Line-in level too hot for sound card

[s4g]

Hi all, have done a quick search but can't see anything that solves my problem.

 

Basically in my church we have 16 mic channels which are split to a FOH desk and also a separate recording desk (a Soundcraft FX16). The main left and right outputs of this recording desk go to a homemade box which splits them into a load of parallel stereo phono pairs. At the minute this allows the connection of a couple of cassette recorders and a minidisc recorder.

 

Recently, I have also connected a Dell desktop computer to this box (via a 2-phono to stereo mini jack plug). The mini jack is going in to the line-in input of the soundcard. The sound desk is generally run so that it peaks around 0dB, and the record level on the minidisc/tape machines is then set to produce a reasonable level without peaking. So to set a level on the computer I put a 1kHz tone through the sound desk at 0dB. Even when the line-in level on the computer sound card was dropped to its absolute minimum (1%), the levels in the software (tried both Goldwave and Audacity) were far too high and constantly clipping. This also happened on a friend's non-Dell desktop.

 

Is there any way in which this can be adjusted by using software? I know the soundcard is just the cheap on-board job, would a more expensive one do any better (eg the sort you would get with a Carillon computer)? I'm guessing there is just far too much level coming from the sound-desk but can't really adjust this as this would effect the tape/minidisc machines. Is it possible to buy/build an attenuator circuit or how does anyone else go about recording directly from sound desk to computer?

[fogg]

You could purchase a small desk such as one of behringers little 2 channel mixers, run the phono outputs into that and then out of that into the computer. You would then be able to control the input volume into the computer wihout affecting the other recording devices.

[Bobbsy]

Your cheap sound card is almost certainly set up for "domestic" line level which has a nominal "zero" level of -10dBu. Line level for professional gear, including your mixer, is set up for +4dBu, i.e. 14dB higher.

 

As has been said, a cheap mixer like the smallest Behringer UB series would do the job. However, frankly you could find a sound card with a +4 line input for a similar (or lesser) amount of money...have a look at the E-mu range for a start.

 

Alternatively, there are in-line attenuators available like THIS ONE which would do the job with a bit of extra headroom but, but the time you buy two for stereo you're almost in the range of the most cost effective sound cards...and a better sound card would also improve other aspects of quality such as the S/N.

 

Bob

[Sound Man]

You could add a couple of resistors in your homemade distribution box to attenuate the output just on one pair of sockets for your PC.

 

David

[gav8298]

are you plugging into the laptops line input or its mic input? (massive level difference)

[Andrew C]

Interesting that this should come up now. I've just bought an M-Audio Firewire 410 interface and the line level inputs clip all over with domestic kit connected. One dual-gang pot and some bits from the spares box later, I now have a variable attenuator for it.

[s4g]

Thanks everyone for the help. And yes I am using the line-in not the mic in.

 

Might pull out the old soldering iron to add some resistance in the line, 100kohm sound about right?

 

Tempted though to go for a decent sound card as suggested, those e-mu ones look pretty good, and as someone said should improve s/n etc.

[Rob_Beech]

I'd say that was far too high

[p.k.roberts]

Might pull out the old soldering iron to add some resistance in the line, 100kohm sound about right?

 

Try the pad calculator here ....

 

http://www.rapco.com/catalog/tpad.html

[s4g]

Update: managed to pick up one of these on ebay for a reasonable price, figured it was worth it to keep the sound quality up and save me messing around with resistors etc. Thanks for all the advice

[Shez]

I hope that does the job for you. The specs on their website suggest that it doesn't have line level inputs - only instrument level. The pictures suggest they're instrument / line. The manual doesn't give a maximum input level for them but the maximum line output level is +1.7dBV which isn't all that high.