Trying to test audiocards...the wrong way? Options

[lordofthediscs]

Hi there.

I was trying to make some tests to audiocards that I own (Roland UA-1G, M-Audio 2494, M-Audio Delta 1010LT), in order to do some other testing after that with several CD, DVD players, Media Centers, etc.

My first thought was something like having the outputs of the soundcard connected to the inputs, play one song and record it on another track (I'm using Nuendo).
That's the part of the process where all things worked out as planned, except...
...I was thinking that by doing this, if I phase reversed one of the stereo tracks, I would end up only with the differences between the two (or nothing, on a perfect scenario).

I had to compensate for the delay and any volume difference, but on the best 'phase cancellation' spot, I still hear (mostly) the very high frequencies.

That didn't surprised me on the Roland UA-1G, as it's a USB card with volume control and dedicated to record instruments on the go, so I would find fair enough that it wasn't very flat on high frequencies. That's something that even REW confirms in the 'soundcard calibration' part of the setup.

But having the same behaviour with both the M-Audio made me wonder if there's something wrong with my test basics.

I'm playing and recording at 44.1 and 16 bit (trying to keep it from the original source to the end Wave file), so any input on this theory would be appreciated.

Thanks

[lordofthediscs]

Thank you both for your kind help.

I've started using Audio Rightmark a few minutes ago, and it also agrees with REW on the frequency response test of the Roland UA-1G (a gentle roll of above 18 khz).

Of course, this alone doesn't tell me what the actual response is for the input and the output, but the link pointed out by db1989 as a lot to read carefully.

My train of thought with phase reversing was the concept applied to Wave, where a perfect copy will completly cancel eachother, but I see that I can't use that concept with audio cards (at least, not at this price/quality point).


What I was trying to find out is how my pc audiocards compare with standalone cd players, iPod running lossless files (without headphones, as I'm thinking only about it's audio performance as a audio source, not a headphone amplifier), and standalone media players.

The concept of my experiment was trying to have a pc recording the same audio track reproduced by these several equipments, normalize the results, and then do ABX comparisons between the recorded files.

This test would be flawed if the audio card has too much "sonic signature" (lol)...

Any suggestions would be greatly appreciated.

Thanks again

[saratoga]

See this as well: http://rmaa.elektrokrishna.com/

[djchristian]

See this as well: http://rmaa.elektrokrishna.com/

Regarding that site. How do you loopback a Clip+? It only have one line out.

[saratoga]

See this as well: http://rmaa.elektrokrishna.com/

Regarding that site. How do you loopback a Clip+? It only have one line out.

The output of the clip is wired into the line in of an A/D.