The astounding new AS-EQ1 SubEQ goes on sale!

**bpape** · **07-05-09, 06:14 PM**

Regardless of the type of filtering, if the center frequency and Q are not exactly the same as the problem frequency, ringing can actually get worse instead of better. If the Q is adjustable on your unit, experiment with it and see what you can do.

While it won't help with the ringing, you can certainly potentially smooth the hump in response via simple seating and sub positional changes.

Bryan

Bryan

**Ed Mullen** · **07-05-09, 07:58 PM**

Quote:

Wayne A. Pflughaupt wrote:

Cutting through Audyssey’s techno-babble, what you’re saying is that FIR filters allow the AS-EQ1 to use a multitude of high Q filters to achieve flat response by addressing every little ripple?

Regards,
Wayne

I don't believe FIR filters have a Q factor in the conventional sense, but yes - the AS-EQ1 has very high filter resolution and the EQ solution it generates (which you can measure by looping the device itself) would be very difficult if not impossible to duplicate with a manual IIR based PEQ - lots of very closely spaced and sharply peaked boosts and cuts.

**jpk** · **07-05-09, 08:00 PM**

Quote:

bpape wrote:

Regardless of the type of filtering, if the center frequency and Q are not exactly the same as the problem frequency, ringing can actually get worse instead of better. If the Q is adjustable on your unit, experiment with it and see what you can do.

While it won't help with the ringing, you can certainly potentially smooth the hump in response via simple seating and sub positional changes.

Bryan

Bryan

Thanks Bryan,
The unit is totally auto-magic, other than moving the mike and sampling to average the response over a wide area.

I did follow your advice in "general no-no's for good sound" and moved the subs along the wall, (but not in corners), they were out like coffee tables, the expected 2-3 db gain was achieved along with some smoothing.

Maybe I should move this to another forum or ?
With this kind of LF resonance, in this room, is it possible or even practical to trap it? My understanding is low bass requires massive amounts of traps?

Thanks,
Joe

**bpape** · **07-05-09, 10:22 PM**

21Hz isn't really practical with velocity absorbers. You can do some tuned Helmholz type absorbers but being tuned that low, they can have their own issues.

Really, your best bet is to try to use seating and sub locations to try to compensate and to avoid being where the mode is prevalent - though that won't help with ringing.

If you can potentially add a secondary PEQ in the sub loop that you can tweak center and Q, that might also help some.

Bryan

**Ed Mullen** · **07-06-09, 10:02 AM**

Quote:

jpk wrote:

I have a resonance problem in the Man Cave

, foot thick concrete walls better not be resonating! There is a partition wall with cheap paneling that may contribute to the problem, but I’m thinking the ductwork and primarily the air return sheet metal is at least the major cause of things.
Has anyone experienced this or know where I can find information to verify and remedy it?

Tapping on the air return seems to have a resonance.

Man Cave = 22 x 26 x 7 ft. w/drop ceiling, 0.5 inch rigid fiberglass ceiling panels. Padded carpeted floor, one side wall partitioned and paneled.

Joe

Your room has an obvious and aggressive resonance at that frequency. Once that frequency is excited by the subwoofer, the room will ring for a certain period of time. This is a function of the room dims and the physical construction of the wall/ceiling/floor boundaries and the building materials.

You could certainly be onto the cause - not that I can bird dog the problem from here, but I suspect it's either your suspended ceiling tile grid-work or your ductwork. I've seen ceiling tile gridwork ring (both visibly and on the decay chart) for well over 1000 ms at its resonance frequency. Certain size/length/shape ductwork can also have a resonance frequency in the subwoofer pass band. Not that this is the case in your room, but other gremlins can be flexible partition walls, large window panes, and even the flooring - all of them can be considered "lossy" boundaries which can resonate in the subwoofer pass band.

Based on the dimensions of your room, the longest dim is (typically top corner diagonally to lower corner) is probably right about 34 feet. So unfortunately the room is large enough to support a 20-22 Hz mode, which has a 1/2 wavelength of about 26-28 feet. I was hoping this was not the case in an email I had sent you earlier today, but now that I've seen your room dims it is definitely possible, so I sent you a follow-up email. Most HT rooms are much smaller than yours and cannot support a mode at this frequency and are well into the pressure response and attendant room gain by this frequency.

Regardless, the less energy the subwoofer imparts to the room at this frequency, the shorter the ring time. As Bryan states, you could certainly notch-out the 20-22 Hz band more aggressively with a manual PEQ cascaded over the AS-EQ1 solution until the ring time falls more into line with the remainder of the pass band, but I doubt the FR would remain flat at that point. No conventional bass trap will be effective that deep, but a Helmholtz trap might work, as Bryan indicated. Maybe he could build you one or at least point you in the right direction.

Regardless, we’re perfectly OK with a return if you are unhappy with the AS-EQ1, but since you said earlier it sounded awesome, maybe you could first look more closely at your room boundaries and other materials of construction which could be resonating in the subwoofer pass band, and/or manually cascading a PEQ over the AS-EQ1, and/or a custom trap tuned to that mode. If not - then we're cool if you want to throw in the towel and we can process a return promptly - just let us know in Tech Support. Thanks!

**jpk** · **07-06-09, 03:54 PM**

Quote:

Ed Mullen wrote:

Regardless, the less energy the subwoofer imparts to the room at this frequency, the shorter the ring time. As Bryan states, you could certainly notch-out the 20-22 Hz band more aggressively with a manual PEQ cascaded over the AS-EQ1 solution until the ring time falls more into line with the remainder of the pass band, but I doubt the FR would remain flat at that point. No conventional bass trap will be effective that deep, but a Helmholtz trap might work, as Bryan indicated. Maybe he could build you one or at least point you in the right direction.

Regardless, we’re perfectly OK with a return if you are unhappy with the AS-EQ1, but since you said earlier it sounded awesome, maybe you could first look more closely at your room boundaries and other materials of construction which could be resonating in the subwoofer pass band, and/or manually cascading a PEQ over the AS-EQ1, and/or a custom trap tuned to that mode. If not - then we're cool if you want to throw in the towel and we can process a return promptly - just let us know in Tech Support. Thanks!

Thanks Ed,
I appreciate this, I would like to try a couple of things. I didn't even think of the flooring (actually ceiling in this case). I'll check with some of the local talent here, Maybe I can borrow a PEQ?
Joe

**Ed Mullen** · **07-06-09, 06:18 PM**

Quote:

jpk wrote:

Thanks Ed,
I appreciate this, I would like to try a couple of things. I didn't even think of the flooring (actually ceiling in this case). I'll check with some of the local talent here, Maybe I can borrow a PEQ?
Joe

I've seen an entire suspended ceiling tile gridwork resonate so badly at 25 Hz that the entire structure visibly shook for well over a second after the excitation source was terminated. I'm not saying that is the case in your room - only that it's possible.

I've also seen and measured a similar phenomenon with cheaply made wooden flooring over an open basement - literally turns into a trampoline at certain frequencies (which is why I detest it for critical audio applications).

Before relying on a PEQ, I would first attempt to identify any obvious resonances from objects/structures in the room by using a slow reverse sine sweep or discrete test tones (don't fry your voice coils though - be careful). If you discover something resonating badly, try to remedy the problem in the physical domain through structural modifications rather than simply attempting to reduce the strength of the excitation frequency.

It could also turn out that your room simply has a strong acoustic mode at 20-22 Hz and nothing is obviously resonating. In that case a Helmholtz bass trap might work, or you could try the cascading PEQ route (or both). You might need a bunch of cut at 20-22 Hz to bring down that ring time though.

If push comes to shove, I have a spare Rane PE-17 I could send you as a loaner. It's a nice unit and can easily notch-out a 20-22 Hz resonance with a high Q filter. It does have a fixed 10 Hz 2nd order high pass, though (just starts to affect the FR at ~14 Hz). If the Rane works, you can either purchase it, or return it to me and purchase a less expensive Behringer digital PEQ (I think the FBQ 2496 is only ~$150 street).

**bpape** · **07-06-09, 08:20 PM**

26ft, 21Hz, that's pretty obvious in my book. Yes - something is skewing it slightly but ceiling tiles rattling aren't going to be at 21Hz. Sorry.

If you have a drop ceiling, the FIRST thing I'd do is make sure that over your head and around the perimeter are stuffed to the hard surface above with insulation before you do anything eles.

Bryan

**Ed Mullen** · **07-06-09, 09:10 PM**

Quote:

bpape wrote:

26ft, 21Hz, that's pretty obvious in my book. Yes - something is skewing it slightly but ceiling tiles rattling aren't going to be at 21Hz. Sorry.

If you have a drop ceiling, the FIRST thing I'd do is make sure that over your head and around the perimeter are stuffed to the hard surface above with insulation before you do anything eles.

Bryan

The room can clearly support a 21 Hz mode based on its room dims and I've said as much.

Please don't question the validity of my personal observations - I have witnessed an entire suspended ceiling gridwork support structure (not individual tiles) with a sympathetic resonance at 25 Hz. The entire ceiling would visibly and obviously resonate at that frequency even long after the signal stopped.

**bpape** · **07-06-09, 09:45 PM**

Sorry Ed. I'm not questioning the room resonance at all. I was merely pointing out that the 26ft and 21hz were very close to being exactly related. It's not a matter of supporting it, it's a matter of exciting it. It will also support 25Hz, 30Hz, etc. but those aren't there.

Yes. Suspended ceilings can resonate very low in frequency. I just think that based on the graphs and length/intensity of the 21hz, it's unlikely that that's the issue specifically and solely.

I suggested that filling the ceiling would not only provide broadband bass control, but would also damp the ceiling resonance if in fact that's part of the issue. Sorry if I didn't spell that out exactly. I assumed it was understood that it would do both by default.

Bryan

**Ed Mullen** · **07-07-09, 06:40 AM**

Understood and agreed - thanks for clarifying, Bryan. This does look like a clear-cut axial mode based on the half-wavelength and the room dims. And stuffing the suspended ceiling won't make that go away, but could help damp other resonances if they exist.

In retrospect, I think all you were saying is that it's unlikely the ceiling gridwork has the same resonance as the axial room mode, and you're probably right - the chances of them being coincident are low - but it's possible.

**cavchameleon** · **07-07-09, 08:39 AM**

Wow, LOTs of discussion here lately! Thanks a lot Ed for all your info (and your's also Bryan). One question Ed, so are you against using a drop ceiling at all? I'm helping my brother set up his room and they were thinking going this route (my route was to use broadband traps as I did in my room, but they want a better asthetic result).

Thanks,
Ray

**bpape** · **07-07-09, 09:10 AM**

Quote:

Ed Mullen wrote:

Understood and agreed - thanks for clarifying, Bryan. This does look like a clear-cut axial mode based on the half-wavelength and the room dims. And stuffing the suspended ceiling won't make that go away, but could help damp other resonances if they exist.

In retrospect, I think all you were saying is that it's unlikely the ceiling gridwork has the same resonance as the axial room mode, and you're probably right - the chances of them being coincident are low - but it's possible.

Agreed. That's a much clearer way to state it than I did.

Bryan

**Ed Mullen** · **07-07-09, 09:30 AM**

Quote:

cavchameleon wrote:

Wow, LOTs of discussion here lately! Thanks a lot Ed for all your info (and your's also Bryan). One question Ed, so are you against using a drop ceiling at all? I'm helping my brother set up his room and they were thinking going this route (my route was to use broadband traps as I did in my room, but they want a better asthetic result).

Thanks,
Ray

Personally I don't like or recommend them. If the cavity is fully stuffed, then I suppose it would OK, but the potential is still there for the gridwork to buzz/rattle.

I would much rather see a solid ceiling populated with a bunch of GIK 242 acoustic panels at the strategic reflection points. But I understand that can be an aesthetic downgrade from a homogeneous drop ceiling.

Still, the GIK 242 comes in several colors, so matching the room paint scheme shouldn't be too difficult. If the system will be front projection, the ceiling (or the majority of it) should be flat black anyway. Try finding a black suspended ceiling tile and metal gridwork, or worse yet try painting and existing one flat black.

I have a flat black ceiling and black 242-style (DIY OC703) panels on the ceiling in my reference music/theater room.

**bpape** · **07-07-09, 10:59 AM**

I'll just add a bit to what Ed said. In addition to the possibility of buzzing/rattling, you also are reducing your shot at good isolation (sound getting IN is as important as sound getting out as it can raise the ambient noise level of the room)

Bryan

**cavchameleon** · **07-07-09, 11:36 AM**

Thanks Ed and Bryan! I'll relay the info to my brother. I was very much against a drop ceiling (they did not do it yet and have a finished, sheetrocked) 12' ceiling, so we have a lot of room to work with. I did my own DIY broadband traps using BAC (bonded acoustical cotton). My brother and his wife will not go the DIY route, so I'll show them the GIK site - I think they can come to some type of agreement on a color that will fit, especially if they paint the ceiling a close color to the traps. Drop ceiling just seem to have WAY to many possible buzzing points (too many 'movable' contact points).

I can't wait to get my hands on the AS-EQ1, when in August are they shipping out?

Thanks,
Ray

**jpk** · **07-07-09, 05:11 PM**

Quote:

Ed Mullen wrote:

Before relying on a PEQ, I would first attempt to identify any obvious resonances from objects/structures in the room by using a slow reverse sine sweep or discrete test tones (don't fry your voice coils though - be careful). If you discover something resonating badly, try to remedy the problem in the physical domain through structural modifications rather than simply attempting to reduce the strength of the excitation frequency.

If push comes to shove, I have a spare Rane PE-17 I could send you as a loaner. It's a nice unit and can easily notch-out a 20-22 Hz resonance with a high Q filter. It does have a fixed 10 Hz 2nd order high pass, though (just starts to affect the FR at ~14 Hz). If the Rane works, you can either purchase it, or return it to me and purchase a less expensive Behringer digital PEQ (I think the FBQ 2496 is only ~$150 street).

Thanks for the offer Ed, I'm going to take a rain check for now.
Last night through my Oppo uni player, I played Super Bass CD w/pre-pro in 2ch mode. Unlistenable from the start, but I did some troubleshooting and I believe the cold air return is the major culprit! I have a call into a HVAC guy. Hopefully he doesn't call the men in the white coats on me!
Later, I replayed it through the 7.1 analog lines, sounded much better and listenable. Nothing like major bass boost to accentuate problems! 10 pages or so back you discussed 2ch bass boost / offset, etc. I'll tweek that tonight.

I understand the room dimensions are not optimal, but if I'm right and this ringing gets reduced substantially, it'll be a lot better!

Joe

**cavchameleon** · **07-13-09, 02:09 AM**

Quote:

bpape wrote:

The problem is that while the flex or duct board is great at not passing vibrations and absorbing mids and highs, it has almost no mass to it so it's effectively a hole for bass to pass through.

Yes - you want bends and length but you want those to occur starting where it enters your room 'aquarium' and goes for at least 15' with at least 3 90 degree bends in it before leaving the MDF box (the mass).

Think of it this way... If you cut a hole in the ceiling that you just spent a ton of time sealing up and getting sound proofed, and then just put 1/4" thick insulation in the flex or the 3/4" duct board, you effectively have a hole in your ceiling for bass to pass straight up to and through the subfloor above you.

I don't mind answering the questions at all. In all fairness to the purpose of this thread, we should probably continue it somewhere else.

Bryan

Thanks Bryan!!! Sorry if this thread got derailed. Here is a new one continuing this topic:

http://www.hometheatershack.com/foru...tml#post176538

Much appreciated!!!
Ray

**XxxBERRYxxX** · **07-15-09, 08:51 AM**

I have two SVS subs that would love to be hooked up to one of these bad boys! SVS makes awesome subs and I can't even imagine how much better they would sound coupled with this!

**cavchameleon** · **07-15-09, 08:55 AM**

SVS does make Awesome subs! But, the room is a HUGE factor and no matter how good a sub is, there will always be issues. So the AS-EQ1 would most likely make a very big difference for 99.99% out there (there 'may' be that 1% that have a 'perfect' room - have not heard any yet).

Ray

**jpk** · **07-17-09, 01:13 PM**

Ed or Doug,
I was re-setting up the EQ again last night, I’ve done this several times since receiving the unit, this time an error message window pops up during the first position.
Sub Eq Ch3, satellite-warning, The type of speaker detected does not match the type specified in the zone config.
Do you wish to cancel? I said no and went on; the volume to the left satellite gets ramped way up and another window pops up:
Multi Eq error: Max level was reached without achieving adequate signal. Please decrease ambient noise and try again.
I closed the software, powered down the EQ box for 1 minute, powered up Eq unit, restarted software. This time I got to position seven before the max level error.
What could be going on?
Thanks,
Joe

**Doug McBride** · **07-17-09, 01:46 PM**

Quote:

jpk wrote:

Ed or Doug,
I was re-setting up the EQ again last night, I’ve done this several times since receiving the unit, this time an error message window pops up during the first position.
Sub Eq Ch3, satellite-warning, The type of speaker detected does not match the type specified in the zone config.
Do you wish to cancel? I said no and went on; the volume to the left satellite gets ramped way up and another window pops up:
Multi Eq error: Max level was reached without achieving adequate signal. Please decrease ambient noise and try again.
I closed the software, powered down the EQ box for 1 minute, powered up Eq unit, restarted software. This time I got to position seven before the max level error.
What could be going on?
Thanks,
Joe

Joe - I have not seen this particular error, but I have seen errors indicating the background noise was too great for it to get a good reading (and it was pretty sensitive - lawn mower about 100 feet away through closed windows).

I'd suggest trying a few things to see if the issue won't go away:

1. Remove power from the unit (unplug) for a minute then re-power.
2. Do a quick 3 measurement cal and permanently save the results to the AS-EQ1.
3. Make sure your microphone connection is clean and tight into the AS-EQ1, as well as checking the physical integrity of the mic itself.
4. Make sure you are using known and verified good interconnects between the AS-EQ1 and your receiver.
5. De-install, then re-install SubEQ.

Steps 1, 2 and 5 are intended to reset and get to a known good state with the device and software. Step 3 and 4 are making sure connections and hardware are sound.

Sorry if these seems a little "shotgun-y", but we've not seen this before. Let us know how it turns out and if these steps do not rectify, we'll take it to Audyssey.

Edit: I just assumed you went through the Level Match process OK, but you know what happens when you assume... Did you, and how did that work out? Are you using the Multi-Channel analog inputs for the Sat? Any digital processing on that input disabled (usually isn't any but I had to ask)?

Thanks,

Doug

**jpk** · **07-17-09, 05:40 PM**

Quote:

Doug McBride wrote:

Joe - I have not seen this particular error, but I have seen errors indicating the background noise was too great for it to get a good reading (and it was pretty sensitive - lawn mower about 100 feet away through closed windows).

I'd suggest trying a few things to see if the issue won't go away:

1. Remove power from the unit (unplug) for a minute then re-power.
2. Do a quick 3 measurement cal and permanently save the results to the AS-EQ1.
3. Make sure your microphone connection is clean and tight into the AS-EQ1, as well as checking the physical integrity of the mic itself.
4. Make sure you are using known and verified good interconnects between the AS-EQ1 and your receiver.
5. De-install, then re-install SubEQ.

Steps 1, 2 and 5 are intended to reset and get to a known good state with the device and software. Step 3 and 4 are making sure connections and hardware are sound.

Sorry if these seems a little "shotgun-y", but we've not seen this before. Let us know how it turns out and if these steps do not rectify, we'll take it to Audyssey.

Edit: I just assumed you went through the Level Match process OK, but you know what happens when you assume... Did you, and how did that work out? Are you using the Multi-Channel analog inputs for the Sat? Any digital processing on that input disabled (usually isn't any but I had to ask)?

Thanks,

Doug

Thanks Doug,

Level match went OK. House should have been quiet? It was after dark. Using 7.1 analog inputs.

I inadvertantly left the speakers to small when starting, possibly the first "speaker type error"? After the level error, I did power cycle the AS-EQ1 and restarted the Audessy software. That level error is scarry, it really drives the speaker!

I have an Outlaw 990 pre/pro using the 7.1 connectors, "The 990 does not offer any matrix processing or steering for the 7.1 Direct input; bass management, channel trim, and delays are all that I know of." I just double checked this on Outlaws site.

http://www.outlawaudio.com/support/990_analog_bm.html

IIRC, settings are what I used previously.

I'll double check your steps over the weekend.

Thanks,
Joe

**blekenbleu** · **07-18-09, 11:11 AM**

When SubEQ preorders are filled in August, will there be prior email shipment notifications/confirmations?
I would hate for mine to be delivered while away for a week or so..

**cavchameleon** · **07-18-09, 04:35 PM**

According to SVS, I contacted them on this, and they said that an email is sent out right before the unit ships (to also let you know that your card will be charged).

Ray

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