A how to for a PC XO.

[ackcheng]

Just want to report here that Acourate has now a new optional upgrades which elimiates pre-ringing of the impulse response.

I turns this


into this


The sound is alot more transparent, with better attacks and dynamics.

This is a magnified photos. The actually pre-ringing before correction is alot worse! Somehow, even the subsequent part of the IR is also matched better.

[ashok]

Originally Posted by lduarte1973

anyone tryed doing a crossover with the new ASUS Xonar Essence STX ?

This is a two channel stereo card !

The Asus Xonar D2X is a 7.1 channel card. That can give you a 3 way x2 crossover and sub. But I haven't yet understood if it is useable with Allocator. I haven't yet read all the other pages to find out if anyone has successfully implemented it!

[KOON3876]

Hi there is new USB to I2S x 4 device here, exaU2I
http://www.diyaudio.com/forums/digit...interface.html

I wrote how to PC XO with Reaper, here.
https://sites.google.com/site/koonau...-FIR-crossover

[dwk123]

Well, don't I feel dumb. I've been using Reaper and ReqEQ to implement IIR filters for a while, but have been thinking I need to get Pristine Space set up and use Octave etc to generate my filters for an FIR setup. I didn't even realize that Reaper had what looks to be a usable FIR engine in place. Pity I'm heading out for a week of vacation tomorrow morning, or I'd definitely be trying this.

Is it only in 4.0? I will have to double check, but I think I'm still on a 3.x series.

[twest820]

It's not a FIR setup. Unless the reduce artifacts box is checked ReaFIR does block based processing using windowed FFTs. Checking the box is of debatable utility; last I did measurements the FIR synthesis was barely capable of 12dB/octave slopes. Good for certain kinds of EQ, not so great for crossovers or suppressing cone resonances or dipole correction.

I'd suggest avoiding brick walls in FFT mode. Management of discontinuities between blocks is limited (unless there have been significant improvements to the plugin since I investigated it last spring) so one tends to get better results with slopes closer to LR4. That said, the price is right and the functionality compares favorably with higher sound quality alternatives such as PLParEQX3.

[KOON3876]

Hi twest820 thanks,
I changed the page URL as
https://sites.google.com/site/koonau...-FFT-crossover
"FFT channel divider, by Reaper and exaU2I Howto"

also please check this page. This is true FIR.
https://sites.google.com/site/koonau...hannel-divider

[twest820]

Yeah, ReaFIR instead of ReaFFT is an odd choice of name.

Brickwalls cause problems in FIR as well. As an example, the graph links at the bottom of this page show how the impulse response widens as the filter cutoff steepens---at least for me the time smearing is still audible with relatively short impulse responses like -mb 90. So you might try backing off the 1kHz wall and seeing where it gets you. Unless a speaker's poorly implemented for directivity (which is actually kind of common, but no so much the case with monitors) or is pushing its drivers more than normal there tends to be diminishing return from crossover slopes above 36dB/octave.

[KOON3876]

Hi anyone who are using VST based PC crossover audio, and has up to date CPU,
Could you try my "SSE FIR Filter" VST? (! sorry you have the risk !) no GPU required.

https://sites.google.com/site/koonau...fir-vst-plugin

Today I tried straight FIR, CPU only, SSE2 compiled on Core i7.
it looks like working but I want to know other person can use this.

[rvrazvan]

@KOON
You're a small genius ). A Ton of work there. I am not able to understand when you have time to build all that, considering the fact that you are not just copying something. Congrats!
But here is my question. Can you do a tutorial for those who want to use standard multichannel cards? It will be a hit