Xref: utzoo rec.music.makers:9723 rec.music.synth:15116 comp.music:1723 Path: utzoo!utstat!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!yale!ox.com!sendai!rich From: rich@sendai.sendai.ann-arbor.mi.us (K. Richard Magill) Newsgroups: rec.music.makers,rec.music.synth,comp.music Subject: Re: dbx vs. Dolby C Noise Reduction Message-ID: Date: 2 Aug 90 17:50:24 GMT References: Sender: rich@sendai.UUCP Reply-To: rich@sendai.ann-arbor.mi.us Organization: Digital Works, Ltd. - Ann Arbor, MI Lines: 50 In-reply-to: apolivka@x102a.harris-atd.com's message of 15 Jul 90 14:27:45 GMT disclaimer: I'm far from an expert, but I've owned and used both a Yamaha mt2x and a fostex 280. In article apolivka@x102a.harris-atd.com (polivka al 60047) writes: dbx --- 1. I understand that dbx is basically a compander. My understanding is that is is a compander that dynamically adjusts to the signal level attempting to saturate the tape constantly. - If it uses a dynamic gain device, then: - How does the playback expander know when and by how much to expand? - Is there a separate control signal recorded that is used to dynamically adjust playback level? Don't know. Dolby C ------- 1. How does Dolby C work? My understanding is this... Dolby B is much like an enhancer in that it boosts the highs before putting them on tape. Then on playback, B cuts them again. My understanding is that Dolby C is much like Dolby B applied twice to the same signal. Comparison of the two --------------------- 1. I've seen advertised SNR's of 85 dB for dbx. What SNR performance does Dolby C achieve? I think I've seen dbx rated generally at about 2db above Dolby C in the equipment I've shopped for. 2. What are the pros and cons of Dolby C vs. dbx, particularly with respect to the application of multitrack recording? 3. The Nov '88 issue of Keyboard magazine, p147, mentions a problem with dbx having a "tendency to cut off leading edges of transient sounds, such as drum attacks and so forth." What causes this problem and how serious is it? I notice it, but I notice something worse. between the transients I hear superflous very annoying hiss. My drum track should sound like "boom boom boom" but what I hear is something more like "boom hsssSSSS!S!S!!! boom hssssSSSSS!S!S!!!! boom". So I've switched to Dolby C.