dbx I vs dbx II

[Mark7]

Hey everyone

As I mentioned in another thread I'm getting a Yamaha MT400 (due next week). I already have a Tascam 388 and I was considering using the MT400 as part of a "mobile" set up to record guitar, bass and drums in our regular practice room. then transferring the tracks to the 388. As far as noise reduction goes the 388 has Type 1 built in and the MT400 has Type 2. Would I have problems if I bounced tracks recorded on a Type 2 equipped machine to one with Type 1? Or are they compatible?

Would it be better to record with dbx on the MT400 (I can't remember if that's possible atm) and then add noise reduction during the bounce?

 

[Beck]

The two dbx types are not compatible with each other. Type II has a greater per-emphasis of high frequencies during encoding, so there will be tracking errors if Type II encoding is decoded by Type I. The best thing to do is to record and playback using the dbx II on the MT400 an then transfer that to the 388 using its type I dbx encode/decode as well. One dbx bounce like this is ok, but anymore than one and things can start sounding too warm with a loss of high frequencies because you're basically sending the signal through two layers of dbx encode/decode.

That being said, certain instruments may fair better than others if decoding Type II with Type I. You'll know the tracking artifacts, like pumping and breathing sounds when you hear them.

 

[Farview]

You can not play a tape recorded with type 1 on a machine that uses type 2. In general, that is one of the problems with dbx, you can only reliably play the tapes back on the machine they were recorded on, unless all thru machines are painstakingly aligned.

What you will have to do is bounce from the first machine to the second and then record from the second machine back to the first to record some more.

Adding dbx after you have already recorded won't do any good, its too late by that point.

Basically what dbx does is it cranks the highs on the way to tape so it can turn them down during playback. turning down the highs reduces the tape hiss. It's more involved than that, because it somehow tracks the audio on the tape and changes what it is doing in response to the audio you are recording, then it does the exact opposite on playback. But the idea is that it changes the audio on the way to tape to add more dynamic range between the audio and the tape noise, then changes it back during playback.

Type 1 and type 2 go about this is a different manner, so one will not decode the other.

 

[Mark7]

Thanks guys. I shall do as Beck suggests.