SVS AS-EQ1 subwoofer EQ

Posted by: grunt

SVS AS-EQ1 subwoofer EQ - 05/12/10 07:37 AM


I wasnít going to start this thread until I had more time with this but Iíve got some weird work schedules coming up and donít know for sure when Iíll get to do some serious testing. Plus I was so impressed with the results wanted to start sharing them right now.

First off this is not my AS-EQ1. Charles ďCVĒ shocked me last week buy offering to send his EQ1 to Sean and I for some testing and reviews. Fortuitous for me since Iíve been having a hell of a time trying to tame the bass from just one EP500 in this room and was considering something like this as an option. So many thanks to Charles for being so awesome to ship his EQ1 here.

The instructions for the EQ1 are pretty easy to understand (downloadable from SVS website) though I took more care than usual in reading them since it isnít mine. The software download and install was flawless and my computer immediately detected the EQ1 when hooked up via USB. It would have at that time automatically installed a firmware update but it was already current to up popped the menu.

Hook ups for the subwoofer input and output and satellite speaker output (for calibration) are all on the back while the USB port and calibration mic hookups are on the front under a magnetically attached removable face plate. Makes for easy connection all around. The calibration mic looks identical to the Audyssey mic that came with my Onkyo 3007 with the same length cord. It also came with a power cord and USB cable. According to SVS website they also now ship a subwoofer cable for adding the EQ1 between the subwoofer pre-out on the receiver and the EQ1. I needed an additional RCA connector (not sure if itís included in the original box) to hook up the satellite speaker out-put on the EQ1 to the left analogue input of my receiver so it can run a level calibration test between the speakers and the subwoofers.

I ran the non-Audyssey calibration routine for the EQ1 as I stopped using Audyssey a while ago since Iíve been doing a lot of speaker position tweaking and hate running it. I wonít give all the details of the calibration routine but it is similar though IMO easier than the regular Audyssey calibration. One nice feature is a redo last option which allows you to discard the just run test and redo it. Nice option if someone happens to knock on your door on the 30th of 32 position readings. Both for simplicities sake and to get the starkest result I ran the calibration for only the sweet-spot using all 32 locations around the head position of my main seat.

Here are the before and after graphs:

BEFORE:



AFTER:





The before graph exactly mirrors the readings Iíve gotten from my SPL meter when not using Audyssey. With Audyssey on it shaves a little off the curves but I canít find my notes as to how much so will have to run a LFE sweep to check it again.


Not being a very trusting person (they could have the EQ1 generate any graph that they want) I ran an LFE sweep with my Avia calibration disk and Radio shack SPL meter. I got slightly more deflection on the meter than the graph would indicate but not much with -4dB to +2dB being the occasional swings, but mostly the needle stayed within +/- .5 dB. Still way better than either no EQ or just the Onkyoís Audyssey.

One issue did arise at this point. The EQ1 wanted me to set the subwoofer distance to 39.2 feet. Problem is the Onkyo 3007 only goes up to 30 feet. To compensate I set the subwoofer to 30 feet and subtracted 9 feet from all the other speaker distances except the surrounds which are only at 6.5 feet to I set them to .5 feet which is as close as I could. In the limited testing Iíve done I didnít detect any problems with these settings. I reset all my speakers to 80Hz crossover so that the EQ1 was handling it.

Sorry to the measurements are everything crowed but I donít give a crap how a graph or meter reading looks I want to know how it sounds. So I popped in my most demoed LFE scene, the opening battle of ďMaster and CommanderĒ Blu-ray version.

This was one of those jaw hitting the floor moments like when my I first turned on my projector. I have never in over 3 years heard the LFE from my EP500 sound this good in any room. The cannon shots sounded just as tight as when I only run my M80s but now with the punch of the EP500. Before there was always a bad rumble from the very low frequencies and way to much high end bass while the mid bass punch always seemed to be sucked out (note in my apartment I got much better balanced LFE). No way I could see to A/B this and IMO no need to. Iíve listened to that scene 100s of times and know exactly how it sounded in this room and this sounded so much better there was no doubt.

Tossed in Avatar to watch the attack. (Note: Sean, I found out why the LFE didnít seem all that strong when we demoed Avatar. My EP500 was turned off at the sub so all we were hearing was the low frequencies mastered into the speaker channels with a 40Hz crossover for the fronts). For that matter I think Iíve been running w/o a sub for a couple weeks and didnít even notice it because of my M80s . ;\) Now I realize there is actually some bass in that scene. Most notable was one explosion that sent a visible shockwave past you on the screen with a corresponding midbass shock wave in the room. Actually made me flinch. Not quite a good a punch as sitting 6 feet from my M80s but getting there.

In the Mines of Moria the footfalls of the Balrog were now more distinctive again, something I hadnít heard since my apartment. Also when it roared there was much more of the misbass in-your-face feeling like it was actually standing right there.

For music I popped in Celtic Women "SŪ Do Mhaimeo Ū" (The Wealthy Widow) to hear those big monster drums. What a huge improvement. In the past even in my apartment I preferred the 2.0 version because the drums just ďrumbledĒ to much, but this was far better now in 5.1.

As another music test I cranked up some Goa Trance and heard rapid deep bass like I had never heard before. Previously I only listened to this with the M80s because the room just screwed up the sound of my sub turning the bass all mushy which just doesnít work at 150 beats/minute. This sounded so good I just let media monkey keep playing trance for half an hour before opening it up to all music. Now for the first time in this room I can listen with the subwoofer on.

More generally I noticed several notable improvements when the EQ1 was on. First there was much more midbass punch likely because the overall subwoofer level was turned up +7dB from pre calibration and the midbass dips were gone. The deep overpowering rumble that likely forced the subwoofer level to be turned so far down was gone but w/o loosing any of the room/furniture shaking when appropriate. The entire bass range sounded tighter and flawlessly integrated with the M80s. I never liked the sub in this room for music before. With the EQ1 I canít imagine not using it.

Ok this was a very limited test and not very realistic since most people will want the EQ for multiple seats. Yes that will be one of the next tests. Also, I believe Sean is going to bring over a pair of matching subwoofers so we can see how well it does with both similar and different subwoofers evening out the bass across multiple seats.

I can say right now without reservation that if you want to EQ a subwoofer for just the sweet spot just go out an buy an AS-EQ1 right now because it works. I hope to see how it does over a row and two rows of seats soon. If anyone has a specific test theyíd be interested in let me know and I will try to work it in or pawn it off on Sean later. ;\)

Iím temped to order an AS-EQ1 right now but plan on holding off until I see the results across multiple seats with both a single and double subwoofers. Also I want to research if anything is available like a pro version that allows a user defined target curves. I would like to be able to up the midbass even more when I want to. ;\)

Thanks again Charles. I never would have expected this much improvement in SQ from the AS-EQ1.

Cheers,
Dean
Posted by: St_PatGuy

Re: SVS AS-EQ1 subwoofer EQ - 05/12/10 09:11 AM

Whoa, sounds like you got immediate and positive results, Dean! Looking forward to hearing it, too.

LOL! That's good to know about Avatar as we were puzzled why others seemed to be raving about the bass. Still, just the M80s alone was pretty impressive.
Posted by: SirQuack

Re: SVS AS-EQ1 subwoofer EQ - 05/12/10 09:48 AM

come on Grunt, don't you know that using such Audyssey products is a snake oil technique. \:\) You know I'm kidding, great results.
Posted by: jakewash

Re: SVS AS-EQ1 subwoofer EQ - 05/12/10 10:54 AM

Great results Dean, makes me want to get an AS-EQ1.
Posted by: CV

Re: SVS AS-EQ1 subwoofer EQ - 05/12/10 01:02 PM

Nice write-up. Already way more helpful than mine. \:\) I'm glad you found it worthwhile in your room. I look forward to reading your further experiences.
Posted by: Anonymous

Re: SVS AS-EQ1 subwoofer EQ - 05/12/10 02:48 PM

 Originally Posted By: grunt
I hope to see how it does over a row and two rows of seats soon. If anyone has a specific test theyíd be interested in let me know and I will try to work it in or pawn it off on Sean later. ;\)


I'd be very interested in hearing your results regarding multiple rows and/or seats.
Posted by: JohnK

Re: SVS AS-EQ1 subwoofer EQ - 05/12/10 10:49 PM

Very good, Dean. One of the interesting aspects is that I'm sure that the 39.2' sub distance isn't the actual physical distance, so the effect of the delays in the sub is again illustrated.
Posted by: CV

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 12:35 AM

Thankfully it showed up as just over 30 feet the first time I ran it and then just under 30 feet the second time I ran it. My Integra also has a maximum distance setting of 30 feet.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 01:44 AM

 Originally Posted By: JohnK
Very good, Dean. One of the interesting aspects is that I'm sure that the 39.2' sub distance isn't the actual physical distance, so the effect of the delays in the sub is again illustrated.


No the actual physical distance is about 11 feet and my Onkyo was setting it around 23 feet when positioned there. It will be interesting to see what distance it gives for one of Seanís smaller subs which I presume donít have DSP chips.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 01:49 AM

 Originally Posted By: CV
Thankfully it showed up as just over 30 feet the first time I ran it and then just under 30 feet the second time I ran it. My Integra also has a maximum distance setting of 30 feet.


Lucky for me most of my speakers are 9 feet or more away most importantly my mains so I could compensate. I will try moving my EP500 closer, about 6.5 feet away so I can get my surrounds set correctly but at least so far Iím not hearing any timing problems with the surrounds set 3 feet closer than any of the other speakers. If I ever get off my lazy but and mount the surrounds up higher that will likely put them closer to 8 feet away.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 01:50 AM

 Originally Posted By: htnut
 Originally Posted By: grunt
I hope to see how it does over a row and two rows of seats soon. If anyone has a specific test theyíd be interested in let me know and I will try to work it in or pawn it off on Sean later. ;\)


I'd be very interested in hearing your results regarding multiple rows and/or seats.


Hopefully I can get to that this weekend as I looks like our fun and games at work are getting pushed back at least to Sunday.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 01:52 AM

 Originally Posted By: St_PatGuy

LOL! That's good to know about Avatar as we were puzzled why others seemed to be raving about the bass. Still, just the M80s alone was pretty impressive.


And they werenít even playing the LFE channel since the Onkyo still thought the EP500 was working since I never deselected it in the receiver.
Posted by: Potatohead

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 05:29 PM

Would someone generally be better off buying an EQ like this, or buying a second sub? I know the second sub will help level frequency response, and increase headroom and output, but I can't imagine it would help as much as the EQ assuming you have ample headroom already with the single sub? Those graphs are pretty impressive.
Posted by: Glitchy

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 06:18 PM

I want one NOW! NOW I just need $800.00 I'm not sure what to do with!
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 08:51 PM

Gasmdude, for a lot less than $800 you could look at something like the Behringer Feedback Destroyer (and yes, it is a bfd)as an inexpensive but effective parametric EQ.

It is not automated and requires measuring software like REW, but the results will be the same.

The cost for the BFD and a mike, or spl meter will set you back 2 bills or less.
Posted by: 1sweetspot

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 08:52 PM

I have a similar question to potatohead...would it be better to but this EQ than a better sub? I have a not too too bad sub now, and that EQ is a few hundred less than the ones I've been looking into.
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 08:59 PM

Dean. Wow, thats some mid bass suckout you have there! I had the opposite problem a hughe midbass peak at 54Hz. left me with less rumble.

Though my peak was just as bad, the effects of eq were much more subtle. I got more rumble and more detail in the upper bass, but it was not night and day when I first tried it. I find I am more sensitive to it now that I am used to the extra detail.

I'm also surprised that you're EP500 starts to roll off above 20 Hz. My EP350 has the same roll off. I guess I just get a lot of room gain here in my concrete bunker.
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/13/10 09:01 PM

 Originally Posted By: sirquack
come on Grunt, don't you know that using such Audyssey products is a snake oil technique. \:\) You know I'm kidding, great results.

EQ is a mixed bag. It is very effective for recalcatrant issues in the sub bass region, but generally does nothing for higher frequencies.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 02:22 AM


 Originally Posted By: Potatohead

Would someone generally be better off buying an EQ like this, or buying a second sub? I know the second sub will help level frequency response, and increase headroom and output, but I can't imagine it would help as much as the EQ assuming you have ample headroom already with the single sub? Those graphs are pretty impressive.


 Originally Posted By: 1sweetspot

I have a similar question to potatohead...would it be better to but this EQ than a better sub? I have a not too too bad sub now, and that EQ is a few hundred less than the ones I've been looking into.


I agree that the graph is very impressive but remember that was only for one seat in the sweet spot. Today I gave a listen in the seats I hadnít run the EQ for and the bass sounded worse than I have ever heard it (remember I only ran the EQ for one seat). I imagine that to EQ multiple seats the final curve will not be nearly so good since it will have to average things out across the whole row(s) and right now the ďperfect curveď for the sweat spot is clearly screwing up the adjacent seats.

I hope to re-run the EQ across both one row and two rows of seats Friday after work, just to much going on right now to do it sooner.

Hopefully I can get Sean over hear fairly soon with his two identical subs so we can compare how the EQ1 does over multiple seats vs two subwoofers and since it will EQ two subwoofers we can also do two subs + the EQ1.

My understanding is that because no one curve can be ideal for all seats itís usually better to get a second subwoofer before applying EQ as it will even things out better so that the EQ doesnít have to do as much should you also choose to use it.

 Originally Posted By: fredk

Dean. Wow, thats some mid bass suckout you have there! I had the opposite problem a hughe midbass peak at 54Hz. left me with less rumble.


Yes it is a big hole in the midbass which is one reason Iíve been toying with the idea of midbass modules but Iíd rather have a more all encompassing solution before going that route.

Fred how many bands does your BFD have, and can you set them any way you want so if you want a bit of a midbass hump you can dial that in? Also, I assume one BFD will only EQ one sub is that correct. Plus does it help to properly set the timing delay. Another big improvement Iíve noticed is that the M80s and EP500 seem much more closely matched timing wise with the EQ1 compared to the Audyssey in the Onkyo.



The tweaker in me would like to be able to set up my own target curve so if say I want a midbass hump I can put it there since I can still get plenty of very low end with my Buttkicker. I havenít researched to see if the Pro version allows user defined target curves but my understanding is that it does.
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 08:34 AM

The BFD has 10 eq channels and two lines in/out.

There is a process for EQing multiple subs on one channel and REW can help a lot there, but it is a manual process. I think the big value of the SVS EQ is that it is automated.

Now, REW will generate EQ settings from a set of measurements, so EQing one sub is as simple as running a sweep, clicking a button for REW to generate an EQ curve and then manually entering the settings given by REW into the BFD. It took me about an hour to figure out the setup and enter the settings the first time.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 09:41 AM

Will REW generate an average curve for multiple seats?
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 10:09 AM

Yes it will. So, if you are trying to average across subs and seats, you need to apply EQ calculated from averaged measurments to the entire set of subs. That's my understanding anyway.

REW takes some time to learn, but once you are up to speed, you can measure and adust to your hearts content. Its a tweekers dream. ;\)
Posted by: michael_d

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 11:12 AM

I looked into room EQ a while back. Started reading up on REW and all the crap Iíd need for the PC interface, time to learn the software, time to analyze the results, time to tweak, time, time, timeÖ.. It didnít take me long to realize that adventure is not for someone with life outside their home theater.

I really like the ease of use the Velodyne SMS-1 offers, and its relatively low cost. However, Iím not certain if it will help much with a multiple sub arrangement. The EQ-1 looks as if it may work a bit better.

Has anyone compared the EQ-1 to the Velodyne to see just what it may do better?
Posted by: casey01

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 12:17 PM

I have an SMS-1 with FOUR subs and as along as everything is balanced(volume) and in phase it does the job well. One thing, however, I have found over the years, is that with any of these EQ devices and regardless of how many positions from which the calibration can be done, one can come up with a level, balanced curve showing on the screen yet it may still not sound quite right and that is generally as a result of the limitations of human hearing.

For eg: a couple of years back when I purchased the SMS-1 and in doing my initial calibration, I noticed a distinct deficiency in my room with the curve between 40-55HZ. Once I got it leveled out, however, I noticed that even though it was showing a proper balance, the lower levels below 40HZ(at least to my ears anyway) were being overpowered by the upper levels, and that was despite the fact it was showing a level curve on the screen.

In my opinion, this is the advantage of having one of these units in that it allowed me to slightly boost up those lower levels to compensate for what I was hearing in relation to the "official" calibrated curve. That is, of course, provided your subs can handle that "extra boost".

In the end, it is what sounds good to you that will determine what your final set-up is, but given the "finnicky" nature of low bass in any room, either the SMS-1 or EQ-1 will give you a better chance of getting where you want to go.
Posted by: Dduval

Re: SVS AS-EQ1 subwoofer EQ - 05/14/10 08:01 PM

I have the SMS-1 with Dual Ep500's crossed over @ 50hz. Makes a big difference for me, now I can't imagine going without it. FYI

Dana
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/15/10 09:03 AM

 Originally Posted By: michael_d
I looked into room EQ a while back. Started reading up on REW and all the crap Iíd need for the PC interface, time to learn the software, time to analyze the results, time to tweak, time, time, timeÖ.. It didnít take me long to realize that adventure is not for someone with life outside their home theater.

Meh, it took a couple of nights to set everything up the first time, figure out the software, calibrate and take measurements. Now its just a quick 5 minute calibration and I'm set to measure.

As for analysis, whats to analyze?? If its not flat, click the eq button and transfer the settings to the BFD.

If you have the $ for the AS-EQ1 thats fine. If you don't, or prefer to spend it elsewhere, REW and the BFD are a viable alternative.
Posted by: SRoode

Re: SVS AS-EQ1 subwoofer EQ - 05/15/10 04:09 PM

With the BFD, I found myself obsessing continously over making my curve flat, more than I found myself spending time enjoying what I had with my family. My solution was simple. I disconnected it.

It did make a noticeable difference in my primary seat however when I was crossed over at 80 Hz. At 40 Hz, I think it would make less of a difference.
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/15/10 04:53 PM

Maybe I'm lucky, but I was able to get a pretty flat response using just 5 of the presets REW defined. No tinkering needed.
Posted by: SRoode

Re: SVS AS-EQ1 subwoofer EQ - 05/15/10 05:14 PM

Me too Fred, but you know how things go. Every little bump and dip became a mountain and a valley in my eyes, and needed to be fixed! \:\) Don't get me wrong, it's a wonderful machine and it does make a big difference!
Posted by: CV

Re: SVS AS-EQ1 subwoofer EQ - 05/15/10 08:22 PM

I've already said it in other threads, but my dream subwoofer EQ doesn't exist yet. Ideally, it would correct up to four subs individually (both frequency and time) and be part of the receiver/preamp's native features. It would be nice if you could EQ the bass separately from whatever the main EQ software is, as if it was an external unit, or along with it. Manual tweaking of the curve would also be great. I don't know how far away a product like this is, but you'd think someone would be working on it. I don't really understand the receivers that do 3 subwoofer outs. A jump from 2 to 4 seems more logical, no?

Requiring a computer to utilize the EQ is a bit of a hassle. It would be nice if a PC connection allowed for greater speed or filter resolution, but otherwise I'd prefer to have the interface be part of the receiver/preamp.
Posted by: fredk

Re: SVS AS-EQ1 subwoofer EQ - 05/16/10 01:08 AM

Steve, I guess I'm just a 'good enough' kinda guy. I get paid to fiddle with stuff all day long, so by the time I get home, bumpy is good enough.

CV, I bet less than 20% of HT owners have two subs, and only you and a couple of other lunati, um, enthusiasts have 4 monster subs. ;\) For what its worth, the SVS eq is a computer, but it can only do one thing.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/17/10 03:03 AM

First I have to give a shout out to Doug at SVS Tech support for corresponding with me this weekend over an issue I seemed to be having. Not many companies or people offer that sort of service so it deserves recognition.

Well might as well get the issue mentioned. After the first spectacular run of the AS-EQ1 in the single center seat I ran it the next day across all three seats getting almost no improvement notable by meter or ear. I ran it about 10 more times in the single center seat trying to recreate the first results and continued to get almost no improvement. This morning I tried again in the single center seat and once again near perfection. Liking the results I was almost afraid to try 3 seats again. This time the 3 seat run came out quite well. I have no idea what was going on. I know the sound of my system after listening and tweaking almost every week for a year and can clearly hear when the EQ is working well and when itís off or not working well so I donít think this was any sort of post calibration measurement anomaly though I could be wrong. I was probably just screwing something up and got it corrected w/o realizing what I was doing. But for now Iím going to leave well enough alone until I get a chance to have Sean come over.

So how did it do this time? Well for the single seat it once again took a 19dB range (e.g. +/-9.5dB) and reduced it to just over 4dB (e.g. +/-2dB). Try to tell me you canít hear the difference in that.

For the 3 seat run I used only 8 of the 32 measurement positions this time since I was also comparing it to what the Audyssey in my Onkyo could do so I used the same 8 positions called for in the Onkyo manual. (Note: this is not the ideal way to run the AS-EQ1 which suggests using measurements 2 feet apart over the seating area with around 18 or so being a good number as above that you get diminishing returns. I will redo the 3 seat single row and 2 row measurements using the optimal configuration.

As I expected it didnít do quite at well as the single seat since it has to average out for a wider area, about 9 feet across (I have big chairs). In this case it took the 19dB range of the center seat and brought it down to 10dB. The 20dB range of the left seat was brought down to 12dB and the 19dB range of the right seat was brought down to 14dB. Remember this was not an optimal use of the AS-EQ1 but a test to see how it performed with the same inputs as the EQ on my Onkyo.

Clearly not as good as calibrating a single seat but that was expected. Hopefully I can have Sean come over soon so we can hook up his subs and do a test with his matching subs and then a mismatch of my EP500 and one of his. My understanding is that the real strength of the AS-EQ1 is calibrating 2 subwoofers at the same time.

As a comparison I ran the Audyssey EQ on my Onkyo in just the center seat and it reduced the normal 19dB range down to 11dB whereas the AS-EQ1 took it down to a 4dB range. When I ran the Onkyoís EQ over all 3 seats it took the center seat range down from 19dB to 14dB whereas the AS-EQ1 brought it down to 10dB. I forgot to measure the outer two seats for the Onkyo but the AS-EQ1 also did noticeably better than the Onkyo there too.

I also ran the Onkyoís EQ in conjunction with the AS-EQ1. Actually you just run the AS-EQ1 and then the Onkyoís one after another with the AS-EQ1 in the chain to the subwoofer. Very simple to do. The Onkyo set the trim level for the sub at +.5 which is exactly what the AS-EQ1 was suggesting. I canít compare the distances since the Onkyo set the distance to 30 feet (the max) while the AS-EQ1 suggested 32 feet. I did the same as before and adjusted the other speaker distance to compensate for the 2 extra feet of the subwoofer.

So far so good. The AS-EQ1 is working nicely and noticeably better than the Onkyo over the range of the LFE channel even though itís not being utilized to itís full potential yet. Probably the next set of test will but one and two rows of seats using optimal measurements for the AS-EQ1. Then the part I canít wait for, calibrating two similar and also two dissimilar subwoofers.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/17/10 03:15 AM

Iím with Michael on the REW thing. While it might be a good route to go Iím not sure I want to take the time and effort learn it (so says the guy testing and opining on the AS-EQ1).

Like Casey I think I might prefer the ability to tweak specific frequencies since I agree that what I prefer to hear is more important to me than a flat FR graph or someone else ďidealĒ curve (Audyssey).

 Originally Posted By: CV

I don't really understand the receivers that do 3 subwoofer outs. A jump from 2 to 4 seems more logical, no?

Not if your just trying to keep ahead of the Joneses. They might be thinking that with 2 output you could Y-connect 2 pair to get 4. Also I might be the exception but 3 outputs would be perfect for me as at most I would have 2 subwoofers but would still like a separate output for the Buttkicker.
Posted by: CV

Re: SVS AS-EQ1 subwoofer EQ - 05/17/10 03:45 AM

Good point on the Buttkicker. Since my pre-pro has both XLR and RCA subwoofer outs, I figured I'd use the XLR for the subs and the RCA for the Buttkicker. Whatever pre-pro I replace this with should likewise have the two types of outputs. Of course, this is one of the reasons I would like the superior subwoofer EQ built into the pre-pro itself or for it to have XLR inputs and outputs. Of course, if it's built into the pre-pro, then it must be applying the subwoofer corrections to both XLR and RCA outputs, right? That's assuming both outputs are active simultaneously. I haven't really looked into it. I'm sure there's some problem with my ideas, beyond what I'm lazily speculating.

Dean, thanks for the extremely detailed experimentation. I knew you'd have a lot more to offer the group.
Posted by: CV

Re: SVS AS-EQ1 subwoofer EQ - 05/17/10 03:51 AM

 Originally Posted By: fredk
CV, I bet less than 20% of HT owners have two subs, and only you and a couple of other lunati, um, enthusiasts have 4 monster subs. ;\)


People make expensive gear for a tiny sliver of the market all of the time. I don't expect what I want to be super-cheap, but it still seems like it could at least exist. Considering they're half-way there, it's not too much of a stretch. It's like getting a multichannel amp instead of a monoblock. The technology's there. It just needs a little more packed into a single box to satisfy a different segment of the market. Or I'm crazy.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/17/10 03:58 AM

 Originally Posted By: CV
Good point on the Buttkicker. Since my pre-pro has both XLR and RCA subwoofer outs, I figured I'd use the XLR for the subs and the RCA for the Buttkicker. Whatever pre-pro I replace this with should likewise have the two types of outputs. Of course, this is one of the reasons I would like the superior subwoofer EQ built into the pre-pro itself or for it to have XLR inputs and outputs. Of course, if it's built into the pre-pro, then it must be applying the subwoofer corrections to both XLR and RCA outputs, right? That's assuming both outputs are active simultaneously. I haven't really looked into it. I'm sure there's some problem with my ideas, beyond what I'm lazily speculating.

Dean, thanks for the extremely detailed experimentation. I knew you'd have a lot more to offer the group.


No thank you Charles as now I know how much better sub EQ can really do in my room big difference moving from theory to reality. Problem is Iím in the same boat as you. The system I really want isnít available yet. So likely a second sub will be my first option unless I drag my feet long enough for the ďrightĒ EQ system to come out.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/20/10 03:50 AM

Iíve done some more listening over the last couple days with the configuration unchanged from when I ran only 8 of the 32 possible measurements.

While using 8 measurements over three seats made a measurable improvement in the FR in all three seats the audible difference isnít so clear. Remember that when I ran the AS-EQ1 on just one seat in the sweet spot the results were nothing short of fantastic both measured, and more important audibly. Over all three seats itís almost impossible for me to tell the difference when itís on or off even with music with lots of bass. The only time I can tell the difference is when sitting in the sweet spot playing drone music with a very heavy bass line and then only when I A/B between having the AS-EQ1 on or off.

Granted this was with only 8 measurements positions and my understanding is that the real strength of the AS-EQ 1 is in equalizing 2 subwoofers at the same time. Something which may not happen for a couple of weeks. I may or may not take the time to EQ for multiple seats using more measurements before then but would actually prefer to wait until Sean is here so we can do blind A/B comparisons.

I may however redo the calibration for the sweet spot alone since I really liked the sound of my system when I had done that before.
Posted by: CV

Re: SVS AS-EQ1 subwoofer EQ - 05/20/10 04:03 AM

I never did try doing all of the measurements from one listening position. Now I'm curious about that.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 05/20/10 04:30 AM

According to Doug from SVS in most cases more than 18 reading even across multiple seats leads to diminishing returns. Some things Iíve read in the Audyssey thread at AVS suggest that you can even get negative returns from taking to many position measurements over a complex seating arrangement like and ďLĒ shape. Though I havenít tested it I donít thing there is actually much advantage to more than 8 readings if just calibrating for one seat in the sweet spot certainly more than 18 would be wasting time from what Iíve learned.

The problem with EQ over multiple seats is boosting or cutting a frequency for one seat will do the same for other seats which might have needed the opposite. Thatís why Doug said to me the AS-EQ1 works best over multiple seats when using 2 subwoofers. Which agrees with the paper I was just reading, the one titled ďLow-Frequency Optimization Using Multiple Subwoofers.Ē

http://www.harman.com/EN-US/OurCompany/T...%20Publications
Posted by: JohnK

Re: SVS AS-EQ1 subwoofer EQ - 05/20/10 09:46 PM

Very good paper by Welti and Devantier, Dean; thanks for linking it. I'd read it in my AES Journal, but wasn't aware that it was now available to non-members online.
Posted by: grunt

Re: SVS AS-EQ1 subwoofer EQ - 06/01/10 03:39 AM

Along with my dual subwoofer workout I was also testing how well the AS-EQ1 does at applying EQ to multiple seats, three in a row in this case. Iím skipping most of the boring details so if you have any questions about how I tested just ask.

I tested both one of Seanís D-10s and my EP500 in the best location. I also tested dual D-10s in 7 locations and a dual D-10 and Ep500 combo located between the two best spots in the room.

The results were all very good except for one, the D-10 + EP500 combo which actually measured worse when EQ was applied.

To gauge the success of applying EQ I measured the subwoofer(s) performance across all three seats noting individual significant results and the range of SPL deviation in each seat. To determine how well it worked across all three seats I summed the individual deviation from each of the seats.

Depending on the locations tested the combined deviations for all 3 seats totaled from 45dB to 70dB w/o EQ. The best measurement 45dB was the EP500 alone in the best location with the worst measurement 70dB being dual D-10s in all cased running either single or dual D-10s the deviation across all 3 seats was cut nearly in half when EQ was applied. Very occasionally a single seat would get slightly worse (usually within the margin of error of 3dB) but overall the 3 seats as a whole got better.

The single best result was running the AS-EQ1 on my EP500 in the best location. The deviations I measured w/o EQ were (L/C/R) 7/18/20dB. With EQ it became 9/9/12. More important is that the very high and very low frequency peaks were gone with most of the variation being at the dip. The improvement in the center and especially the right seat are very noticeable to the ear/body.

One other thing I did notice was that while the EQ improved the FR in the seating area some other areas notably the kitchen were very negatively effected and sound better with the EQ turned off. Not an issue since I usually only play my M80 ďwhole house audio systemĒ when wandering around.