Subwoofer setup and MultEQ

Fourier is involved, but the acronym stands for Finite Impulse Response.  I misread your comment earlier.  Setting the crossover at 120 Hz is sending more content to the sub and so you should be getting a better response.  I would stick with that. Don't worry too much about the directionality issue.

I know it is a very technical subject you cover, I didn't mean to belittle Mr Fourier work. And I appreciate your support, thanks.

More tinkering......

Hi Chris

I have the Kef HTB2SE sub i have been reading your posts and note that the sub level is best set at 75db if possible mine is at about 87 and i can not lower it. The sub as far as i know is factory set at 80Hz and really my only option is phase 0 or 180. (set at 0)

The onkyo sets my sub at -12.5, from reading your comments this is probably because i had my front left right and center set as large so that can be changed however, am i loosing out not being able to raise the sub cross point from 80 - 120hz please.

Many thanks

Allan

Hi Allan, I think you're fine.  It appears that the Onkyo can go all the way to –15 dB for the sub so the –12.5 dB setting is within range.  The level setting of the sub is not related to whether your fronts are set to Small or Large.

If the sub really has a fixed lowpass filter on the input (note: this is not a crossover) then it will roll off above that frequency.  Ideally, the speakers that you are trying to blend with the sub will roll off just below that frequency so you can achieve a good blend.

Many thanks Chris good news re the -15db the sound is very good so i think for now i shall keep the kef allthough from some of your posts it does sound as if adding a second sub may help a little.

Best regards

Hi Chris,

What is the difference between running just Audyssey and running Audyssey Flat?  The Audyssey Flat, to my ears, sounds brighter.

Thanks in advance.

Rob

Hi again Chris,

Is MultiEQ XT designed for one subwoofer or can multiple subwoofers be used?  How does this differ from MultiEQ XT32?  Can MultiEQ XT be used with Velodyne SMS-1 or is that redundant?

Thanks in advance.

Rob

Hi Rob,

You can read about target curves here.  There is also a lot more basic info in the Audyssey 101 section.  MultEQ (all versions) will work with any number of subwoofers that the AVR makes available.  Some AVRs don't provide individual control of multiple subs and so MultEQ has to treat them as one.  There is no need for additional sub processing as the filter resolution in MultEQ is much higher (thousands to tens of thousands of points) than the few bands of EQ in these processors.

Hi Chris,

Do you recommend crossing at 80 Hz regardless of how low your speakers are capable of going?  For example, if all your speakers are capable of going well below 60 Hz, should you cross over at 80 Hz or 60 Hz?

Thanks in advance.

Rob

Please take a look at the Audyssey 101 post about this here.  Sending more content to the sub is a good thing if you have MultEQ or MultEQ XT because the filter resolution in the sub channel is 8x higher.

Hi Chris,

Thank you for all your help.

What about the Distance settings.  MultiEQ XT's measurements are not the same as actual.  Should I adjust the distance settings to the actual?

Thanks in advance.

Rob

Which speakers? If it's the sub, read this for answer.  Audyssey doesn't measure distance. It measures delay and that can be a function of acoustics and electrical filters in the path.  Wireless speakers add a lot of delay to the signal as well.  It's usually best to trust the measurements.

Hi Chris,

Thanks for all your help.

I setup Audyssey and on some intense bass scenes my subwoofer is bottoming out; however, when I turn off Audyssey and play the same scene at the same level, the subwoofer does not bottom out.

Why is this happening? Is there a way to prevent this from happening?

Overall the sound with Audyssey is much better than without Audyssey, so I would like to keep using Audyssey but I do not want to bottom out and damage my subwoofer.

Hello Chris,

Is there a difference between MultiEQ XT 32 and the SVS AS-EQ1?

Thank you in advance.

Hi Robert,

What subwoofer make and model do you have?

The subwoofer filter resolution in MultEQ XT32 is the same as the one in the AS-EQ1.

Hi Chris,

I have an SVS PC12 Ultra and it is set to 16 Hz.

Someone on one of the forums said that his subwoofer used to bottom out with MultiEQ XT, but when he switched to a receiver with MultiEQ XT32 the problem was gone.

Does XT32 manage the bass more effectively?

Thanks in advance.

Rob

Hi

I have the same SVS sub used on an Onkyo TX1009 mine is only set for 20Hz and when set with the Multi XT the sub does not bottom out. Have you added the foam baffle in the sub port i understand the sub will bottom without the foam

Chris may i ask what is AS-EQ1 please

Thanks

Allan

@Rob: I suspect you are hearing port noise, but can't be sure.  Audyssey doesn't do any bass management.  That is done by the AVR.  The difference between MultEQ XT and XT32 (please note: there is no "i" in MultEQ) is in the filter resolution.  XT32 has tens of thousands more points and will catch narrower peaks and dips in the response.  But neither will cause overdriving of the sub.

It's possible that the filter is applying a boost that is causing more air to come out the port and cause this noise.  In general, it's better to cover the port because that will allow the sub to extend to a lower frequency rather than play louder.  Deeper is always better than louder when it comes to accurate reproduction of content.

Hi Allan, the AS-EQ1 was (now discontinued) an external subwoofer processor made by SVS using Audyssey MultEQ technology.

Thank you Chris

May have to try the lower settings on my sub see if i like it in honesty i did not think much source sound went below 20Hz so i thought i hd no loss of sound.

You may have guesses i switched the Kef sub for the SVS so still learning yet.

Allan

Hi Chris,

Thanks for all the help setting up Audyssey.

I have a question about sealing my home theatre room vs. not sealing it.

My home theatre room is 18X12X8 (1728 cubic feet) with a 7X4 opening to another room that is 30X10X8 (2400 cubic feet).  When I setup Audyssey, does it matter if I leave the doors on the home theatre room opened or closed?  Is there an advantage with keeping the doors closed (i.e., more bass because of room gain)?

The reason I am asking is because something odd happens when I close the doors on the home theatre room and run the subwoofer test tone - I get a slightly lower SPL (using a Radio Shack SPL meter) reading in my sweet spot with the doors closed than with the doors opened.  I am not sure why this is happening and I am wondering if running Audyssey can correct this problem or not.

Any suggestions would be appreciated.

Rob  

Hi Robert,

If these are typical home doors, then they will make little difference in stopping the bass from leaking to the next room.  They may make a difference in the upper bass range and that could explain the difference in readings.  I would recommend running Audyssey for the conditions that will be used during listening (presumably with the doors closed).

I've read in forums online that Audyssey sometimes boosts very low sub frequencies exceptionally high -- to a dangerous breaking point.  Concerned about that, in setting up my new sub on my Denon AVR 2310CI, I set Audyssey to "skip" the sub on auto setup; but after completing Audyssey and enabling the sub, Mult EQ would not work (it told me to rerun Audyssey, which is what the Denon owner's manual confirms should happen).  So I reran Audyssey with the sub as part of the test.  After completing the test, I went to check the boost for the sub on the low frequencies.  But in the Parameter Check > EQ Check menu, it only lists detailed frequency adjustments for the 5 main speakers -- no sub.  Is that because the sub is fed the low frequencies from each speaker (such that I can tell if everything's okay for the sub by looking at the lower half of the other speakers' levels)?  If not, how can I check whether the sub's parameters are at "dangerous" levels?

Ah yes, the "Internet"... It's a source of all kinds of wrong info. Audyssey filters don't boost beyond the capability of the sub. The measurements look for the roll off point and stop boosting below that. The main reason people write these comments is because they are expecting their smaller subs to play at reference levels in large rooms. That will lead to overdriving.
If the sub (or any speaker) were not there during measurement then they can't be added later without rerunning the measurements.
Denon, for some reason, doesnt show the filter created for the sub. Onkyo doesn't show any of the filters at all. These are decisions made by each AVR maker independently.

Thanks for the responsive info and the healthy dose of skepticism, Chris,

Please forgive my ignorance. I have a Marantz SR6003 with MultiEQ. I know MultiEQ does adjustments to the satellite speakers but I'm nut sure about the sub. I don't see any EQ settings for the sub only the volume setting will change (higher or lower). Since MultiEQ is not as good as XT or XT32, is my sub really getting EQ adjustments? Second, I can get MultiEQ pro to work with the Marantz SR6003?

One last question. I can take up to six measurements with MultiEQ but if have a small room and only a love seat which only give me 2 listening positions. Do I need to still take all 6 measurements or is 2 enough? and if I should take all 6 measurements, where the heck to I put the mike after I take first 2 measurements. Thanks again.

Hi Chris

I have an SVS pb10-nsd subwoofer and a Denon avr 1910. The subwoofer is in the back corner of the room so it is behind me to the side. I know it’s not the optimal position but it’s the only one. My problem is that i get localization issues and too much bass in the upper part of the bass sound-image if I set lpf for lfe to 120hz like you recommend. So i have set it to 80hz instead. Could this be because the subwoofer is placed in the back corner?

Also. I have 2 tower speakers that go to 40hz or lower. I have set crossover to 60hz instead of the normal 80hz also to reduce the upper level bass. 

If i set lpf for lfe to 120 and crossover to 80 I get quite a lot of sound in the upper bass range. So my problem is I can’t get the recommended settings to work properly. 

Any ideas as to what might be wrong? Subwoofer placement maybe? And am I missing out in the bass-area with these settings?

Kind regards

Jens

Hi Jens,

First let's be sure we are talking about the same thing.  There is an LPF filter in the Denon that is applied to the LFE track only.  This must always be set to 120 Hz because the LFE track is authored with content up to 120 Hz.  But, this filter has nothing to do with crossovers.

There is also a filter on the back of the sub that is applied to the incoming signal.  That filter may interfere with the lowpass filter applied in the Denon to the bass managed bass signal and so we recommend setting it as high as possible.  

But, again, the LPF for LFE filter is not at all related to the crossover filters set for the speakers.  It only applies to the LFE track found in 5.1 content.  You can easily test this by playing 2-ch stereo that has no LFE track.  Changing the LFE filter will have no effect on the sound.

Hi Chris,

I've gone through all the comments and can't seem to find anyone having a similar problem to me.

I have an Onkyo 707 AVR with a 5.1 speaker setup. My sub is a Pure Acoustics Noble which I believe is a decent mid-range sub.

It is connected to the low level input. I have the frequency knob all the way up to 150, I make sure the auto switch is set to 'on' (not auto). Phase set to normal. So far so good.

The issue I'm having is that I have to turn the gain down on the sub substantially after having run MultEQ. To get a good trim level (between -12db and +12db) the gain has to be at least half way up. If it's any lower then I get a +12db trim and I've even had a no sub detected error with the gain set a quarter of the way up. So, after having a decent trim (Currently at -7db) set by MultEQ,  I then play a movie or music and the bass is way too high, I'm talking window rattling, deep rumbly bass that almost sounds distorted. I have to turn the gain back down to a quarter of the way up to have the right amount of bass, and when I say the 'right amount' it is of course still personal preference, but it is still deep and rumbly, but not too much so. In fact it sounds very good.

I'm sure that I shouldn't have to adjust the gain after running MultEQ so what could be going on here? I have run MultEQ several times with different gain levels on the sub, an although the trim levels vary, the end result is always the same, ie. way way too much bass after running MultEQ. It's as if the MultEQ calibration is sending a lower volume signal to the sub than what it is sent when listening to movies. I doubt very much that this is what's happening, it just seems that way.

thanks for your help,

Rob

@Kevon: Yes, MultEQ applies high resolution correction to the sub.  But for some reason Denon and Marantz don't show the correction in the GUI.

You should always, always, always take all the available measurements regardless of the size of the room.  It's not a matter of placing the mic in every seat. The algorithm needs to collect data from the listening area and the recommended mic placement is shown here.