...I am in the process of running audio tests on 8 different portable recorders ( Olympus LS-7, Olympus LS-11, Olympus LS-100, Sony PCM-M10, Tascam DR-40, Tascam DR-100 MK2, Zoom H1, Zoom H4n ) that I will publish in July when I finally start my own blog.
In my quest to size up these recorders I thought of an easy way to test if 24-bit recordings actually make any difference over 16-bit recordings with these low cost recorders. Here's what I did:
1- Connected the recorder to a Sound Devices mixer, turned on the 1 kHz test-tone and adjusted the recorder until the test-tone was showing -12 dB.
2- Next I added a 50 dB pad ( LINE to MIC ) to the audio connection, and recorded 10 seconds of test-tone at 48 kHz 16-bit and 48 kHz 24-bit.
3- I brought these two wave files in to Sony Sound Forge, and boosted both recordings by +50 dB.
When listening to the boosted sound files, the 16-bit recording sounded "rough" ( almost "grainy" ) compared to the 24-bit recording, which sounded exactly the same as if I had recorded it at -12 dB.
...In testing these 8 recorders ( 6 down, 2 left to go ) I found that most of them show a quieter RMS noise-floor when set to 16-bit recording instead of 24-bit. ( the difference can be up to 10 dB quieter at the 16-bit setting ) Which makes me think that the 16-bit setting is probably the better one to use if you are careful about getting a good level while you are recording, but if there is any chance the audio levels are going to be low ( i.e. you want to be sure that a really loud sound won't clip, so you set your levels at -20 dB or lower ) then you are better off using the 24-bit setting, because boosting a weak 24-bit recording will sound better.
BTW, the reason why I won't post this until July is two fold: I am new to blogging, so it's going to take some time for me to figure out WordPress, and because I want to record live music for the mic test portion. I will post samples for people to download and decide for themselves which recorder mics they like, and I won't have time for this until the end of this month.
In my quest to size up these recorders I thought of an easy way to test if 24-bit recordings actually make any difference over 16-bit recordings with these low cost recorders. Here's what I did:
1- Connected the recorder to a Sound Devices mixer, turned on the 1 kHz test-tone and adjusted the recorder until the test-tone was showing -12 dB.
2- Next I added a 50 dB pad ( LINE to MIC ) to the audio connection, and recorded 10 seconds of test-tone at 48 kHz 16-bit and 48 kHz 24-bit.
3- I brought these two wave files in to Sony Sound Forge, and boosted both recordings by +50 dB.
When listening to the boosted sound files, the 16-bit recording sounded "rough" ( almost "grainy" ) compared to the 24-bit recording, which sounded exactly the same as if I had recorded it at -12 dB.
...In testing these 8 recorders ( 6 down, 2 left to go ) I found that most of them show a quieter RMS noise-floor when set to 16-bit recording instead of 24-bit. ( the difference can be up to 10 dB quieter at the 16-bit setting ) Which makes me think that the 16-bit setting is probably the better one to use if you are careful about getting a good level while you are recording, but if there is any chance the audio levels are going to be low ( i.e. you want to be sure that a really loud sound won't clip, so you set your levels at -20 dB or lower ) then you are better off using the 24-bit setting, because boosting a weak 24-bit recording will sound better.
BTW, the reason why I won't post this until July is two fold: I am new to blogging, so it's going to take some time for me to figure out WordPress, and because I want to record live music for the mic test portion. I will post samples for people to download and decide for themselves which recorder mics they like, and I won't have time for this until the end of this month.