Playback on DR-40 problem

[KipSurfer]

When I play back a live recording of a bowed string instrument, I hear a high whistling sound in the background. If I had to guess, it sounds as if it's rapidly cycling through the upper partials of the overtone series. This extra sound is not hear during silences--only when my instrument is playing. Playback equalization is turned off. Any idea what might cause this? Should I try to use a filter to suppress these higher frequencies?

 

[KipSurfer]

Well, I solved the problem. The recording format defaulted to MP3 32K, but once I raised it to 320K, it sounded decent. Actually, I finally settled on WAV 24-bit. Why did they not say this in the manual? By the way, the manual is really deficient, and has very little in the way of explanations.

 

[Tony Arnerich]

New member to the forum here, who is highly amused by the restroom logo they've assigned to my avatar image.

Tascam only supplies the owner's manual in the product box which as you say is really basic. You can download the much more detailed Reference Manual from the download section of Tascam's DR-40 product page. But I'm not sure if it covers what I'm about to write. I found it online, elsewhere.

Doing the math on 44.1 kHz x 2 channels x 16 bits you get 1411 kilobits/sec for the raw data, before it is encoded into MP3 and recorded. The 32 kbits/sec setting therefore is compressed* by 44:1 which can't avoid some rather noticeable damage to the sound spectrum. That lowest quality setting is probably well suited to recording voices in a business meeting but maybe not much else. It would have been nice if the manual mentioned appropriate scenarios for the different settings.

My understanding is that WAV is not compressed, so if the file sizes are acceptable, you've settled on a good solution for your music.

(*compression in this case refers to digital data compression, not audio level compression in the voltage or sound pressure domain)