Room correction setup guide for ML’s

[tcwerner77]

phase problems

I'm lucky enough to have access to some nice sencore equipment. I found, when running near field phase test, that my Vantages stat pannels and cone drivers where out of phase with one another. This was also true with the puritys in the back. However when you move the mic back from the speakers a bit they measure as they should. I was wondering if this sounds right and could sometimes also be a factor in the dreaded phase error showing up. I ended up using the auto eq for levels, distances, and crossover; but manually did the eq with my rta. I liked the results better then the auto eq. great article, thanks for the info

 

[jtwrace]

I'm lucky enough to have access to some nice sencore equipment. I found, when running near field phase test, that my Vantages stat pannels and cone drivers where out of phase with one another. This was also true with the puritys in the back. However when you move the mic back from the speakers a bit they measure as they should. I was wondering if this sounds right and could sometimes also be a factor in the dreaded phase error showing up. I ended up using the auto eq for levels, distances, and crossover; but manually did the eq with my rta. I liked the results better then the auto eq. great article, thanks for the info

Welcome. I just learned about Bozeman, MT...there is a auto race team there. Very interesting place for one.

 

[VanDaRo]

Excellent post. Thank you for the tips. As a beginner, I have run across several of the anomalies that you mentioned and have had to find my own way through them. Where were these tips a year ago ???

~VDR

 

[jmschnur]

This is very useful- thanks. I found that using a dspeaker antibmode 8033 has helped with some serious low frequencies modes in my room that Audyssey multi eq in my onkyo pre pro could not handle. I did the anti mode first than the Audyssey-

sub = Descent i
Vantage
Cinema i- atttached to ceiling with a two foot drop just above sight plane of 60" Pioneer Kuro 151.
2 NHT surround dipoles, 2 NHT in the ceiling behind couch. Couch ~5' from real wall-9' from TV.

Results were quite good.

Joel

 

[urskog]

Re-read this thread once more since I bought a Classé SSP-800 and a XTZ Room Analyzer.
I don't have the help of Audyssey but all the steps before the actual measurement should still be valid so thanks again JonFo
Now all we need is for JonFo to acquire his own XTZ Room Analyzer so he can update his recommendations for the specific things that it might need.

 

[Wsmatau]

Jon,
Great thread. I have an Integra DHC9.9 w/ the audessy (Non -pro) software. Unfortunately, my ML Spires have been banished to an unfinished basement. Should I bother trying to make the adjustments before I finish the basement (It may be a year or more away)? I just see myself getting all sorts of reflections and getting frustrated trying to make adjustments before I have a more "controlled" environment.

Thanks:bowdown:

 

[JonFo]

Jon,
Great thread. I have an Integra DHC9.9 w/ the audessy (Non -pro) software. Unfortunately, my ML Spires have been banished to an unfinished basement. Should I bother trying to make the adjustments before I finish the basement (It may be a year or more away)? I just see myself getting all sorts of reflections and getting frustrated trying to make adjustments before I have a more "controlled" environment.

Thanks:bowdown:

You will definitely find a benefits for running this, especially if it will be a year before it's finalized.

Actually, the worse the environment, the more benefit.

Go for it!

 

[pjgregory]

Audyssey in a VERY large room

Hi Jon

I have just taken delivery of a pair of Ethos speakers so that I can start listening to music again as a break from the cinema. So far I have just placed them in the lounge where I had my old Epos speakers and started the 70 hour burn in. Outstanding so far, but I already know that they will be limited in performance by my room acoustics.

Our main living area is 18m (57ft) long, 5m (17.5ft) wide and extends some 8m (25ft) up to the wood beam roof. There is a gallery some 2.5m (8ft) above the seating area supported by a partial internal concrete wall, but the room still has the acoustics of a small Church!. I can put some absorbent panels on the side walls to dampen the early reflections but I have no chance of taming the base resonances or the extended reverberation time with acoustic treatments alone.

As a Consigliere d'Audyssey, do you think that the processor would help with these issues? As I live in the wilds of Italy, it is not quite as simple as getting your local dealer round for a home demo. I would probably have to buy and try and then resort to e-bay if it does not work.

Any advice would be most welcome.

PJG

 

[JonFo]

...

Our main living area is 18m (57ft) long, 5m (17.5ft) wide and extends some 8m (25ft) up to the wood beam roof. There is a gallery some 2.5m (8ft) above the seating area supported by a partial internal concrete wall, but the room still has the acoustics of a small Church!. I can put some absorbent panels on the side walls to dampen the early reflections but I have no chance of taming the base resonances or the extended reverberation time with acoustic treatments alone.

As a Consigliere d'Audyssey, do you think that the processor would help with these issues? As I live in the wilds of Italy, it is not quite as simple as getting your local dealer round for a home demo. I would probably have to buy and try and then resort to e-bay if it does not work.

Any advice would be most welcome.

PJG

First, I would recommend taming the side and front walls with absorption. In a room that large, the mid and high frequency reflections are your biggest obstacle to clear reproduction.

An Ethos will not overpower a room that large with bass. If anything, you might need a good sub to pair up with them if your processor supports that.

As for room correction, yes, an Audyssey full-range processor (or included in a preamp) would indeed help tame resonances created by the 'church-like' dimensions
The ability to perform time-domain corrections is one of the hallmarks of their technology, and very helpful in situations like these.
But a difficult room like yours will require extra careful Audyssey measurements to ensure it has the right inputs.

Please start a separate thread in the Room acoustics sub-forum to discuss your room treatments a bit more. The alcove around your seating area is something to explore further.

 

[jmschnur]

Using an Audyssey pro kit my center cinema I speaker the mulitpro program has a reported trim of 6 whilst a good phonic meter says it should be -.5 to match my left main. The Cinema i is 2.5' from front wall and 2' from ceiling aimed at listeners heads that are 10' away . MLP is about 4.5' from rear wall.

This result was 1st obtained with 12 measurements and then on another day with 15.


Normal Integra mic gave normal trims for center during a standard Audyseey calibration. The trim for the other 6 speakers are similar with the pro kit results. The Center speaker trim is close to the one obitined with my Phoonic meter to match my left main.

Unit is Integra 80.2 xt32

All other pro kit trims and all xovers make sense. Corrected center trim sounds fine in system with my vantage lr speakers and nht dipole surrounds.

After serveral runs I find that following the advice to sample different heights to get the vantage right seems to take the microphone out of the sweet spot for the cinema I
If the trim setting comes from my first measurement then my putting the mic 10" from the back of the sofa brings the tip of the mic out of the sweat spot which is where our ears our closer to the back of the sofa.

Any suggestions for a Audyssey calibration that would get the center speaker trim correct?

Thanks for your advice.

 

[Waboman]

Audyssey Inconsistencies

I decided to redo my Audyssey the other night. Why? I guess I'm a glutton for punishment. It's never the same, no matter how many times I run it.

Two things that are sticking in my craw. This time Audyssey set my center channel at +0.5db down from it's previous setting of +4.0db. Also, both my subs were lowered from Audysseys' previous setting to -11.0db and -10.5db. Down from -10.5db and -9.0 respectively. What's bizarre is, I seem to be getting more LFE now. Almost too much (if there's such a thing). I busted out my trusty SPL meter and with the exception of one channel every other channel is below 75db. Not a big deal, as I'm sure room refections were a big reason why. However, I did bump my center back to +4.0db.

Why the big increase in LFE at lower settings? And why such a drastic decrease at my center channel?

Previous Audyssey settings:

Latest Audyssey settings:

 

[Waboman]

Well, I ran another Audyssey and the inconsistencies continue. This time it put my sub levels back to where they were previously. But it raised both L&R speakers considerably. I have noticed how much more aggressive my subs are even when placed back down to their respected levels. Not sure what's going on here. But simply watching the Food Network there was way too much LFE.

Just while running this current cal, I noticed how much more aggressive my subs were than the rest of my speakers

So, for even more torture, I unplugged the subs, then I will plug 'em back in and run another Audyssey. Yep, two cals in one night.

New speaker levels. The inconsistency baffles me.

 

[JonFo]

...
After serveral runs I find that following the advice to sample different heights to get the vantage right seems to take the microphone out of the sweet spot for the cinema I
If the trim setting comes from my first measurement then my putting the mic 10" from the back of the sofa brings the tip of the mic out of the sweat spot which is where our ears our closer to the back of the sofa.

Any suggestions for a Audyssey calibration that would get the center speaker trim correct?

Thanks for your advice.

Sounds like the pattern you are using places the mic well outside the coverage area of the center speaker, which leads to a large boost in level (and probably some pretty serious boosts in mid-frequencies as well).

This is because the ML centers have a narrow vertical dispersion on their mid-range coverage due to a very short panel height. One reason they added the dynamic tweeter is give better vertical (and horizontal) coverage to the center.

So if during measurements you take readings too close to the speaker, the mic will be below the coverage. Likewise, being too far back and too high will move the mic above the beam from the panel.

The trick is to find the best compromise of locations where ALL beams overlap and keep the mic within those.

The problem with a high-mounted center is that the beam intersection with the mains will be relatively small. That’s not too big a deal, just measure inside that area.

Better to have corrected for that smaller footprint, than have inappropriate EQ applied and overboost the sound for the sweet spot.

 

[JonFo]

...

Why the big increase in LFE at lower settings? And why such a drastic decrease at my center channel?

Yep, frustrating that this process is not as repeatable as one would like, but I can tell you, very small changes in mic positions make significant changes in impulse response measurements.

Unless you've played with acoustic measurements a lot (>100hrs worth), it's hard to comprehend just how complex sound-fields really are, and how tricky measurements can be.

So, why did you get better LFE?

Possibly measured a more uniform pattern that caught more room modes, or the spacing clustered the measurements differently and the algorithm decided to correct with fewer LF cuts.

The decrease in the Center is likely related to what I outlined in my response above. Your latest measurements probably caught more of the center channel in the prime beam covered by the centers panel. A good thing I'd say.

However, I understand why you turn it up a little, as any seat outside the prime location(s) where the center panel and L/R speaker panel beams intersect will have too low a volume.

Sort of why I wound up building my own center

 

[Gordon Gray]

Hi Waboman,

If you keep running the calibration and it continues to give you different results, why do you continue to do it?

Ever tried tuning just trusting your ears?

GG

 

[jmschnur]

Thanks for this. I thought I had been correcting the height. How limited is the horizontal dispersion?


How far left and right of the center of can I go.


I assume I can only use the center aiming point for the vertical dispersion now. I had been putting a laser on top and bottom of the speaker and just putting the mic between those the top and bottom of the speaker and then placing the mic between the edges defined by the lasers. I will now go for the exact center.


How much better is the stage than the cinema I with respect to these issues?

 

[JonFo]

Thanks for this. I thought I had been correcting the height. How limited is the horizontal dispersion?

For vertical, dispersion is very tight. Only the height of the panel, so about a foot. Not kidding.

For Horizontal, it's better, with a roughly 30 degree spread.
But I find the coverage at the edges of that is marginal, so try and get the seats within a 25 degree angle.

How far left and right of the center of can I go.


I assume I can only use the center aiming point for the vertical dispersion now. I had been putting a laser on top and bottom of the speaker and just putting the mic between those the top and bottom of the speaker and then placing the mic between the edges defined by the lasers. I will now go for the exact center.

Correct, and intersecting the center channel coverage as well.
Within that set, do vary mic height a bit, but it's all about figuring the correct measurement 'bubble' for your setup.

How much better is the stage than the cinema I with respect to these issues?

The Stage is a much better speaker, but still suffers from limited vertical coverage. Only a solution like my SL3XC or a third unit of whatever model you use for L/R will really address that problem.
I hate to say it, but unless you've heard a 48" tall (or bigger) center channel panel, you've not really heard multichannel ESL magic.

 

[jmschnur]

Sounds like the pattern you are using places the mic well outside the coverage area of the center speaker, which leads to a large boost in level (and probably some pretty serious boosts in mid-frequencies as well).

This is because the ML centers have a narrow vertical dispersion on their mid-range coverage due to a very short panel height. One reason they added the dynamic tweeter is give better vertical (and horizontal) coverage to the center.

So if during measurements you take readings too close to the speaker, the mic will be below the coverage. Likewise, being too far back and too high will move the mic above the beam from the panel.

The trick is to find the best compromise of locations where ALL beams overlap and keep the mic within those.

The problem with a high-mounted center is that the beam intersection with the mains will be relatively small. That’s not too big a deal, just measure inside that area.



Better to have corrected for that smaller footprint, than have inappropriate EQ applied and overboost the sound for the sweet spot.

Thank you very much for your advice- it has been very helpful.
Since I do not have a projection system, the tower center concept which looks great by the way, will not work for me. I will persist with the cinema i for a while and redo very carefully my calibrations.

Once I have that down- I may go for the stage. I have head ML is putting out a new center speaker in about 12-18 months. Any chance that will have wider vertical dispersion?

Joel

 

[jmschnur]

Another question:

Is the jim powers flashlight alignment tweak appropriate for use in an Audessey calibration?

 

[JonFo]

The 'flashlight' alignment technique is OK to follow for speaker setup.
It primarily is geared to ensure your rear-wave is not directly bouncing back into the panel, which really destroys imaging and sound quality.