Tascam DBX units

[evm1024]

OK so I have heard good things and bad things about the Tascam DBX units. Currently I have 2 units (a 4 channel and 2 8 channel) and I like to tinker.

So what do you think of them? What is their problem? How do they sound - whats good and whats bad.

I'm thinking to do a few side by side tests....

-Ethan

 

[RRuskin]

OK so I have heard good things and bad things about the Tascam DBX units. Currently I have 2 units (a 4 channel and 2 8 channel) and I like to tinker.

So what do you think of them? What is their problem? How do they sound - whats good and whats bad.

I'm thinking to do a few side by side tests....

-Ethan

Which units do you have and what machine(s) are you using them with?

 

[evm1024]

Its a more general guestion on peoples experiences

I have 2 DX8ds and one DX4d THe DX4d would be used on the typical br-20,32,34,38 and the DX8ds on an MS16.

-E

 

[Talldog]

I use the ones on my ms16 with great results. It is the 15ips version. Is there a way to post some tunes?

 

[RRuskin]

I have 2 DX8ds and one DX4d THe DX4d would be used on the typical br-20,32,34,38 and the DX8ds on an MS16.

-E

As far as audio goes, the only difference between these is the number of channels. Both are type I encoder/decoders and are compatible with each other and any other type I units regardless of origin.

What "bad" things have you heard?

 

[evm1024]

Just a few comments

From Jim Williams and others. Usually it is about stomping on freq response or dynamics.

_e

 

[ethyrvalve]

Jack Endino has some pretty harsh words for the dbx on the ATR-60 here:
http://www.endino.com/graphs/
"This machine came with DBX noise reduction built-in. God help you if you used it... it kills the noise, but exaggerates these curves dramatically. (Signal is compressed by the DBX before going to tape... then played back off tape with these curves superimposed on it... then expanded by the DBX.)"

 

[evm1024]

Jack Endino has some pretty harsh words for the dbx on the ATR-60 here:
http://www.endino.com/graphs/
"This machine came with DBX noise reduction built-in. God help you if you used it... it kills the noise, but exaggerates these curves dramatically. (Signal is compressed by the DBX before going to tape... then played back off tape with these curves superimposed on it... then expanded by the DBX.)"

This is one of the other ones that I was thinking about.... Thanks

 

[analogkid]

People that bitch about DBX fall into two groups usually: Those that learned to record in the post-analog era, and therefore have next to no experience with them, and those that are/were too damned stuck in their ways to learn the differences in technique necessary when using DBX - for instance if you are recording a classical guitar you are better off turning the DBX off. Since thousands and thousands of records recorded in the 1970s and 1980s used DBX effectively, it is clear that it works just fine - when properly employed.


AK

 

[sweetbeats]

AK,

Very well-stated.

Do you or anybody know of good n/r primers? I'm coming from the digital arena and I want to avoid falling into the all one or the other camp with n/r but learn how to use it effectively, and when not to use it...

 

[RRuskin]

The performance of a dbx system relies primarily on
1. the proper alignment of the tape machine it's mated with and
2. being savvy enough not to print "hot."

 

[sweetbeats]

Ethan, I don't know much, but I have gotten the impression that if you are using the -10dBv I/O on your deck then there is an advantage to using the Tascam units as they lack unnecessary level calibration circuitry like my dbx 150X units. The 150X units will handle -24 ~ +10dBv I/O levels, which is great if you need that, but of course there is all that circuitry to accomodate that flexibility. I am now second-guessing my purchase of these because, with my M520 now in the mix (no pun intended), and with an understanding that the unbalanced I/O on my 58 may actually be cleaner[/], AND the fact that I likely have no reason to need the balanced I/O anyway, I may be in the market for a couple DX-4D's. Straight-through = cleaner.

As far as the n/r circuitry, without really knowing the particulars, its licensed from dbx in the DX units...Same chips as in the 150X's? Dunno...will they perform different/sound better? Dunno. I bet with schematics from each somebody (like you ) might be able to surmise something...

My 2p.

 

[evm1024]

Guys, Guys, Guys....

...I'm looking for specific objections to Tascam DBX design.

If you ignore the 8 or so adjustments inside the DXB unit (for calibration) they are easy to use . The DX8ds takes it a step further and hooks into the loop inside the MS-16.

I'm trying to track down the sonic details that some find objectionable. When they are working as they should you "should" not be able to hear them. Reality is different of course.

I think that Jim Williams knows how to use a DBX....

-Ethan

 

[analogkid]

I'll look through my literature and see if I have any primers on DBX use - RRuskin is correct hough, the biggest mistake people make is to over-record when using DBX, which causes the playback to be so hot that it distorts. Back to the issue at hand:

As far as I know, there is zero difference between the TASCAM DBX units and the DBX branded ones - if anything one might assume that the TASCAM branded units might be calibrated closer to optimum for use with Tascam decks, but of course that assumes all the equipment is perfectly calibrated.

The whole idea of DBX noise reduction with tape is to push the tape noise itself below the audible threshold by compressing the signal 2 to 1, and then when the track is played back the signal is expanded 1 to 2, basically making the tape noise half as audible. This is obviously a gross oversimplification of the process, I will try to find a better more technical explanation and post that here.

The biggest complaint about DBX has nothing to do with poor frequency response - it has to do with what happens to very soft sources. A solo classical guitar for example has a HUGE dynamic range, all the way from whisper quiet to very loud (at least to a microphone) and at times on playback you can hear a 'pumping' sound of the tape noise level changing, and it can in fact be terribly annoying. As with anything, trial and error will tell you when and when not to use DBX.



I don't know Jim Williams or Jack Endino - though WIlliams I have heard of obviously - and I am not trying to belittle or insult them in any way. It just seems to be a popular pastime these days to slam DBX just like people slam Microsoft and certain political figures - not necessarily based on any reality but just because everyone else is slamming them.


AK

 

[sweetbeats]

Ethan,

Maybe more to the point:

I have heard of no negative issues related to the Tascam design specifically, only the potential positive I mentioned above. I realize that is not a technical response, but its all I know.

 

[evm1024]

Ethan,

Maybe more to the point:

I have heard of no negative issues related to the Tascam design specifically, only the potential positive I mentioned above. I realize that is not a technical response, but its all I know.

This is exactly what I am looking for. We all know about "breathing", noise level modulation based on signal levels and overdriving into nasty levels of expansion. As well as the purest viewpoint.

I'm looking for the sounds like crap because it did this or that or even sounds ok to me type of answers.


Thanks to all.

--Ethan

 

[SteveM]

I think it sounded both good and bad. I could never decide whether to use it or not so I didn't. The 38 is fine with out it. It does add headroom but of course once it's there you can never play it back with out the dbx units. For that reason I think I decided not to use it, and the crazy amount of cable you need to run. I think it's going to depend on what you do. I also may have found it fatter, air-ier and more natural without it.

 

[sweetbeats]

And then of course there is the whole interaction issue with the n/r and the response curve at the head mentioned in the endino article, but you know about that already because you gave me the article.

Yeah, in the discussions and research I've done that relate to your inquiry I've basically heard that n/r units, when used appropriately for the right application sound in and of themselves totally fine and do what they are supposed to do (which is good), and that the Tascam units are no exception; that there may even be a slight edge to the Tascam units when you are integrating them with the deck for which they were designed (i.e. two DX-4D's with a 38/48/58, two DX-8DS's with an MS-16 and so on) due to the absence of level-matching circuitry...this goes a step further with the MS-16 since, as you mentioned, the connections are internal to the I/O loop so you are not limited to using the unbalanced I/O or having to contend with level conversion hardware...very nice.

And so this potential edge makes perfectly logical sense to me, and I'm certain that there are lots of recordings out there with satisfied engineers that used the DX-8DS's on a Tascam deck, and like an MS-16 related comment I made over in Talldog's MX-70 vs MS-16 thread that is supported by the Endino article, I have yet to read/hear of/discover any kind of consistent achilles heel overall to the MS-16...anything that I have encountered has not been fair to the format or price-range of the MS-16 and I do believe that Tascam hardware from that era stacks up formidably well all things considered. To consider then that the DX-8DS's are, more often than not, part of that MS-16 rig and that I just hear no news on it means something. I think in this environment no news can be very good news. Endino even stated that the MS-16 sounds "quite good" at 15ips with +9 tape...that may or may not have been in conjuction with the DX-8DS's in action, but he made some negative statements about n/r on other decks, and the MS-16 was being thrown into a pool with some very fancy fish, and, at least in my interpretation, swam quite well. The same company that engineered that well swimming fish engineered those DX-8DS's...just some logic to munch on...

Not to be redundant, but without exception all the antagonistic statements I've ever read/heard about n/r on this format range of recorder/reproducers were philisophical in nature, not hardware specific, and, again, I've sensed a deference to the Tascam units with a Tascam deck that has the control signal capability.

Enough redundancy now...goodness.

 

[mamm7215]

Well, IMHO since I've gotten my TSR-8 in Jan of this year and calibrated it myself, I agree with the statement above: You CAN'T record hot. It'll distort and not be pleasant. If you stay within your tolerable rec levels for the tape/cal you're using, it's fine. It absolutely gives you that "tape" sound and if you need more "air", eq it in later, it's not gone. I feel a lot of misconceptions about tape recording arise from
the same misconceptions about digital recording/effects. You have to play and experiment. Lots of folks load up one preset or engage dbx without enough experience to know what to expect and don't get what they expect and it "sucks"
Dbx reduction on my TSR-8 is excellent, and I don't record without it. That said, I don't use the TSR-8 for ALL my recording. Some I do itb, mix and match to taste.
Hope this insight helps.
M.

 

[dementedchord]

and there's the rub... if you ignore the calibration you're screwed... the problem as i understand it is it essentially applys an eq curve pre-compression and if the post expansion curve doesnt match you're fuct...

and it's a safe bet williams would know... one of the best techs in the biz...