DJSandro

Hi everyone, Thanks for the comments. I did solve the issue. Tim, you were right on, something was "amiss." In fact, it was a little audio daemon program running in the background on top of core audio. The daemon was installed with a audio shareware program that I installed a few months back on a (stupid) whim and quickly deleted. The program is called "OSS 3D", never use or install this program, it's just awful. I thought that was it once I deleted the application, but the process (located in the library/application support folder) just kept loading into memory on startup. It was sitting there doing something to my audio stream from core audio. Once I located and deleted the daemon, of course, the sound quality now exceeds that of my CD player. So, lesson learned, I guess. Thanks. Sandro

Hi Tim, Thanks again for your reply. I definitely don't have sound check or enhancer turned on and I have run the tests that you described. It doesn't help to run from the laptop out directly into the headphones or the stereo. I tried de-installing the 4 Gb of RAM back to the OEM 2 Gb of RAM. This actually helped and the sound improved noticeably. There is still distortion, but that may be due to my choice of program material. Apparently my MBP 2.2 core2duo was not happy with 4 Gb of RAM of which only 3 was addressable. It was causing logic to crash, and also degrading sound quality. So I wouldn't say "problem solved" but I think that the RAM issue was one aspect of the problem. There is still a difference between the sound coming out of my Firebox and my CD player, but it's pretty minimal now. Thanks everyone for the input. Sandro

Why would iTunes add gain, I thought "full volume" was unity gain, as Chris C has mentioned? Ripping to CD is not the culprit because I can take a store-bought CD and play it back through the Sony CDP and it sounds fine, then burn it to lossless or AIFF or whatever and play it through my Firebox and it is noticeably worse, muddier, less presence, reverb tails are lost,etc... I'm going to borrow my friend's Macbook and try some listening tests to eliminate the possibility that my firewire port is bad or I'm having a system setup issue.

Thanks for your advice. What are the usual suspects that I could check in this case? I don't think the problem is with iTunes, the sound quality is degraded with VLC or Play as well. Also, if I just plug my headphones straight into the computer's headphone out the sound is degraded as well vs. Sony CDP. Could it just be a bad choice of program material? Is dance music just too hot for the DAC to handle gracefully? Somehow the Sony player is more robust in this regard...?

Hello everyone, I'm new here, this is my first post. I've been reading a lot on the site, and initially found this site when I figured out that I needed to get better sound out of iTunes. I am a computer musician, I write and record music (and monitor on headphones) through a Presonus Firebox connected to a Macbook Pro Core 2 Duo OS 10.4. My library of songs is stored on a Glyph Pro Audio Firewire drive in lossless format (using error-checking and Apple's built-in encoder to rip). My question: When monitoring a lowly 256 kbps AAC file from iTunes Plus (let's say a Dance music track, for example) using iTunes > Firebox DAC > Firebox's Headphone out > AKG 240S cans, there is clear distortion and muddiness with iTunes gain set to Unity (all the way up) and Core Audio at 44.1 kHz/24 bit. If I turn down the gain, then distortion goes away, but loss of clarity and image remains. Here's where it gets interesting. When I burn that same dance music AAC file to CDROM and play it back in a Sony CD player with pulse DAC from 15 years ago, using the Sony's headphone out OR the firebox headphone out, it sounds much improved. Clearer, more space, better definition, better stereo image and no audible distortion. What could be going wrong? How is it possible that my music sounds better through an old Sony CD player than through a $300 firewire interace? The obvious corollary: How do I get CD quality sound from my Macbook Pro setup? I don't want hi-rez sound, just CD quality like my old Sony player gives me. Thanks for any input. Sandro