Alesis 3630 Compressor - a bad choice for generic use?

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leecovuk

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Hello anyone who knows about the 3630,

I've seen various other threads on this unit but decided to start a new one. I hope that's ok.

I recently bought a new 3630 (ebay) having seen various net reviews singing its praises for the price. Now, I am trying to get a decent sound out of it and have found this forum.

My usage is in an (amateur) radio studio type set up, where I need a compressor/limiter on the mixer output to significantly raise low levels and compress high ones. ie act as a fairly hard level evener / normaliser.

Essentially, am I right in my findings that the 3630 pumps quite badly on various kinds of music when compressing quite hard? I'm finding that, having tried all manner of settings.
I can get some songs and most speech through it sounding okay, then other songs or music with presumably different beats per minute sound awful. Obviously I need a unit I can set carefully then leave to cope with all that runs through it.

I'm thinking I made a bad choice here for my needs.
Would anyone agree? I'm assuming 'yes' having seen some other threads.

Before the 3630 I also tried a Drawmer DL241, which, although good quality, didn't give me significant raising of low levels during compression. I sold that on ebay at a slight loss.
I'm used to a Drawmer LX20 whose basic characteristics I need to replicate in any other compressor. ie, significant raising of low levels as well as compressing of high ones during fairly hard compression, without nasty pumping or other audible issues on any type of audio. (any EQ added after the compressor, to avoid weighting the signal before compression).

So... the eternal question .... which unit to try now? I'm tired of reading reviews and pondering carefully, then finding out it's not right for me.

Thanks for any experience and advice,
Lee
England
 
Some of the early 3630's were difficult to set up and hence the bad rap. If you are only using the comp for speech and not music you should have no problem dialing it in. Myadvice is to start with everything set at about 9:o'clock go from there using small adjustments till you get what you are listening for. Use the gate to minimize any noises between spoken words.
I have a 3630 in my rack that I mod'ed with newer better sounding chips and it sounds AWESOME, real audiophile quality, but I put many hours into carrying out the mod's and tweaking the unit to get it to sound right on MY MUSIC. Your mileage will vary depending on your skill and patience in the tweaking phase..



chazba
 
Hello Chazba,

My unit was apparently new/unused. I don't know exactly how old it is though, although the latest year mentioned in the manual is 1995.
I won't be trying to mod it.

Unless I stumble across a revelation, I think yet again I'll be reselling this back on ebay.
I need a unit like the Drawmer LX20. The only reason I'm trying other units is because some pots/knobs on my LX20 have become crackly and unstable, and Drawmer told me once they no longer have such parts for the LX20.

Lee
 
It sounds like you are just setting the attack and release badly. You need a fairly quick attack and a very long release.
Soft knee
About 4/1 ratio
RMS not peak.

Set the threshold pretty low and the makeup gain high.

Real radio stations aren't using $100 compressors. Most of them are using duckers, multiband compressors, phase rotators and multiband limiters. Plus some other processors that I can't think of right now. You are asking a lot from a cheap single band compressor.
 
Thanks Farview,

I am interested in how real radio stations process their output. Mine however only falls into the category of amateur or hobbyist thus not justifying a great financial commitment.

I will persevere for a little longer.
The trouble seems to be mainly when I drive the compression ratio quite hard; I think I need to do this to try and significantly raise low levels during the compression?

If you or anyone else wants to suggest some specific settings for the 3630 suiting my needs, having looked at the summary below (recap of what I've already said), then feel free to do so. (Assuming they are different to the ones already given by Farview; if they are still suitable, just say so :) )

What I am doing is wanting to significantly raise low speech and generic music levels as well as compress (near to limiting) all high levels. The sound doesn't need to sound 'punchy' although I don't mind if it does or sounds 'compressed', but without nasty unexpected 'pumping' or 'swallowing' of beats or vocals.
I appreciate the average input level is probably significant as well as the unit's settings, so let's work on the assumption that most levels entering the compressor stretch about half way across the 3630's input meter.

Thanks again,
Lee

PS I sometimes wonder if the characteristic that I like of the LX20 in significantly raising low levels during compression, might be due to its single control for compression ratio and threshold. Maybe this somehow creates a result which cannot be achieved with conventional separate controls ..... ?
 
I've been very happy with my 3630 (had it about 15 years), however I think that if you know the Drawmer does what you want, why not try to get one of those?

If you persevere with the 3630, I agree with Farview that it sounds like you're not setting the attack and release appropriately.

I think you are expecting too much from one unit. As you describe it you're looking for compression and limiting which means two units set up differently. Maybe the behaviour of the Drawmer meets the need in a single unit.
 
Hello iqi,

I haven't yet found another LX20, except used ones that most likely will have the same crackle problems as mine by now.
I would however consider getting it refurbished by somebody for a reasonable price.

I may be having more luck with the 3630 since backing off somewhat on the compression ratio to no more than 6:1. I have the Threshold set around '9 O'clock'.
My limiting needs however aren't any more than just wanting to use a higher compression ratio really are they? I'm not expecting an actual definitive hard limit.

btw of course, if I'm using RMS mode I can't adjust the attack or release.

At this stage, having read the manual and experimented quite a lot, I'm still not really sure how RMS or Peak mode compare as to how they process the sound.
I'm not sure about the difference between soft-knee or hard-knee compression either, although I loosely appreciate the written theory behind these options.

Thanks again,
Lee
 
leecovuk said:
I may be having more luck with the 3630 since backing off somewhat on the compression ratio to no more than 6:1. I have the Threshold set around '9 O'clock'.
Click to expand...
4/1 would probably work better

leecovuk said:
btw of course, if I'm using RMS mode I can't adjust the attack or release.
Click to expand...
Ooops, I forgot about that. Put it in peak mode and set the attack at 9 o'clock and the release all the way up.

leecovuk said:
At this stage, having read the manual and experimented quite a lot, I'm still not really sure how RMS or Peak mode compare as to how they process the sound.
Click to expand...
Normally, this would mean that the detector would ignore the transients in RMS mode and not in peak mode. But the 3630 just uses some sort of 'smart' attack and release settings in rms mode.

If you aren't broadcasting in stereo, you could always run one channel into the other. Set one to compress and the other to limit.


leecovuk said:
I'm not sure about the difference between soft-knee or hard-knee compression either, although I loosely appreciate the written theory behind these options.
Click to expand...
Hard knee is when the compressor doesn't touch the signal until in reaches the threshold, then it processes the signal at the ratio that you set it to. Soft knee sort of eases into the compression. As the signal approaches the threshold, it starts compressing at a lower ratio. The closer the signal gets to the threshold, the closer the ratio gets to the one you set. It makes for a smoother transition.
 
leecovuk said:
My limiting needs however aren't any more than just wanting to use a higher compression ratio really are they? I'm not expecting an actual definitive hard limit.
Click to expand...
I misread your original post. If you're setting a low threshold to bring up quieter stuff then that's just compression.
 
Thanks again iq and Farview for that detailed help.
I think I _might_ be getting somewhere with this.

Would it be fair to say that this unit (my model anyway) works best at mild-to-moderate compression, and also you have to essentially ignore the calibration markings on the setting controls. ie try each one somewhat randomly even to extremes, and listen, disregarding any understanding of what a printed specific setting should do.
It does seem a little odd, although my technical understanding of how compressors work is by no means expert.

I'm currently going with this ... I'll try to resist fiddling for a while and see how it goes ...

Peak mode, Soft- knee.
Threshold : 12 O'Clock (I think I was previously forcing gain reduction too hard)
Compression Ratio : 2 O'Clock
Attack: 7 O'Clock
Release : 5 O'Clock
Output : 3 O'Clock
Gate : Not using, 7 O'Clock (I never use gates really unless strongly necessary to mask out significant 'hiss' in otherwise silent periods)

Lee
 
You need to go to Ramsey,s web site.


http://www.ramseyelectronics.com/Default.asp

There is a forum there and some of those boys are doing the same thing you are.
I used to have a low power station here and used a 3630 on it and it worked well. Sorry I dont remeber what kind of setting I was using with it but it did great for me.
But I was playing real music through it and not hip hop or rap stuff that had huge bass in it.
 
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