Speaker/Room calibration

[rbbert]

... I only rely on Audyssey (Auto) in my own system & from my very humble two subs. But the qualitative results are tenfold compared to without Audyssey (XT flavor only, till I upgrade to XT32). For both Movies (multichannel) and Music (2-channel) listening.

I have Audyssey XT in my Denon AVR in my home theater set-up, but I have never been able to have it sound better "in" (i.e., with correction) than "out". I've redone the set-up on several occasions with similar results, for whatever reason the sound seems to lose dynamics and clarity with the Audyssey XT "in", and the frequency balance doesn't seem much different.

 

[rbbert]

You guys are moving way to fast. Bruce posted 2 graphs, Hasn't shown what the contros are capable of dong and you have him getting 3 to 4 subs...

I was actually just speaking from my own experience, not responding to Bruce's graphs at all. A smallish room is going to have more peaks and nulls in the bass than a larger (e.g., 22' x 36' x 11') room.

 

[NorthStar]

You guys are moving way to fast. Bruce posted 2 graphs, Hasn't shown what the contros are capable of dong and you have him getting 3 to 4 subs. Nothing like throwing gas on the fire.
He needs to get a base line, figure out that he can achieve thru speaker and listening position, what the EQ options are, ect..
REW is a great tool and can really help - so move slowly and with purpose.

Yes, but Bruce waz the one who asked for suggestions.

Besides, multiple subs are better than a lonely one; best way to balance the bass in any room.

 

[RBFC]

Yes, but Bruce waz the one who asked for suggestions.

Besides, multiple subs are better than a lonely one; best way to balance the bass in any room.

Perhaps this may be true in the end, but it would still be beneficial to optimize everything else before adding more bass transducers/locations. Then, once the positioning of mains and seating is as good as it can get, it might be a good time to experiment with the subs. In this manner, you will know the degree of improvement brought about by the addition of the subs (and not due to any other changes).

Lee

 

[NorthStar]

I have Audyssey XT in my Denon AVR in my home theater set-up, but I have never been able to have it sound better "in" (i.e., with correction) than "out". I've redone the set-up on several occasions with similar results, for whatever reason the sound seems to lose dynamics and clarity with the Audyssey XT "in", and the frequency balance doesn't seem much different.

Very quickly here (sorry Bruce); what did it for me was the microphone positioning:

1. Away from any surface (including my loveseat's back); so higher than ear level by few inches.
2. The full 8 mic position measurements; and by taking my time for the best spots:
=> 3, 1, 2, and then in front; 4, 5, 6, and finally between those two rows; 8, 7.
3. Disconnecting the fridge (that was done at the very beginning, before any measurements).

EDIT: If I may also add:
- Position the mic about 12 inches from your seat's back (or couch),
in addition to be also slightly higher than your seat's back.
- Use a microphone boom with an adapter having the proper thread for the Audyssey mic.
Don't use a camera tripod.

These small details worked not only for me but also for many of my friends.
Before we readjusted to these small but important mic positioning variables & tools (mic boom),
Audyssey room equalization did not work as intended, and personally I left it off.
I wasn't happy with the results; in particular with 2-channel Music listening.
-> Now, Audyssey is always engaged (Movies & Music), and the final results,
as compared to before, are night & day. ...Meaning excellent.

* If you need more tips to improve your Audyssey sound, post your questions here.
I will do my best to help by working with you.

 

[NorthStar]

Consider what happens with an infinite bass trap: playing the speakers outside. There is no dip. The dip means the bass is in fact not being trapped.

It's so much more effective to kill these bass modes with multiple subs, no room should be designed without them.

Perhaps this may be true in the end, but it would still be beneficial to optimize everything else before adding more bass transducers/locations. Then, once the positioning of mains and seating is as good as it can get, it might be a good time to experiment with the subs. In this manner, you will know the degree of improvement brought about by the addition of the subs (and not due to any other changes).

Lee

Lee, I was simply replying in accordance to Roger's quote just above yours.

 

[Bruce B]

Bruce,
Can you tell us where the listening positon and the speakers are located.
Also can you move the mic so it is 4'6" from the rear wall centered left and right and post that for us.
John

Here is my baseline and set-up.

Speaker controls at default
Repositioned my speakers to the "Golden Process" on the EA website. Rule of thirds not feasible.
New Speaker position - from side wall to center of speaker - 44.7" (was 36")
New Speaker position - from front wall to front of speaker - 72.4" (was 66")
New Sitting position ~ 78-84".. just past the triangle and about 118" (was ~84") from back wall

Measured 20Hz - 200Hz, no smoothing

Overlay =
Green tracing is mic 4' 6" from back wall
Gold tracing is mic at new seating position ~118" from back wall

Looking Good!

Edit: just took a quick listen... all I can say is Holy Crap!!

 

[RBFC]

Nice, Bruce! What a change! Now, it should be apparent that locational changes in the existing factors (mains, seating) have made a SIGNIFICANT improvement to the FR at the new seating position. With a little more tuning, it would be far easier to utilize extra subwoofers when there are less dramatic problems to correct!

Lee

 

[Roger Dressler]

Yes that was my point. I know that Roger is using four subs in his own room.

Yes. That choice was driven by two factors. The option for a pair of midwall subs (one of the better Welti solutions) was not physically possible as a retrofit to the room. And the BassQ supports 4 sub outputs, so why not?

And Roger is using his own method to calibrate his room to taste; with his Classe preamp and some external equalizers.

The external EQ being the BassQ driving the subs. All other EQ happens inside the SSP.

You guys are moving way to fast. Bruce posted 2 graphs, Hasn't shown what the contros are capable of doing and you have him getting 3 to 4 subs. Nothing like throwing gas on the fire.

Yes, it will be important to first see what those two speakers do when driven together. Looking forward to that. But none of those controls are going to matter.

 

[Roger Dressler]

Measured 20Hz - 200Hz, no smoothing

Looking Good!

Edit: just took a quick listen... all I can say is Holy Crap!!

Bruce, is this plot showing the response of one speaker, or both? Could you run a plot with both driven as mono?

 

[Bruce B]

Bruce, is this plot showing the response of one speaker, or both? Could you run a plot with both driven as mono?

Roger, all graphs that have been posted have been both speakers driven in mono. I assumed this is what I was supposed to do. Bob Hodas did it that way and said he was looking for phase/cancellations as well.

 

[Ron Party]

Yes. That choice was driven by two factors. The option for a pair of midwall subs (one of the better Welti solutions) was not physically possible as a retrofit to the room. And the BassQ supports 4 sub outputs, so why not?

The external EQ being the BassQ driving the subs. All other EQ happens inside the SSP.

Exactly what I am doing.

 

[Roger Dressler]

Roger, all graphs that have been posted have been both speakers driven in mono. I assumed this is what I was supposed to do. Bob Hodas did it that way and said he was looking for phase/cancellations as well.

Ahh, ok. So it looks like those "woofer" locations are not doing much to cancel that 40 Hz mode. The new plot does show a much improved response, one that looks addressable by EQ, if that were an option... I understand the subs self-powered. Do you have access to the line level input signal?

Is it possible to physically displace the subs from the rest? The speakers seem to be modular. Could run the middle section like an MMone, then have 4 subs to place around the room where they'd give optimal response.

 

[FrantzM]

I wouldn't want to turn this into a do we need subs fest.. There are certainly passive ways to take care of some of these resonances. They involve likely more traps whose construction may be problematic due because they will make the room smaller, eating up some of the available space/volume in this room or adjacent rooms. As it is this is a good response.. it can however be improved. I am not sure I could be of help in the construction fo the traps or their position or the impact of these traps in the general feel of the room, since they will have some impact over the rest of the frequency band. I would think based on my prior experience that in the region where these problems are manifest, the most efficacious solutions would be:
a) Multiple subs at least 3. In many ways this would be the least deleterious in principle to an all-analog chain… There could be some processing in the subwoofer but these are likely to be minimal.
b) Digital EQ.. This would be a much different approach involving A to D .. Unless there is a way to only apply it on the woofer section…

I find most interesting is Bruce B. humility and perfectionist approach. I laud the willingness to share his knowledge and discoveries with the audiophile community. Most Mastering Engineers would have shroud themselves in a quasi-Mystical aura of infinite knowledge and savoir-faire. Despite Bruce immense knowledge, his humble and refreshing approach is admirable and explains the sound we hear from albums coming from his facilities. Kudos Bruce! You are a gift to the proper reproduction of Music.

P.S. I just read the last Roger Dressler post and would have left the MM3 alone and add three of the subs module to try out ... Some kind of "Distributed MM6" ... mhh??

 

[rbbert]

- Use a microphone boom with an adapter having the proper thread for the Audyssey mic.
Don't use a camera tripod.[/I]

I did everything but this, so maybe I'll re-try. Thanks.

 

[theguesswho]

Bruce did you get that last few percentage that you were looking for? It sounds like he was cured allright. And now there is no need for an eq to be put in the signal line to preserve the purity of essence of the system.


According to Nyals article here http://blog.acousticfrontiers.com/storage/AMS for Stereo List. Rms.pdf
you are within the accepted limits of +- 10db. Though you were not that far off to begin with.

Standard: In room low frequency (LF) response measurement at listening position should be:
• Within +/10dB
at 1/24th octave resolution from 20Hz to 250Hz for both speakers
measured together.
• Within +/5dB
at 1/3rd octave resolution from 20Hz to 250Hz for both speakers
measured together.

Jack
POE143
"if the first octave sucks, why continue?"

 

[Roger Dressler]

There are certainly passive ways to take care of some of these resonances. They involve likely more traps whose construction may be problematic due because they will make the room smaller, eating up some of the available space/volume in this room or adjacent rooms.

I agree, and suspect all the trapping at the front/rear of the room is doing rather little for the 40 Hz mode, as that rattles between the side walls so would still exist even if Bruce knocked the front/rear walls out of the building.

I wouldn't want to turn this into a do we need subs fest.

the most efficacious solutions would be:
a) Multiple subs at least 3.

P.S. I just read the last Roger Dressler post and would have left the MM3 alone and add three of the subs module to try out ... Some kind of "Distributed MM6" ... mhh??

The cool thing about these Evolution speakers is their modular design. This solves the #1 conundrum of full range speakers since they were first devised: the subs want to be somewhere else than the midrange/tweeters. So here we have Evolution supplying separate modules for each, and what do we do -- bolt them together in a stack!

Those 4x 15" 1000W subs are more than plenty for the job, if they are placed advantageously, and driven in mono and EQ'd.

Another alternative, requiring no purchase of stands or subs, would be to run the mains full range like MMTwo's, and place the loose pair of mono subs for modal treatment. This could have a slight benefit for a mastering sensibility where hearing some sense of "stereo bass" is important. It just makes the bass management and EQ process a wee bit trickier.

 

[bblue]

I don't know why folks are so gung ho for sub woofers. I'd bet some 24" diameter 4' high ASC tube traps or equivalent across that back wall would help immensely. The two rear corner traps aren't going to be enough.

--Bill

 

[Roger Dressler]

I don't know why folks are so gung ho for sub woofers.

Umm, so one can hear the bass?

I'd bet some 24" diameter 4' high ASC tube traps or equivalent across that back wall would help immensely. The two rear corner traps aren't going to be enough.

How would that help the lateral modes?

 

[microstrip]

P.S. I just read the last Roger Dressler post and would have left the MM3 alone and add three of the subs module to try out ... Some kind of "Distributed MM6" ... mhh??

Or just feeding two of the active subs from separatly equalized feeds using an external crossover? Distributed MM3 2+1+1