# DBX in a modern day system



## Jack N (Oct 7, 2006)

Way back when, I used to use a 3BX (which I still have in storage) in my sound system. I plugged it into one of my tape loops and could process everything through it before sending it to the amp. Now that the CD loudness wars have reduced the dynamic range to probably something less than the old vinyl used to have, I'm seriously thinking about going back to a DBX again. So my question is, rather than using the tape/CD loop (because it would probably mess up the DVD surround) can I use it between the CD player and the pre-amp of my RX-V3300? I'm not sure what kind of signal strength differences there are.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Sure, you can connect it like that, but I’m not sure how much good it will do you. The 3BX increased dynamic range by lowering the noise floor – which was sorely needed with LPs and cassettes. CDs already have a now noise floor. What they’re doing there is peak limiting so that they can push the signal higher without clipping. It allows them to use an overall higher signal, but there is no room left for dynamic attacks from drums, etc.

I used to use a 3BX Series II with TV programming, which is severely compressed, and it did help to some extent with the noise floor in quiet passages. However, I could not tell any audible improvement in “impact” – i.e., the increase in level you should get when guns fire or a car crashes.

What you might do is try a 3BX III, if you don’t have one. Those have an “Impact Recovery” function that might be helpful. I’ve never used one, so I can’t tell you how well it works. I have noticed, however, that the III gets nearly twice the price that the Series II does on eBay, so it must have some added value. There was also a later 3BX DS that had a three-band Impact Recovery function that would be even better than the III’s single-band function – assuming the feature works at all.

Regards,
Wayne


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## Jack N (Oct 7, 2006)

Thanks Wayne. Your reply brings up another question. By noise floor, I’m assuming that you’re referring to relatively quiet background noise. Correct ? I was under the impression that the 3BX monitored all the frequencies, not just the noise floor, and either increased or decreased the signals’ loudness depending on where it/they landed with respect to the transition point. Thus, the loud signals got louder, and the soft signals got softer, resulting in an increased dynamic range. Am I way off base ?

I wasn’t aware that the 3BX-DS had 3 band impact restoration. That’s very interesting. The 3BX-DS has been averaging right around $300 on eBay, and the 3BX-III has been averaging about $330 for roughly the last week or so. Does the 5BX-DS have 5 band restoration ? The last one went for almost $670.


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## Wayne A. Pflughaupt (Apr 13, 2006)

> By noise floor, I’m assuming that you’re referring to relatively quiet background noise. Correct?


 Yup. As we all know, albums and cassettes (especially factory casssettes) had a pretty high noise floor compared to CDs. The 3BX does a good job of reducing the noise floor on the former and median, but on songs that fade out, you do get an abrupt “drop” when the music signal gets down to about the level of the noise. Still, to me that’s a good trade off to get the lower noise floor.



> I was under the impression that the 3BX monitored all the frequencies, not just the noise floor, and either increased or decreased the signals’ loudness depending on where it/they landed with respect to the transition point. Thus, the loud signals got louder, and the soft signals got softer, resulting in an increased dynamic range. Am I way off base ?


 Yes, that’s the way it should work – theoretically at least. Practically, however, I never saw much evidence that the louder sounds got louder – i.e., more dynamic. At least not with CDs or TV programming. I think I was able to get at least some increase when I ran my bass guitar through it. Popping a string would get a little bit of signal increase, if I recall.

But you know, with compression it’s virtually impossible to re-process and get back the lost dynamics. Radio and TV programming, for instance, are so squashed they have virtually no dynamics. CDs are generally better, but even the best-sounding ones have a lot of compression or at least peak limiting.

But you said you have one. Do you think it was able to increase dynamics? Maybe your experience is different than mine. Can’t hurt to hook it up and give it a try! If nothing else, it looks really cool in a rack!  I've always wanted to try the Impact Recovery, but never could stomach the high prices of the 3BX III.



> Does the 5BX-DS have 5 band restoration ? The last one went for almost $670.


 Judging from the picture and description, it does. Don’t know much about those; they are pretty rare, as is the DS series in general. The most common seem to be the Series Two and III models, 1BX, 2BX and 3BX.

Regards,
Wayne


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## Jack N (Oct 7, 2006)

I agree. It did a great job of reducing background noise, but didn’t do a whole lot for increasing dynamic range. But I’m beginning to think that if I get any benefit from it, it’s better than nothing. The CDs now days sound so lifeless. I’ve still got it packed away somewhere (I moved about a year and half ago) so as soon as I can integrate it into the system I’ll see just how much difference it makes. My ears have had a lot more “training” since I’ve used it last so I might notice a bigger difference now. If there’s a readily audible difference, I just might have to try one of those DBXs with impact restoration.


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