"Official" Audyssey thread (FAQ in post #1) - Page 719

In the almost 120 films I've mixed, I can count only one where we didn't have anything in the LFE.... and weirdly enough, the one I am mixing now will only have LFE during the WB logo at the beginning... to be technically correct, however, even if it says "5.1" that doesn't mean it will have information in all 6 channels (it's rare, however, if it doesn't.)

There is usually LFE on most scores, source music, and of course sound effects/design as needed...

I low pass (24db/octave slope) everything I feed to the sub at 120Hz at the console (so do most mixers)... most encoders also brick wall the LFE channel into the encoder..

Noah.... please take no offense to my following comments, but in doing research on the Danley, it amazes me how it can be considered a desirable sub for anyone who is serious about accurately reproducing film sound tracks... there is so much information in the 1/2 octave between 80 and 120Hz it seems a bad choice for anything but rattling the walls and breaking plaster... from the LFE channel we only have a max SPL of 110db.. a product like the Danley is missing out on a lot of what is in the LFE track and accentuating alot of what isn't meant to be heard at the extreme SPL numbers it puts out... just my opinion.

While it might sound cool, there is nothing I see in the specs or frequency response graphs that indicates it is a good match for some one who wants to hear tracks as I do on the mixing stage. (and I have 12 18" subs on my stage for the LFE channel alone (with another 6 handling low end extension to my main LCR's...))

DRC is set to off in my Oppo. I likes my dynamic range.

If "Xternal" bypasses the sub's own crossover network, you should set it to that and let the Onkyo handle the bass management. 2EQ does not create filters to correct the sub's in room response, but it does set the sub level. You should read the Audyssey Setup Guide linked in my signature.

That's the Dolby encoder at 120 Hz. But what happens with a DTS encoder?

[ETA: I found this reference on the DTS Film format: "Prior to data compression, the LFE track is rolled-off above 80Hz, split into two, and combined with each of the two surround channels". So anything in the LFE source above 80 Hz is being cut off.]

Just curious... The commonly regurgitated knowledge (usually from THX) is that most mixers don't put much above 80Hz in the LFE channel for fear of making it too easy to localize. What I've always thought was that even if you're placing sub-80Hz audio in the LFE channel, those sounds can still have harmonics above that which lend them a certain tone but would not be significant enough in level to make them directional. A good example that I've found of this is the bass sweep that occurs in LOTR:Fellowship when Sauron is defeated at the beginning. If you LPF the LFE channel at 80Hz, you totally lose the distinct tone that sweep has when you leave the LPF at 120Hz. Would you say that this is the case (i.e. most mixers self-limiting so the bulk of the LFE is below 80Hz) or is there actually a lot of 80-120Hz audio being placed in the LFE channel that isn't just harmonics of lower frequency sounds?

When I originally installed my Hsu VTF-2 Mk3 and recaled my system a couple of weeks ago, it appeared that a polarity setting of "180" on the sub gave the best response. However, upon recalibrating everything this past weekend with the new boom mic stand (http://www.avsforum.com/avs-vb/showp...ostcount=21516), I find that a polarity of "0" on the sub works best.

Today I received an e-mail from Onkyo tech support responding to my question about whether the 706 was inverting or noninverting from input to output. According to Onkyo, the 706's output is inverted compared to the input. That makes me wonder why the best sub interface would be achieved with the sub set to "0" vice "180". I also noted during the calibration that neither a polarity setting of "0" nor "180" resulted in a speaker phase error for the sub as Chris implied would happen.

Any thoughts on this seeming contradiction of expected results with regard to polarity?

Also, any thoughts on why the Hsu measures closer to the listening position than it actually is even though the Guide was followed exactly and there were no vibrations present in the room that could have been picked up by the mic?

I really can't speak for other mixers and all there habits... but I never lower my filter from 120.

Most sound editors don't deliver discrete elements that are designed to only for the LFE... a lot of what ends up there is synthesized on the stage.. some mixers like to directly send music into the sub (I always use a synthesizer to create the LFE for music.)

I think there is an disconnect in most conversations about directionality in how it relates to LFE and bass managed frequencies, which are obviously, two different things...

Directionality isn't desirable in bass management since the upper part of the spectrum is coming from a very localized source... hence the recommended THX crossover of 80Hz...

LFE is in and of itself a localized "speaker..." Since it is a controlled channel (bass redirection isn't malleable, i.e. you can't dynamically change it as a program is playing) it will always but localized just like a main channel, which IMO isn't a problem.

No offense taken.

I do think you're putting a bit too much importance on the DTS-10's unsmoothed freq resp; whose raggedness is apparently largely inaudible because our ears behave as 1/6 (or is it 1/3) octave integrators.

Have you read what people have said about its sound?

I also have a pair of Maelstrom 18's in the back of the room, which hopefully will smooth things out, as well as a QSC DSP30 to pre-tame the DTS-10 before running Audyssey.

I suspect Audyssey see's this as more of a "distance" issue. Also, for some reason, Onkyo AVR's tend to be less prone to producing to "phase warnings" than say Denon AVRs

WRT the Sub's phase switch, the only thing you need to worry about is what's happening at the desired crossover point vs. the mains (pre Audyssey run.)


How much closer? ... again this could be an artifact from the phase switch "experiment."

Did you read the detailed post on my calibration? It is linked in the post you are quoting from.

Thanks, just to clarify, you're saying to set to Xternal instead of Direct?

If Xternal bypasses the sub's own internal crossover network, yes. And read the Guide.

I assume that you are refering to the half space FR charts taken outdoors, or perhaps the close mics? You do know that most speaker manufacturers publish little to no real information on their products at all? Including many of the "pro" companies and the ones that do post nothing comparable. The DTS-10 is fine up to about 100hz and really covers 10-100hz in a "relaxed" manner that very few LF systems can. Yes it does have a huge notch at 105-120hz. LFE specific content in that range that is forefront, or even notable in the mix seems rare to me.

From what I've seen using spectrum analyzing software the LFE channels content is usually exhibiting a pronounced roll off well prior to 120hz presumably because an abrupt cut off of content at the 120hz brickwall is not going to sound natural. Obviously you have more experience in this area though. It looks to me like normally the content present in the LFE channel is started rolling off at about 80hz. Is that not the case?

110db? Theoretical max SPL from the LFE channel with redirected bass from all other speakers to the subs at calibrated REF level at the listening position is a tiny bit over 121db (121.24 I believe) Obviously this will never happen in reality with actual content, but 118-120 might not be out of the question on some soundtracks if you choose to listen that loud.



Agreed. Given the way that the human ear responds and the dominating affect the rooms acoustics will have on the bass response, an incredibly flat anechoic response seems less important than other properties especially in these days of cheap dsp eq.

If the sub is being fed from the processor output, its built-in crossover should be set as high as possible or, if possible, completely bypassed to let the processor handle all the filtering.

I have used audyssey on my onkyo 1007 with some success to set up a 9.1 system with height speakers, but never with a tripod. Today i got my hands on a good tripod, but i have a question. The subwoofer is directly behind the couch (a pb13 ultra) and facing it. Should i set up the tripod to be on the couch at ear level, or should i just move the couch out of the room and put the mic at ear level that way? what difference would it make? this is the best location in the room for the subwoofer, so i am keeping it there regardless

Correct.. DTS for the cinema is encoded as a 5.0 format, and everything in the surrounds below 80Hz ends up going to the subs.

Thanks for your comments, Ricci.

I'll go w/bigger boxes for the Wides to get them down to 100 Hz.

I also forgot to emphasize that we're comparing the DTS-10's unsmoothed response to everyone else's smoothed ones.

I'm sure if people saw Audyssey's unsmoothed ones they'd be up in arms, though unappropriately so because of the aforementioned smoothing our ears/brains do.

All I am saying about that sub (and in reading the commentss about it's perrormance and looking at the graphs) is that it seems to produce a more visceral, rather than reference, playback... Noah was the first to say it wasn't very accurate above 80Hz, and I was simply saying that if someone's primary concer is faithfully recreating a sound track, it doesn't seem to be the best choice...

That's not to say some might prefer what it sounds like in their space.

When SPL'in during mixing (89-91db for theatarical, 85-90 for home theater mastering) the max SPL of the LFE/.1 channel is ~110db since there is only 20db of headroom above -20dbfx/0Vu...

The LFE channel and sub output are two differnt things, and your math is correct when talking about the later.

You don't want to move furniture and you definitely don't want to put the tripod on the couch. I'm sure you located your sub where you did because

a. It sounds good there and

b. it vibrates the couch.

Well, that vibration can potentially wreck havoc when doing sub measurements as the couch vibrations will get transferred to the Audyssey mic and cause problems.

Your best bet is to borrow/purchase a boom mic stand and camera adaptor (do a search on those terms in this thread and they should pop up as they are discussed quite a bit). Then you need to read the Audyssey Setup Guide (a link is in my sig) for the proper way to use the mic stand and perform a calibration. Good luck and have fun.

I had some time today so I found my rat shack meter and put it to work. Found some interesting results:

Dynamic EQ on, LFE trim at 0dB, Oppo DRC Off (tried auto vs off but did not get any different results). Sub still tuned to 20Hz for now.

Receiver test tones at 0dB volume showed all channels at 70dB (+/- 1dB) with the exception of the sub which was at 73dB.

Then I used the test tones on the AIX Records disc which came with the Oppo. At a volume of 0dB, the fronts (L,C,R) were at 88dB and the L & R Surrounds were at 89dB. The sub, however, was at 94dB, 6db hot. At a volume of -12dB the sub was 9dB hot!

I also ran the Avia tones and got almost identical results.

So, I turned Dynamic EQ off and found the sub to be still 6dB hot at 0dB, but only 5dB hot at -12dB, as compared to 9dB hot with Dynamic EQ on.

I like the sound better with Dynamic EQ on, so I lowered the sub level by 5db and no longer bottom out the sub. Just for fun, I watched the needle jump to around 110db a few times in the scenes where the sub bottomed out prior to the adjustment.

I'm not sure exactly what Audyssey and Dynamic EQ do as I'm not an engineer, but, after cutting the sub level by 5dB, I saw 93dB at 16Hz during the subwoofer frequency sweeps at a volume of 0dB and it pretty much stayed there throughout.

Yes, I have read about Audyssey being more accurate than a SPL meter and how meters suck with subs but using my meter helped me solve my problem.

I'm back in crazy love with my SVS again! Thanks to everybody for your help!

Curious...are you saying that HE specifically shouldn't put tripod on teh couch (because of his sub location)? Or are you saying no-one should?

Following the guidelines document for location of MIC, I did 3 readings with the tripod on my couch. I do not have a boom tripod.

I guess if that is the case, then I wonder what the 8 recommended locations would hcange to, or maybe I should say, what 3 locations should I use in lieu of setting it on the couch.

right in front of the couch is fine, the 1 ft difference isn't going to be the end of the world...

the point is to get a nice spatial sampling of the acoustic problems in the listening space. Chris has stated over and over that you shouldn't get all worked up over the precision of the measurement points. In your case, running MultEQ XT (since you mention 8 points) you can easily run the 7th/8th positions right behind the couch also so you will have effectively sampled the listening area.

Total noob here. I've tried following the Official Audyssey thread and have read the Audyssey Setup Guide by giomania. Some of the technical discussions just flew over my head. I have the Integra 7.8 and tried using its Audyssey setup for my 7 speakers and 2 subwoofers system, but am not sure if I did it right. First, I used a SPL meter to adjust each subwoofer separately to 75 db output level by turning the volume slightly past it midway point (about 1:00 position). My subwoofers only have a volume knob and they are situated in the front equal distance apart from each other and my seating area. Then, I ran the Audyssey setup for all 8 locations. In the results, (i) the speakers' distances were correct, (ii) the crossovers varied all over, so I set all the speakers to 80 Hz because I have Onkyo THX speakers and Integra indicated 80 Hz for THX, and (iii) for the SP level, all the speakers ranged within +/- 2 dB, but the subwoofers were at -6.5 dB. Is this about right or way off? Can I turn down the subwoofers' volume knob down and bring the Integra SP level setting closer to 0 dB? Or will this throw off the Audyssey calibration. So, should I leave it as is or should further adjustments be made and how?

When I played the Transformers 2 and Black Hawk Down Blu-rays, it sounded low at -24 dB volume. I had to crank it up to -10 to get decent movie sound. Isn't that kind of high and too close to 0 reference? But, when I played some redbook CDs, the sound was really loud at -24 dB and I had to turn it down to -32 dB for more bearable listening. Why is there such a big difference? Is this normal? Are CDs recorded much hotter than Blu-rays? My system is mostly for movies so I would prefer it the other way around. I understand reference level is different from preference level. But, the question is have my efforts resulted in the proper reference calibration? How would I know?

Any comments or suggestion would be much appreciated. Thanks,

Wow ... that thud you just heard was my interest in your "problem" going poof. Good luck.

Audyssey Pro question. While I think I know the answer to this, I would like to be sure. Since Pro (on an Onkyo 885) allows me to assign different target curves to different speakers, could I set the target curve for L, R, C, LS, RS to flat in the bass but have the sub target curve be elevated at some frequency. I'm pretty sure the answer is "no" but it doesn't hurt to ask!

Huh?


You posted this in response to my two questions:


I asked the following question, because the answer to "How much closer?" as well as other relevant information is contained in the linked post and I wasn't sure you saw it.


For some reason you found my question insulting. Oh, well. Thanks anyway.

The Guide says this:

B. Mount the microphone on a boom arm microphone stand with an adapter or a camera tripod.

1. While more expensive, the floor-standing boom arm microphone stand allows more precise microphone placement and the possible reduction or elimination of mechanical vibrations, which can affect low-frequency measurements. The boom arm microphone stand rests on the floor, while a camera tripod typically rests on the seat(s).

a. Search the web for On Stage CM-01 to see one microphone stand adapter.

I and others have taken flak from people about placing the mic on the couch seatback or placing a tripod on the couch/having any other mic mounting device touching the couch.

After all this time the same questions.

Just place the mic in free space avoiding any close reflecting surfaces: seats, couches, walls etc. And avoid off axis measurements with respect to the front main speakers.

A tripod works very well.

Joe

Seems like a bit of a Catch 22; if you're going to sit on the couch and you're supposed to put the mike where your ears are, then the mike will necessarily be near the couch back.

Unless moving the couch back out of the way (as opposed to forward where the front speakers would reflect off of it) is considered acceptable.

Audysssey is not designed to measure a specific point in space. The goal is to provide a balanced, ROOM corrected solution over an area that suits your listening space.

This thread is almost three years old. Seems to me that some, perhaps not you Noah, are old two channel "head in the vice" audiophiles with the misconceptions that wind up discussed here. I used to be part of that silly group. It never really made any sense. But way back when it seemed reasonable with only two "perfect point sources" radiating. Complete nonsense.

5.1, 6.1,7.1 and now even more. Any way to have perfect coherence at one "sweet spot" ? In any room, under any circumstances?

Some of us have only needed one or perhaps a second run of Audyssey to confirm.

Now that I think about it the rather large Fraser Fir Christmas tree now placed in the back of my HT room is probably screwing up the back channel radiation. Don't want my holiday guests to suffer from poor audio.

Ah, heck none of them can tell the difference between a dB and an Hz. I'll leave it alone.

Happy Holidays.

Joe