Considering these 2 for my future new home theater and was wondering if the $700 difference (axiom<svs) in price was worth it? It's gonna be pared with either a set of Axiom's, or Paradigm's (which i'm leaning towards).

Search the threads and find the specifics on these subs.

That being said, the SVS is a much better sub, but it's $700 more.
The axiom is a very good sub and it's $ 700 cheaper.

You really cannot compare the two.

Considering these 2 for my future new home theater and was wondering if the $700 difference (axiom<svs) in price was worth it? It's gonna be pared with either a set of Axiom's, or Paradigm's (which i'm leaning towards).

If you have the $700, get the PB-13 Ultra. The driver in the Axiom isn't that impressive. The Ultra driver is built more like the JL Audio drivers.

the tests ilkka did on the EP600 have horrible power compression and THD ... what was Axiom's explanation?

the pb13 on the other hand has super good third party test results.

The 13Ultra will easily outperform the Axiom in every possible way. Whether it is worth the $700 difference to you can only be determined by how important the $700 is to you. If you are serious about your bass performance, the Ultra is the pick hands down.

How is the PB13 $700 more than the EP-500? Am I seeing incorrect prices on Axiom's site or SVS' site?

i think it's because the OP is in Canada

i'm in canada and am factoring in other costs such as shipping. the axiom is free shipping, and the ultra will cost over $100 to ship.

lol you beat me to that ribbit

The PB-13 Ultra wins hands down in every way.

i'm in canada and am factoring in other costs such as shipping. the axiom is free shipping, and the ultra will cost over $100 to ship.

Ah, righto.

So...how much would the PB12NSD be then? :)

canada for the lose! :p :D

http://www.joketshirt.com/pics/shirt009front.jpg


(just kiddin)

would be $844+tax (includes shipping). $65 shipping on the pb12nsd, and $125 on the pb13 ultra. $1824+tax on the ultra, and $1144+tax on the ep-500.

The Ultra-13 is an excellent subwoofer. The EP500 with its cutting edge DSP controlled amp was a much better performer than the old Ultra. But from what I heard at PBCs I'd be tempted to give the nod to the new Ultra-13 as long as its amp doesn't malfunction. How it stacks up to a EP600 will be put the test on Nov. 4 when we compare JL113, DD-18, EP600, Servov2, Ultra-13 with a replacement amp and a pair of mini EP400s.

Is the ULtra-13 worth $700 more than an ep500 is tough to say. I'd suggest for a few hundred more over the price of an Ultra-13, a pair of the small sealed EP400s which have that same DSP controlled 500w amp over the Ultra-13. I was given a pair of the new small footprint EP400s to demo yesterday and set them up as stereo subs. I was very impressed with the detailed, tight sound from such a small sized sub. Axiom has been dropping the prices on all their products as the Canadian dollar continues to soar so I'd expect another price cut soon.

http://i30.photobucket.com/albums/c337/JohnPalumbo/EP400BlackGrilleOff2.jpg

Jakeman do you have an Ultra13 or is someone else bringing one for the Nov 4th comparison?

PBC has the Ultra-13 and I have the rest of the subs except for the Servov2 which I'm hoping Huff can bring. TheBogg and Jesse will join us for the blind listening 4 hour session in my HT. Should make for some interesting results and I'm curious to see the comments and rankings.

Cool. I'd be interested to see if your suggestion for the dual ep400 holds up.

Me too. I was given a pair of this new EP400 model sub to audition when I visited the Axiom labs yesterday. This new sealed sub is only 1.4cf in volume and measures a scant 13.75" x 10.5" x 16.8" . However it is a DSP controlled sub with a 500w amp powering a 8" driver to output 106db in an anechoic environment or 116db in room. What I like best is its ruler flat FR from 18hz-150hz +/-1.5db.

http://i30.photobucket.com/albums/c337/JohnPalumbo/EP400_graph.gif

I was blown away by just how tight and detailed they sounded while listening to several music DVDs last night. Axiom suggests 4 of them are meant to be used in an HT and avoids the use of outboard equalization but I found them outstanding as stereo subs. I've only played with them last night and I will post again as I get further impressions with a variety of material. I'm going to compare them against some of the other sealed subs in my collection on my own.

These subs are of such quality that its causing me to reassess the question of going for one top line sub or a pair of capable smaller subs. Adding that second sub in an HT really ramps up sound quality across the seats but its usually quite expensive. Up until these subs I always suggested one top sub over duals. The SQ in such a small package is really something. :cool:

True but consider the price as well. At least on the US side, someone could buy two VTF3-HO cheaper than two EP400 and get a lot more bang for the buck if they have the space for two large subs. There is a substantial efficiency compromise with such a small sealed subwoofer (just look at the SVS SB12-Plus versus a normal Plus).

If we go by craig's list a pair of JL 113s will equal a single Ultra13 in performance so I'm wondering how much chance a couple 8" 500w subs will have.

If we go by craig's list a pair of JL 113s will equal a single Ultra13 in performance so I'm wondering how much chance a couple 8" 500w subs will have.

Its Craig's comparison so I'd rather not comment about his ranking criteria or results. Suffice it to say that in our listening session the four of us preferred to the JL113 overall but gave the Ultra-13 the slight edge in HT material. In music material it wasn't close, the JL is in a different level but its much more expensive. For its price point the Ultra-13 is a great contender but concern over the amp which shutdown in our session holds me back from unequivocally recommending it.

The VTF3-HO is another terrific sub and its always a great question how a pair of any sub will stack up against a more expensive sub. It depends where you want to draw the line on performance and budget. A pair of VTF3-HO or Ultra-13s would be a fine choice for anyone's HT. It depends where your point of diminishing returns kicks in for the incremental improvement in quality.

I'm not a good example for budget or tolerance to diminishing returns seeing how I'm currently running a JL113, a DD-18 and a HGS-18 in one room and the EP600 and the EP400 pair in another.

If we go by craig's list a pair of JL 113s will equal a single Ultra13 in performance so I'm wondering how much chance a couple 8" 500w subs will have.

...about the same chance Cleveland has of making it into the World Series. ;)

You must have heard a pair recently. :rolleyes:

You must have heard a pair recently. :rolleyes:

I just really doubt that a pair of 8" drivers are going to rock anyone's world. I'd bet against.

In a tiny little room, maybe. Otherwise, just stop and think. How much air can be moved by a pair of 8" speakers? It's simple physics.

I just really doubt that a pair of 8" drivers are going to rock anyone's world. I'd bet against.

In a tiny little room, maybe. Otherwise, just stop and think. How much air can be moved by a pair of 8" speakers? It's simple physics.

in that case, we should throw the Epik Tower into the mix :D........wonder how a ultra long throw 15" driver (nearly 50lbs), 6" port, large ported enclosure, tuned by one Chad Kuypers, coming in at a whoppin $1099, would fare against the single EP400. http://smiliesftw.com/x/kekekegay.gif

I doubt one would even notice the Axiom in the room.

I doubt one would even notice the Axiom in the room.
your bank account would sure notice though :p

this isn't a serious comparison,right?



SEC refs suck!

Considering these 2 for my future new home theater and was wondering if the $700 difference (axiom<svs) in price was worth it? It's gonna be pared with either a set of Axiom's, or Paradigm's (which i'm leaning towards).

Tell us about your room and listening habits. What is your goal for your HT? How loud do you like it? Any aesthetic concerns?

Clean bass is addictive. It takes power and displacement. Do not waste your time on an 8" driver.

You might also consider the SVS Plus/2. It's on sale for $ 1199 right now.

This is a dual 12" woofer, 1000w amp sub. It performs very well against the
Ultra.

I just really doubt that a pair of 8" drivers are going to rock anyone's world. I'd bet against.

In a tiny little room, maybe. Otherwise, just stop and think. How much air can be moved by a pair of 8" speakers? It's simple physics.

The question has to do with the use of duals to improve sound quality in room vs a single larger sub and whether it gives you more performance for the budgeted dollars. Its rather naive if you link performance only to how much air a driver can move and we are talking about sealed not vented if you want to skew that discussion further. Then there is the quality of the amp which for reasons not clear to me seems to not factor into any discussion about subwoofer components or performance. Many sub fans refuse to acknowledge that BASH amps are cheap solutions which lack dynamic headroom and clip terribly at peak power demands regardless of how efficient the design. Big boxes help keep that clipping point at bay but not in demanding passages where many subs audibly groan.

There is no denying the benefits for controlling room nodes with dual subs across more seats. In addition my comment is directed at quality of the sound in room. If all that interests you is highest output at certain frequencies read no further, and buy the vented sub every time. Last I checked sound quality is not restricted to size of the driver.


I stacked the pair last night and the extra 6db was nice but separating the pair in room makes for a neat excellent sounding WAF friendly solution. Call me silly but I've become very appreciative of nice things in small packages lately. In any event the guys will get a chance to weigh in on the 400s in a few weeks when they get compared to the JL113, dd-18, Ultra-13, EP600 etc. For that session, I'm trying to decide whether to stack them or separate them as intended.

I doubt one would even notice the Axiom in the room

Yup. That's part of the design idea and an advantage for many. Most married guys would understand that one.

You might also consider the SVS Plus/2. It's on sale for $ 1199 right now.

This is a dual 12" woofer, 1000w amp sub. It performs very well against the
Ultra.

Output wise yes, sound quality wise no.

Great post John, there seems to be a large contingent of quantity over quality and looks be damned guys around here. If you have a dedicated man cave HT I suppose no big deal, but some of these living room HT systems are laughable. It's really not much different than parking your Harley in your living room (are you listening Shervin?).

The question has to do with the use of duals to improve sound quality in room vs a single larger sub and whether it gives you more performance for the budgeted dollars. Its rather naive if you link performance only to how much air a driver can move and we are talking about sealed not vented if you want to skew that discussion further. Then there is the quality of the amp which for reasons not clear to me seems to not factor into any discussion about subwoofer components or performance. Many sub fans refuse to acknowledge that BASH amps are cheap solutions which lack dynamic headroom and clip terribly at peak power demands regardless of how efficient the design. Big boxes help keep that clipping point at bay but not in demanding passages where many subs audibly groan.

There is no denying the benefits for controlling room nodes with dual subs across more seats. In addition my comment is directed at quality of the sound in room. If all that interests you is highest output at certain frequencies read no further, and buy the vented sub every time. Last I checked sound quality is not restricted to size of the driver.


I stacked the pair last night and the extra 6db was nice but separating the pair in room makes for a neat excellent sounding WAF friendly solution. Call me silly but I've become very appreciative of nice things in small packages lately. In any event the guys will get a chance to weigh in on the 400s in a few weeks when they get compared to the JL113, dd-18, Ultra-13, EP600 etc. For that session, I'm trying to decide whether to stack them or separate them as intended.



Yup. That's part of the design idea and an advantage for many. Most married guys would understand that one.

The question has to do with the use of duals to improve sound quality in room vs a single larger sub and whether it gives you more performance for the budgeted dollars. Its rather naive if you link performance only to how much air a driver can move and we are talking about sealed not vented if you want to skew that discussion further. Then there is the quality of the amp which for reasons not clear to me seems to not factor into any discussion about subwoofer components or performance. Many sub fans refuse to acknowledge that BASH amps are cheap solutions which lack dynamic headroom and clip terribly at peak power demands regardless of how efficient the design. Big boxes help keep that clipping point at bay but not in demanding passages where many subs audibly groan.

There is no denying the benefits for controlling room nodes with dual subs across more seats. In addition my comment is directed at quality of the sound in room. If all that interests you is highest output at certain frequencies read no further, and buy the vented sub every time. Last I checked sound quality is not restricted to size of the driver.


I stacked the pair last night and the extra 6db was nice but separating the pair in room makes for a neat excellent sounding WAF friendly solution. Call me silly but I've become very appreciative of nice things in small packages lately. In any event the guys will get a chance to weigh in on the 400s in a few weeks when they get compared to the JL113, dd-18, Ultra-13, EP600 etc. For that session, I'm trying to decide whether to stack them or separate them as intended.


When it comes to the advantages of multiple subs, you are preaching to the choir here. I've got four subs running simultaneously in various stereo plus LFE configurations.

It just seems that at a total of $2200, the 2 x Axiom400 solution sounds a bit overpriced for a pair of 8" subs.

How it stacks up to a EP600 will be put the test on Nov. 4 when we compare JL113, DD-18, EP600, Servov2, Ultra-13 with a replacement amp and a pair of mini EP400s.


Hmmm ... that's a lot of subs, be at your house at 6am John? :eek: That may be too early for scotch, typically 7am is the earliest I start drinking. :D

It just seems that at a total of $2200, the 2 x Axiom400 solution sounds a bit overpriced for a pair of 8" subs.

You got that right! Gees, that is insane. They may be good little subs, but physics...

I like Axiom speakers, but their subs seem like they should all be priced at about 50% of what they are.

Axiom can price them wherever they want to as far as I'm concerned... maybe they want to keep the sales numbers low.

Some good points John. :) Just a couple of quick comments:
The question has to do with the use of duals to improve sound quality in room vs a single larger sub and whether it gives you more performance for the budgeted dollars. Its rather naive if you link performance only to how much air a driver can move and we are talking about sealed not vented if you want to skew that discussion further.
Nobody will argue the value of having multiple subs...that's for sure. Heck, part of the reason I'm gonna experiment with quad avalanche 18" sealed cubes with twin Crown K2 as the power plant, is just that. The ability to control the room with multiple subs in different positions is one of the great unknowns till recently.

However, we can't confuse what multiple subs will create in terms of SQ and headroom, vs what kind of subs to use as such mentioned "multiple subs". An Axiom EP400, as magical as that DSP can be, at the end of the day it will continue to remain an 8" sub with a $1100 price tag. I have a hard time believing anyone would rather choose that over an Epik Tower at $1099 as well and use two Epik towers spread in the room. Similarly with multiple HSU HO's, etc.
Then there is the quality of the amp which for reasons not clear to me seems to not factor into any discussion about subwoofer components or performance. Many sub fans refuse to acknowledge that BASH amps are cheap solutions which lack dynamic headroom and clip terribly at peak power demands regardless of how efficient the design. Big boxes help keep that clipping point at bay but not in demanding passages where many subs audibly groan.
Again, I agree with the importance of an amp.....but we have to take into account the entire system. Once again, it can be a massive amp with great power components and Transformer, and a neatly designed and programmed DSP, but at the end of the day it is driving an 8" driver.

I just bring this issue of DIY for this one issue alone, and wont mention it again, but I agree with you John about the importance of power plants, and thus, most DIYers with capable drivers have been looking at excellent pro-amps as their power plant. In my case, for example, there is no amp that Axiom or SVS or HSU or any other sub manufacturer could put up that would supply transient response and peak hold response as a Crown K2 could offer:
http://home.pacbell.net/lordpk/proamps/Crown_K2.jpg
http://www.avsforum.com/avs-vb/showpost.php?p=11650937&postcount=252

In addition my comment is directed at quality of the sound in room. If all that interests you is highest output at certain frequencies read no further, and buy the vented sub every time. Last I checked sound quality is not restricted to size of the driver.

Well, yes and no. The size of the driver does have tremendous influence on its headroom, extension, and how it will handle output compression and transient response, given high output levels. A single 15" driver will have more air displacement and excursion that multiple 8" drivers, so if we compare multiple larger drivers working at lower limits than multiple 8" drivers working at near max limits, it is pretty easy to see how "sound quality" starts to be affected by distortion and output compression.

As a mere exercise, at low volume levels, the SQ should not be too dependent on the driver size. But we all know that most myths about small drivers vs large drivers (15" and 18") sounding better, or sealed vs ported sounding better, have been thoroughly proven to be wrong.

Great post John, there seems to be a large contingent of quantity over quality and looks be damned guys around here. If you have a dedicated man cave HT I suppose no big deal, but some of these living room HT systems are laughable. It's really not much different than parking your Harley in your living room (are you listening Shervin?).
now now Rob....play nice! :D I'm not the only one here with big mamoth subwoofers in their living/family rooms. That said, my family room, albeit not the most aesthetically pleasing per se, now that I have everything dialed in pretty much, has one of the most accurate, transparent, dynamic, and visceral acoustical signatures one can ever hear, period! I've heard systems that cost $50K-$70k in gear alone and don't come close to mine.

Now granted, the Proceed AVP2+6, the Nautilus 802's, the Denon 3910 modded, the Cinenova Grande, etc, have a lot to do with it besides my twin towers.....;)

I knew you could take a punch (and don't give a shite what others think;)).

It is the rest of your gear that makes your system balanced and overall I'm sure, a world beater. This chase for the bass Holy Grail (or Brown Note) that is the obsession of so many in this forum is strange to me when the rest of the system components are sub-par (pun intended). I love bass too but only when it is in balance with the rest of the system.


now now Rob....play nice! :D I'm not the only one here with big mamoth subwoofers in their living/family rooms. That said, my family room, albeit not the most aesthetically pleasing per se, now that I have everything dialed in pretty much, has one of the most accurate, transparent, dynamic, and visceral acoustical signatures one can ever hear, period! I've heard systems that cost $50K-$70k in gear alone and don't come close to mine.

Now granted, the Proceed AVP2+6, the Nautilus 802's, the Denon 3910 modded, the Cinenova Grande, etc, have a lot to do with it besides my twin towers.....;)

I knew you could take a punch (and don't give a shite what others think;)).

It is the rest of your gear that makes your system balanced and overall I'm sure, a world beater. This chase for the bass Holy Grail (or Brown Note) that is the obsession of so many in this forum is strange to me when the rest of the system components are sub-par (pun intended). I love bass too but only when it is in balance with the rest of the system.
hear hear! :)

Sherv when's your next gtg to show off all that gear? :)

Sherv, nice to hear from you. Great gear you have assembled and with your fine video equipment it must be sweet times indeed when the film or music starts. :cool: Multiple subs, at least duals, make a significant difference in the audio system. Your point is well taken about what kind of multiple subs to use since much depends on room acoustics and system synergy. Those Epiks look neat and I am looking forward to hearing them but they don't look aesthetically pleasing which counts with our better halves. Hence the need for small subs which can still perform. That's the niche the Axiom folks are trying to fill with the 400. Now price is an issue for some and not for others, it depends whether the small size is worth paying up for. $1100 will buy you alot more output but that isn't what this sub is targeting. Its for the person who doesn't want the large size and wants the sound quality.

The Crown K2 is one of my favourite amps and again its nice to see you implementing it in your DIY stuff. I'm envious since I'm still studying Cable-Making 101. :D Beats the BASH amps by a long shot.

Sure we're talking about a 8" driver but its...ummm...not the size but how you use it. :D That's why I would never suggest just one of these for a HT solution, in fact the Axiom engineers would like these used in lots of 4 specifically to eliminate room nodes and avoid equalization. The more subs you use the less output is a factor in bass reproduction but it does depend on how loud you want to play them. I was initially skeptical when I saw how small these 400s are, 1.4cf:eek: but surprised by how much quality bass these things put out. Its an interesting friendly looking solution to an acoustical problem which plagues all our rooms. I don't have 4 to test but it seems to me setting up 4 400s in a room up to 4000cf would solve many issues.

As a pair of stereo subs in a 2 channel rig a pair of these 400s provide an excellent bass foundation. I kept listening over and over to Cowboy Junkies Trinity Revisited which features several bass heavy tracks, the other night and was quite impressed with these which again look pretty and don't overwhelm the rest of the audio equipment. To put it into perspective the EP600s are over 5x as large by volume.

Currently I have a DD-18, HGS-18 and a JL113 in my HT and its much more headroom than I need but three subs does wonders for smoothing my room peaks and nulls without extensive equalization. A quad of avalanche 18" sealed cubes ...nice. ;)

It is the rest of your gear that makes your system balanced and overall I'm sure, a world beater.

Except for that eenie-weenie monitor :p

It is the rest of your gear that makes your system balanced and overall I'm sure, a world beater. This chase for the bass Holy Grail (or Brown Note) that is the obsession of so many in this forum is strange to me when the rest of the system components are sub-par (pun intended). I love bass too but only when it is in balance with the rest of the system.

Wise words Robert. I agree the quest for quality bass should start with the other components since the system is only as good as its weakest link. :cool:

Except for that eenie-weenie monitor :p

Oh yeah, good point Drew.;) I forgot about how much he loves small plasma monitors over big image projectors. Let's give him a pass because his audio system is smoking hot. :D

If I wanted two relatively small subs, I would give serious consideration to the new Emotiva subs. A pair of them with an 800 watt outboard amp with built-in EQ. All of this for $999:

http://www.audioholics.com/reviews/speakers/subwoofers/emotiva-drs-1

Wise words Robert. I agree the quest for quality bass should start with the other components since the system is only as good as its weakest link. :cool:

It's a vicious cycle though! You start replacing your weakest component, and then the next one, then the next one. Eventually you are balanced but the oldest component in your chain starts getting long in the tooth and starts looking like the weakest component, and then you repeat all over again.

Tell us about your room and listening habits. What is your goal for your HT? How loud do you like it? Any aesthetic concerns?

Clean bass is addictive. It takes power and displacement. Do not waste your time on an 8" driver.


Well the room i'll be using this in now will just be temperary due to the fact i'm renting ATM, and would like to be getting into my own house within a year or so. This is a small 3 bedroom (1 floor w/1 bedroom suite downstairs) that has a long rectangular living/dining/kitchen area. I added a big curtain to try and add more seperation to the room, and while it doesn't add a solid barrier it does so by apperance. The measurements of the room from curtain to wall (where tv will be) is 17.5' L x 11.3' W x 8' H. Not too big but let's just say I would like to future proof myself. As of now i'm using a Panny 1200w HTIB and while the sound is decent it's nowhere near what I could be experiancing with a full blown system. The sub will be matched with either a set of Axiom or Paradigm mains, and a decently sized reciever (around 130w's). For music playback I listen to a lot of rap, hard rock/heavy metal, top 40, and also a lil bit of everything else. I have about 300 dvd's so we can say I watch a lot of movies, and would like it to give me some great sound while gaming. I've always been into booming bass, and a fan of ported enclosures over sealed back from my multiple car installs. Overall I would just like to get the best bang for my money, and even the Ultra is a little more then i'd like to spend but will if it's all it's cracked up to be.

Thank you

No contest, get the Ultra. It is almost always to spend more and get more than to spend less and wish you had more...

lol the reason why i'm getting 50" plasma instead of a 42" ;).

lol the reason why i'm getting 50" plasma instead of a 42" ;).

Exactly! ;)

It just seems that at a total of $2200, the 2 x Axiom400 solution sounds a bit overpriced for a pair of 8" subs.
Hey guys don't laugh! Jake doesnt know this, but I have been testing the little Axiom400 for quite some time now. What I wound up doing is selling the dual Ultra's for the Axiom... pure bliss I tell yuh!;)


http://i3.photobucket.com/albums/y75/stevenn/000_0230.jpg

Can't say I blame you Steve. Exploding amps and uneven FR would get to anybody. Try Velos or JLs next time. :p:D

To funny! Sorry Jake, I couldn't resist:D Thanks for the suggestion though,.. but I think I'll stay over on the DIY/dark side for now??:)

Good jokes Steve. :) Inspired by your pic, here are some shots of the EP400s to give you some perspective of just how small they are. It should be called "The Little Subwoofer That Could" ;) because its essentially a mini EP500

Here is a shot in my smaller HT.

http://i30.photobucket.com/albums/c337/JohnPalumbo/dcp_1557.jpg

On top of a EP600. It really is over 5x the size.

http://i30.photobucket.com/albums/c337/JohnPalumbo/dcp_1552.jpg

Beside a Velodyne DD-18.

http://i30.photobucket.com/albums/c337/JohnPalumbo/dcp_1551.jpg

And next to the small but larger Fathom FL113.

http://i30.photobucket.com/albums/c337/JohnPalumbo/dcp_1550.jpg

Nice pics. I like my EP400 finish better though :P

I must say the EP400s look like little toys..

And am I missing something? I thought the EP500 was somewhere around $700-800, but now its above $1000?


Also, $1100 for an 8"?
Jeez.

I must say the EP400s look like little toys..

And am I missing something? I thought the EP500 was somewhere around $700-800, but now its above $1000?


Also, $1100 for an 8"?
Jeez.


You have just entered the twilight zone of woofage.:p

The driver size makes it look deceiving. Yes the price looks high at first but these puppies are actually small sealed EP500s...same amp, same DSP circuits, smaller enclosure, smaller driver, lower price. They are very versatile and surprisingly powerful for their size. If any of you guys watch Prison Break you know their are plenty of LFE effects and this pair again surprised me. It's a solution for people who want big performance in a small package. I'm enjoying them as stereo subs in my small HT but later this week I'm going to compare them with some of the bigger subs in the large HT.

Nice pics. I like my EP400 finish better though :P

Really, here I thought I had the first pair? What colour is yours? A pic would be cool.

They are cute. They look like computer speakers.

Those look real big for sealed 8" subs, you did say they were sealed right? You could fit a good 12" woofer in an enclosure that large and have 3-6dB's on that little 8"er and the price would at least make sense.

You have just entered the twilight zone of woofage.:p

Ha. :D I guess new subwoofer designs can be like that:

" ...a dimension not only of sight and sound but of mind, a place of things and ideas, between the pit of Man's fears, and the summit of his knowledge".

jpmst3 you've got to get out of the pit stage and move to the summit. ;) I have to admit to being excited by all the very neat breakthrough designs in the last year or two by all the sub manufacturers . Hats off to all their ingenuity.

Those look real big for sealed 8" subs, you did say they were sealed right? You could fit a good 12" woofer in an enclosure that large and have 3-6dB's on that little 8"er and the price would at least make sense.

The price is what it is mainly because of its amp and electronics. I bitched about the FL113 for a long time until I finally bought one and realized that sub was worth every penny. Like I said the EP400 looks deceiving but it has clean, tight bass which is surprisingly powerful for its size. To hear it is not what you would expect by its looks. The idea is to utilize several of them in an HT application and avoid equalization but I think they make wonderful, versatile, stereo subs.

By the way Axiom also released a new 12" EP350v3 with a 300w amp and analog circuit for around $750 which is closer to what you describe. I don't think they are nearly as good as the smaller albeit pricier EP400.

They are cute. They look like computer speakers.

Seriously.
Leave the 8"ers for your girlfriend/wife.
Real men have 25 cu ft enclosures with 18"s. :p

Those look real big for sealed 8" subs, you did say they were sealed right? You could fit a good 12" woofer in an enclosure that large and have 3-6dB's on that little 8"er and the price would at least make sense.

That's true, but you would probably then have a natural rolloff that would start higher up, hence requiring more eq.

If I wanted two relatively small subs, I would give serious consideration to the new Emotiva subs. A pair of them with an 800 watt outboard amp with built-in EQ. All of this for $999:

http://www.audioholics.com/reviews/speakers/subwoofers/emotiva-drs-1


For the price of 2 of the Axiom 400's I could get 4 of the new Emotiva subs with 1,600 total watts, and four twelve inch drivers.

Comparing the 400s with the Emotiva DRS-1 subs would be an interesting shootout. Looks like Emotiva is also marketing a multi-sub HT solution. Any graphs on those yet?

For the price of 2 of the Axiom 400's I could get 4 of the new Emotiva subs with 1,600 total watts, and four twelve inch drivers.
is this the new subwoofer of the week that you are trolling in every other thread with? For christ sakes!!!:rolleyes::rolleyes:

OP, I also have the EP500/EP600 and the PB13 on my short list (will buy within next 2 months) and am asking myself the same relative $$$ benefit question as you re: (a) EP500 vs. PB13. And further, I'm weighing (b) EP600 vs. PB13 and (c) dual EP500s vs. PB13.

Regardless of the lack of love for Axiom around here, for Canadians I feel the EP500/600 warrant serious consideration - mainly due to the very nice flat freq. response and significant max. output for the $$$. Reports of higher than ideal measured distortion levels don't scare me away since they very well may be inaudible to me - I'd like to let my ears decide that. And there is a 30-day risk free trial (only pay return shipping if do not keep it ... original shipping is included in price).

I'll get a chance to hear the EP600 and PB13 side-by-side Nov. 4 at jakeman's and will report back on my thoughts after that. If I was buying today, I would not buy the PB13 (even though I've heard it and was very impressed) because I'm not convinced the amp issues have been resolved completely and I do not wish to go through the hassle of sending amps back and forth. I'll monitor that situation over the next month to see if I feel it is totally cleared up. You also have 45-day risk free trial for PB13, but if you return it I think you pay for return shipping AND do not get a refund for original shipping (at least that's what I interpret from SonicBoom's web site wording ... someone correct if wrong please!). So it could cost significantly more in shipping $$$ to return the PB13 than the Axiom.

Still, if you really are down to these 2 subs, why not just buy 1 of each and demo them at home? You can then 100% decide for yourself which one is better for you and the only thing you'll be out is the shipping charges to return 1 of them. I know it may be hard to swallow the extra $$$ spent to return 1, but you're really buying total peace of mind in knowing you got exactly what you wanted.

I think I got the first "in the wild" ep400 but not 100% sure. The sticker says made for "Trade Show" since I got one that was used at the audioholics show on Oct 6th (there were 4 total). I got it for a very nice price too.

http://lh3.google.com/jgillow/RwmSFyoWMsI/AAAAAAAAEo0/Jw2G3jhDWm8/DSCN3183.JPG?imgmax=512 http://lh5.google.com/jgillow/RwmSISoWMuI/AAAAAAAAEpE/k3dj8kHjkAc/DSCN3185.JPG?imgmax=512

Comparing the 400s with the Emotiva DRS-1 subs would be an interesting shootout. Looks like Emotiva is also marketing a multi-sub HT solution. Any graphs on those yet?


I am not aware of any graphs on the Emotiva subs.

I think I got the first "in the wild" ep400 but not 100% sure. The sticker says made for "Trade Show" since I got one that was used at the audioholics show on Oct 6th (there were 4 total). I got it for a very nice price too.



Good deal, Jeremy. You can see how versatile these 400s are by the way you it's tucked in your shelf (bookshelf sub!). What tube amp and centre are you using?

Gear list link in my sig. Onix SP3 and Onix Ref100.

Those ep400's are cute:)

That's true, but you would probably then have a natural rolloff that would start higher up, hence requiring more eq.

It wouldn't be hard to find a 12" driver that would be naturally critically damped in that size enclosure, it would cost more, probably about $350-400, but still. Also, it may not even need more power if the motor were strong enough (a definite possibility for a 12" driver that hits a Q of .5 in a 1cubic foot enclosure.)

It wouldn't be hard to find a 12" driver that would be naturally critically damped in that size enclosure, it would cost more, probably about $350-400, but still. Also, it may not even need more power if the motor were strong enough (a definite possibility for a 12" driver that hits a Q of .5 in a 1cubic foot enclosure.)

The RSS315HO would work. Even though its xmax is only 12mm, I'd take it over an 8" with considerably more xmax. Actually, two 315HOs might give a nice low Q in around 1ft^3. I am in a library now and can't sim it, but I have a sim saved. Forgot what the Q was though:

http://i27.photobucket.com/albums/c199/wadeere/Simulations/CBResponseDaytonReference12.gif

Some good points John. :) Just a couple of quick comments:

Nobody will argue the value of having multiple subs...that's for sure. Heck, part of the reason I'm gonna experiment with quad avalanche 18" sealed cubes with twin Crown K2 as the power plant, is just that. The ability to control the room with multiple subs in different positions is one of the great unknowns till recently.

However, we can't confuse what multiple subs will create in terms of SQ and headroom, vs what kind of subs to use as such mentioned "multiple subs". An Axiom EP400, as magical as that DSP can be, at the end of the day it will continue to remain an 8" sub with a $1100 price tag. I have a hard time believing anyone would rather choose that over an Epik Tower at $1099 as well and use two Epik towers spread in the room. Similarly with multiple HSU HO's, etc.

Again, I agree with the importance of an amp.....but we have to take into account the entire system. Once again, it can be a massive amp with great power components and Transformer, and a neatly designed and programmed DSP, but at the end of the day it is driving an 8" driver.

I just bring this issue of DIY for this one issue alone, and wont mention it again, but I agree with you John about the importance of power plants, and thus, most DIYers with capable drivers have been looking at excellent pro-amps as their power plant. In my case, for example, there is no amp that Axiom or SVS or HSU or any other sub manufacturer could put up that would supply transient response and peak hold response as a Crown K2 could offer:
http://home.pacbell.net/lordpk/proamps/Crown_K2.jpg
http://www.avsforum.com/avs-vb/showpost.php?p=11650937&postcount=252


Well, yes and no. The size of the driver does have tremendous influence on its headroom, extension, and how it will handle output compression and transient response, given high output levels. A single 15" driver will have more air displacement and excursion that multiple 8" drivers, so if we compare multiple larger drivers working at lower limits than multiple 8" drivers working at near max limits, it is pretty easy to see how "sound quality" starts to be affected by distortion and output compression.

As a mere exercise, at low volume levels, the SQ should not be too dependent on the driver size. But we all know that most myths about small drivers vs large drivers (15" and 18") sounding better, or sealed vs ported sounding better, have been thoroughly proven to be wrong.


now now Rob....play nice! :D I'm not the only one here with big mamoth subwoofers in their living/family rooms. That said, my family room, albeit not the most aesthetically pleasing per se, now that I have everything dialed in pretty much, has one of the most accurate, transparent, dynamic, and visceral acoustical signatures one can ever hear, period! I've heard systems that cost $50K-$70k in gear alone and don't come close to mine.

Now granted, the Proceed AVP2+6, the Nautilus 802's, the Denon 3910 modded, the Cinenova Grande, etc, have a lot to do with it besides my twin towers.....;)

But what do you do for phase control?

Well the room i'll be using this in now will just be temperary due to the fact i'm renting ATM, and would like to be getting into my own house within a year or so. This is a small 3 bedroom (1 floor w/1 bedroom suite downstairs) that has a long rectangular living/dining/kitchen area. I added a big curtain to try and add more seperation to the room, and while it doesn't add a solid barrier it does so by apperance. The measurements of the room from curtain to wall (where tv will be) is 17.5' L x 11.3' W x 8' H. Not too big but let's just say I would like to future proof myself. As of now i'm using a Panny 1200w HTIB and while the sound is decent it's nowhere near what I could be experiancing with a full blown system. The sub will be matched with either a set of Axiom or Paradigm mains, and a decently sized reciever (around 130w's). For music playback I listen to a lot of rap, hard rock/heavy metal, top 40, and also a lil bit of everything else. I have about 300 dvd's so we can say I watch a lot of movies, and would like it to give me some great sound while gaming. I've always been into booming bass, and a fan of ported enclosures over sealed back from my multiple car installs. Overall I would just like to get the best bang for my money, and even the Ultra is a little more then i'd like to spend but will if it's all it's cracked up to be.

Thank you

Hi-

I think you know this... the curtain will do nothing in terms of giving you a smaller room to pressurize.

Based on what you're saying above, it looks like you want deep extension (movies, rap) in addition to mid-bass response (rock, metal!). Stay away from the dinky subs if you want any extension.

I am a fan of dual subs place on opposite sides of the room, mid-wall to smooth out response. I have not been able to do that in any of my rooms. That said, since this is a temporary set-up for you, you might want to look at just one sub for now.

I have the new PC-U. The thing just rocks across the whole frequency range (deeper than 16hz in my open room). If you go over to the home theater shack you can see how it (the PB version) measures using some very tight standards. The EP500s bigger brother, the EP600 is measured there as well. The measurements show the PB-U is cleaner and more linear, with less group delay than most of the subs our there.

A lot of times these "this versus that" threads get heated and closed down. We all have our preferences. You should listen to as many subs as you can, in your room. Absent of that, the measurements are a good starting point. The inter-modular distortion is a more-recent stress test that highlights if a sub can handle multiple tones without adding its own color. AVtalk has one where they characterize the distortion audibility. All good reading.

I have both the EP500 and the SVS Ultra13.
The ultra13 does seem a little better (deeper) But not to the extent that others have indicated (most have never compared them side by side) The axiom is a great sub, shakes the house and you will not be disapointed in it. I have it up staires in a family room with an all Axiom surround system.
I bought the SVS for the basement theater due to it being installed on a solid concrete floor and wanting that little extra punch.
But the Axiom performed great down there. I needed a second sub for the basement so I went with the SVS.
You would be very happy with the Axiom, very impressive back plate....no hype needed.

I have both the EP500 and the SVS Ultra13.
The ultra13 does seem a little better (deeper) But not to the extent that others have indicated (most have never compared them side by side) The axiom is a great sub, shakes the house and you will not be disapointed in it. I have it up staires in a family room with an all Axiom surround system.
I bought the SVS for the basement theater due to it being installed on a solid concrete floor and wanting that little extra punch.
But the Axiom performed great down there. I needed a second sub for the basement so I went with the SVS.
You would be very happy with the Axiom, very impressive back plate....no hype needed.

Nothing like hearing an objective report from someone who actually owns both subs. Thanks Skers.

The Ultra-13 is a big step up in performance compared to the old Ultra and the fact that the SVS flagship sub now has linear FR means far better detailed sound in the mid and high bass. However that sub is flawed because of the cheap relatively low powered amp it contains. Even the replacement amps are having shutdown problems reproducing demanding passages such as the Ipods emerge scenes in WoTW, so I would caution the OP about buying this sub until this problem has been satisfactorily resolved.

Also be careful about reading too much into graphs based on impulse bursts or low level short reverse sine waves as they do not tell the whole story about subs and often do not correspond well to performance.

Regarding the EP600 graphs the group delay measurements are picking up feedback in the DSP circuit near the upper and lower filters and are not directly comparable to conventional group delay. It simply is not audible when listening which is why the bass sounds so clean and articulate. We will be comparing the EP600, Ultra-13 and three or four other subs in a side by side session on Nov. 4 where others will also post their impressions.

As far as the EP400 is concerned it does not have the headroom of the EP500 or 600 subs, as should be expected. The idea is to use multiples of this small sub in small to medium sized rooms to address room problems without using equalization or as a pair of stereo subwoofers where their tight sound enhances soundstage and imaging. My understanding is that the EP400 addresses a growing customer demand for smaller sized high performance subs, as contradictory as those terms may be to some people.

Also be careful about reading too much into graphs based on impulse bursts or low level short reverse sine waves as they do not tell the whole story about subs and often do not correspond well to performance.
how so? :confused:

Even the replacement amps are having shutdown problems reproducing demanding passages such as the Ipods emerge scenes in WoTW, so I would caution the OP about buying this sub until this problem has been satisfactorily resolved. .

heehee, it would be very hard to produce gigabytes of music coming out of the ground ... Ipod nanos, touch, iphones :)

just kidding


Also be careful about reading too much into graphs based on impulse bursts or low level short reverse sine waves as they do not tell the whole story about subs and often do not correspond well to performance.

Regarding the EP600 graphs the group delay measurements are picking up feedback in the DSP circuit near the upper and lower filters and are not directly comparable to conventional group delay. It simply is not audible when listening which is why the bass sounds so clean and articulate.

thanks, good info :D

Regarding the EP600 graphs the group delay measurements are picking up feedback in the DSP circuit near the upper and lower filters and are not directly comparable to conventional group delay.
Care to explain a little bit more?

Here is a good discussion on the subject.

http://www.hometheatershack.com/forums/home-audio-subwoofers/6656-subwoofer-tests-fall-2007-a-5.html#post54813

Here is a good discussion on the subject.

http://www.hometheatershack.com/forums/home-audio-subwoofers/6656-subwoofer-tests-fall-2007-a-5.html#post54813

i saw that response from Cj, but still, how are the current CEA2010 standards of testing, even with bursts and reverse sine waves, not good enough??:confused:

the ability the handle longer times by its capacity for thermal compression/distortion, etc, will also be a capacity of not only its power plant but more importantly, its driver capacity.

perhaps I'm misunderstanding what you originally meant with "be careful" and "often do not correspond well to performance", because the measurements done using the CEA2010 standard, and even older methodologies like Ed Mullen's testing, has an extremely close parallel to how a subwoofer will perform.

Sherv, as you can see from the discussion these points are debatable but my perspective is that CJ really nailed it. As you know from watching DVDs on subs (and speakers) are having to reproduce more intense LFE than ever before. Impulse burst measurement arose because many researchers believed it was a good proxy for real world sound reproduction of music. With intense LFE of long duration, impulse bursts are just not as accurate a representation of the signal. In fact, some scenes like WoTW or FoTP more closely resemble continuous sine waves of long duration. Those scenes are becoming more frequent.

Continuous loading does effect the properties of the amp and driver differently than short impulse bursts. Compression, voice coil resistance, IMD, THD, FR are all affected depending on the strength of the signal. That's why CJ is correct when he states,

" Actual program material is somewhere between tone-burst and continuous sine-sweep. I would say that music is probably nearer the tone-burst end and HT material rather closer to the continuous end but this is debatable. You takes your pick as to which you think gives you a better handle on real-world program performance"

It also why I suggest that graphs based on impulse bursts may not be a good way to assess performance of a sub under continuous loading. Listening closely to a sub distorting and its amp clipping during such scenes confirms it. :)

jakeman,

I'm still not getting your point? For example Ilkka uses BOTH, bursts and continuous sweeps so that one sees how subwoofers perform when using different kind of signals. Isn't that a win-win situation?

John, I don't think anyone is disputing that continuous loading obviously is a good measuring stick....I'm certainly not. And listening impressions are fine as well, as long as they are taken for what they are: subjective impressions which can vary greatly given a particular sampling.

However, I still don't see how the current CEA2010 and techniques used by Mullen and Avtalk "often do not correspond well to performance" :confused:

So far, with the exception of the Axiom offerings, the findings on most of these measurements from Ilkka/Avtalk/Mullen/et al, have correlated extremely closely with some of the listening impressions done by numerous sources.

Looking at how a subwoofer measures, what its components (driver and amp in particular) look like, and what its source has been, will give anyone a pretty darn good idea of how it will perform. It is repeatable and measurable.

cheers.. :)

I refrained from further argument in that thread because it's Ilkka's thread and I don't like peeing in someone else's pool particularly. However, I thought it might be useful to throw in a few points for discussion and leave it for others to debate.

Here's a few more for consideration.

Take-up of the standard by manufacturers. Polk Audio, who were involved in the development of the standard, undertook to publish these numbers for any new subs they released. As far as I have seen, they only did this for one model, the in-wall CSW155. I also understand that these figures are actually incorrect as there was a flaw in the measurement software at the time. When they released their new RM series in September, there was no mention of CEA-2010 numbers. No other manufacturers that I am aware of have published any official numbers. Other than Ilkka's published numbers, this is it. Unless take-up improves pretty soon this standard is still-born.

Ilkka has started publishing his numbers as RMS values, normalized to 2m. If the standard mandates 1m, peak numbers then this is perverse as you can't compare apples and apples any more. If we're not all going to stick to the letter of the standard, it defeats the whole point of the exercise.

While the CEA-2010 harmonic weighting is better than straight THD in terms of reflecting audibility, it is not the last word on the matter. Hence why we started experimenting with GedLee metric numbers. Even this is not perfect.

While the ability to deliver 100dB SPL at 20Hz is of interest, I am much less concerned about the ability to deliver 120dB at 60Hz. Beyond a certain point, the maximum output at any frequency is rather academic. I am more interested in knowing that when I drive the sub with a certain signal drive level, I will get xdB SPL at 60Hz and x-ydB at 20Hz . The smaller y is, the better the compression performance. In other words, I am more interested in linearity of frequency response than the ability to deliver some maximum SPL figure during a 6.5 cycle burst.

The actual maximum clean output numbers are fine for ranking subs but I'm not sure how useful the absolute number is. It doesn't tell you anything about how clean the sub is at lower levels. It won't tell you how loud your sub will play WOTW pods emerging scene in your room. You still need all the other measurements plus listening to fill in the gaps.

Sherv, I didn't say the current CEA2010 and techniques used by Mullen and Avtalk often do not correspond well to performance?? I guess I wasn't being clear with what I posted. I'm sure not disputing the importance of repeatable measurements. But neither would I suggest that they tell you everthing about how the sub will perform. I thought the thread posted explained the point well. :)

The CEA standard and related techniques based on impulse bursts are useful but are not always representative. In that regard, I'm agreeing with the notion put forth by CJ from AVtalk that impulse bursts are not as revealing as many people would like to believe with modern soundtracks. The point being made is that recent intense LFE material often resembles long cycle waves not short cycle bursts. Its something to be aware of when trying to assess performance using graphical measurements based on impulse bursts. The sub will perform differently than measured, with soundtracks that result in continuous loading. Ideally, we could see measurements using both techniques but continuous loading runs a greater risk of damaging an amp or driver so its not the favoured approach. A fine point perhaps but something to keep in mind when looking at the graphs.

Ideally, we could see measurements using both techniques but continuous loading runs a greater risk of damaging an amp or driver so its not the favoured approach. A fine point perhaps but something to keep in mind when looking at the graphs.
Exactly, and that's what Ilkka is doing. He uses both, CEA-2010 bursts and long sine sweeps. I already asked if this isn't a win-win situation?

Take-up of the standard by manufacturers. Polk Audio, who were involved in the development of the standard, undertook to publish these numbers for any new subs they released. As far as I have seen, they only did this for one model, the in-wall CSW155. I also understand that these figures are actually incorrect as there was a flaw in the measurement software at the time. When they released their new RM series in September, there was no mention of CEA-2010 numbers. No other manufacturers that I am aware of have published any official numbers. Other than Ilkka's published numbers, this is it. Unless take-up improves pretty soon this standard is still-born.
That's an unfortunate fact. But if you turn it around... do you see ANY kind of measurements taken by the manufacturers? Aren't you and Ilkka pretty much the only ones making these kind of measurements in the world? At least the ones who publish them.


Ilkka has started publishing his numbers as RMS values, normalized to 2m. If the standard mandates 1m, peak numbers then this is perverse as you can't compare apples and apples any more. If we're not all going to stick to the letter of the standard, it defeats the whole point of the exercise.
I think you answered this already. To which other measurements they could be compared when there aren't any?

I believe Ilkka said that he changed to 2m RMS because that's the way every other measurement is being shown/normalized (yours and Ilkka's). That way one can more easily compare for example burst numbers to sine sweep numbers.


While the CEA-2010 harmonic weighting is better than straight THD in terms of reflecting audibility, it is not the last word on the matter. Hence why we started experimenting with GedLee metric numbers. Even this is not perfect.

That's true.


While the ability to deliver 100dB SPL at 20Hz is of interest, I am much less concerned about the ability to deliver 120dB at 60Hz. Beyond a certain point, the maximum output at any frequency is rather academic. I am more interested in knowing that when I drive the sub with a certain signal drive level, I will get xdB SPL at 60Hz and x-ydB at 20Hz . The smaller y is, the better the compression performance. In other words, I am more interested in linearity of frequency response than the ability to deliver some maximum SPL figure during a 6.5 cycle burst.

The actual maximum clean output numbers are fine for ranking subs but I'm not sure how useful the absolute number is. It doesn't tell you anything about how clean the sub is at lower levels. It won't tell you how loud your sub will play WOTW pods emerging scene in your room. You still need all the other measurements plus listening to fill in the gaps.
And that's why you have frequency response and power compression measurements which show this particular information. In that thread jakeman linked, Ilkka stated pretty clearly that the CEA-2010 test isn't telling the whole story. That's why he will also take other measurements using other techniques. But also the CEA-2010 tells something that the other measurements won't.

Sorry to interrupt this spat, but I had a legit question in my post above.

Sorry to interrupt this spat, but I had a legit question in my post above.

You can effectively adjust phase by changing the distance setting in your reciever. Other than that, the 0/180 control is set by your wiring of +/- to the driver.

But what do you do for phase control?
you can adjust distances with your SSP, and you can also switch the wiring on your sub (+ to - ). Simple.

That's an unfortunate fact. But if you turn it around... do you see ANY kind of measurements taken by the manufacturers? Aren't you and Ilkka pretty much the only ones making these kind of measurements in the world? At least the ones who publish them.

I believe the idea of the standard was to try and get away from manufacturers quoting inflated wattage numbers as a means of conning people into thinking their subs gave the best performance. By encouraging them to use a common standard, it was hoped that there would be more honesty and it would make the decision easier for Joe Public. It would seem that there is little appetite for such honesty in the industry. Which is disappointing, if understandable.

I think you answered this already. To which other measurements they could be compared when there aren't any?

I believe Ilkka said that he changed to 2m RMS because that's the way every other measurement is being shown/normalized (yours and Ilkka's). That way one can more easily compare for example burst numbers to sine sweep numbers.

The trouble is, it is a published standard. You can't really change the criteria and still call it a CEA-2010 standard measurement. I'm sure if manufacturers started changing the criteria for THX certification to suit themselves, THX might have something to say about it. I suspect the CEA might act similarly. Perhaps Ilkka can persuade them to adopt his criteria as the standard in retrospect?

And that's why you have frequency response and power compression measurements which show this particular information. In that thread jakeman linked, Ilkka stated pretty clearly that the CEA-2010 test isn't telling the whole story. That's why he will also take other measurements using other techniques. But also the CEA-2010 tells something that the other measurements won't.

It certainly does. I just maintain that what it tells you isn't particularly useful. But it's just an opinion. :p

Btw CJ, I really like that GedLee metric you guys are using. I wish you could recreate it, retro-actively to your older tests. Any chance of that?

Cheers,

I have actually crunched the numbers for all the old measurements (several hundred hours of CPU time on a quad-core machine). However, I have not chosen to publish them yet. The reason for this is that I took some advice offered by Earl to Keith Howard that the GedLee Metric squared correlated better with audibility than the straight GM value as documented in their AES papers. So I computed all the GM values on this basis. Having now done considerable testing on the audibility of various patterns of distortion and correlated them with THD, THD CEA-2010 weighted, and GM, I think that this assumption may be wrong. In fact the original GM values seem to correlate better. Before I go to the effort of recomputing everything yet again with the square root restored, I want to be sure that this really is the best option. So I am still conducting further listening tests.