Subwoofer setup and MultEQ

Hi Chris,

Assuming I made a mistake when placing the mic during MultEQ correction setup and that caused unnecessary tone adjustments, I am going to re-run the MultEQ, but I still have questions about mic placement:

1) Can a speaker (including the subwoofer) partially obstructed with a piece of furniture cause the mic to measure inaccurately resulting in incorrect tone adjustment? Should I remove anything that may even slightly obstruct the mic signal sent to a speaker?

2) Is it OK to place a tripod on a couch, rather than on the floor?

3) If I follow the recommendation of observing at least 2 feet distance between measurement positions (which will be in the same line) should the minimum 18'' distance also apply to side walls?

4) The last measurement tip says: "Focus on the central listening area and avoid extreme positions such as the back wall or too far beyond the left and right speakers" - does this mean that I should place the mic in the center of the room even if my listening position is further back to the wall? "Too far beyond the left and right speakers" - what is the specific distance that's considered to be "too far beyond"?

Thanks a lot for your help, Chris

Best regards,

Alex

Hi Alex,

A speaker obstructed by furniture will most certainly give bad measurements.  It's essential to have a clear path from the speaker to the mic.

Yes, it's fine to set the tripod on the couch.

Yes, it's a good idea to keep the minimum distance from the side walls as well.

No, "center of the listening area" is intended to mean the center of the area where the listeners sit.  The mic should not be placed in positions that are outside the span of the front L and R speakers.

Hi Chris,

Thanks so much for getting back with the answers. I have re-run the MultEQ setup following all your recommendations (which also involved shifting some furniture) and now I think I got rid of those harsh bass peaks and overall sound got much clearer. Previously I didn't realize that correct placement of setup mic is itself a part of tone equalization process and even slight mic placement inaccuracy, like 1 inch or so,  in terms of observing distances (especially the distance from back wall) can boost or cut bass dramatically - so I put the tripod with the mic on the couch exactly at the level of listeners' ears observing the minimum back wall distance you recommended and the 2 feet distance between the listening positions. It's a great pity that in their user manuals AVR manufacturers like Onkyo do not bother to provide specific mic placement details like minimum required wall distance and distance between measurement points, furthermore, let alone first time users, even a so called "professional installer" who was setting up my system didn't realize the importance of accurate mic placement and the effect it has on tone equalization and placed the mic as if its measurement location didn't matter at all, and that's really sad. Anyway, I'm quite satisfied with the sound so far, and thank you ever so much again for your detailed recommendations.

Best regards,

Alex

Hi Chris,  I finished running Audyssey a few times, making volume adjustments on my subwoofer because the trim was set to -12dB on the initial Audyssey setup.  I also carefully followed your guide for placing the sub and the setup microphone.  I also read the various posts and discussions on this.  Thanks for your help!

The end result is a sound that I am very pleased with!  I list the channel levels and crossover frequencies below.  Do you suggest any further adjustment?

1. Channel Level:  FL -4.0dB, FR -4.5dB, C -6.0dB, Sub -3.0dB, SL -3.5dB, SR -3.0dB
2. Crossover Frequency:  F 40Hz, C 40Hz, Surround 60Hz

(All speakers set to SMALL.  LFE set to 120HZ.)

Chris - this is a superb forum.

For a sub-woofer which (like the BK XLS200) for example) has High and Low level inputs, is it advisable to use both?  I have the Denon 4311.

Thanks,

Steven

Hi Steven,

It's not advisable to use both.  You should use the low level (line level) inputs so that the crossover is properly performed in the AVR and not in the subwoofer as would most likely be the case with the speaker (high) level inputs.

OK - thanks Chris.

Chris,

Is there any software reason why when Audyssey applies EQ cut/boast to the LFE/sub-woofer channel that it stops applying it below a particular frequency? I am using the Denon AVP-A1HDCI(A) pre-amp.

Relative to 75dB I have a wide -10dB dip in my room response centered on approximately 58Hz with a large broad peak of +10dB at 32Hz.

After running Audyssey several times using all eight locations there is no apparent correction applied after the first dip at 58Hz. I have checked this at all eight measurement positions. All that happens is that the 58Hz dip is reduced by approximately -6dB, then I measure no apparent changes in levels below this frequency.

Does Audyssey stop correcting when it cannot add enough boast to hit its target level?

Hi Chris, I have a Onkyo 3007 AVR conbined with 4 HSU ULS15 subs, one in each corner of the room. The Onkyo has two sub outputs and I have my two front subs on Sub1 and my two rear subs on Sub 2. I have been reading your notes on how to prepare the subs and room for running the audyssey program and have a couple of questions.

1)When working with the manufacturer, they had instructed me to make sure the subs are in phase with each other by starting with one, then adding a second while watching the sound level meter. flip the phase switch back and forth leaving it in a position that provides the highest sound level. Makes sense, but, as I like to run audyssey should I do this? And as I already have them set (2 are at 0 and two are at 180) is there a reason to reset to zero?

2) The comment above about the furniture in the way of the speakers, I ran audyssey by placing the mike in position 1 (the main seating area), if i sit in that seat, I cannot clearly see the fronts as the front row of seats slightly blocks the view. In order for the mic to have a clear line to the fronts I would have to put it 6 inches above where my head would be in that listening position. Is that the correct thing to do raise it above the ear position?

3) THe manufacturer of my subs stated as follows, " When you set the ULF trim to 16hz, the ULS Amplifier will use more electronic deep bass boost to extend the frequency response. So with the trim set to 16hz, Audyssey will need to use as little deep boost as possible. After runing Audyssey, in order to have higher headroom or a less deep sound, you can always manually turn the ULF trim knob higher. No need to rerun Audyssey after doing that." Can I get your input on that.

4) Many poeple on the net recommend running audyssey then zippin over it with a sound meter to adjust the sound levels for the main listening position. As I am mainly the only person in my theater, I have been running the 8 point audyssey and then putting a sound meter in the pprimary listening position to get the best results for my seat. Is this really neccessary and does it effect the room equalisation that your product does?

One final question Chris, from your standpoint, the AVR set the crossovers for the front and mains at 40, I have always changed those to 80 after running audyssey, is that correct from your standpoint? Again thanks in advance

@Bob: Yes, there are limits to the amount of boost that Audyssey will apply.  These are based on the measured response of the speaker.  Boosting below the roll off point is never done.  Also, boosting to fill holes in the response due to normal modes is not done--it would be pointless.

Hi Paul,

1) Audyssey will measure the two subs and come up with the best correction filter (amplitude and phase).  I don't think there is much point in playing with the polarity switch, but it can't really hurt either.

2) It would probably be best to raise the speakers a littler higher so that the back row is not obstructed.  If that's not possible, then slightly raising the mic is OK as you suggest.

3) I agree with the manufacturer

4) Not sure what this means... Audyssey sets the levels from the first mic position which should be in the main listening position.  If a properly calibrated sound level meter is placed in the same location then it should register the same level as what Audyssey measured.

It's OK to move the crossovers higher.  This sends more content to the subwoofer MultEQ filters that have higher resolution.

Thanks Chris, for the great answers.

2) Well they are not terribly obstructed.

4) I didnt realise that the levels were set in the first positioning of the mike, thanks that helps a lot.

One other snag I have been fighting with

As the Onkyo has two sub outs, the Audyssey seems to set those levels independantly of each other and to the same level as the other channels, I have verified that with a sound meter and test tones. Now if I use a sound meter and run a LFE test tone from the dvd player (which outputs to both two sub channels),a 8db higher reading is the result, so the subs are running real hot. Is this by design of Ausyssey or an issue that was overlooked by Onkyo? Should in theaory the subs only be at best 5db higher?

Paul, I would start by checking the disc.  It has been a common problem in some of these so-called calibration discs that have been authored incorrectly and have a 10 dB higher LFE test signal.  The best way to check is using the internal test tones in the AVR.

Well its the AIX Record Audio calibration DVD that comes with the oppo Bue Disc player, the 96hz 7.1 tones Interestingly I cannot check the LFE on onboard as, like i stated, the tones test the sub channels separately. The problem seems to be when playing material from a alternate source as the two levels seem to add to each other. With the Onkyo and Audyssey does it allow for the simultaneous playing of the two sub outputs when playing an LFE track? I know when Audyssey runs through it tests in does the two seperatly

so chris is it safe to assume that audyssey is setting the two sub outputs and allows for the conbination of both when setting the Levels?

In your model, Audyssey doesn't ping both subs together.  That started in later models using what we call Sub EQ HT.  In your model Onkyo allows individual level and delay adjustment of each sub by Audyssey and so they are each set to the same level.  Presumably, since you have told the AVR that you have two subs it is making an adjustment in the summed bass signal--but that's something Onkyo will have to give you more info on.  

Chris,

As always thank you for your prompt responses.

Based upon the dimensions of my room, the measurement postions that I am using are not at any simple room node or antinode positions. They may however be located at complex mode inetrefernce points.

I am now extremelye confused. When driving my two PB12NSD's using the Velodyne SMS-1 I can easily create a flat response from 15Hz to 80 Hz, +-1.5dB. This response holds good for my three seat locations.

Am I therefore to assume that Audyssey views the"significant" first dip in the LFE channel response to be the subs roll off and no further EQ is applied?

If the above is the case what would be your advise in order to "make" Audyssey continue its EQ process down to 20Hz? Should I first run the SMS-1 to obtain a "nominally" flat response with no severe peaks and dips then let Audyssey run?

Unfortunmately due to the rooms design relocating the subs from their current quarter room width in from the front side walls is not an option, I could however add two more smaller subs in the rear corners or purchase the SVS AS-EQ1 if you felt that would be  a better option.

In advance thankyou agian for your patience.

It seems that the Onkyo receiver isnt making an adjustment to offset the summing of the bass, unfortunate but, I will have to fix. How would you suggest to fix that problem using a sound meter etc? I was thinking let Audyssey set the channels, use an external tone and adjust both sub channels unifromally down to a more acceptable level?

Hi Paul,

Strange... Yes, let Audyssey set the individual channels and then use narrowband pink noise (not tone) to adjust the combined level with a meter.

For subwoofer, my level was 11.0db after running audyssey. Should I lower the level of my sub? Thanks

Hi Liam,

Do you mean that Audyssey set it to –11 dB?  That indicates that the volume control on the sub is set very high, but you are still within the range of adjustment that the AVR provides (it goes up to –12 dB usually--some allow –15 dB).  

Yea, Audyssey set it to -11db. If it is set very high is it worth turning down a notch and redoing the auto setup, will it make a difference? 

No, I wouldn't worry about it.  It will make no difference as the AVR is still in range.  You will simply get a level setting closer to 0, but it's just a relative number depending on where the sub volume is set.

Hi Chris

I have a Paradigm PDR-12 subwoofer and there is two knobs, one is labeled "Subwoofer Level" and the other one is labeled "Subwoofer Cut-Off Frequency (variable 50hz - 150hz)".  I am not sure what is the purpose of the second knob since my understanding is the AVR manage the Cut-off frequency...

At which position I have to set the second one? Completely clockwise or completely anticlockwise? 

Thanks

Hi Jules, the Frequency knob applies a lowpass filter to the signal.  It's there for people with legacy analog 2-channel gear that have no bass management.  If you can't turn it off, then set it to the highest frequency allowed (150 Hz in this case) and leave it there permanently.  More info here: http://ask.audyssey.com/forums/84181/entries/76175.html

Hi Chris

I have 2 front floorspeakers (large), center(small), 2 surround (small) and a Subwoofer.

By the last audyssey meeting step,   I see by speaker config check: the front is set to Large and by Crossovercheck: Front Fullband, center 90Hz and  surrount 60Hz.

In the audyssey meeting I cannot set my font to small, is that normal?

After audyssey meeting I can set manualy by speakerconfiguratie the front to small.

1e question: is manualy change to small oke, or gifs that conflict with audyssey configuratie.

2e question: is manualy change crossover from fullband to 40Hz oke or gifs that conflict with audyssey config. and is 40Hz oke for floorspeakers ?

Hi Wim,

The decision to make the speaker Full Range is made by the AVR not by Audyssey.  They use 40 Hz as the decision point.  So, this means that your front speakers are found to roll off at 40 Hz or below.  You should change them to Small by setting a crossover.

This is done in the Setup menu after you finish and store the calibration.  It is OK to do this.  In fact, we highly recommend it.

Hi Chris,

Thanks Cris for your anwer. When I set the crossover to 50Hz en speaker to small before Audyssey calibratie and then start the calibratie is than the result that the speakers well set to small?

I hearth when you change setting after calibration, the changing crossover will effect the Audyssey parameters. Is that true?

What is the best crossover setting for my floor speakers in combination with a subwoofer.

What is the best crossover setting for center (small)after callibration 90HZ and surround(small) after callibration 60Hz

Hi Wim,

You can not make these settings before running Audyssey.  All internal settings in the AVR are ignored during the calibration.  You have to make the changes after the calibration is finished and stored.

Changing the crossover to a higher frequency has no effect on the Audyssey filters.

The best crossover setting will depend on the acoustics of the room and the placement of the speakers.  That's why it is important to measure.  In your case it seems that the speakers are found to be extending down to 40 Hz, which is why the AVR is setting them to Large.  I recommend setting them to Small by selecting a 60 Hz crossover.  

The center and surround speakers do not need any adjustment from what Audyssey measured.