"Official" Audyssey thread (FAQ in post #1) - Page 1959

That's a good idea, since there has there has been everything from forum posts to YouTube tutorials on using analogue mics (+soundcard) and analogue connectons to the receiver with Room EQ Wizard. Using USB mics and HDMI outputs with REW is relatively new, so it would be helpful to start a thread on the subject, even if it may appear to be a narrow topic at first.

And it does appear simple at first: mic into laptop, HDMI out to receiver, what could go wrong? ...What do you mean ASIO drivers? What's ASIO? If the thread also ends up also being a refresher course on 'best practices' when measuring, then that would be fine as well; can't have enough reminders on good measuring technique.

 

+1.

 

Whatever it's called, I hope it soon gets started!

 

Sections on measuring technique and graph interpretation would be very helpful.

Hi Stuart,

So, I tried everything, but it seems "any speaker" can only be paired with one more speaker or better to say one more channel. For example, pairing L + R in REW and letting the AVR redirect the bass contents of those two channels below the crossover to the sub will allow for a combined L + R meaurement. Your setup with the Mythos STs is a bit peculiar in this case.

BTW, why do people want to measure multiple channels at the same time? If that was adventageous, you would think that licensed room correction technologies (Audyssey, Trinnov, Dirac) would be doing that, but they don't.

 

Feri, does this mean that you cannot do L/C/R plus sub?

 

Isn’t it important to measure the combined output of the main speakers plus sub?  That is what we hear when we listen. I'm not challenging you, Sanjay - just asking.  Hopefully, this is the sort of thing that will be explained/discussed in the new REW thread.

Since Stuart has the Mythos STs with built-in powered subwoofers for front L/Rs, it will be interesting for him to see how the built in subwoofers combine their output down in the modal range, especially in a multi-seat environment.

Stuart?

Unfortunately Keith, that is what it means. But if anyone with REW + HDMI + ASIO4ALL 8 channel setup could chime in to confirm or deny, that would be welcome. Maybe another topic for the new thread!

It is important to measure combined response of each one of the main speakers with sub, in the first place. This is how they usually will play. If you are listening in stereo mode, i.e. without center channel it might be possible that measuring both of the main speakers will uncover some interference problems, but, it is only interesting after both mains are measured separately, so there is some reference curves to compare the combined one to...

 

OK, thanks Feri. I don't think it matters all that much to me anyway. Usually measuring L+R + Sub or C + Sub is good enough for me - well, it has been so far.

 

Oh - can it do that?  L+R+Sub? Or is it L or R + sub?

 

I guess this will all come out in the new thread.

 

OK thanks Igor. I get it now. I think ;)

Keith, any two channels, but only two.

I should have clarified: by 2 channels, I meant (for example) L+R simultaneously. If it is important to know how those channels interact, why don't room correction systems measure and correct for the interaction rather than each speaker? Notice that Audyssey does this for the interaction of a pair of subs but not a pair of speakers.

Because pair of subs are designed to play everything at the same time always. But L and R can play and actually will play some sounds separately. Two subs are really matched in level and delay only, and then corrected as it would be one sub. You can't do it for any other speaker or their separate responses would be more wrong than their combined response is in cases when they interact.

 

Got it now, Feri - thanks. 

 

You make a compelling point!

This thread has gotten locked into REW which has caused me to order the new USB mic but I have another unrelated question.

I am considering adding either wides or heights (leaning to wides). Is it really worth the expense/trouble? How much improvement should I expect? Some (CraigJohn?) have suggested wides don't work on all material. I would be interested in your thoughts. My primary use of the wides would be movies versus music. Comments, warnings,or recommendations are welcomed. I am currently using an Integra 80.2 (7.2 or maybe 7.4).

Also, how much speaker do I need for wides? Other than matching the timbre of the fronts, how much do they reproduce? can they be the same as my rears/sides?
Edited by audioguy - 1/5/13 at 2:21pm

Well, yes, but there's more to it than that. I should clarify that I also have real subs (dual HSU-15 to be exact), which I bought after I realized that I wasn't happy with the quality of the bass response for HT, in pre-Audyssey days. IOW, I'm not assuming my Mythos are connected by LFE or are 'full range' WRT bass management. And BTW, I have the onboard volume of the speakers set to level-match the 'sub' and 'non-sub' portions of each speaker.

The real question is how the Mythos ST mains, and my CS-8080 HD center, combine their output in conjunction with the actual subs below, around, and above their respective crossover regions to result in the smoothest overall response (and I do test at least three positions with OmniMic, after 8+ position Pro Cals). As my preference is multichannel music, followed by HT, combined response is at least theoretically more important to me than the relationship between each speaker to subs.

My Mythos ST mains have a powered woofer/bass radiator combination, as does my CS 8080 center (the latter upward firing rather than forward, so I have it on an open shelf). Without getting too much into the logistics, in my room, pre-cal, the ST can go down to about 35 Hz @ -3 db, and the center to about 80 Hz--but with dips in the 90 to 120 Hz region.

However, due to placement and overall capability of my Hsus, the overall bass response I measured with OmniMic is smoother if I do a crossover over 60 Hz for the Mythos ST (I use 80 typically) and over 90 Hz for the center (set to 110 currently). Aside from L, C or R vs subs, that has been tested for L/R vs. subs in two-channel stereo (mains small, with subs on), C vs. subs (Dolby PLII Cinema), and L/C/R vs. subs with Mono Movie mode (mono sine sweep, full range, to all three speakers, and bass management sending signal to the Hsu subs). Remember, at least for OmniMic, one uses a test CD that feeds the AVR, and the AVR handles which speakers are activated, as well as the processing mode.

In effect, since crossovers aren't brick walls, my feeling is at least in my setup, the pure two-channel approach (i.e. L vs sub, R vs sub, L vs R) isn't the entire story. Hence it's interesting to see how changing, say, the center channel's crossover or distance impacts my overall bass response. Just looking at C vs. subs wouldn't be useful. And to my ears, the soundstage doesn't sound 'deep' or well-imaged without testing L/C/R for MC music I test.

Thus, if the HDMI output with ASIO4ALL could manage more than two independent channels (i.e, a 'bivariate' approach), it would be more than 'icing on the cake'.

However, it's possible that the OmniMic testing encourages 'incorrect' testing, and the argument that sdurani and Igor are making represents a 'best practice'. Hence maybe reinventing the wheel with REW may be worth the re-education.

A bit rambling, but I hope this explains where I'm coming from, Feri .

@ Keith: why no RC software measuring speaker interactions as sub interactions are captured? Because of a lack of dedicated processing power, and disinterest in rewriting algorithms, why else?

Pity that AFAIK nobody has used 'fuzzy math' to manage speaker interactions the way that Audyssey uses cluster analysis to address multiple measurements WRT its filters. Or perhaps it does but we don't see it.

OTOH, I don't think that modern AVRs are quite up to latent structure models
Edited by sdrucker - 1/5/13 at 2:26pm

@audioguy
Wide and height speakers channels are not included in the original signal mix and thus have to be synthesized by special matrixing algorithms.
Depending on the quality and the contents of the originals source material (clues) this might work more or less.
Edited by gurkey - 1/5/13 at 3:19pm

I know that the height and wide channels are synthsized and I also know that some prefer heights, some prefer wides and some prefer neiither. And some think they work on all material and others dont. I 'm just looking for comments from existing users of either or both.

I just hooked up a pair of Heights to my Denon 4311. The Denon has a 3 way "strength" adjustment (low, medium, high) I'm watching the Bengals-Texans game and definitely notice enhanced crowd noise, and additional clarity when the Public Address announcer speaks. Haven't listened to any music or BD/DVD's yet.
I should note that I'm using the Dolby set up guideline (approx. 3' directly above front left & right speakers) as well as Dolby PLIIz. I 'm also using an inexpensive pair of speakers from a mini-stereo system just to see what content Heights reproduce. So my suggestion would be to hook up wides and/or heights if you have any unused speakers - you can always upgrade later if you like what you're hearing.

hey guys, i have a question, if i buy a new set of speakers, do i need to break-in the speakers for lets say 24 hours and then run auddysey or i can run auddysey right after i hook up the new speakers? will it affect the results?

You will find many differing opinions on this subject. When I purchased new speakers, I did two things. First, I called the manufacturer. They told me no break-in period was required. Second, I did quite a bit of Internet research. Again, the overwhelming results were that for modern speakers, no break-in period is required.

Having said that, who cares? You act as if you are going to do one Audyssey calibration in your life, and you want it to be perfect. The truth is, you will end up doing many calibrations, and by the time you do your last calibration, I guarantee the speakers will be "broken in". Move on, Dude...

 

I use Heights and I love them (my system is movies only).  They expand the front soundstage in an interesting and (IMO) enjoyable way. I dislike Audyssey DSX because it derives the Height information from the L&R channels and also messes with the surrounds in a way I find displeasing. This results in a very front-centric presentation.  I use Dolby PLIIz and much prefer this - PLIIz derives the Height information from the surround channels and to my ears gives a better 'bubble'. As Heights and Wides are non-Reference, YMMV.

 

What Jerry said.

yea but i have the EQ settings from my previous speakers within auddysey, so when i hook up the new speakers, obviously the receiver will continue using the EQ from the old calibration but now there are different speakers in the systsem, so should i calibrate right after i set up the new speakers or do i need to wait like a day or 2 for the speakers to break in?

 

Perhaps you didn't read my response.  Calibrate now.  The benefits of a proper calibration with the new speakers far outweighs the insignificant (if any) impact of the speakers not being broken in.

got it , thanks.

There are a couple of reasons I asked. First, because every so often I see people mention measuring their L&R speakers together. Also, I don't think it is as cut & dry as you describe.

For example: I listen to lots of 2-channel music, and much of the lower frequencies in modern music recordings are the same in both channels (maybe for mono compatibility), with very few recordings that have truly decorrelated bass. Also, the most important content in music recordings, like vocals and instrument solos, are mixed equally in both channels. So a good bit of the time, there will be significant content (significant in amount and importance) being played back as dual mono. In which case, it might make sense to check the interaction of the L&R speakers.

However, I'm not sure how well our hearing correlates with what's being measured. Some of the things we can measure, like comb filtering when two speakers are playing the same signal, doesn't seem to be noticed by our human hearing (otherwise 2-speaker stereo wouldn't have worked all this time). And there is an additional wrinkle when I use surround processing to extract a centre channel, leaving only residual dual-mono content in the L&R channels. In which case, there will be very little interaction between those speakers.

Anyway, just thinking out loud (and probably overthinking it). Like I said, just curious whether anyone has a reason to measure more than one speaker at a time.