tried to read the AVS thread, but couldn't make it pass the 4th page.

I have no idea what the hell's going on with all that banter.

I just finished reading the whole thread (took almost 2 hours and I read pretty fast) and didn't learn anything past about the 10th page. The executive summary is :

- Craig and Ilkka both did excellent reviews; Craig focused more on listening tests while Ilkka focused more on measurements

- They came to somewhat different conclusions. The main issue was THD; Ilkka's THD numbers on the 600 were suspiciously high, to the point where many suspected a problem with the measurements. Ilkka concluded the problem was "Axiom's wimpy driver", which seems both premature and probably wrong to me

- many pages of vitriol, including accusations that both Craig and Ilkka had falsified their measurements to let their favorite vendor win. To me, this seems insane and childish to boot; both are doing this as a hobby; neither would even consider fudging the numbers to affect the outcome

- several pages of confusion between "Axiom confirmed that the EP600 was typical" and "Axiom agrees with all my measurements" resulting in nearly everyone being pissed off

- it does seem possible that the spiffy DSP firmware in the 500/600 is kicking in on test tones (but not on real movie/music content) and mucking up the results. Axiom has revised the firmware at least once to fine-tune the limiter code which some interpreted as an improvement and others claimed were a clear sign that Axiom was shipping defective product. Not worthy of comment unless you think Axiom is the only company to ever release a firmware upgrade

- there has apparently been a slight change in the port characteristics on the 600. Details are conflicting -- seems to involve lowering the tune point a few Hz, which presumably might require a corresponding update in the DSP firmware

- a couple of EP600 owners piped in, including at least one owner ("jakeman") who also owns an SVS Ultra. Jakeman contacted Axiom to get more info and ended up visiting (he lives pretty close to them) which inflamed the avsforum people even more

- decision to organize an impartial test at NRC, presumably initiated by Craig (I'm guessing here), with invitations sent to both Axiom and SVS in case they want to participate directly

- another round of muck-raking, to the point where now people are questioning whether the NRC would be impartial because Ian used to be involved with their research (as were the technical leads of Paradigm, PSB and Energy)

- a couple of suggestions that a fist-fight between Craig and Ilkka might settle things

- a side discussion on body fat % that I still don't fully understand

Anyways, hopefully this will all settle down. After reading 23 pages of posts my personal impressions haven't changed at all, being :

- if you ripped out the DSP from the EP600 and just compared hardware, the Ultra would probably outperform the 600 by a small margin in terms of maximum clean SPL around 20 Hz. Since Ilkka's tests focused on single tones, his conclusions leaned the same way. Even so, his THD readings (>10 % at pretty much all frequencies and SPLs) seem suspect. There was some discussion that background noise (wind ?) might have been a factor.

- playing real content, the 600 seems to be a stellar performer and multiple people have indicated that it seems to outperform an Ultra in many listening tests, giving the perception of more headroom and more useful output over the Ultra

Which is better ? No easy answer there.

bridgman sized it up pretty well.

Indeed! Fantastic job, John. The only thing you left out (and reasonably so, since you probably are unfamiliar with it) is the history between Craig, Ilkka, and many of the rest of us. There are those, over at AVS, who would, should Craig say it's November, call up some ancient calendar, and say that he's deleted a month, and/or is incapable of reading a calendar, or is out to deprive us of Christmas. They accuse him of incompetence or malfeasance and try to discredit him every time he posts. Craig, for the most part, keeps it relatively civil. Though I have seen his posts, over the years, understandably, become more acerbic, compared to his detractors, he still remains on the higher road. And, had you witnessed what he's been through, as I have, you would marvel at his restraint. Sometimes, enough is enough, and you have to speak up in your own defense.

As for Ilkka, I have a personal gripe that I will not go into in depth. Suffice it to say, that I took the time to lend a hand in what I felt to be a gracious gesture, and was slapped in the face. I plead guilty to an unrelenting negative bias. Add to that his knee jerk defensiveness, his need to demonstrate to all how intelligent he is, and his tendency to personally insult anyone who dares disagree with him, and, bright though he may be, I find him insufferably condescending. He is 24 (or so) and seems to have a pathological need to impress one and all.

After all his insulting questioning of Craig's ability, and integrity, I plead guilty to enjoying his outrage, and righteous indignation at having me, and others, question HIS motives and methods. I'm not necessarily proud of that reaction, but I am human, and one can only stand so much.

Ahh, that explains a few things. If it helps at all, I was probably worse than Ilkka when I was 24

I found it very interesting that this Ilkka fellow ABSOLUTELY refused to listen to the EP subjectively in it's correct orientation. He stated "But I was using the EP-600 in the downfiring configuration (placed a few books on each end) and it obviously didn't like it. There was a good 2.5" between the woofer and the floor, but when looking at the results, airflow was propably restricted" because "I had to use this configuration, because others were giving me a very bad FR." Note also that he tested an upright 600 in a horizontal orientation. I don't know if his claims that this makes no difference is true. I have seen posts from Ian in this forum stating that you shouldn't do this. I do know that Scott Mitchell put up great numbers as QB for the Detroit Lions a few years back but was eventually released because in reality he made bad decisions and lost games. Numbers are never the whole story.

Nice job, as usual, bridgman! You have condensed the "Free-For-All" thread at AVSforum posted by some character known as "Ilkka" nicely. And thanks Ajax for the insightful history of the relationship between between the rather vengeful members at AVS and their all out assualt on Craigsub. It helps keep things in perspective.

I recieved my epic 80/600 7.1 system several weeks ago, and haven't regretted one minute of time spent (or one dollar spent as well) enjoying this combination of speakers. I have never heard a sub come across so deep/powerful/smooth all at once, as the ep600. I am relatively new to the subwoofer culture but I have heard some fairly exotic sound systems in the past. The ep600 has the most refined deep bass that I have witnessed to date.

Nice job Craigsub on your gracious responses to the harsh criticism. Thats a though line to hold and you do it well...

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Note also that he tested an upright 600 in a horizontal orientation. I don't know if his claims that this makes no difference is true. I have seen posts from Ian in this forum stating that you shouldn't do this.

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Whenever I ordered my 600 I was asked by the Axiom folks if it was to be the 600V or 600H....meaning either Vertical or Horizontal. Regarding performance, I don't think it matters whether the sub is positioned in either configuration.

I personally believe you could put this sub in the neighbor's house and it would *still* knock your socks off ... from across the street.

You guys serve as constant reminders as to why this is the only forum I'm involved with!

Right you are, Mark.

I've zipped around thru some of the others off and on through the last few years, and this is the Only One I've ever contributed to(or detracted from)

The only one that seems to be a comfortable place to stay!!





(insert "Cheers" theme song here)




Rich

Hi gents, This does get tiring, for sure. I just cannot let the total slam of a great product go unchallenged. I hope you guys can keep this thread going. IT is nice to actually get the occasional encouragement ...

(Read aloud with deep voice):

CraigSUB..... CraigSUB....CraigSUB......

Let's start a "wave"...

You guys crack me up.

I loathe "the wave". It was invented by and for people who are disinclined to actually watch the game they paid to attend.

However, I do deeply appreciate Bridgeman's synopsis, Craigsub's candor and Jack's eloquence.

The Axiom forum remains my online home for these and many other reasons.

I loved the observation about numbers not telling the whole story. Has anybody looked at Dave Krieg's career stats?

I just want to know how what happened at the Axiom plant………when are those results going to be shared?

Thank you for the summary of the discussion at AVSForum. As you may have gathered, we have an issue with the test procedures used, which I brought up before these tests began. At the time, I was assured that these problems were going to be worked through together before any data went public; unfortunately that agreement and the opportunity to increase the accuracy and relevance of the results being tested were ignored after the subwoofer was shipped.

The two main problems with the procedure are the linearity accuracy and the relationship of THD & Noise to real world conditions. First for linearity; the frequency response measurement used by Ilkka, and quite a few others, utilizes a smoothing calculation. The problem with this is that products that are linear simply remain linear (and in fact may even be worsened by smoothing), by pulling down information at the crossover or filter points. The smoothed graph of the EP600, for example, shows a gentle sloping decline or roll-off at the filter points of 15Hz and 100Hz which does not appear in reality with precise measurements. Products that are not linear, however, are made linear by this technique. Linearity is a paramount indicator of the quality of the end performance and should never be modified by using smoothing, or a low number of data points, both of which will hide anomalies in frequency response.

The THD & Noise methodology used in the Finland test is to plot a graph of 7 points from 20 to 80 Hz at a max level of 10% THD. There are a number of problems with this. First, the general problem of noise occurring during the listening experience, such as woofer bottoming, happens below 20 Hz. So in order to relate such measurements as this to the listening experience two things need to be done: one is to establish at what level of THD & Noise the listener experience will be compromised, and two is to then apply this level to all frequencies. We use 100 data points between 150Hz and 10Hz to determine THD & Noise.

Once a level of volume is attained that has audible distortion - at any single frequency - that is your maximum SPL for all frequencies, because the distortion that occurred will intrude on the listening experience each time that frequency is produced. Obviously, listening to movies or music is a dynamic experience, and frequencies change constantly, so that volume is defacto the maximum logical usable SPL output. The method of plotting distortion at various frequencies, and then connecting those points like a response curve, is not a measurement that can be translated into any usable real world condition. For us at Axiom, we have determined through extensive listening tests that this level is when the THD & Noise exceeds the signal frequency. Neither the EP500 nor EP600 will allow the THD & Noise to exceed the signal level at any frequency no matter the volume level setting. If the tester decides that 10% THD & Noise is the level at which audible distortion will occur in the listening experience (our tests have never shown this to be the case), then this, at the very least, needs to be applied to all frequencies.

As you can see, this is a fascinating subject that has spawned numerous Audio Engineering Society papers and decades of research at the National Research Council (NRC). The real fun begins when you start to prove out each measured number utilizing scientifically controlled listening tests. I can hardly believe I have been doing this research for 25 years now but I look forward to continuing to discover more over the next 25 years.

Thanks so much for commenting, Ian. That Ilkka failed to honor his word is very disappointing. In my mind, this only confirms the belief that his goal was to disparage the EP600, rather than do an honest review. Hopefully, down the road, his irresponsible behavior will cause him more discomfort than it has you and Axiom.

Ian, thank you very much for not only taking the time to share your observations and educate us, but also for doing so in such a gracious manner.

Two things to me are worth noting. First, that you have, in fact, been conducting this type of scientific research under controlled conditions for your entire professional career. Your sustained success and proven talent in loudspeaker design deserve corresponding respect. Such pursuits are extraordinarily complex, and extend well beyond the experience and expertise of a talented hobbyist with a microphone in a Finnish parking lot.

Second, I could not resist the opportunity to underscore

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not a measurement that can be translated into any usable real world condition

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This phrase again reminded me of the nugget attributed to Twain or Disraeli - "There are three kinds of lies: lies, damned lies and statistics". It has been proven repeatedly, in this discpline and in others, that numbers simply do not tell the entire story, and that methodology and motive ought to be considered by astute readers.

Try as we might to reduce music and its reproduction to numbers, it retains creative and artistic components that defy simple quantitative analysis. For me, the joy is in the listening, not in the testing. For the products that provide that ongoing joy in my life, and for the way you conduct your business, I thank you.

In reply to:

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This phrase again reminded me of the nugget attributed to Twain or Disraeli - "There are three kinds of lies: lies, damned lies and statistics". It has been proven repeatedly, in this discpline and in others, that numbers simply do not tell the entire story, and that methodology and motive ought to be considered by astute readers.

Try as we might to reduce music and its reproduction to numbers, it retains creative and artistic components that defy simple quantitative analysis. For me, the joy is in the listening, not in the testing. For the products that provide that ongoing joy in my life, and for the way you conduct your business, I thank you.

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Very, very well said Tom!

In reply to:

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For me, the joy is in the listening, not in the testing.

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I couldn't agree more. Sometimes all it takes is a step back, a closure of the eyes along with a little imagination and these Axioms has a way of putting me into a completely different, and pleasant place.

Thanks Ian and your whole Axiom crew, you folks are great!

I have absolutely no idea what all you said means Ian, not a clue, but thanks! It sounds great!

I just hope it wasn't my inquiry that inspired you to put that much effort into a reply.

I was just curious to how the visit went with the other AVS fella at your factory. Jakeman??

If it means anything, I'm buying a 600.

Ian has been great to work with during this whole process. There will come a time when I post a detailed enough response to everything that has transpired through this process. For now, it has been quite a learning experience. Ian's patience with me has been ... amazing.

Wonderful subwoofer, too.

Sorry to resurrect an old thread, But, any updates on the use of the EP 600 ? If I have not missed anything, then you have been using it for the last few months. I am thinking of upgrading from SVS PC+20-39 to the EP 600. Any comments on this sub ?

Yes - It is still making fantastic bass. Powerful, musical, and did I mention powerful ?

You already do have a really good sub, it will be an incremental improvement - not a night and day difference.

Wow! That was quite a lesson! I expect the Sub Wars will go on for many more centuries! I have only one EP600, and I love it! :-)

Ritchie. The EP600 is an outstanding sub which excels in many important areas: high SPL, exceptionally linear frequency response, clarity, detail, low distortion, deep bass, won't bottom, low port noise and good aesthetics. While their are subs with more extension below 16hz such as your SVS, my review indicates much of the output in that range is harmonic and other distortions which explains why Axiom has chosen to limit output on this 12" driver subs to 16hz. The step up from the SVS 20-39 to the EP600 is significant. It is less the case with the EP500 but overall when you compare their relevant features, the 500 is also a better sub.

Thanks for the update. I saw a few threads about EP 500 refusing to wakeup and auto detect signals, I assume that the same problem does not exist in the EP 600. Do you guys have it in auto on mode or do you use trigger cables ?

I have my EP600 in auto mode. Never fails to wake up!

Actually there isn't really an 'auto-mode' with Axiom's 500/600 series subwoofers, they are either turned 'on' or 'off' with the power switch and while turned on the amplifiers stay on and do not go into an idle mode like the EP350, EP175 and EP125's do ... the 500/600's stay powered and on the ready at all times.

EP-500/600 Quick Setup Sheet

This is worrying. In Oman Summer, the whether can climb up to 50 centigrade (around 120 F). The house is naturally air-conditioned but when we leave for a long weekend or a holiday the house really heats up by the time we come back. This amp may fry in the excessive heat.

I noticed a trigger cable at the end, can this be used to switch it on and off when it is in the off mode ?

Nat:
You can always unplug it while you're gone...

Actually Nat, I don't think it can. It's a bit confusing, but the "trigger" seems to be an output, rather than an input, used to activate a second subwoofer. I could easily be mistaken however. Here's what the manual says about the "trigger."

"LINE OUT (RCA, Trigger and XLR Balanced):
An RCA line-level (female) output and balanced XLR output (male) are provided for connection to a second subwoofer. Use a standard shielded coaxial cable for connection of the RCA Line Out to the second subwoofer. If you are using balanced XLR connectors, then use the balanced Line Out for operation of a second EP500 or EP600."

Hopefully Alan, or someone else can explain the trigger's function better.

Should the trigger not be usable in the manner you wish, you could, of course, simply unplug the subwoofer while you're away. Another thing you could do is find a power controller that has switched and/or delayed outlets. These allow you to turn off anything you have plugged into a switched or delayed outlet without unplugging. I don't know what's available in your part of the world, nor what they would cost. I have the Belkin PureAV PF60 which I love, but it is EXPENSIVE. Much less expensive units can be found which will do the job, such as the PureAV PF30 which can be found, here in the states on the internet, for around $110. There are even less expensive units available. Just look for any power strip/conditioner/center that has switched and/or delayed outlets.

Edit: I just talked to Dennis, and he informs me I'm full of doodoo (as usual). He'll be along any minute to correct me. I failed to see that there are TWO trigger thingees, one an output as outlined above, and one an input. So yes, you CAN turn on your subwoffer with a trigger. Apologies for my misinforming everyone.

Here's what I overlooked in the manual:

"3.5mm MINI-Jack: this is for any 3Volt to 30Volt power on trigger. It is also intended for trigger-controlled operation with future Axiom products."

Nat. I'm currently running 1 EP600, 2 EP500s and an Ultra in a quad setup. I've never had a problem with auto-start. The most important thing is to calibrate them properly. Also keep in mind the Axiom subs DSP chips react differently to single tone sine waves than analog subs when calibrating. For example some people report sudden surges in volume with slight changes in sub gain. It's easier to calibrate by raising gain above calibration reference then lowering sub gain at the processor/receiver to reference levels.

The trigger and XLR functions can be a bit confusing in the sub woffer manual. The following information is what I learned from Axiom folks about ten months ago when I was adding the second 600. So unless they have changed the software since that time, this is how the triggers should work.

A siganl sent to the trigger IN will fully turn the woffer on/off, this can be verified by the indicator light changing from green to red, or red to green. If one connects a trigger wire from the OUT to the IN on a second sub, then both will be controlled for the on/off operations.

As for an auto mode, my understanding at that time was the 500/600 do not have this function. They do however go into a low power usage mode after a period of time of not being active, using very little voltage, so leaving them on 24/7 is nothing to be concerned about.

Hope this helps clear up the questions.

Yes it does. Thanks to all.

This clears things up.

Well, this sound like the Sub to go for. I will talk to Axiom now to find some finer placement information and will probably order one when they come up with the real wood veneers (Feb / March).

Thanks to all.

Nat, I double-checked with Tom Cumberland, who engineered the amplifier:

In reply to:

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The EP500/EP600 will easily handle 130 degrees F. Because it does not generate heat on its own, the ambient temperature is inconsequential. Also, CSA has done high temperature tests for this unit both in humid and non-humid conditions to verify its safety.

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(CSA is like UL) So it looks good!

Thanks Amie.

I checked with JC@axiom with the same question. He replied with a similar answer


Quote:

Heat will not be a factor for the EP500 / 600. It has been tested by the CSA for room temperature exceeding 65 degrees celsius.It goes in a sleeping mode (power saving mode) after a signal absence of between 10 to 20 minutes. Back to operation is commanded through DSP software when an audio signal is perceived.

End Quote.


BTW: What is CSA & UL ?

UL

CSA

UL is Underwriter's Laboratory.

CSA is the Canadian Standards Association.

Both groups approve products which meet certain codes and standards of safety and health.

CSA = Canadian Standards Association

UL = Underwriters Laboratories -- not 100% sure, but I was told this started as a product evaluation lab for a collection of insurance companies and grew from there.

Thanks. So They are independant third party testers.

Excellent.

For the sake of completion of this thread with all EP 600 discussions, and to save the nice people in Axiom some more questions emails , please find the last email I exchanged with JC in Axiom relating to the EP 600 product.


Question 1: Through other owners of the EP600 on the Axiom Board forum, I found out that the EP 600 does not have an auto-on feature on detection of a signal detection. I live in a very hot country and am worried for the Amp of the sub to heat up when the temprature on the room raises. I understand that the sub goes into power saving mode when not in use for a while. How correct is this ? and is the sub likely to be affected by room temprature of slightly less than 50 centigrade (when not in use, but the switch is on) ?

In reply to:

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Heat will not be a factor for the EP500 / 600. It has been tested by the CSA for room temperature exceeding 65 degrees celsius.It goes in a sleeping mode (power saving mode) after a signal absence of between 10 to 20 minutes. Back to operation is commanded through DSP software when an audio signal is perceived.

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Question 2: My room measurements are 18 feet X 14 feet X 10 feet = total area ~2600 cu feet. I know that the EP 600 will be an overkill for my room, but I like the idea of owning top of the range. My question is, will I be better off accoustically with the EP 500, or will the EP 600 fit well in my setup ? (my other speakers are the M80's+VP150+4 QS8).

In reply to:

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There would be no acoustic benefit of an EP500 over an EP600 in your room.

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Question 3: My Denon 3805 does not have separate crossover points for different speakers and it has a single crossover point. I know from reading some posts that the M80's can be crossed over at 60 or even 40, whereas the remaining speakers that I have require 80 of more crossover point. The Question is that, I am thinking about setting the M80's to Large in the 3805 and sending the full signal to the sub and setting the crossover of the sub to 40 hz and feeding it to the M80's. In addition, I will need to connect the Sub out from the 3805 to the new Sub. will that setup work fine or am I mising something ? Can the sub accept two inputs from the in speaker terminals and the sub line in ?

In reply to:

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In your room, I would select small for all my speakers including the M80Ti. Select 80Hz at the receiver and select bypass on your EP600. You cannot simultaneously connect both the high level inputs and the line level input on your EP600. Use a subwoofer coaxial cable from the subwoofer output on your receiver to the line level input on your EP600. After you are familiar with the sound provided by these settings then you can try a 60Hz crossover setting in your receiver. Choose and keep the one you prefer.

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Nat, JC's response from Axiom appears to be right on target. On 3. in particular there may be a misimpression that the setting for the internal sub crossover(e.g. 40Hz)affects the mains if connected through the sub. The sub crossover is only a low-pass filter on its own response and has no effect on the full-range signal passed through to the mains.

The fact that a speaker such as the M80 has very good response to below 80Hz doesn't make it necessary(or even advisable)to cross it at other than 80Hz. Especially with subs as excellent as the EP500 and EP600, they should be allowed to carry the major load in the lowest frequencies which they handle even better than the M80s and relieve them(and the amplifiers driving them)of more of the load.

Thanks for clearing that up.

I just checked the sub manual (the EP 600 and my existing sub) and the crossover settings are not clearly mentioned. I genuinly thought that the sub corssover would crossover from the speakers to the sub.

Just learnt something new

I'm having real trouble wrapping my mind around the idea of a single 12" driver having more output and impact than 4 SVS 12" Ultra drivers. My wife has basically told me to get what I want and shut up about the subwoofers but now I can't decide what to get. I want a sub that can do pipe organs and kick drums equally well. :-) That doesn't seem to exist in my price bracket. (About $2000) My room is every bit of 4000 cubic feet. I also don't want to mess with plugging ports because in my experience this has led to port noise that I was able to hear.

Whatever I get I have to be happy with for the next 10 years at least.

Two EP500s from the factory outlet would just barely be over your budget and it's likely two subs will give you more even bass throughout the room...

The EP-500's won't pass the "pipe organ" requirement. :-(

You should try an EP 600 then. It's in room responce is 15 Hz. That would get you down into the pipe organ territory.

When you said that you wanted a sub that could do pipe organs and kick drums, I wasn't thinking that you were looking for FLAT to 16Hz.....sorry about that!

Have you looked at the ACI Maestro? 15" driver and sealed, and goes down to 18Hz. Just a hair over your budget.

Yeah, I'm not fooling around with wanting 16 Hz FLAT.

I have read about the Maestro but I am worried about output in my room. I currently have an SVS 25-31 PC+ and it's not enough in the room. I can put it in 20 Hz mode for additional extension but then I lose too much output. I am thinking I would need two Maestros for the room.

Stupid Pipe Organs. ;-)

For less than 2K you could go with 4 SVS PB 10s. It seems that would give you the output and the 16Hz your looking for.

I am thinking that I am deciding between two SVS 16-46 PC+, two HSU VTF3HO with turbo, or one EP-600 for subs that seem to be in my price range and capability.

SVS: I don't know if the high end bass will be greater than what I already have. Output below 25 Hz will be ridiculous compared to what I have now but I don't know about the 60 to 80 Hz area.

HSU: Who know when it will be out. Who knows how it will perform.

EP600: I'm back to having trouble believing this sub can output more and better than 4 SVS Ultra drivers. Actually, I don't have a problem with the "Better." It's the "more" that I have trouble understanding.

As I understand it, an Ultra will put out a bit more energy than a 600 at the lowest notes and highest volumes. Where the 600 pulls ahead is "real world loud playing" -- you can run the system at a level where the Ultra would be overdriven by the lowest frequencies (as would a 600 without DSP) and the 600 sounds fine because it automatically cuts back the volume when necessary -- but 99% of the time it isn't necessary. As a result, movie and music tests seem to give the 500 and 600 a slight advantage over an Ultra despite the Ultra's better driver.