[Erik_C]

I received a nice Logitech Audiohub as a gift. It's a USB speaker. Using it as such takes up alot of my CPU time/power. Is there any way to use my soundcard, which has a digital out, to let the soundcard do the work instead of the CPU? Or, if not, is there an easy way to bypass the DAC in the speaker and add an analog line-in jack?

 

[sejarzo]

Sure looks as if you're stuck, there is no digital receiver on that end to receive an S/PDIF signal, and you'd have to hack it up to get to the amp input.

What do you consider "alot" of CPU time?

 

[Erik_C]

roughly 50% of my CPU! And it's the same regardless of the player I use (Winamp, Windows media, etc)

I have no problem adding a headphone jack if it's easy. I do know how to solder; I just don't know where to solder it to. I opened up the speaker last night and there's 2 boards inside -- one with caps and one into which the USB plugs into.

Quote:

Originally Posted by sejarzo /img/forum/go_quote.gif Sure looks as if you're stuck, there is no digital receiver on that end to receive an S/PDIF signal, and you'd have to hack it up to get to the amp input. What do you consider "alot" of CPU time?

 

[Scrith]

That's odd. I'm guessing that the USB device requires a certain format for the audio data (e.g. 16-bit, 48Khz) and your PC is being forced to re-clock the data (if you are playing 16-bit, 44Khz music, for example) before sending it to the USB device, which can be time consuming. If it were me I think I'd try some regular speakers and let the sound card deal with re-clocking (or, ideally, use a sound card that can play 44K music without resampling, which is not an easy thing to find if you're used to buying sound cards at a place like Best Buy).

 

[sejarzo]

Quote:

Originally Posted by Erik_C /img/forum/go_quote.gif roughly 50% of my CPU! And it's the same regardless of the player I use (Winamp, Windows media, etc) I have no problem adding a headphone jack if it's easy. I do know how to solder; I just don't know where to solder it to. I opened up the speaker last night and there's 2 boards inside -- one with caps and one into which the USB plugs into.

Wow, you are certainly right to question a CPU load that high--it has to bog down things.

Does that unit require its own driver, or operate as a plug-n-play Windows USB Audio device? Some people complain about the CPU load when running an 0404 USB via ASIO with its driver, and that tends to be only 12-15% on peaks for me. Some users get concerned when they have to devote more than 5% to audio, which frankly is beyond me (though I don't run high usage apps concurrently with high quality audio playback....guess it must be a gamer thing.)

Anyway, the plug-n-play devices usually don't consume that much CPU usage as far as I know. Maybe someone else has a better idea on that--I tried to see if there was any documentation about that on the Logitech site, but came up empty.

The problem is that the point at which you would need to wire in an analog input would almost certainly be into some pads on a board, and you might have to cut other connections, etc. etc. Without a schematic and a clear knowledge of the board layout, no one can say what is easy or possible.