What determines a good compressor?

Discussion in 'Effects [BG]' started by QUSP, Feb 5, 2003.

  1. QUSP


    Aug 8, 2002
    Hercules, CA
    Im interested in buying a compressor for my rig and I wanna get as much info as possible. So what determines a good compressor? Wha's a good price to pay for one? What's the difference between single and double channel? Any other info would be greatly appreciated.
  2. BFunk

    BFunk Supporting Member

    There are many ways of determining what is a good compressor. Some compressors are very transparent. This means that they change the signal envelope but do not impose a lot of compression artifacts. Compression artifacts are unwanted side-effects of compression. Amoung the most common are loss of high-end, (definition), pumping, breathing, and distortion. Pumping means that there is a pronounced momentary change in volume. This often occurs when you are using a high compression level, moderate attack time, and fast release time. Breathing occurs when the compression goes on and off in rapid succession due to fluctuations in the input signal. Distortion is caused by the compressor riding the input signal. This is very common when you use very fast attack and release times on low notes. It is essentially an extreme form of pumping. Generally good, transparent compressors are designed to minimize these artifacts. Examples are the FMR RNC1173, Drawmer 241, and Aphex 651.

    Other compressors are designed to color the sound in a particular way. Often optical compressors and tube compressors, (and their cousins tube levelling amplifiers), are employed. Examples are the Urie 1176, and the Demeter VTCL-2C. These are more exotic types. Generally you want to stay away from these for general use unless you really have to have that sound. (They can really sound good!)

    Also, there are compressors that allow you to adjust all 5 parameters associated with compression continiously, and those that have some parameters fixed, or semi-fixed. The former allow you to really tweek the sound to your liking, the later is much easier to use. It can be difficult for the novice to learn how to set the compression parameters, but once you get the hang of it, you never want to go back to (semi-)fixed systems again.

    Also, there is price. One of the best bargains in compression is the FMR RNC1173. For $175, you get one of the best sounding, most transparent compressor for under $2000.00. It allows you to control all parameters and has a wide range of values. It can sound great if setup correctly and awful if not. (But that is true of any compressor.) Also check out the DBX 160A, for about $400. This is a classis 70's design compressor. The Aphex 651 for about $500 is also good. More exotic stuff includes the Empirical Labs Distressor and the Cranesong Trakker.

    Amoung the one's I suggest you skip are anything by Alesis, and the low-end stuff from DBX and Behringer.