The astounding new AS-EQ1 SubEQ goes on sale!

[Doug McBride]

AS-EQ1 FAQs are up:

http://svsound.com/as-eq1/as-eq1_subeq_faq.pdf

Doug

[Lordoftherings]

Thanks Doug for the link, any additional information about the AS-EQ1 SubEQ is always welcome.

Bob

[Rookie100fun]

Hi Ed & Doug,

If I play 3 subwoofers with the AS-EQ1, what is your advise?

Many thanks!

[Doug McBride]

Rookie100fun wrote:

Hi Ed & Doug,

If I play 3 subwoofers with the AS-EQ1, what is your advise?

Many thanks!

Be happy to help. Can you tell us more about your room and subs? How large is your room and where are the subs placed? What brand and model are your subs?

What we want to do is determine which two subs should be combined and what level they should be set at. If the subs are all the same, level setting is easier since they all have the same performance characteristics. If you have a mixed bag, we need to do a little analysis to determine the relative levels each subs should be set at to make sure you have plenty of headroom and don't push any of them past their limits while the other loaf.

Thanks,

Doug

[Texxen]

I've just received my AS-EQ1 and got a few questions. Maybe Ed or Doug can help me.

1) Auto EQ Assist should be set to "On" only if I use the avr's mic and test tone to calibrate the system? My Avr is Yammy. I calibrate my system with avr's test tone and SPL meter, and never use the avr's mics and built-in YPAO. In my case, can I just set Auto EQ assist to "off" and proceed directly to the Level Matching section?

2) On the level matching screen, there is a part in the little guide section on the left that says;

"Disable the AVR or Pre/Pro bass management crossover by setting the selected satellite speaker to Large or Full Range."

My speakers are set to "Small", LFE set to "Subwoofer", and Crossover set to "80Hz". Do I need to change the speakers to "Large" according to the guide? If so, at what point in the test do I change the speakers back to "Small"? I tried using both options with the result below;

2.1) When I set the speaker to Large and run AS-EQ1, the end result asked me to set my speakers to Large.
2.2) When I leave my setting as is (Speakers = small, Crossover = 80Hz) and run the AS-EQ1, the end result asked me to set my speakers to Small with a crossover of 40Hz.

Your help will be much appreciated

[Timoxx4]

I am going to get one of these units in the second batch and i have the same questions as Texxen above.

I also have a Yamaha AVR (3800) and i too do not use the built in YPAO. So any help on how one would go about setting it up and using it with the EQ1 would be great here too.

[Doug McBride]

Texxen wrote:

I've just received my AS-EQ1 and got a few questions. Maybe Ed or Doug can help me.

1) Auto EQ Assist should be set to "On" only if I use the avr's mic and test tone to calibrate the system? My Avr is Yammy. I calibrate my system with avr's test tone and SPL meter, and never use the avr's mics and built-in YPAO. In my case, can I just set Auto EQ assist to "off" and proceed directly to the Level Matching section?

2) On the level matching screen, there is a part in the little guide section on the left that says;

"Disable the AVR or Pre/Pro bass management crossover by setting the selected satellite speaker to Large or Full Range."

My speakers are set to "Small", LFE set to "Subwoofer", and Crossover set to "80Hz". Do I need to change the speakers to "Large" according to the guide? If so, at what point in the test do I change the speakers back to "Small"? I tried using both options with the result below;

2.1) When I set the speaker to Large and run AS-EQ1, the end result asked me to set my speakers to Large.
2.2) When I leave my setting as is (Speakers = small, Crossover = 80Hz) and run the AS-EQ1, the end result asked me to set my speakers to Small with a crossover of 40Hz.

Your help will be much appreciated

1) That is correct.

2) Were you using a multi-channel analog input for the "Sat Out" of the AS-EQ1? I only ask because most AVRs do not apply any bass management/DSP to these inputs so it's the same as setting speakers to "large".

In any case, SVS always recommends setting your speakers to "small" and your crossover at a frequency commensurate with the capabilities of your speakers and that will provide good blending of your sub(s) and speakers, letting the sub(s) handle most of the low frequencies since that is what they were designed to do. If you've been happy with your 80Hz crossover, that's a great place to have it.

On another note, how does you room sound now you are using the AS-EQ1? Notice any difference?

Doug

[Texxen]

Thank you for a speedy reply, Doug.

So if I actually connect the AS-EQ1 "sat out" to my avr's analog multi-channel input, I can just leave my avr setting as "small, subwoofer, 80Hz" throughout the test and don't have to set it to Large as per the guide?

I did connect the AS-EQ1 "Sat Out" to my avr's multi-channel input. But the noob question is how do I tell if it's the analog or digital? I'm a bit of HT noob

Also, follow on from your reply, let say at the end of the calibration, the AS-EQ1 still recommends the cross over at 40Hz. If I set my AVR to the usual 80Hz instead of AS-EQ1's recommended 40hz, wouldn't that caused any anomaly. ie. wouldn't the overall end result be different that what it really should be ? (since the AS-EQ1 has probably applied its adjustment for the 40Hz crossover environment with the assumption that I will be using the recommended 40Hz crossover, but somehow I decided to stick with my original crossover of 80Hz instead) ?

In regard to how my room sounds now, would you believe I haven't tried it out yet? I was gonna wait for your reply before I finalize it I did have a look at the graph though. It's not a total flat line but close to that. The original line was like a sine wave so overall I was very impressed

[janly]

I got my AS-EQ1 in house last week and tried to run it yesterday. My setup are Avantgarde Trio Omega speakers with Avantgarde large Basshorn. It is these basshorn I want to use the AS-EQ1 on. This is a 2-channel setup, and I use an Cary tube preamp that the basshorn get it's signal from. The signal are stereo. I run the AS-EQ1 as Dual discrete IN to dual discrete OUT and has set the subwoofers SPL to 75 dB in the SubEQ application before calibrating. After calibrating the SUB A and SUB B (I can not calibrate with "satelites" in this setup) I choose the Transfer to AS-EQ1 button. Then my problem occurs, I can't view the result. If I click on "View results" I get an error in the browser saying that it can't find the document. I have searched for the html document, and it don't exist. I can't Create HTML Certificate Document either. So it seems that the AS-EQ1 doesn't generate any result to view.

The plan is to equalize the basshorn and calibrate the speaker and subwoofer channel levels using an alternate source later.

Does someone know of this problem??

Janly

[Doug McBride]

janly wrote:

I got my AS-EQ1 in house last week and tried to run it yesterday. My setup are Avantgarde Trio Omega speakers with Avantgarde large Basshorn. It is these basshorn I want to use the AS-EQ1 on. This is a 2-channel setup, and I use an Cary tube preamp that the basshorn get it's signal from. The signal are stereo. I run the AS-EQ1 as Dual discrete IN to dual discrete OUT and has set the subwoofers SPL to 75 dB in the SubEQ application before calibrating. After calibrating the SUB A and SUB B (I can not calibrate with "satelites" in this setup) I choose the Transfer to AS-EQ1 button. Then my problem occurs, I can't view the result. If I click on "View results" I get an error in the browser saying that it can't find the document. I have searched for the html document, and it don't exist. I can't Create HTML Certificate Document either. So it seems that the AS-EQ1 doesn't generate any result to view.

The plan is to equalize the basshorn and calibrate the speaker and subwoofer channel levels using an alternate source later.

Does someone know of this problem??

Janly

Hi Janly - if you are running Vista, you are not the first to report this. We think we've narrowed it down to SubEQ running on some localized versions of Vista (does not affect XP as far as we can tell). This has been reported to Audyssey and they have confirmed it is fixed in the next version of the software which is tentatively scheduled for later in July.

The problem is that the subdirectory in C:\Program Files\Audyssey Labs\Audyssey SubEQ 3.1 called certOutput does not get created at the time you are finishing your measurements in SubEQ and preparing to graph them.

We've been looking for a user to help us test a workaround to see if it has any effect. If you want to try it and report back that would be cool:

1. Change locale to US
(see here: http://windowshelp.microsoft.com/Win...3464d1033.mspx)

2. Re-run measurements

3. See if graphs get created in certOutput (will show in your browser and you will have the certOutput subdirectory)

4. If not, uninstall SubEQ, re-install and re-measure

5. If after 4. and it works, try resetting locale to where it is normally set and re-measure using a different number of measurement positions so we can see if the new measurements get graphed (look on graph output for number of positions as a way to check different measurement runs).


Thanks,

Doug

[Doug McBride]

Texxen wrote:

Thank you for a speedy reply, Doug.

So if I actually connect the AS-EQ1 "sat out" to my avr's analog multi-channel input, I can just leave my avr setting as "small, subwoofer, 80Hz" throughout the test and don't have to set it to Large as per the guide?

I did connect the AS-EQ1 "Sat Out" to my avr's multi-channel input. But the noob question is how do I tell if it's the analog or digital? I'm a bit of HT noob

Also, follow on from your reply, let say at the end of the calibration, the AS-EQ1 still recommends the cross over at 40Hz. If I set my AVR to the usual 80Hz instead of AS-EQ1's recommended 40hz, wouldn't that caused any anomaly. ie. wouldn't the overall end result be different that what it really should be ? (since the AS-EQ1 has probably applied its adjustment for the 40Hz crossover environment with the assumption that I will be using the recommended 40Hz crossover, but somehow I decided to stick with my original crossover of 80Hz instead) ?

In regard to how my room sounds now, would you believe I haven't tried it out yet? I was gonna wait for your reply before I finalize it I did have a look at the graph though. It's not a total flat line but close to that. The original line was like a sine wave so overall I was very impressed

All good questions.

If you check your manual where it discusses the analog multi-channel inputs, it will probably say you cannot apply any DSP modes to that input, and may even say there is no bass management performed (most of the units manuals I've looked at are pretty indirect - vague if you will - on the topic). If there is no bass management being performed on that input, that's the same as setting your speakers to "Large". If no digital processing is done on that input, it will be totally analog.

What kind of speakers do you have? Can you look up the specs and tell me what your response is rated at at the -3dB point? It may say something like "Frequency Response +/-3dB" and then give a range.

Let me know if, after using the Multi-channel inputs and providing the specs on your speakers if SubEQ still recommends a crossover as opposed to "Large".

Doug

[Texxen]

Hi Doug,

My speaker is Paradigm Monitor series. I couldn't find the FR at +/-3dB on the spec sheet. All I could find is this;

FRONT SPEAKERS (http://www.paradigm.com/en/paradigm/...1-2-4.paradigm)
Frequency Response:
On-Axis ±2 dB from 54 Hz - 20 kHz
30° Off-Axis ±2 dB from 54 Hz - 15 kHz

CENTER (http://www.paradigm.com/en/paradigm/...1-3-4.paradigm)
Frequency Response:
On-Axis ±2 dB from 80 Hz - 20 kHz
30° Off-Axis ±2 dB from 80 Hz - 17 kHz

REARs are some 10 yrs old JBL Floorstanding. I can not find the spec for it

SUB: PB13-Ultra

[janly]

Doug McBride wrote:

Hi Janly - if you are running Vista, you are not the first to report this. We think we've narrowed it down to SubEQ running on some localized versions of Vista (does not affect XP as far as we can tell). This has been reported to Audyssey and they have confirmed it is fixed in the next version of the software which is tentatively scheduled for later in July.

The problem is that the subdirectory in C:\Program Files\Audyssey Labs\Audyssey SubEQ 3.1 called certOutput does not get created at the time you are finishing your measurements in SubEQ and preparing to graph them.

We've been looking for a user to help us test a workaround to see if it has any effect. If you want to try it and report back that would be cool:

1. Change locale to US
(see here:

2. Re-run measurements

3. See if graphs get created in certOutput (will show in your browser and you will have the certOutput subdirectory)

4. If not, uninstall SubEQ, re-install and re-measure

5. If after 4. and it works, try resetting locale to where it is normally set and re-measure using a different number of measurement positions so we can see if the new measurements get graphed (look on graph output for number of positions as a way to check different measurement runs).


Thanks,

Doug

Hi Doug, and thank you for your help! It's correct - I run the SubQ on a Vista 32 PC. I changed the locale to US, restarted the computer, started the Audyssey application and ran the measurements. A document did not get created in certOutput. I then uninstalled SubEQ, re-installed it and re-measured. Then it worked and I got the results

I did not have the time to play much music to hear the result, but the first impression was a tighter and cleaner bass.

Thanks,
Janly

[Doug McBride]

janly wrote:

Hi Doug, and thank you for your help! It's correct - I run the SubEQ on a Vista 32 PC. I changed the locale to US, restarted the computer, started the Audyssey application and ran the measurements. A document did not get created in certOutput. I then uninstalled SubEQ, re-installed it and re-measured. Then it worked and I got the results

I did not have the time to play much music to hear the result, but the first impression was a tighter and cleaner bass.

Thanks,
Janly

Janly - thanks much for trying this and reporting back your findings! We'll make sure we share this with others who are having the same problem.

One more question - did you set your locale back to Norway to see if it still worked?

Thanks again for your help. I think after you've had a chance to listen for a while you'll be able to notice some interesting differences.

Cheers,

Doug

[Ed Mullen]

Texxen wrote:

Thank you for a speedy reply, Doug.

So if I actually connect the AS-EQ1 "sat out" to my avr's analog multi-channel input, I can just leave my avr setting as "small, subwoofer, 80Hz" throughout the test and don't have to set it to Large as per the guide?

I did connect the AS-EQ1 "Sat Out" to my avr's multi-channel input. But the noob question is how do I tell if it's the analog or digital? I'm a bit of HT noob

Also, follow on from your reply, let say at the end of the calibration, the AS-EQ1 still recommends the cross over at 40Hz. If I set my AVR to the usual 80Hz instead of AS-EQ1's recommended 40hz, wouldn't that caused any anomaly. ie. wouldn't the overall end result be different that what it really should be ? (since the AS-EQ1 has probably applied its adjustment for the 40Hz crossover environment with the assumption that I will be using the recommended 40Hz crossover, but somehow I decided to stick with my original crossover of 80Hz instead) ?

In regard to how my room sounds now, would you believe I haven't tried it out yet? I was gonna wait for your reply before I finalize it I did have a look at the graph though. It's not a total flat line but close to that. The original line was like a sine wave so overall I was very impressed

Hi Tex:

The multi-channel inputs on your AVR are analog. Usually they do not have a bass management function, but some advanced AVRs do have BM on the analog inputs, so just be sure to disable that if it exists.

The reason to disable any BM on the analog inputs is two-fold: 1) so the test tone SPL is accurate, and 2) so the AS-EQ1 can accurately detect the LF limit of the speaker.

Regardless of the XO you choose for the speakers, the AS-EQ1 will always target a flat response for the subwoofer to as high a frequency as possible. This will not change no matter what XO you select for the speakers. The upper limit of the AS-EQ1 is typically when it encounters an internal low-pass in the subwoofer amp or the woofer simply starts to tail-off. There is an upper FR limit in the AS-EQ1, but it's much higher than any subwoofer will ever normally play, so the subwoofer itself is always the limiting factor in the upper FR bandwidth.

So don't worry about selecting an XO which is different than the AS-EQ1 recommends for any given speaker; it won't affect the subwoofer performance or FR at all. For your speakers, I'd pick 80-100 Hz for the center and 60-80 Hz for the mains. If you only have a global XO, then let the smallest (i.e., least bass-capable) speaker dictate your global XO.

[nathometheatre]

Doug McBride wrote:

In any case, SVS always recommends setting your speakers to "small" and your crossover at a frequency commensurate with the capabilities of your speakers and that will provide good blending of your sub(s) and speakers, letting the sub(s) handle most of the low frequencies since that is what they were designed to do. If you've been happy with your 80Hz crossover, that's a great place to have it.
Doug

Doug,
I agree with your recommendations for settings mentioned above. That being said, I have the Denon avr-4308ci, and just did a calibration for four seating areas using the Audyssey MultEQ-XT mic that came with the receiver. My front 3 speakers are Klipsch RF,RC-7 series, and after the calibration was done calculating everything, it had my front 3 set to large, and the X-Over set @ 40Hz. I've never had my sub set that low before. Do you still agree that i should reset them to small, and set my X-Over back to 80Hz? I have a PB12/Plus2 (best sub I've ever owned by far), so I want to make sure I'm getting the maximum performance out of my SVS. Thanks, Kev

[Texxen]

Ed Mullen wrote:

Hi Tex:

The multi-channel inputs on your AVR are analog. Usually they do not have a bass management function, but some advanced AVRs do have BM on the analog inputs, so just be sure to disable that if it exists.

The reason to disable any BM on the analog inputs is two-fold: 1) so the test tone SPL is accurate, and 2) so the AS-EQ1 can accurately detect the LF limit of the speaker.

Regardless of the XO you choose for the speakers, the AS-EQ1 will always target a flat response for the subwoofer to as high a frequency as possible. This will not change no matter what XO you select for the speakers. The upper limit of the AS-EQ1 is typically when it encounters an internal low-pass in the subwoofer amp or the woofer simply starts to tail-off. There is an upper FR limit in the AS-EQ1, but it's much higher than any subwoofer will ever normally play, so the subwoofer itself is always the limiting factor in the upper FR bandwidth.

So don't worry about selecting an XO which is different than the AS-EQ1 recommends for any given speaker; it won't affect the subwoofer performance or FR at all. For your speakers, I'd pick 80-100 Hz for the center and 60-80 Hz for the mains. If you only have a global XO, then let the smallest (i.e., least bass-capable) speaker dictate your global XO.

Thank you for the explanation, Ed. Now I can finalize my calibration

[Ed Mullen]

Texxen wrote:

Thank you for the explanation, Ed. Now I can finalize my calibration

You are most welcome.

Just to be clear, the fact that the AS-EQ1 recommends a certain XO for a speaker channel will not alter its inherent/native EQ solution for the subwoofer. It always targets a flat FR for the subwoofer to as high a frequency as possible (usually the upper limits of the sub amp or the woofer).

Naturally, selecting a XO for the speaker channels will high pass the speakers and will also low pass the subwoofer at the same frequency. This low pass occurs upstream of the AS-EQ1, as intended.

[rmk]

Doug McBride (SVS’s Software Hired Gun and all around good guy) was kind enough to bring his AS-EQ1 by for an in-home demo the other day. Doug's living close by made this easy and I thank Doug and SVS (Ron and Ed) for making this possible. Also joining us was fellow Shakster Randy (ransac).

The idea was to compare the AS-EQ1 to my Velodyne SMS-1 from an overall subjective sound quality standpoint. My system is made up of dual Danley TH-SPUD subs, JTR Triple 12LF LCR speakers, Revel in-wall surrounds with an Integra SSP. A Sunfire TGA 400/7 powers the speakers and a QSC pro audio amp drives the Danley Subs. Unfortunately due to my setup and time constraints we were not able to directly (A/B) compare the SMS-1 to the AS-EQ1. Instead, we compared it (the AS-EQ1) to no EQ. We also disengaged the Audyssey in my Integra so as not to have over lapping (dueling Audyssey’s). We started off by running though some music selections that included bass heavy passages and moved on to some familiar DVD and Bluray movie scenes.

With my treated dedicated room the before system sounded pretty good (to me anyway) and I admit I was skeptical that there would be a significant advantage in using the AS-EQ1 but the early reports were so positive I decided that I had to hear it in my room. The funny thing is that Doug was of a like mind. I think we were both surprised at the noticeable difference that the AS-EQ1 made to the LFE channel in my system especially with music.

Onto the demo, we played music tracks from the bass heavy Boney James, Sweet Thing CD and kept to that disk in order or better hear the differences from EQ to no EQ on the LFE track. To be fair, I am very familiar with this disk while Doug and Randy were hearing it for the first time but we all were all able to hear the differences that Audyssey made to the music. With music, the less is more Audyssey theory pans out very nicely. I believe we were unanimous in feeling that the taming down of the low bass made the mid range bass and hence the music more enjoyable (listenable) than with no EQ applied. The bass seemed over extended with no EQ but the AS-EQ1 brought it under control and so each note was easily distinguished.

With movies, the Audyssey EQ seemed to cut much more of the impact out of bass intense passages. We used the sound canon scene from The Incredible Hulk (much to Doug’s amusement) as the tester here. Both Randy and I noticed that the sound canons had been pretty effectively neutered by Audyssey while other bass parts of that scene maintained their impact and slam. My impression was that Audyssey was doing to the LFE channel what I initially though it did to the higher frequencies when I use the Audyssey Multi EQ in my Integra SSP i.e. over treating the bass response.

As it turns out Audyssey does indeed flatten out the room response. The Audyssey graph showed a dramatic difference between before and after graphs. To validate this, we put up the Velodyne SMS-1 real time display showing the rooms FR at various listening positions using the Velo mic. This experiment also showed the large differences in graphed response that slight mic movements made across my HT seating area. For me even more interesting was how these graphs did not necessarily correlate to significant changes in the sound in moving from seat to seat. I believe that is due to a fairly good native (no EQ) bass response across my seating area aided by dual subs, room treatments and the room itself. Whatever Audyssey does right for music, seems to lessen the impact I have become acoustomecd for movies. After running the AS-EQ1, it recommended increasing the LFE trim by 12db over the previous SMS-1 trim setting. I can't help but wonder if others who have the unit have had the similar delta with the LFE trim. While increasing the LFE channel trim helped with movies, I can't help but wonder why this is necessary. In re-setting my system later in the day, I was nearly blown out of the room by the sub channel when re-running the level settings. It required a 12db cut to get things back in sync.

While I could hear a difference with Audyssey engaged, it was subtle in both a positive and negative sense. In many untreated or open room with lots of hard surfaces I’m sure the AS-EQ1 will work wonders. In my room there was a difference but it was less dramatic.

I plan on getting an AS-EQ1 and hope to do an A/B test like we were able to do with the AS-EQ1 on and off testing today. I would also like to spend more time tweaking and playing with the levels and also setup the two Audyssey’s together as recommended by both SVS and Audyssey. The AS-EQ1 is very cool technology and just what a crazy hobbyist like me needs to while away all those hours I could be spending outside doing more healthy or productive things.


Here are the before and after graphs of my subs

First, the separate before/after graphs


Then the combined response before/after

[myc52002]

Rob, I couldn't agree more with your assessments. I have had mine for a couple of weeks now and have tried several different setups including trim level changes etc. I too found that with music it cleaned up things very nicely but I seemed to have lost some of the impact on movies. I found a +10 trim made a world of difference on movies. I still will not part with the unit because it does much very right. I am going to pursue more room treatment because I do have a significant null problem (non-eq'd) between 30-40hz and even though the EQ! does a really nice job of helping that, I can't help but believe better treatment will help.

[Doug McBride]

nathometheatre wrote:

Doug,
I agree with your recommendations for settings mentioned above. That being said, I have the Denon avr-4308ci, and just did a calibration for four seating areas using the Audyssey MultEQ-XT mic that came with the receiver. My front 3 speakers are Klipsch RF,RC-7 series, and after the calibration was done calculating everything, it had my front 3 set to large, and the X-Over set @ 40Hz. I've never had my sub set that low before. Do you still agree that i should reset them to small, and set my X-Over back to 80Hz? I have a PB12/Plus2 (best sub I've ever owned by far), so I want to make sure I'm getting the maximum performance out of my SVS. Thanks, Kev

Hi Kevin - my personal opinion is "yes". Even the best towers will run out of gas in the lower ranges of their design center, especially for HT use. The design center for subs is primarily 120Hz and below and they do a great job there. I also think relieving the mains from the lower octaves also leaves more headroom in the amps hence increasing dynamic range.

Through observation, it seems that most AVR and Pre/Pro auto cal systems look to see if there is any usable output below 40Hz, and if so, recommend "large". Where they work well in my opinion is when the satellites are less capable of playing low, and the recommended crossover might be more appropriate. Also, remember these auto cal systems (minus the room EQ) are really meant to help the novice get somewhat close to a proper setup whereas before - if they even bothered - would be setting channel trims by ear and running speakers whose -3dB point is 90Hz as large...

I think the 40Hz crossover you mentioned above is for the sub? If you set your speakers to "small", your Denon will be handling the crossover at your desired set point so the sub crossover should be defeated using the Defeat switch on the plate amp.

Doug

[azjimmy]

Hi,
I've been reading this thread for the last few days, but I don't recall seeing any waterfall/impulse graphs to show how AS-EQ1 handles tough "room modes" and ringing. Any takers?

[SAY IT LOUD]

You can get the AS-EQ1 SubEQ from DEEP HZ Audio CALL 0434 550 782 but you will pay AU$1,499

[Ed Mullen]

azjimmy wrote:

Hi,
I've been reading this thread for the last few days, but I don't recall seeing any waterfall/impulse graphs to show how AS-EQ1 handles tough "room modes" and ringing. Any takers?

The AS-EQ1 generates an impulse response and does indeed look at the time domain component (ringing profile) of the room when it builds the minimum phase FIR filter solution, as opposed to just looking at the magnitude response.

The AS-EQ1 impulse duration is easily long enough to capture all relevant time domain information and attendent modal problems in any conventional size HT/music room, and the filter length is (in layman's terms) "as long as it needs to be" to adequately address the time domain component of the room. The actual filter length is considered proprietary by Audyssey, though.

While this is likely to become an evergreen debate, in our opinion IIR filters with high Q (narrow band) values have phase problems which are indeed audible. And attempting to avoid high Q filter values (by using wider filters with less resolution) simply causes them to overlap neighboring bands, thus reducing the efficacy of the EQ solution.

Furthermore, Audyssey applies a proprietary pyschoacoustic weighting to its filter coefficients in order to apply filter correction appropriately.

The combination of eliminating audible IIR phase problems by employing minumum phase FIR filters, and the use of pyschoacoustic weighting on the filter coefficients, results in a superior sounding EQ solution.

[rmk]

Ed Mullen wrote:

The AS-EQ1 generates an impulse response and does indeed look at the time domain component (ringing profile) of the room when it builds the minimum phase FIR filter solution, as opposed to just looking at the magnitude response.

The AS-EQ1 impulse duration is easily long enough to capture all relevant time domain information and attendent modal problems in any conventional size HT/music room, and the filter length is (in layman's terms) "as long as it needs to be" to adequately address the time domain component of the room. The actual filter length is considered proprietary by Audyssey, though.

While this is likely to become an evergreen debate, in our opinion IIR filters with high Q (narrow band) values have phase problems which are indeed audible. And attempting to avoid high Q filter values (by using wider filters with less resolution) simply causes them to overlap neighboring bands, thus reducing the efficacy of the EQ solution.

Furthermore, Audyssey applies a proprietary pyschoacoustic weighting to its filter coefficients in order to apply filter correction appropriately.

The combination of eliminating audible IIR phase problems by employing minumum phase FIR filters, and the use of pyschoacoustic weighting on the filter coefficients, results in a superior sounding EQ solution.

Good Info Ed, thank you. FOr me, setting Q values with the Velo SMS-1 has always been a guessing game due to the limited feedback the low resolution SMS-1 graphs provide. I have resisted the impulse to get REW and dive into the deep end of the pool and perhaps the AS-EQ1 is the right solution for someone like me.