Search found 2332 matches

by chris661
Wed May 27, 2020 8:25 pm
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

Re: FIR And FIlter Stuff

What I am suggesting is I don’t think the DSP will add anything if done right. The source will add, I have a rule for vinyl, if it was recorded on an analogue system/mixing desk - I would buy it. If it was recorded and mixed in a modern studio then it’s digital, so keep it digital. I like this appr...
by chris661
Wed May 27, 2020 5:51 pm
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

Re: FIR And FIlter Stuff

To, to clarify, you'd suggest taking the vinyl signal and running it through DSP? Interesting approach. FWIW, if someone does like the vinyl "sound", then it seems pretty sensible. If anyone's interested, there's some good reading/watching here: Article - had to use the Wayback Machine as the origin...
by chris661
Wed May 27, 2020 9:28 am
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

Re: FIR And FIlter Stuff

Well, it looks like here we part ways. I won't turn this into a digital vs analogue debate, as it's usually the case that neither side will ever change their views. Suffice to say that I consider digital superior, but vinyl can be nice on occasion. Best of luck with your journey, Mark. If you're sti...
by chris661
Tue May 26, 2020 3:35 pm
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

Re: FIR And FIlter Stuff

Don't worry about calibrating SPL - all that does is make sure your vertical scale is accurate. Unless I'm doing THD vs SPL measurements, I don't really care about the absolute SPL. Feel free to post an REW file and I'll take a look. Chris PS - Chances are the reflection within a few cm is the baffl...
by chris661
Tue May 26, 2020 12:00 pm
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

Re: FIR And FIlter Stuff

From what I can tell so far, it's not a sort of method that can easily be adapted to working one section of a speaker - looks like you have to run the whole frequency range from it - bearing in mind the delay or latency or whatever. This is discouraging, as I've worked very hard to get maximum tran...
by chris661
Mon May 25, 2020 6:47 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

I've put a post up: viewtopic.php?f=9&t=7848#p176066

Which outlines the implementation of FIR processing, with real-world results.

Chris
by chris661
Mon May 25, 2020 3:44 pm
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

Re: FIR And FIlter Stuff

Thought I'd put together a more complete report. My HiFi system is as follows: - Laptop source. Well, half a laptop - the screen & hinge were damaged, and the result passed on to me. I removed the screen and hinge, connected it to the projector via HDMI, and there's a USB connection to... - A Cambri...
by chris661
Sun May 24, 2020 10:32 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

Double-post, but hey. I recreated what I did for the HiFi speakers, because I didn't save the settings first time around. See before/after graphs (link in the post above) for how this worked when I measured the speakers with processing in place. https://i.imgur.com/SOVZSpp.png The number of taps (an...
by chris661
Sun May 24, 2020 10:21 pm
Forum: Assorted Stuff
Topic: FIR And FIlter Stuff
Replies: 15
Views: 221

FIR And FIlter Stuff

Nick, I'm certain I'm talking about FIR filtering here, although I can understand the confusion - I think it should take more processing, too. Here are a couple of images to show what I've been doing: First, I use RePhase to make an impulse file (32-bit .WAV) with the curves I want. https://i.imgur....
by chris661
Sun May 24, 2020 6:27 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

Ah, okay. I can see how 9600 total would be more limiting, but IIRC I used 2048 taps on my Powersoft amps and managed to flatten down to 100Hz.
I'd recommend trying RePhase to make and simulate FIR filters. It's really handy.

Chris
by chris661
Sun May 24, 2020 4:39 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

Yes. If I went into my Powersoft amps and used an FIR filter on one channel but not the other, the FIR'd channel would have some delay. How much delay there is will depend on a few factors. Another approach would be to use IIR crossovers (analogue or digital, line-level or speaker-level) etc, and th...
by chris661
Sun May 24, 2020 3:17 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

I am limited to 9600 taps at 48khz with the Nadja.. so no FIR capability, except at the top end of the frequency range, where I don’t need it. That's quite a few taps. My Powersoft amps have 2048. Playing with RePhase, 9600 taps should be enough to make some adjustments down to 100Hz-ish. Have a pl...
by chris661
Sun May 24, 2020 1:33 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

The simplified idea is that if you implement a delay for the entire system, you then have wiggle room to move some frequencies forwards in time, others backwards, and get it so that, when the sound emits from the speakers, all the time information of the record is maintained. I don't believe its ju...
by chris661
Sun May 24, 2020 9:19 am
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

what exactly are you chaps trying to achieve with DSP? Pretty much what Nick said. FIR filtering allows us to exchange a system-wide delay for the ability to arbitrarily alter the phase response. The simplified idea is that if you implement a delay for the entire system, you then have wiggle room t...
by chris661
Sat May 23, 2020 9:56 pm
Forum: Speakers
Topic: Something stirs in the Undergrowth
Replies: 2628
Views: 415373

Re: Something stirs in the Undergrowth

I'm reading with interest . However I am also getting alternative reports from elsewhere about even well-done FIR not being that good. Will take the ears to decide when we can get some face to face experiments done again. I'm curious, Mark, as to where you're reading those reports. The reviews of F...