alsa equalizer

Zarneth · 08-08-2005, 11:33 PM

I've got a new 5.1 satelite+sub speaker set (It was a bargin I can assure you) Great for when you want a nice big sound but the sub is a bit too loud for general use even when the sub's turned to minimum and my housemate's allready been complaining.

What I'm trying to find is an equaliser that works with ALSA. (or at least a way to fix the eq in xmms which isn't working for oggs)

All I've been able to find is retq http://sourceforge.net/projects/rteq/
Which has absolutly no documentation on how to use or run it.

Any ideas?
Thanks

foo_bar_foo · 08-09-2005, 12:13 AM

this first method is kind of wierd and but can sound great after alot of fiddeling
there are some equalizer plugins that come with LADSPA plugins that are equalizers
the one i like is Multi Band EQ by steve harris
i run it with ecamegapedal
start ecamegapedal with
ecamegapedal alsa alsa

the enable capture and wave capture but just turn up the capture a tiny bit

now you have a loop and you have to adjust the eq like it's a huge pa system and tune the feedback away. if you turn up master or wave volume then feedback comes back.

just like a huge pa this also causes some echo (digital delay)

second method is to use jack sound server
this one is 100% clean
output xmms using jack plugin
output jack to Jamin (jack audio mastering)
edit: start jack with qjackctl so you have the connections window
connect JAMin outputs to alsa
Jamin has:
* Linear filters
* JACK I/O
* 30 band graphic EQ
* 1023 band hand drawn EQ with parametric controls
* Spectrum analyser
* 3 band peak compressor
* Lookahead brickwall limiter
* Multiband stereo processing
* Presets and scenes
* Loudness maximiser

Zarneth · 08-09-2005, 01:21 AM

I'm leaving the first option for now as there's no debian package.
For jack though. I've installed packages jackd and jamin.
The command "qjackctl" isn't found.
Also running the jack daemon with "jackd -d alsa" and telling xmms to output to jack, xmms sais "cannot open audio" (Looking foward to tweaking around with Jamin when it works thoguh)

There may be another possible solution. I've been running the speakers with a connecter that allows me to plug all the channels into just a stereo output. This lets me have the output on all speakers as I've been unable to find an xmms plugin to output to all channels (tried an oss one but that didn't work)

I've discovered the "duplicate front" setting in the alsamixer though. This outputs the front two channels to the rear two and has some interesting effects.
-No center/Lfe channel. This causes a lot less base, possibly a bit too less and I'd like to be able to still have that base sometimes.
-The master volume controll doesn't affect the rear speakers. Not sure if this is normal due to the dismal use of surround sound in all the movies I've tried.
-Having the pcm(front speakers) and surround volumes at diferent level's increases in bass.
I honestly don't think this sounds quite right though.

So I guess now I need a way to get xmms output to all channels particularly including lfe/center. Aswell as getting an eq working.

Sorry if I'm rather undecided. I'm just too picky when it comes to audio. Any sugestions or help would be greatly appreciated.

foo_bar_foo · 08-09-2005, 02:31 AM

start jack like this
jackd -m -dalsa -dhw:0 -r48000 -p1024 -n2

qjackctl is another app but you really don't need it (it helps to understand jack)
i think there is a debian package

then in jamin choose as "in" the odd looking ones bio2jack_0_9649
those are the xmms output
lots of different apps can connect to jack at once and you can pass sound between them (it's soooo cool)

might need this in your ~/.asoundrc

Code:

pcm.jackplug {
	        type plug
	        slave { pcm "jack" }
	}

	pcm.jack {
	        type jack
	        playback_ports {
 	               0 alsa_pcm:playback_1
 	               1 alsa_pcm:playback_2
 	       }
 	       	capture_ports {
 	               0 alsa_pcm:capture_1
                       1 alsa_pcm:capture_2
        	}

	}

there might be a way with your asoundrc to make proper 5.1 output
what kind of soundcard do you have ?

Zarneth · 08-09-2005, 03:59 AM

Still no luck with Jack and Xmms
When running qjackctl. Only Alsa, and when it's running Jamin are appearing in the connections window. Same for the in and out on in Jamin.

My soundcard is unfortunatly only onboard audio. VIA 8235 according to the mixer I'm using here.
Being able to map all the channels to the correct volume controlls would be nice. Assuming my speakers don't decide to be nasty I'll just be able to turn down the LFE channel then. I think?

foo_bar_foo · 08-10-2005, 06:14 AM

and you have this
http://packages.debian.org/cgi-bin/s...ords=xmms-jack
xmms-jack package and choose output plugin libjackout.so

sorry can't help with the sound chip -- those things are so confusing like hidden sound chip with another chip VIA 8235 in the way
you can try the mother board manufacturers website to see if they make a linux driver
one of them even distributes a mixer for linux i saw once
msi supplies a Linux driver for the underlying sound chip too so it's worth a look