Sound Quality Issues

[Unregistered]

Hi, A question for the experts...

I'm now successfully recording internet radio broadcast on T1/DSL (receiving over a 384KADSL) using the neat dMC Auxiliary Input...Lame encoder with 7:1 compression...

The sound quality when transferred to CD-ROM is good but not great, no skipping but sound is somewhat tinny and breaks up a bit on the high end.

Q: Is this due to the internet connection speeds, the radio station, or the Sound Card I have (an old "FM801")?

Thanks.

Craig

[Spoon]

If you try recording it as wave - then that will tell you the quality as it comes in, from there you can further determine what effect Lame has on it - internet audio isn't known for its high quality.

[Unregistered]

Hi!

I am trying to use the "Aux Input" to record (convert to MP3 directly) from a cassette player. Problem is: the recorded sound has warbling, similar to the sound given off by a badly streched tape, or hum riding on the original sound-track. Important: the "quiet" parts of the sound track do NOT have any hum/warbling at all! (Generally, if there is hum, it will become noticeable in the quiet stretches.)

The setup is as follows:
1. PC: Compaq Presario 5000 (specs: P-III, 733 MHz, 100 MHz FSB.)
2. OS: Windows 2000
3. Audio source: Aiwa-make "walkman" stereo, run on rechargeable batteries.
4. Audio connection: From "headphone out" of the "walkman" to "line in" port of the PC; through a two-wire 1.5 meter cord.


Some relevant observations:
1. Because the PC runs on a UPS (An AC/DC unit followed by DC/AC unit), the mains hum can not pass through.
2. Since the "walkman" runs on batteries, hum can not come from there also.
3. The sound quality of the "walkman" output is perfect-as checked on headphones. I have tried several brand-new tapes, but they all have the *same* result.
4. The 1.5 m cord also seems to be perfect: I have connected it between the player and the headphones - it does not introduce any hum/warbling; even at very high volumes..
5. I tried recording at different amplification levels, and also adjusted the volume control of the "walkman" at different levels, but the results are always the same.
6. Since the "walkman" does not have earthing facility, I can not make a common ground between the PC and the "walkman".
7. To ensure that all PC resources are fully available, I run only this application while recording; and close all other applications-including applications running in the background... The conversion time is near-instantaneous.

And lastly..
Even the Presario's internal sound recorder utility gives the same problem; so I guess this is really a setup issue, and nothing related to the dBMC or Aux input module.. But, still, I suppose many users are facing such issues, and so if anyone can resolve this, it will be a great help to all of us!

Thanks in advance,

Narayan

[Spoon]

Try using the 'Test Record' button - and adjust the volume first on the tape player, then in Windows - it sounds like there is too much volume from the tape player.

[narayan]

I *am* using the test record button- (there is no other way to adjust the volume anyway) :smile:

Initially I also thought that I may be overdriving (saturating) the pre-amplifiers; and so I tried the lowset volume from my walkman (at which I can barely hear the sound in the headphones). This did not change the situation.

Then I tried different combinations of-
>> walkman's volume control and
>> Amplification in the Test Record dialog box.

Initially, I kept the sound level indicator (the red traingle in the test record box) to the "optimum" level tickmark using the adjustments mentioned above. Afterwards, to avoid saturation of the amplifiers, I varied this level also till it reached a near-zero level.

None of this has worked: the warbling simply does not stop.

A doubt: Can a floating metallic chassis of the PC be the reason?

(Because of the UPS, the earth is isolated from the chassis).

[daren]

Hi,

I can't comment on the warbling, but the hum could be due to the
high impedance of your sound card input (headphones generally
have a much lower impedance - typically 8-32 ohms). I've had
this before when using high-impedance headphones.

Try soldering a 32 ohm resistor between signal and earth (2x for
stereo, of course). This will load the output of the walkman the
way headphones would.

....or you could try using a seperate home hi-fi cassette deck...

HTH,
Daren.

[narayan]

Yes, I will try that.. Thanks!