Xtr Filters - Why do they sound so good?

I am pretty sure that during the filters initialization the GPU is not involved, just the CPU. Then once playback starts the GPU is now active. I have a 6700K processor with a 1060 card and I cannot do the non-2s XTR filters at 512, the 2s are fine as is every other filter except the non-2s xtr.

Only thing I have that can do non-2s xtr filter to DSD512 is i7-6950X CPU with 4x DDR4-2400 CL12 RAM… And then it is already running all 10 cores around 90% load…

I want to see how the new Ryzen 9 with 16 cores will do and what will be the price…

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Thanks Jussi,

Can you tell us some more about the xtr filters, where they fit in terms of length, phase change, bandstop, frequency and time domain, pre and post ringing etc. Why are they so computationally intensive ?

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Only the Chinese with their Super Computers have heard it.
And they say: Sounds just fantastic!

I created it for people who like Chord Dave -style filters. It is about 5 times longer than poly-sinc and thus about 5x heavier. Offered in linear- and minimum-phase variants. Stop-band attenuation exceeds needs of 40-bit PCM, being over -240 dB. Normal poly-sinc filters are created to reach excess of 32-bit PCM resolution (> -192 dB) stop-band attenuation.

Since high-rate modulators can reach peak SNR higher than 32-bit PCM resolution at audio band frequencies, I thought it could be useful…

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Coincidentally, the June issue of Stereophile just published a review of the Chord DAVE. In the digital filter measurements, check out the length of that FIR ringing, symmetrical both pre and post. The MQA advocates must be rolling in their graves.

AJ

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Well there you go, looks like I enjoy the sound of pre-ringing !

I had read that poly-sinc-xtr had more than even poly-sinc. Maybe all that ringing gives it that full and euphoric sound quality I like. :blush:

It’s interesting to read the rest of the DAVE review that Andrew linked above. Rob Watts talks about his goal with filtering, which is to enable the most accurate reproduction of transients.

Also Roon user @JOHN_COULSON gets a mention for writing about Stereophile Encore. Nice one John !

I guess no one told him he was suppose to use mp for that. :slight_smile:

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FWIW I can’t hear a great deal of difference in transient reproduction using the mp and lp versions of the xtr filters. I can hear better focussed soundstage with the lp version, so it’s now my new fave !

I run the Auto Rate; poly-sinc-xtr-mp-2s, ASDM7, SDM = DSD256.
My little Intel NUC7 i5 (2cores) works at around 50% load. No so bad, still quiet.
So, I don’t get why people need super-computers for this?
OK, with DSD512 the i5 (15W TDW) would maybe not enough, but the i7 should be plenty.
Just my 2 cent!

It is mostly when people want to run that with non-2s filter variant. Then it gets heavy…

I got my new DAC a couple days ago. Immediately went DSD128 and poly-sinc-xtr.

I’m now noticing a little too much left and right focus and slightly recessed center image. My new DAC has spectacular specs. That euphoric like widening and richening might no longer be the right choice.

Might have to try poly-sinc-ext again, it worked well with the ridiculously awesome noise and cross talk numbers of the Devialet.

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EXT doesn’t work with the Mirus Pro, a little closed in and too laid back. Now I’m rocking good old regular poly-sinc with DSD7. I find ASDM7 widens and warms things a bit to much, DSD7 is more focused and clear.

I’ve gone back to PCM for a spell. Just upsampling to 352.8 or 384 in Roon with Max PCM (power of 2) with Precise Linear and 7th Order CLANS. Enjoying the weight in the bottom end.

I don’t find PCM adds bottom end weight, maybe I have more than enough of it with my Mc gear. :grin: You definately get more attack and precision with PCM.

Interesting how different impressions can be. To me, DSD7 is slightly dark with a deeper stage, whereas ASDM7 is wider and more forward…but far from warm. I’n back to poly-sinc-short-mp / ASDM7 / DSD256 here. With admittedly no scientific basis to back this up, I feel like XTR brings a noticeable dryness or lack of air to trumpet sounds and other instruments of the same timbre / register. It does sound amazing on the vast majority of material, and the less “audiophile” the more the benefit.

I agree ASDM7 is wider but in achieving that I think it might lose some focus and a bit of attack. So maybe I feel ASDM7 is rounder more so than warmer.

I sometimes wonder…

Before I had Naim SL2 speakers, which need boundary positioning, I would often move my speakers to nullify a deficiency or augment a positivity.
The I just accepted sometimes the music sounds better than others, time of day, electricity usage in the area, how I’m feeling etc.

Then I go HQPLAYER and I could metaphorically move the speakers again and every few days would hear deficiencies and change filter.

Then I went back to presuming Chord know their biscuits and just let the Hugo do what the Hugo does.

The music can still show deficiencies every now and then but I try beer first before I contemplate any further changes and I find this very effective.

.sjb

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