The astounding new AS-EQ1 SubEQ goes on sale!

[Ed Mullen]

stevefish69 wrote:

This is also assuming that if 1.2v (for instance) goes into the Processor from the EQ1 at -11db MV to make 75db that 1.2v will be output to all channels too at the same MV when running normally.

There are two sets of trim levels on my AP, but all trim levels are within 1-2db on both analogue and digital domain. Could it be something to do with the dreaded -10db LFE channel thingy.

If i don't get it sorted (and know it's technically correct) then TBH i may go back to using a BFD, flog the EQ1 and have a holiday in the sun instead

Right - the AS-EQ1 is simply duplicating externally what the AVR test tones do internally. You play the test tone, set the master volume at a fixed level, adjust the trim levels for all speaker channels, and then adjust the subwoofer gain to obtain the same SPL as the speakers. The process is absolutely the same.

So when the master volume is changed, the voltage driving all speaker channels and the subwoofer channel also changes by a uniform/global amount, so the SPL of all channels and the subwoofer also changes by that same amount (volt change = dB change).

If you have two sets of trim levels, then make sure the analog settings you generated using the AS-EQ1 are migrated over to the digital input trim level menu.

The 10 dB LFE channel issue may very well be responsible for your problem - I can't tell from here, and I don't know what player and AVR you are using or how they are connected. For the edification of others, the LFE channel must boosted 10 dB during the decoding process before dumping to the analog domain. The LFE channel is therefore 10 dB louder than the redirected bass from the speaker channels. If the LFE channel is not correctly boosted during the decoding process, then it can result in weak bass, even if the speakers and subwoofer are calibrated correctly.

Some AVRs have an LFE channel attenuation control, which you should check. This is not the subwoofer channel level and the two should not be confused. The LFE channel level control usually has a range of -10 to 0, and it should always be set to 0.

[stevefish69]

Thanks Ed for taking the time to educate my stupid mind

I've PM'd Russ Will over on AVF as he currently has an EQ1 for review / comparison and uses exactly the same Processor as me - I'll shut up now, leave the Sub channel set where it is and see if he has experienced a similar problem.

[Ed Mullen]

stevefish69 wrote:

Thanks Ed for taking the time to educate my stupid mind

I've PM'd Russ Will over on AVF as he currently has an EQ1 for review / comparison and uses exactly the same Processor as me - I'll shut up now, leave the Sub channel set where it is and see if he has experienced a similar problem.

Well ultimately your satisfaction is all that matters, because obviously you love the AS-EQ1 but there is a problem with your subwoofer level somewhere in the signal chain (we just haven't found it yet).

From an academic standpoint, it will be interesting to see exactly what is causing this problem - what player and processor are you using, and how are they connected? If you are using analog outputs from the player, I'm immediately suspicious of the 10 dB LFE decoding issue, since that's been a problem with various players for years now.

I have a simple test I run for this exact problem when troubleshooting systems - it's a Dolby Digital DVD with a 40 Hz sine wave on all five speaker channels and the LFE channel all encoded at the same level. If all the speakers are set to Small, the tone plays at the same SPL for each speaker channel, and then plays 10 dB louder for the LFE channel. Simple test pass/fail.

Some enthusiasts have tried the work around of boosting the analog subwoofer feed from the player by 10 dB, but the problem that creates is it also boosts the redirected bass 10 dB (which doesn't need any boosting), so it simply creates the same problem, just 10 dB louder. The only way this work-around is actually successful is if all speakers are set to full-range in the player and only the LFE channel is output from the player's subwoofer pre-out. Then that channel can be boosted 10 dB on the AVR end without problem. Of course this assumes the AVR can perform bass management on the analog inputs, and many of them can't. So in that case you're stuck with running all speakers on full-range and that doesn't work very well either.

[stevefish69]

Ed Mullen wrote:

From an academic standpoint, it will be interesting to see exactly what is causing this problem - what player and processor are you using, and how are they connected? If you are using analog outputs from the player, I'm immediately suspicious of the 10 dB LFE decoding issue, since that's been a problem with various players for years now.

Are you poor guys at SVS not sick and tired of me yet

I'm using the kit in my Sig list.

An Audiolab 8000AP Processor hooked up to two Parasound Power amps.

For DVD / HD-DVD i use the Tosh XE1 via HDMI outputting 5.1 PCM
For Blu Ray and games i use the PS3 again hooked up via HDMI and outputting 5.1 PCM

I just re-ran the internal tones on the Audiolab and to get 75db the MV needs to be -22db. The main channels are all showing 75db on C-weighted slow and the Sub channel is showing 73db with the Sub gain at 10am not 9am as the EQ1 suggests. It's strange that in every case the differences are around 10db

I'm gonna leave things as they are now at with the Sub gain at 10am and have a listen tomorrow night to see what how it sounds.

[Ed Mullen]

I just read your post over at AVForums. It does sound like you may have a fixed voltage differential which exists between the subwoofer channel and the loudspeaker channel.

There is only one way around this IMO. Set the AS-EQ1 to calibrate the subwoofer at 75 dB (per the SubEQ GUI and mic) - this will allow it to generate the EQ curve without digital headroom/clipping problems. Then use a Dolby Digital calibration DVD like Avia to set all your channel levels and the subwoofer level.

I don't trust what is happening in your processor with respect to how it generates test tones which cause the subwoofer to play 10 dB lower than the speakers - something is screwy there. We've seen (many times) the subwoofer output jack fail on pre/pros and AVRs and it sometimes manifests itself in the early stages as a low voltage level (i.e., lower than the speaker channel pre-outs).

[Patrick Nevin]

jagman wrote:

The new curve looks pretty but it killed your low end output. You had a beautiful house curve with the output at 20Hz a few dB hot and solid output down to about 15Hz. Now your response takes a nose dive at 20Hz. The only thing you needed was a 5dB boost at 50Hz. How do low end effects on blockbuster movies sound? Have you noticed a difference? That's great if your happy... I just know I wouldn't want the really deep stuff cut off like that.

I like it much better. This weekend I am going to change the position of the sub to face the room instead of the wall and see if that gets a better response. I think the sub could sound a little bit louder. I calibrated all the speakers using the internal tones of the Yamaha 2700 to 75 db and the sub to 73 db to account for the inaccurate readings using the rat shack meter.

Thanks
Patrick

[myc52002]

I have attached my before / after graphs. I must say I am impressed. This room has been nothing but a pain from the beginning to get these to integrate well. I think I am well in my way to solving this issue. I was like many running the subs too hot so this was a revelation but not totally surprised since I was trying everything to make them work well. My immediate experience has been a MUCH crisper bass region that seems to improve the mid bass as well. A kick drum now sounds like one should. If there is no low bass recorded, the system is not trying to make it be there. This is something new for me and better I must say. Once one hears certain instruments the way they are meant to be heard you can immediately hear that difference.

My system consists of a Lexicon MC12 V5eq, Legacy Audio FOCUS as mains and (2) PC Ultra/2 co-located in a dedicated theater room

I do have a couple of questions for Ed.

1 The MC12 uses a 4 mic calibration setup. I did this calibration with 1 MC12 mic only since it needs to route through the AS-EQ1 during that process. However I think I can still leave the other 3 mics connected directly to the MC12 since there is no output sent to the sub during calibration (so these other 3 hear nothing) which should continue to "fool" the MC12 into seeing a flat sub setting...anything wrong with this thinking?

2 Any reason it would roll the system off before 20Hz after calibrating? That seemed odd to me but not an issue for me either

3 When I set up the MC12 to calibrate it I first deactivated the LFE output because I have it connected to buttkickers rather than having that signal sent to the subwoofers. I basically wanted to keep the LFE out of all the processing loops since it has nothing to do with the subs. Would this in any way incorrectly cause the EQ1 to calibrate the subs incorrectly? After I finished the processor calibration and AS-EQ1 processing I reactivated the LFE output.

Thanks for a great product at a great price.

[malikarshad]

Ed Mullen wrote:

"SubEQ calculated the trim level of -4.1 and distance of 19.3. The sub is about 11feet physically from the main listening position."

That may change if you re-run with the AS-EQ1 connected directly to the subwoofer.

"The Sub phase is set to 0. The sub crossover is disabled. The subsonic filter is set to 20 Hz. There are no ports plugged on the sub."

Please plug one port on the subwoofer. Running with all ports open and the tune switch set to 20 Hz is a mismatch and can damage the woofers. That is also why your FR is rolling off earlier after the AS-EQ1.

"Given all this I want to understand why there is a dip at 35Hz in the REW graph. JimP suggested to reverse the polarity of sub in the processor but I don't have this option."

I'm not certain at this point whether you are measuring the FR of the subwoofer or the speakers. If you measure the FR of the subwoofer only, the test rig should be connected directly to the subwoofer.

If you want to measure the FR of the speakers and subwoofer combined, then you'll need to connect the test rig to the AVR with the speakers set to Small. This may cause some phase anomalies between the speaker and subwoofer which cannot be fully resolved with just the distance controls, and could create a dip in the combined FR at some point in the pass band.

Here are the changes I made

• I plugged one port on the subwoofer and it's set at 20Hz tune
• I re-checked all the options on the Integra processor for any LFE or subwoofer level boost or attenuation and there is none.
• I ran the SubEQ again and results are almost identical. The trim level is -4.2 and distance 19.4ft.
• I took REW measurements of Sub only, Fronts without sub and Fronts with Sub.

Looking at the graph it seems

• The Fronts graph with the subwoofer has the same 35Hz dip and is identical to FR that I had taken earlier
• Fronts graph without the subwoofer has no 35Hz dip
• The subwoofer graph looks good.

My question is what can be done to resolve this 35Hz dip. Or does it really matter?

About Level matching

• I level matched the Left speaker to 75db and subwoofer 75db before taking measurements with SubEQ.
• Previously I'd level matched all my speakers using SubEQ test tones. I verified the level again with Integra internal test tones and they matched.
• When I checked the subwoofer test tone then its off by -8db. So I used DVE disk to verify the subwoofer test tone and it matches accurately with the speakers. Then I used the Avia disk and then it was again off by -6db.

So now the question is why the AVR internal test tones & Avia shows a -8db lower than the speaker levels. This confuses me

So for all of us what's the best way to verify the subwoofer level after SubEQ.

[JohnM]

malikarshad wrote:

My question is what can be done to resolve this 35Hz dip. Or does it really matter?

Your fronts are out of phase with your sub at 35Hz, hence the dip in the combined output that mirrors the peak in the front response. If you are running your fronts full range, try them with a crossover instead, or try changing the sub phase - but that will likely shift the problem rather than fix it if the fronts are full range.

[Ed Mullen]

Agree your front speaker and the sub are out of phase @ 35 Hz. Are your speakers vented towers with a rated extension of 30-35 Hz? The phase response of a vented speaker changes rapidly at/near the system tuning frequency, which can create the null you are seeing.

Also agree all your speakers should be set to Small with a crossover frequency which reflects their respective bass capabilites and is protective of their woofers at higher playback levels. Usually 60 Hz works well for towers, and 80 Hz is good for larger centers/surrounds. For smaller center/surround, use 100 Hz.

Do NOT use DVE to check any subwoofer levels. DVE uses the LFE channel for the subwoofer calibration tone and has an encoding level error of exactly 10 dB. The subwoofer tone is mastered at the same level as the speaker channels and thus failed to account for the 10 dB boost to the LFE channel from the surround sound processor during decoding. So the DVE subwoofer tone is 10 dB too hot, which causes users to calibrate the subwoofer 10 dB too cool. But I digress.....

With the speakers and subwoofer calibrated to 75 dB with the AS-EQ1, what does Avia say for the same speaker channel and for the subwoofer? I'll need both readings, because I'm not so much concered about the absolute SPL differences as I am in the differential between the speaker and subwoofer.

A preemptive caveat - Avia uses redirected bass for the subwoofer, so the speaker must be set to Small in order for the subwoofer tone to play through the subwoofer. The speaker will handle some of the subwoofer tone too, obviously, so to the extent they are in phase and couple over the crossover bandwidth there can be some reinforcement over the subwoofer playing alone. Conversely, if the speaker and subwoofer are not in phase, there will be some cancellation compared to the subwoofer playing alone. If you want to really get fancy, you can report the speaker tone, the subwoofer tone with the speaker/sub both playing, and the subwoofer tone with the speaker disconnected.

[malikarshad]

JohnM wrote:

Your fronts are out of phase with your sub at 35Hz, hence the dip in the combined output that mirrors the peak in the front response. If you are running your fronts full range, try them with a crossover instead, or try changing the sub phase - but that will likely shift the problem rather than fix it if the fronts are full range.

I run the fronts at 80hz xover in the processor. But when I run AS-EQ1 SubEQ I set them to full range to take measurements and then i revert it back to 80Hz xover.
The REW measurements are with 80Hz xover enabled in the processor.

What confuses me is that when the xover is enabled the FR from 15Hz-80Hz should be identical to that of subwoofer? Why is the signal sent to Fronts when the xover is enabled in the processor?

Setting the phase on the sub after SubEQ defeats the purpose of AS-EQ1. But I'm naive so I'll let SVS answer this.

[lorca]

Please plug one port on the subwoofer. Running with all ports open and the tune switch set to 20 Hz is a mismatch and can damage the woofers. That is also why your FR is rolling off earlier after the AS-EQ1.

Tell me if i'm being dumb but doesnt the manual tell us to set the switch to 20hz with no bungs in.

SVS Tuning Chart Subsonic Filter Knob
Stock tune (no ports blocked) 20Hz
With one port-blocked 15Hz
With two ports-blocked * 10Hz
With three ports-blocked Sealed

if you put the subsonic filter into the 10Hz mode (* contact SVS about details
on the use of this deepest mode). This simple table indicates the settings you
should use in setting up your sub blocks and the subsonic filter knob.

[Ed Mullen]

myc52002 wrote:

I have attached my before / after graphs. I must say I am impressed. This room has been nothing but a pain from the beginning to get these to integrate well. I think I am well in my way to solving this issue. I was like many running the subs too hot so this was a revelation but not totally surprised since I was trying everything to make them work well. My immediate experience has been a MUCH crisper bass region that seems to improve the mid bass as well. A kick drum now sounds like one should. If there is no low bass recorded, the system is not trying to make it be there. This is something new for me and better I must say. Once one hears certain instruments the way they are meant to be heard you can immediately hear that difference.

My system consists of a Lexicon MC12 V5eq, Legacy Audio FOCUS as mains and (2) PC Ultra/2 co-located in a dedicated theater room

I do have a couple of questions for Ed.

1 The MC12 uses a 4 mic calibration setup. I did this calibration with 1 MC12 mic only since it needs to route through the AS-EQ1 during that process. However I think I can still leave the other 3 mics connected directly to the MC12 since there is no output sent to the sub during calibration (so these other 3 hear nothing) which should continue to "fool" the MC12 into seeing a flat sub setting...anything wrong with this thinking?

2 Any reason it would roll the system off before 20Hz after calibrating? That seemed odd to me but not an issue for me either

3 When I set up the MC12 to calibrate it I first deactivated the LFE output because I have it connected to buttkickers rather than having that signal sent to the subwoofers. I basically wanted to keep the LFE out of all the processing loops since it has nothing to do with the subs. Would this in any way incorrectly cause the EQ1 to calibrate the subs incorrectly? After I finished the processor calibration and AS-EQ1 processing I reactivated the LFE output.

Thanks for a great product at a great price.

1) You can leave the other three mics connected, but make absolutely sure there are no sources of ULFs in the house while the AS-EQ1 is looping the signal back to the Lexicon mic jack. The AS-EQ1 calibration mic jack also sees the loop-back signal and this in essence shunts the mic output, and prevents it from contaminating the loop-back signal in the event any low level ULFs are present. The same is not true for your three other Lex mics (which have an unshunted direct feed to your pre/pro), so any ULFs (dryer, furnace, garbage truck, etc.) will contaminate the looped back signal and cause the Lex to build an EQ file. So just make sure your house is completely silent if you leave the other three mics connected during the loop-back step.

2) We don't make a PC-Ultra/2, so please clarify the model, and what tune it's running. If it's a PB12-Ultra/2 in the 25 Hz tune (all ports open), it will roll-off at about 22-23 Hz. If it's a PC13-Ultra in the 20 Hz tune (all ports open), it will roll-off around 21-22 Hz.

3) You need to clarify "LFE output" vs. subwoofer channel output - they are potentially two different things. If you mean the subwoofer channel pre-out - that should be routed to the AS-EQ1 during the loop-back Lex calibration step, and then disconnected after that point. The AS-EQ1 is connected directly to the subwoofer during the level matching and calibration step, so the Lex subwoofer pre-out would have zero effect at that point.

[Doug McBride]

malikarshad wrote:

I run the fronts at 80hz xover in the processor. But when I run AS-EQ1 SubEQ I set them to full range to take measurements and then i revert it back to 80Hz xover.
The REW measurements are with 80Hz xover enabled in the processor.

What confuses me is that when the xover is enabled the FR from 15Hz-80Hz should be identical to that of subwoofer? Why is the signal sent to Fronts when the xover is enabled in the processor?

Setting the phase on the sub after SubEQ defeats the purpose of AS-EQ1. But I'm naive so I'll let SVS answer this.

Out of curiosity, what input are you using for the REW tone? If it is a multichannel input it probaby has no bass management so your crossover will have no effect. Check to see if bass management works on that input and no DSP modes are set. I only speak from painful experience (d'oh!).

Are your front speakers MTS-01s?

Doug

[Doug McBride]

lorca wrote:

Tell me if i'm being dumb but doesnt the manual tell us to set the switch to 20hz with no bungs in.

I believe his sub is a PB12Plus/2. The native (all ports open) tune of that box is 25Hz. One port blocked is 20Hz, 2 ports blocked is 16Hz, and the sub was not designed to run sealed.

Doug

[malikarshad]

Ed Mullen wrote:

Agree your front speaker and the sub are out of phase @ 35 Hz. Are your speakers vented towers with a rated extension of 30-35 Hz? .

Yes the speakers are vented in the rear and it can be sealed using a port plug. Its a 2-way QW Transmission Line with a FR of 42Hz-20kHz(+/- 3db). here is the link to the specifications http://www.salksound.com/speakers_so...wt_specs.shtml

Ed Mullen wrote:

With the speakers and subwoofer calibrated to 75 dB with the AS-EQ1, what does Avia say for the same speaker channel and for the subwoofer? I'll need both readings, because I'm not so much concered about the absolute SPL differences as I am in the differential between the speaker and subwoofer.

With Avia the Left Front measured 82db and the sub measured about 74-72db(as the RS needle kept fluctuating btw it). so the differential was about approx -8db. Its the same differential I noticed on the AVR internal test tone.

Doug McBride wrote:

Out of curiosity, what input are you using for the REW tone? If it is a multichannel input it probaby has no bass management so your crossover will have no effect. Check to see if bass management works on that input and no DSP modes are set. I only speak from painful experience (d'oh!).
Are your front speakers MTS-01s?
Doug

For REW I use the analog stereo inputs on AUX input of the integra processor and the bass management is enabled with EQ set to Audyssey. No DSP is set. The processor is set to stereo mode.
The Speakers are Salk SongTowers as mentioned in the link above

[Ed Mullen]

malikarshad wrote:

With Avia the Left Front measured 82db and the sub measured about 74-72db(as the RS needle kept fluctuating btw it). so the differential was about approx -8db. Its the same differential I noticed on the AVR internal test tone.

Please disconnect your left front speaker when the subwoofer tone is running and report the results again. Thanks.

[lorca]

Doug McBride wrote:

I believe his sub is a PB12Plus/2. The native (all ports open) tune of that box is 25Hz. One port blocked is 20Hz, 2 ports blocked is 16Hz, and the sub was not designed to run sealed.

Doug

Apologies I was being dumb

[JimP]

Ed has the patience of a Saint. We need to come up with a special hometheatershack award just for Ed. He deserves it.

I would have nuked malikarshad several post back.

[jagman]

Patrick Nevin wrote:

I like it much better. This weekend I am going to change the position of the sub to face the room instead of the wall and see if that gets a better response. I think the sub could sound a little bit louder. I calibrated all the speakers using the internal tones of the Yamaha 2700 to 75 db and the sub to 73 db to account for the inaccurate readings using the rat shack meter.

Thanks
Patrick

Cool. That's awesome that you hear such good improvment .

Do you know why your "after" plot drops off so steeply below 20Hz? It is interesting as your "before" plot had solid output to approximately 15Hz. "After" plots posted by other people don't seem to lose the low end response. I wonder why there is a difference... did you add a high pass filter at 20Hz?

Regardless it's nice to see that it is working so well for so many people. A quick, relatively easy fix for a pair of subs is a wonderful addition to the market.

[stevefish69]

JimP wrote:

Ed has the patience of a Saint. We need to come up with a special hometheatershack award just for Ed. He deserves it.

I would have nuked malikarshad several post back.

Many Thanks to Ed for sticking with me yesterday during my hours of need.

I've left the gain set at 10am and the ratshack measures 75db on all channels apart from the sub which is reading 73db. I've mailed my Processor manufacturer with a link to this thread, but i'm not holding my breath into finding the answers as to why i have this problem.

I've just watched my 1st film since changing and the difference is astounding. I still cannot locate the PCU in the room, my 3D soundstage has not collapsed and i was greeted with wave after wave of nice clear Bass. Not once did it sound overbloated, larger than life or too loud but by it was great and Super fast. My PCU had a chance to strut it's stuff again for the 1st time in about a month

A Gunshot in the film was so fast and forcefull that i physically jumped up in my seat with fright . The cat also made a mad dash for the door and the wife had a grin ear to ear and was just gobsmacked

[jagman]

Ed --

This device looks extremely promising... and the user reports indicate a top notch product. But, I have one concern. By looking at the plots here on this thread, it looks like this unit employs a 20Hz hi-pass filter. I read through the owners guide and I didn't see anything about a hi pass filter for the sub. I may have missed it. Many of us at the Shack are bassheads... our subs, whether SVS or not (most of have DIY subs), have solid output well below 20Hz. I for instance, have two high excursion 18" drivers in an infinite baffle (and I plan on replacing them with two high excursion 22" drivers). Even my little 18" drivers have an in room -3dB point of 8Hz. Obviously I don't want to lose the last octive.

So...

1. Is there a 20Hz hi pass filter used?
2. If so, is it adjustable?
3. If so but not adjustable, can it be made user adjustable with a firmware update?

Thanks in advance for answering these questions!

[Doug McBride]

lorca wrote:

Apologies I was being dumb

Too many subs to keep track of...

Doug

[Fatawan]

http://www.avsforum.com/avs-vb/showt...4#post16507654

I don't think there is any hi pass filter--check my graphs at that link

[Ed Mullen]

stevefish69 wrote:

Many Thanks to Ed for sticking with me yesterday during my hours of need.

I've left the gain set at 10am and the ratshack measures 75db on all channels apart from the sub which is reading 73db. I've mailed my Processor manufacturer with a link to this thread, but i'm not holding my breath into finding the answers as to why i have this problem.

I've just watched my 1st film since changing and the difference is astounding. I still cannot locate the PCU in the room, my 3D soundstage has not collapsed and i was greeted with wave after wave of nice clear Bass. Not once did it sound overbloated, larger than life or too loud but by it was great and Super fast. My PCU had a chance to strut it's stuff again for the 1st time in about a month

A Gunshot in the film was so fast and forcefull that i physically jumped up in my seat with fright . The cat also made a mad dash for the door and the wife had a grin ear to ear and was just gobsmacked

Awesome. Mission accomplished. Now grab a beer and kick back and discover all your blockbuster movies all over again.