The 1,000,000th compressor question

Discussion in 'Effects [BG]' started by blamkin, Dec 6, 2001.

  1. blamkin


    Nov 28, 2001
    Broomfield, Co
    Sorry, I searched on compression for my answer, and there's something like 150 pages of compression threads. :eek: I couldn't find my answer in the first three pages, so I just lamed out and asked. Sorry if the answer's out there and I just didn't see it.

    My question is about placement of rack-mounted compressors in a *live* signal (not recording, but rather, on stage live).

    I know that stomp-box compressors go (usually first) in the chain, before the preamp/head. Cool. My guitar player friends tell me that's what I want, but it's hard to argue with a rack-mounter that I can use for other instruments, etc.

    Here's my question:

    If I get a dbx 160 or RNC, do I just put it in the effects loop of the preamp, or does it go between the pre- and the amp? Where does the thing go in the signal path?

    I'm confused, because if it's blended into the regular signal in the effects loop, won't the original uncompressed signal simply spike up above the compressed signal?

    I realize the compressor will keep the signal "alive" longer for sustain, and that would be mixed in to the effects loop.... but, I mean, if the compressed signal is simply blended in, won't the original spike-y signal still be there?

    Thanks, and sorry in advance
  2. If you put it in the fx-loop.. it will compress the sound after it has been put thru pre-amp and EQ..
    so if the input from your bass has spikes, they will be boosted, EQ'd and then compressed..

    imho it would sound better to put it in front of the pre-amp.. so

    bass -> compressor -> amp

    The best would be to get a dual-channel compressor ( Behringer autocomp or, better yet.. behringer composer ), and put do this :

    bass -> compressor chan. 1 -> pre-amp + eq -> compressor chan 2 -> power amp.
  3. blamkin


    Nov 28, 2001
    Broomfield, Co
    Thanks for the reply/suggestion. I assume the compressor can handle both the guitar-level input (passive bass), and the output of the Preamp...

    Also, I've been looking for the ART tube-based preamps -- thanks for the suggestion on the Behringer.

  4. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    It is true that compression can tend to color the EQ a bit. However, I recommend post-Preamp compression because of noise. Compressors tend to add noise to any signal, so if it is pre-preamp, you are seriously going to lower your s/n ratio. It will be much quieter if you go post-preamp.

  5. I suggested Behringer coz they're about a third of the price that the DBX costs, and they're just as good :)

    the Behringer's are also switchable per channel between +4 / -10 dB
  6. mthoople


    Nov 1, 2001
    Denver, CO
    If your preamp has a side-chain effects loop, the blend control should be set to full "effect" with a compressor in the loop.

    Tubes tend to react dynamically in response input level. My SWR IOD can go from fat to funky to mild distortion with variations in playing volume. A compressor at the front end would limit the dynamic tone along with the volume. However, the IOD effects loop is ideal for a compressor since it is in-line (not side chain) and comes between the input/tube stage and the eq.

    Also, as Chasarms stated, compressors ALWAYS decrease the signal/noise ratio when the signal is compressed. The increased apparent noise is then amplified at every follow gain stage. Mic pres increase the signal level before compression for this reason.

    The Behringer compressors compare well to lower priced DBX units like the 266. But higher priced DBX units are more transparent. I have a Behringer Composer, DBX 1046, and Bellari RP282a, and the DBX is easliy the most transparent and natural sounding of the three.

  7. lo-end


    Jun 15, 2001
    Generally, you put the compressor in before the preamp. But as Chasarms said, you can put it after the preamp for less noise. You should probably just experiment with where you put it in the signal chain, because there are pros and cons for wherever you stick it.

    By the way, I think the dbx 160A is probably the best compressor Ive ever seen in my life. The thing rocks!
  8. Slater

    Slater Bye Millen! Hello?

    Apr 17, 2000
    The Great Lakes State
    I've been using an ART Levelar in the FX loop of my Peavey T-Max, and I've been very happy with the results...
  9. I am getting a Behringer soon, because we have them at work and do pretty much this exact same thing with some of the feeds. We compress a little before feeding them into the mixer, and then compress them more afterwards. Sounds great to me. and I HIGHLY recommend the Behringer Composer
  10. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001
    that's the one I'm getting. For $99.00 you can't go wrong. Is it me or have compressor prices falllen through the floor recently?
  11. Ideally, a comp should be inserted post input gain, pre EQ like the insert points on most mixing consoles. The insert is literally in the signal chain, not sidechained. Unfortunately, most amps' effects loops are sidechains.... There's no real correct way, but you will lower the s/n ratio if you don't put it in front of the preamp. Try both and do whatever sounds best. I don't think putting one channel of compression between the bass and the preamp and one after the preamp is a very good idea, though. All you get by doing that is twice as much noise. Behringers are all right I guess. If you like noise, pumping and breathing, top end smear and wildly inaccurate controls.... The reason they're cheap is.....uh... they're cheap. The Alesis and DBX 266 series are pretty bad, too. The ART Levelar is actually pretty nice.... The DBX 160 and the RNC are nice as well. Maybe I'm just spoiled from using BSS, Drawmer and DBX blue range comps:D.
  12. nope.. Behringer is just good material for real good price..

    that's why i'm getting my composer this X-mas :D
  13. maxvalentino

    maxvalentino Endorsing Artist Godin Guitars/ Thomastik-Infeld

    ah Behringer...the masters of "reverse engineering". Yes they do offer reasonable gear at VERY good prices, but you make find some noise issues when it comes time to record. Their circuitry and input sections are not the cleanest or quietest out there....just some advice.
    The ART Levelar is a very good deal for a compressor, which just happens to work GREAT with bass. I also have a RNC, but find it somewhat deficient for bass...hmmm maybe I have been spoiled by my LA2A?
    If I use a compressor live, which is rare these days, I take the ART...and depending on the type of gig route it either pre or post preamp, but (usually) before anything else in the chain.
  14. By "reverse engineering", you mean "blatant ripoff" right? :D The similarities of Behringer's stuff to Mackie and others is quite remarkable don't you think? Anyhoo, my Behringer experiences have been less than stellar... I've actually stipulated in the technical riders I've drafted (for bands that I tour/toured with) that I won't use them. I'd rather not use compressors. They really have a pretty negative effect on sound, so Caveat Emptor folks.
    LA2A? I'd guess you're spoiled:p Droooool.... I've got a set of schematics for one of those, I do intend to build one one of these days, if I can only find the transformers.
  15. ME TOO!!!! YEAH!!!!!!!!!