R972 Trinnov User Notes - Page 16

If it's not too much trouble could you post the before and after impulse measurement graphs of those measurements?

I'm interested in seeing the results of the first reflections and how well Trinnov takes them into account.

Thanks

Curt, the time on the original graphs is 300ms. It's kind of hard to see, but on the top right there is "300ms" in very small print.

Here is the same graph with 0-20ms. Hopefully this will help.

And here's another with 0-20ms but only 20-200Hz



It's interesting to compare the decay at ~57Hz to other frequencies

Here's the noEQ

And here's both overlaid:

Thanks for the graphs.Do you have any of the impulse response?

I am afraid I lost all my measurements as my computer lost power and I did not yet save the results. It will probably be a few days before I can measure again.

Steven, did you want a specific frequency for the IR? I can have no filter, or 63Hz, 125, 250, 500, 1000, 2K, 4K, etc.

Here are some filtered IR at 250Hz, 0-250ms

no EQ, no Remap:


flat EQ, no Remap:

Thanks amt.

Just a question,are you taking the measurements from the same exact position as the center of the Trinnov mic for every measurement?

Could you adjust the impulse graphs to display the full frequency range and zoom in the graphs to around 150ms?

Steven, I am trying to get the 2 microphones as close as possible to the same position, hopefully with no more than an inch difference in any direction. The Trinnov and Dayton microphone are not placed at the same time. The Dayton microphone is calibrated and that calibration is used in REW. The Art Dual Pre USB DAC is also measured in loopback and its correction is also applied in REW.

I forgot to mention that these new measurements (the IR graphs) are with my surround speakers moved to front L & R. I did this because I wanted to avoid any possible issues with bipolar design that the DefTech BP30's have. These are quite old 2-way Paradigm speakers with 1" dome tweeter and 8" woofer. I have not posted the FR graph yet, but it's pretty obvious these speakers do not go as low as the BP30's (single 8 inch vs 4 x 6.5 inch woofers).

I should be able to post the graphs you asked for in a few hours. I am also trying to get a measurement of the preamp out to see what the actual correction looks like.

Here's 0-150ms with no frequency filter applied:


Here's just first 35ms with 1000Hz only:


Both of these graphs have noEQ (blue) and FlatEQ (purple) overlaid

I was trying to a calibration today. Noticed few weird results. Each speaker was going to max tries, 9 bursts. I tried it twice, no change. I let it finish all the speakers. Strangly it got the distance for all the speakers, but none of the horizontal or vertical angles. What could be wrong?

I have done calibrations before with this setup, never had an issue.

Edit: Never mind. Shut off the receiver, reconnected the mic. started the unit again. That took care of it.
Edited by adude - 12/7/12 at 10:13pm

Nice graphs! The preamp out with the actual correction filter response would be a great idea.

Also,if you could take the same measurement file you used for the first unfiltered impulse response and show the noEQ and flatEQ using the "%FS" mode instead of the dBFS, using the same 150ms windowing, that would be helpful as well.

Hey guys,
I just got my R972 and want to set it up for 7.1 setup. I know there is a user guide but unfortunately it didn't help me much. Is there a link or document or a post that explains how to setup 7.1 with it?????
thanks

Connect your speakers and you're good to go. Just make sure Zone two is off. Many recommend doing a factory reset before playing and I found if/when I got crazy Optimizer results (speaker distances, etc) doing another reset would resolve it.

Friends,

I just ordered 972 from A4L. I am planing to use it as a 2-channel pre-pro.

I have 103db Horn speakers with dual passive subwoofers. (140Hz x-over) I can run them as full range OR sats with dual subwoofers.

Any recommendation? I did read the user notes but not clear about my set up.

AS

I would like to thank Curt for the Trinnov notes as well as everyone who has posted in this thread. In the past 3 1/2 months I have bought 3 R-972s and am VERY happy with the sound quality. The speakers really do seem to disappear after properly running the Trinnov calibration.

Thanks again everyone.

I have taken some new measurements with pre-out's also measured. The results are kind of interesting.

The first graph has 5 measurements, 3 towards the upper half that are in "loopback" -no microphone. I made sure these did not have the microphone calibration applied. This is essentially the correction Trinnov is doing. The colors are:
red: R972 in pure audio mode (no Trinnov)
magenta: R972 with position 1 selected, but EQ set to none
blue: R972 with position 1 selected and EQ set to flat

The remaining 2 are in-room measurements:
yellow: R972 with position 1 and EQ none
green: R972 with position 1 and EQ flat.

Note that the scale for SPL for pre-out and in-room may not be exactly the same.

The smoothing is set to 1/12 octave for the in-room measurements in this graph. The loopback (pre-out) measurements have no smoothing at all. Notice how smooth the loopback corrections are. Also notice how they get a little "fuzzy" after 10KHz.


That got me thinking, maybe this version of Trinnov calculates its corrections based on a certain smoothing factor. Perhaps due to a limited number of filters, or just because they know trying to correct in a higher resolution doesn't really make it sound any better. So I played with the smoothing on the in-room graphs to see if I could get one to correlate very closely to the pre-out corrections measured. What I arrived at was 1/3 octave smoothing. I'd say that's a pretty close correlation!


And here is a close-up of the "fuzzy" lines for the pre-outs, 15-20KHz. I doubt this is intended correction, but possibly some kind of noise or artifact of the correction. Note that pure audio is much cleaner than the no EQ and Flat EQ. Maybe the extra A/D and D/A conversion is part of it (does Pure Audio skip the A/D and D/A?)

Nice!

I doubt that it's a result of having a limited number of filters at least above 300hz.The R-972 uses 1024 FIR filter taps from around 300hz up.By doing that and using IIR (parametric) filters below 300hz they are using up less computational resources that would be needed to correct the bass range and require more FIR filter taps.It's part of their quoted "compensated with the most efficient and best-sounding compromise" method.The R-972 still doesn't have enough computational resources to correct the subwoofer channel as it would have needed even though it's using the less computational intensive IIR filters there. If anything you would see some seriously fine over correction going on if they were using the full filter resolution over 300hz.I think they are smoothing the response prior to correcting it to avoid the over correction like you mention.

This is a similar looking result to what Audyssey XT32 is now doing past the Schroeder frequency vs. what XT was doing,but they are using other efficient methods of "squeezing resolution" and determining where it's more effectively needed (mostly in the bass range because of the sheer amount of filter taps required the lower you go) by using strictly FIR filters that are tweaked using their proprietary methods.

Nice work!

Did you ever get a chance to look at the impulse response before and after correction measurements you took using the "%FS" scale vs. dBFS using REW?

I would still be interested in seeing them if you could post them.

Thanks for the feedback.

I am not sure if this is exactly what you want:

no EQ:


flat EQ:


There certainly is some difference between the two.

AS, I think it will come down to personal preference on what to use. My concern would be losing some of the stereo effects from mid-bass with a 140 Hz crossover when using single sub channel.

Hello guys,
Just bought R972 . I have 7.1 setup in the room which is ideal for sound purpose (no obstacles in between speakers. During calibration, I heard exactly 3 loud sounds coming from each speaker. So this tells me that everything is fine.
But when I am watching movies, I run into issues. I used batman, Lord of the rings (all blueray) for testing purpose. I am using PS3 to watch movies. All are related to surround sound options,
When I am watching, I only have VS Wide, VS Ref and Multi PCM available. But when I pause movie, I can see a few more (PL2 Movies, PL2 Game, New 6 Cimema new 6 Music, natural, theater, hall, stadium...). I Manual, I see many Dolby and DTS options but none are available to select.

Is it PS3 doing it? I did check PS3 audio menu and it does show that it supports Dolby and DTS options.
Please help.

Yep,that's what I wanted to see and there definitely is reflection level reduction going on.I've never seen any Audyssey graphs that showed that type of result outside of there own marketing graphs.

Thanks for taking the time and effort to post these graphs.I believe your probably the first to show such graphs of Trinnov in this manner.

Very nice work!

Did you try setting the PS3 to output bitstream?

No because based on this article http://www.avforums.com/forums/av-amplifiers-receivers/984906-attempt-explain-high-definition-audio.html

PS3 should be set to Linear PCM instead of bit=stream. is that article incorrect and should PS3 be set to bit-stream????

I am trying to use 3D Mapping which everybody is saying is the best way to produce sound. During calibration, each speaker produced 3 sounds which guarantees that each speaker is fine. But when I switch to 3D mapping using following option

Setup ==> Quick Audio Ref
Trinnov Position ==> From None to 1
Trinnov Spatial Mode ==> 3D Remap
Trinnov Remmaping ==> Cimena

I can't hear any sound from Sub-woofer and felt like all surrounding speakers are not producing sound as much. Here is the table after calibration

Speaker Level
Front L 19dB
Center 18
Front R 19
SurrondRight 14
Surround Back Right 18
Surround Back Left 19
Surround Left 18
Subwoofer 5

Subwoofer level looks way off. What should I do?
Thanks

When you send LPCM from PS3, you should see Multi-PCM on the R972. That is the "correct" thing. When doing this there is no way for the R972, or any AVR for that matter, to know if it is a TrueHD or DTS-HD before being decoded. When you pause, my only guess is that either the PS3 is sending just 2 channel PCM, or not anything at all and the R972 defaults back to stereo.

Some PS3 players can do bitstream, but I am not sure exactly which ones do. IMO, there should be absolutely no sonic difference between the two.