Who has an Edirol R4 or R44, and can run a little experiment?

[Robert Rozak]

I'd like to get a sense of the feasibility of daisy-chaining tracks to yield 2 recordings of the same mic, where the first recording is backed-off 12dB or so (to provide further overload/headroom margin).

Here's what I'm thinking:

1) Baseline Recording:
- plug a mic into input 1, and record your voice with peaks at -12dB FS (with quiet periods, to get the sense of SNR). (keep the LEVEL knob at 0dB, and only dial in the SENS)

2) Daisy-chain backup track
- plug a mic into input 1, and set up so your voice peaks at -24dB FS (keep the LEVEL knob at 0dB, and only dial in the SENS)
- plug the RCA output from track 1, into the mic input of track 2
- adjust track 2 so your voice peaks at -12dB FS (keep the LEVEL knob at 0dB, and only dial in the SENS ... may need to switch MIC/LINE to LINE?)
- record your voice (with quiet periods, to get the sense of SNR) on both tracks 1 and 2

Please post your WAV's and throughts ...

Then we could take the WAV's, normalize the peaks to compare SNR.

Track 2 might suck, because you're taking away 12dB of signal from the track 1 output D/A. But, on the other hand, it might not be that bad, because you're throttling back the preamp via the SENS. If it works OK, then all you would need to do is adjust the track 1 LEVEL (aiming for -24dB FS) during a live mix, and you'll have 2 tracks (where one has more headroom margin in case somebody screams or something).


'ya never know for sure until you try it ...

Many thanks ...

-R

[Chad Johnson]

I may try it when I get a chance with an R4pro. I am actually shooting a yoga class with my iPhone sitting on the battery of my ex1! To the instructor it looks like I'm really operating my camera with great concentration.

FYI there is no line level switch on any of the Edirol 4-track recorders. I think the outer sensitivity knob is line level at full counter clockwise. But RCA line level, I think, is with the sens knob at 12 o'clock.

Oooooooooooooooooooommmmmmm...

[Chad Johnson]

I've just done the test.

I added one element to the Baseline recording in part 1. I did record voice in ch 1 at -12db as requested, but I also recorded from the ch1 RCA line out back into ch2 Mic XLR in. The ch2 level was set to around -24db. Both files were normalized.

Then for part 2 I left the connections the same and flipped the sensitivity levels so ch1 was at -24db and ch2 was at -12db.

Check the attachments to hear for yourself. It seemed that the noisiest track was from part 1: R4Pro_Ch2-24dbFromLineOut_16bitNormalized.wav

[Robert Rozak]

SOLD!!!

I'm going out and picking up a R4Pro, and probably a R44 as well ...


Chad,

Thank you so much for conducting these tests! The results were much much better than I was guessing that they would be.

This gives me a great new product idea. I'll send you a proto in about a month and a half ...


-R

[Chad Johnson]

Robert, why not try the Dr-680? Much nicer and less expensive. I just got one modified by Busman Audio. Check it out.