RCA input low volume

[slampus]

Hi!

Im kind of new to the AudioInjector, got everything working exept the Volume input. Im running Rasbian OS and using the Audioinjector+RPI as an audioplayer, but also as a playthrough for my computer.
For some reason when i play music on my RPI the volume is much higher than when i play music on my computer and use the RCA input.

Would be nice with some help,
Thanks!

[flatmax]

Hi there,
Can you use the input potentiometer to trim the input RCA connectors until the passthrough volume matches the pi volume ?

thanks
Matt

[slampus]

Even when i have the potentionmeter on full i still cant have same volume as my pi.
Offcourse i could lower my pi-volume to match the input but it would be lovely to get full volume out of input.

Thanks!

[flatmax]

Assuming you are doing analogue pass through, there is a half volume on input in hardware to avoid clipping. However half volume is not significantly different.

Have you considered trying to use arecord | aplay to go through the mixer (which has up to 12 dB of gain on the input lines) ? You could pipe the input to the output through the mixer and set the input gain levels up (in alsamixer) to match the input to the output volume level.

The format would be similar to the following :
arecord -D hw:0,0 -r 48000 -f S32_LE -c 2 | aplay -D dmix:CARD=audioinjectorpi,DEV=0 -r 48000 -f S32_LE -c 2 -

Because aplay is using the dmix device, you would have to use the dmix device again. You should even be able to use .asoundrc to set up specific devices which accomplish other things.

Matt

[foobrizio]

Hi. I have a problem with audio volume from RCA input. I'm trying to record some music, but the volume recorded is too low, even with all parameters in alsamixer and pavucontrol set to maximum. I don't know what else to do.

Here is my .asoundrc

Code: Select all

pcm.!default {
	type hw
	card 0
	slave.pcm "dmixer"
}

pcm.copy {
	type plug
	slave {
	  pcm hw
        }
	route_policy copy
}

pcm.dmixer {
	type dmix
	ipc_key 1024
	slave {
	   pcm "hw:0,0"
	   period_time 0
	   period_size 1024
	   buffer_size 4096
	   rate 44100
	}
	bindings {
	   0 0
	   1 1
	}
}

ctl.dmixer {
	type hw
	card 0
}

ctl.!default {
	type hw
	card 0
}

Write me if other infos are needed.

[foobrizio]

Hi guys. I'm having a similar problem with my AudioInjector sound card. I need to record some music and, after a Fourier analysis on the frequencies, detect the right note played from the instrument. My algorythm doesn't work well (it makes mistakes too often) because the sound captured by my sound card via RCA is simply too low. I used both Audacity and arecord for recording audio, capturing it both with a microphone put in front of an amplifier and via direct connection with a guitar. Assuming that I already tried to turn the potentiometer several times, and that my equipment (guitar, cables, microphone, amplifier) works very well, what can I do to increase the input volume?

[flatmax]

Hi there,

Have you used alsamixer before ?
In alsamixer (run it from the command line) there are all sorts of gain control, including microphone boost. You should be able to get plenty of volume out of the card.

thanks
Matt

[foobrizio]

Thanks for finally approving my posts, flatmax. I wrote twice because it took too long from the first one that I wrote without being approved and I had started thinking that I made some mistake in my attempt. Anyway I am an ArchLinux user since 6 years. Alsamixer is a dear old friend, and was the first tool that I tried to use to solve my problem. I also used Pulseaudio volume control (pavucontrol) trying different settings. I can say that alsamixer's volume is 100%, every channel is unmuted, the pulseaudio daemon is started and jackd too. The problem didn't change at all...the volume was always the same. I also firstly used the .sh script to configure the sound card. I don't want to think that my RCA input hardware is defective.

[flatmax]

OK, thanks for clearing that up.

The input signal has a -6 dB hardware decrease, however you should be able to recover that in the codec mixer, by applying gain.

If you remove the audio injector out of the equation, can you confirm that you get the same problem, the sound level is still too low ? i.e. plug directly into your amplifier without the audioinjector in the signal chain.

thanks
Matt

[foobrizio]

Sorry flatmax, I didn't understand very well what you mean with the equation stuff..Are you asking me if my equipment works well if mounted on other devices? In this case the answer is yes, I connected the aux cable into a notebook with Windows installed on and it recorded sound very clearly. In order to be clear, I'll specify here the equipment used:
1) Guitar, connected via jack cable to an amplifier
2) Microphone put very close in front of the amplifier
3) male/male Jack 6.3-3.5 adapter, followed by a female jack 3.5-male RCA adapter inserted into the AudioInjector

I also tried to connect the guitar directly into the AudioInjector and, this morning, I added into the signal chain a preamp that slightly increased the volume received from the AudioInjector, but it was still too low.