Hi I tested my Micro2440 audio interface with Qtopia player and headsets. I noticed that there are no low freq sounds at all. There is high-pass filter with 10kOhm and 10uF components. These components makes high-pass filter cut-off freq to 1.6Hz which is wery low. I think that hardware changes doesn't make lower sounds. In UDA1341TS (audio codec) datasheet is mention of BassBoost setting. I think it is set off in default. So how to change this? D.
I've noticed the lack of low-end frequencies when using headphones directly in the audio jack as well. I suspect that the low value of the bypass caps (10uF) coupled with the low impedance of normal headphones (typically 20-30 ohms) results in a fairly high corner frequency on the DC blocking network of about 500Hz. That corresponds pretty well with what I'm hearing. To test this, instead of using headphones try driving the line-level input of amplified PC speakers. I did this and had much-improved bass response. Conclusion: The audio output jack on the mini2440 isn't designed to drive headphones, but works just fine with line level inputs.
Hi If you look UDA1341TS.pdf page 17, you can see BassBoost setting and around that also more important settings. How I can configure these settings? Or is there any driver support for these settings? D.
1.6Hz is way into InfraSound. According to Wikipedia hearing, more or less, stops at 20Hz. So a 1.6Hz cutoff shouldn't be a problem. :) If you don't have bass then you are probably trying to drive to heavy a load. Thank you, Errol
What's the application that you use? Try to use madplay or mplay to
reproduce an mp3 file. Or, in last case, try this:
cat /dev/urandom > /dev/dsp
which should give a deafening noise.
I don't believe at all that the circuitry is wrong. If your board is like
the schematic, everything's ok.
Sérgio