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Trinnov Altitude / JBL SDP-75

DonH56

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Starting a thread to discuss these high-end processor twins. Our own @Kal Rubinson was even impressed and several of us are owners. I have had one for several months but only set it up a couple of days ago (busy, intimidated...)
 
From other threads:
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Somewhat off-topic, I finally got my SDP-75 set up yesterday. Still need to get the Harman tweaks loaded (apparently they do that remotely), and do some fine tuning, but so far it seems nice. :) Ain't shipping to Amir, don't want to know... :) But the spec sheet is decent for an AVP. Not as good as many of the DACs he has tested, but they don't do all the processing this thing does. Documentation needs some work...

Wasn't really expecting much change in sound coming from Dirac Live to their Optimizer but it sounds better to me. Purely expectation bias, but the measured impulse response is better than before, and the subs seem to have integrated well where before I had to spend hours dialing them in.

I had forgotten just how much I hate mucking around with all those cables. I have a massive clean-up job pending to dress the cables that I just yanked out of my old processor and ran around to the new.
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North_Sky said:
Trinnov or Dirac Live better?

Don't really know. The simulated impulse response from Trinnov is better than Dirac Live measured but that is apples and oranges. Dirac Live does some things well, but fell behind my manual tweaking of my old Pioneer AVR, both frequency and impulse response. After tweaking Dirac Live settings for a while I got them to be comparable. Some of it may be Emotiva's implementation of Dirac Live (been debated quite a bit on other fora). I never could tell which I preferred and did not personally hear a big difference from my heavily tweaked MCCAC settings to tweaked Dirac Live setup. I did think I noticed a difference with Trinnov but don't really trust them. My initial impressions are that the center is more "present" (so probably louder) but the overall levels are higher so subjective impressions are pretty worthless. Bass actually seems a little less but I have done almost no listening and I have not made any measurements (and probably won't for a while -- the virus that has most folk at home has my wife and I working gobs of extra hours so free time is limited). I withhold any sort of judgement until I have some measurements.

Long-winded way of saying I don't know.

Last night I managed to get my Harmony set up for it -- only took one day to get fed up having to handle four remotes to do things.
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SFM (Harman) requires a miniDSP or on-site calibrator to implement (mucho $$$). I have enough channels to handle the subs in the unit, but not enough funds (that I can justify) to have them come out and implement it (plus they are on travel lock down for COVID-19 so it would be later this summer at the earliest). I did not realize it required on-site personnel to do SFM in the unit, vexing.

If I get a miniDSP I could compare SFM to MSO. That would be interesting, and something I'd love to do, whenever my work hours become less than insane.
 
You don‘t need the Mini DSP. If you have 4 channels available, you can create sort of a MiniDSP within the Trinnov:

1588704006588.png



1588704142680.png
1588704092542.png
 
The issue with these h/w devices is the number of filter taps available that limits the the effectiveness of their low frequency correction.
As a maths example, the miniDSP 2x4 HD product datasheet talks about 4096 taps. But this is the total number. For 4 channels you have 1024 taps each channel available. The frequency resolution of a 1024 taps filter @ 48 kHz samplerate is 48000/1024 = 46.875 Hz. So e.g. below 100 Hz there are just 2 frequency bins at 46.875 and 93.75 Hz. This seriously limits the control over the lower frequency range, and especially right where you need it.

If I remember, the Trinnov has 4096 taps (better than miniDSP 2x4) with a maximum filter length of 100ms. I believe the JBL SDP-75 is similar...
Whereas Acourate or Audiolense has 65,536 or even 131,072 filter taps and 500ms to 700ms of low frequency control at 10 Hz (user can set). The difference is both measurable and audible...

There also is an issue relative to Dirac Live, which uses IIR filters in the low end, which means no excessphase correction capabilities. i.e. it has no way to control standing waves at low frequencies. This is why we see similar graphs where the low frequency still has a lot of peaks and dips in the (measured) corrected response.

Don't get me wrong, not being critical of these devices. When it comes to room eq/correction, there are technical limitations one should be aware of so expectations can be realistically set.
 
You don‘t need the Mini DSP. If you have 4 channels available, you can create sort of a MiniDSP within the Trinnov:

View attachment 62014


View attachment 62017View attachment 62016
That's what I thought, but the JBL version disables/hides PEQ. I do not understand why, but there it is... Ironically, it allows you to load speaker-specific AEQ curves, so it is using PEQ in the background, just does not give the users access. Maybe as a group (consumers at large) we're too stupid so screw it up and thus it is a support nightmare for them? Dunno'...

At any rate, my option for now is a miniDSP or somethings similar.
 
The issue with these h/w devices is the number of filter taps available that limits the the effectiveness of their low frequency correction.
As a maths example, the miniDSP 2x4 HD product datasheet talks about 4096 taps. But this is the total number. For 4 channels you have 1024 taps each channel available. The frequency resolution of a 1024 taps filter @ 48 kHz samplerate is 48000/1024 = 46.875 Hz. So e.g. below 100 Hz there are just 2 frequency bins at 46.875 and 93.75 Hz. This seriously limits the control over the lower frequency range, and especially right where you need it.

If I remember, the Trinnov has 4096 taps (better than miniDSP 2x4) with a maximum filter length of 100ms. I believe the JBL SDP-75 is similar...
Whereas Acourate or Audiolense has 65,536 or even 131,072 filter taps and 500ms to 700ms of low frequency control at 10 Hz (user can set). The difference is both measurable and audible...

There also is an issue relative to Dirac Live, which uses IIR filters in the low end, which means no excessphase correction capabilities. i.e. it has no way to control standing waves at low frequencies. This is why we see similar graphs where the low frequency still has a lot of peaks and dips in the (measured) corrected response.

Don't get me wrong, not being critical of these devices. When it comes to room eq/correction, there are technical limitations one should be aware of so expectations can be realistically set.

Yep, when it comes to filters size indeed does matter. :D

Capture.JPG
 
The issue with these h/w devices is the number of filter taps available that limits the the effectiveness of their low frequency correction.
As a maths example, the miniDSP 2x4 HD product datasheet talks about 4096 taps. But this is the total number. For 4 channels you have 1024 taps each channel available. The frequency resolution of a 1024 taps filter @ 48 kHz samplerate is 48000/1024 = 46.875 Hz. So e.g. below 100 Hz there are just 2 frequency bins at 46.875 and 93.75 Hz. This seriously limits the control over the lower frequency range, and especially right where you need it.

If I remember, the Trinnov has 4096 taps (better than miniDSP 2x4) with a maximum filter length of 100ms. I believe the JBL SDP-75 is similar...
Whereas Acourate or Audiolense has 65,536 or even 131,072 filter taps and 500ms to 700ms of low frequency control at 10 Hz (user can set). The difference is both measurable and audible...

There also is an issue relative to Dirac Live, which uses IIR filters in the low end, which means no excessphase correction capabilities. i.e. it has no way to control standing waves at low frequencies. This is why we see similar graphs where the low frequency still has a lot of peaks and dips in the (measured) corrected response.

Don't get me wrong, not being critical of these devices. When it comes to room eq/correction, there are technical limitations one should be aware of so expectations can be realistically set.

That is some good info, Mitch, thank you! I had not thought about the tap lengths -- what little real-world IIR/FIR filter design I have done has not been DSP-based and at such high frequencies that many taps wasn't practical to implement. And my few graduate DSP courses were long, long ago (but in this galaxy). But your comments resonate (see what I did there?) as MCCAC had phase adjustment I could tweak, along with the phase adjustment on my subs, that made it a lot easier (not easy, mind) to dial them in than with Dirac Live.

Need to dig out your book and look again, pick up Acourate or something... Of course, now I'd fear wasting a bunch of moola on this new toy. I may hate you yet, Mitch, despite you being such a nice guy and all... :)

How important are the very long lengths (and correspondingly long times) in smaller rooms? Though Trinnov is coming from mostly large spaces so you'd think they want even more...
 
You can always try your best not to peak:p

Been doing that all my life, rather successfully in fact, or did you mean "peek"? :D
 
Starting a thread to discuss these high-end processor twins.
Sure, and make all us poor folk green with envy.
Thanks a lot!!! JK
I'd really love to see some measurements and if either beats the mid-fi stuff by a large margin. ;)
 
I'd really love to see some measurements and if either beats the mid-fi stuff by a large margin. ;)

Go. Away. :)

The feature sets are a little different but the HW in both units is the same. Mine is B-stock but recently upgraded (a dealer return due to the HDMI problem they had last year so practically brand new plus a new HDMI board).

The past few years a combination of fantastic deals, mainly blems and B-stock units, some good bonuses, and a very understanding wife ("just get it before we retire") has netted me a system an order of magnitude beyond anything I ever dreamed. The thing I lack is any time to enjoy it...

This current episode has me thinking becoming a local setup/calibrator-type guy could be an interesting retirement job. I did that kind of stuff in college so come full-circle. My local dealer is amenable.
 
That is some good info, Mitch, thank you! I had not thought about the tap lengths -- what little real-world IIR/FIR filter design I have done has not been DSP-based and at such high frequencies that many taps wasn't practical to implement. And my few graduate DSP courses were long, long ago (but in this galaxy). But your comments resonate (see what I did there?) as MCCAC had phase adjustment I could tweak, along with the phase adjustment on my subs, that made it a lot easier (not easy, mind) to dial them in than with Dirac Live.

Need to dig out your book and look again, pick up Acourate or something... Of course, now I'd fear wasting a bunch of moola on this new toy. I may hate you yet, Mitch, despite you being such a nice guy and all... :)

How important are the very long lengths (and correspondingly long times) in smaller rooms? Though Trinnov is coming from mostly large spaces so you'd think they want even more...

Haha :) I would suggest the smaller the room, the more low frequency excessphase correction is required to smooth out the low frequency reflections. i.e. typically the smaller the room worsens the peaks and dips so you get +20 dB or more SPL variation at low frequencies below Schroeder. Of course, room ratio plays a major role as well as size.

As far as the h/w devices are concerned, the filter tap limitation can't be overcome as it is fixed by the DSP devices being used.

The other issue is IIR versus FIR. Unfortunately, IIR filters (PEQ's Biquad's, whatever) don't have any excessphase correction capabilities at low frequencies and therefore are not the best design for "room eq/correction." So it is a double whammy in the low end, not enough filters taps and of the wrong filter type...
 
Haha :) I would suggest the smaller the room, the more low frequency excessphase correction is required to smooth out the low frequency reflections. i.e. typically the smaller the room worsens the peaks and dips so you get +20 dB or more SPL variation at low frequencies below Schroeder. Of course, room ratio plays a major role as well as size.

As far as the h/w devices are concerned, the filter tap limitation can't be overcome as it is fixed by the DSP devices being used.

The other issue is IIR versus FIR. Unfortunately, IIR filters (PEQ's Biquad's, whatever) don't have any excessphase correction capabilities at low frequencies and therefore are not the best design for "room eq/correction." So it is a double whammy in the low end, not enough filters taps and of the wrong filter type...

Got it. Trinnov/SDP-75 use an Intel processor inside, not a standard DSP chip. So they could do more... But I may be misremembering or misreading the literature I have seen.

Understand on the IIR/FIR issue. Trinnov has both, as they are mentioned and seen in the GUI and you can tweak their parameters, but I am not sure exactly where/how they are implemented in the system. Have to dig some more, but it is likely there are no real details provided to consumers. I do know they use PEQ to smooth the bass, and that is almost certainly using IIR bi-quads or similar (FIR's would be tremendously long as you said), so I think you are spot-on.
 
Got it. Trinnov/SDP-75 use an Intel processor inside, not a standard DSP chip. So they could do more... But I may be misremembering or misreading the literature I have seen.

Understand on the IIR/FIR issue. Trinnov has both, as they are mentioned and seen in the GUI and you can tweak their parameters, but I am not sure exactly where/how they are implemented in the system. Have to dig some more, but it is likely there are no real details provided to consumers. I do know they use PEQ to smooth the bass, and that is almost certainly using IIR bi-quads or similar (FIR's would be tremendously long as you said), so I think you are spot-on.

With the larger number of taps and using FIRs at LF delay would increase and that would make lipsync hard to get correctly.
 
With the larger number of taps and using FIRs at LF delay would increase and that would make lipsync hard to get correctly.

That's the problem and probably why FIR is rare in AVRs
 
With the larger number of taps and using FIRs at LF delay would increase and that would make lipsync hard to get correctly.

Makes sense... Most systems I have seen do not delay the video as there is usually so much more delay in video processing that audio always "hits" first. Stick in some 100 ms FIR filters and likely that is no longer true... Where I have run into latency issues in audio is on the recording side or DAW (digital audio workstation) when you introduce filters in one channel and all of a sudden transients get a little "smeared".
 
The past few years a combination of fantastic deals, mainly blems and B-stock units, some good bonuses, and a very understanding wife ("just get it before we retire") has netted me a system an order of magnitude beyond anything I ever dreamed. The thing I lack is any time to enjoy it...
Understood, your rig over there is my dream system also, your my hero man.
But dig this, you better slow down a bit, if you should keel over and croak, guess who'll be knocking at your door to give his sympathy to your wife? Widows always need consoling and a shoulder to cry on. :eek::p
 
Moving some stuff from the initial thread and adding some waterfalls to illustrate the effectiveness of long filters in small rooms (mine is 4 x 5 x 3 m):

1588710755097.png


Trinnov Basic

1588710835739.png


Trinnov + MSO

1588710856670.png


Audiolense

1588710885896.png
 
Moving some stuff from the initial thread and adding some waterfalls to illustrate the effectiveness of long filters in small rooms (mine is 4 x 5 x 3 m):

View attachment 62045

Trinnov Basic

View attachment 62046

Trinnov + MSO

View attachment 62047

Audiolense

View attachment 62048

Cool stuff, Ollie. In my room, the LF -3 dB point is/was around 7 Hz, using MCCAC or Dirac Live, after tweaking (mainly to work out a 30 Hz null, did not muck around below that, so it's cabin gain in my modest room and fiddling with the four little subs). No idea how Trinnov did yet. I plan to work with Harman (they will do some basic stuff remotely) and twiddle a bit before I get around to measuring again. I think some of the filter settings could be fine-tuned before running the optimizer again.
 
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