Limiting Equipment

[shellsteven 0]

Chaps, I'd like a bit of advice please. I've been looking at sound governing devices for use in-line with my amps, of which one of them was blown recently by a rather eager and inexperienced DJ. Basically, I need to set a limit to which the amps cannot be fed any higher. I found a very expensive device which is obviously built for this job - Formula Sound - AVC2. However, would a device such as the MULTICOM PRO-XL MDX4600 offer a suitable alternative?

[ChrisPointon 0]

Consider the Behringer range of compressor-limiters which fit in the signal chain between your mixer and amp(s).

 

The Behringer MDX-1600 Compressor-Limiter is especially good value for money at around £78.00 inc vat retail.

 

For those on a tighter budget the Behringer MDX-2200 Compressor Limiter is available for around £50 - £65 and is the one which I use, and it is a great piece of kit http://www.dj-forum.co.uk/html//emoticons/thumbup.gif

[Gary 0]

Firstly http://www.dj-forum.co.uk/html//emoticons/Welcome.gif to the DJs United forum for UK mobile DJ's, Steven http://www.dj-forum.co.uk/html//emoticons/042.gif

 

Feel free to use the search facility to go through the many gems of information that the members have accumulated so far here on DJU.

 

I'm sorry to hear of your "Morning after the new DJ 'ad a go" problems...and you're right to be looking at a hardware method of controlling them.

 

The Formula Sound AVC2 is a formidable bit of kit, with all sorts of clever options such as being able to be linked up to a warning light and have a secuirty cover fitted to prevent a troublesome DJ undoing, adjusting, or defeating the safety which the AVC2 is adding to your system. The AVC markets itself as being better than a compressor limiter - indeed its been marketing itself as being better than compressor limiters for over a decade.

 

Meanwhile, during that same decade compressor/limiter technology has been refined and improved. I use a Behringer MDX2600 compressor/limiter on my show and it helps me a great deal in keeping my levels level even especially near the end of the night when my tired/re-threshold shifted ears (thats a whole new topic all on its own) think that it needs turning up more, when it doesnt.

 

Take a look at the DJs United review of the Behringer MDX2600 here.

 

To prevent tampering of the controls by an "over curious" new DJ, I'd recommend fitting the compressor limiter behind a panel in the rack, if possible. A Pro-audio (but pricey) company called Canford stock a range of security covers, such as the ones you can see by clicking here.

 

and again........ Welcome to DJU.

 

[Corabar Steve 0]

You could always run from the "record" output on your mixer, which has a reduced peak to avoid distortion when recording. It still allows fading up & down but ultimately leaves the main volume control at the amp. The only setback with this is the dandger of overdriving your amp, but if the amp is powerful enough then you shuold have no problems & it's cheaper than buying a new bit of kit!

Edited April 22, 2005 by Corabar Steve

[cj_65 0]

Hi Chris (& Gary) -

 

could you post some step-by-step advice on how you set up

the MDX2200 etc. I read the review which is excellent

(thanks Gary) but I'm still not confident I've got it

set up right - eg do you increase the

gain until clipping and then set the limited to just below

that level - then set up the amp and use the gain on the

mixer to control the volume level?

 

I asked a sound engineer friend of mine who started

telling me to generate sine waves etc etc

 

Sorry if these are all dumb questions 8(

 

All the best, Chris.

[norty303 0]

As Gary says, an anti-tamper panel is a good buy but get a perforated one so you can still see what's going on with the compressor. Terralec might be a bit better for price than Canford too.

 

I'd be curious to know why the amp blew through hard use if it was mine. The usual thing to go is the driver in the speaker. Amps normally cutout first on one of the safety circuits (thermal in this case i would think)

 

The common things that kill amps are short circuits in the speaker wiring but even then they should have protection for that too. Are you running a lot of speakers off of this amp? Is it still operating within it's specifications i.e. only specc'ed for up to 4ohm loads but you're showing it 2.6 or less.

 

If your amp is a bit tired or old you may be better off spending the money on a new amp (Behringer EP series are great for the money and have all the protection you could want, bar contraception ;) ) that has enough headroom to cope with overzealous use of the master volume. The only worry then is your drivers.

 

Don't forget that a hard limiter, whilst stopping the amp clipping, will still raise the average signal of the music much higher, and whilst an amp may be comfortable runninmg at max 50% of the program, the compressor may well make that up to 80% or higher, at which point the amp could still fail (or more hopefully thermal)

 

The Formula Sound unit will actually start to reduce the level once you've reached a set threshold and is a very effective unit. They are pricey though. A few of the Digital Crossovers have dynamic EQ now which will do the same thing and the cheapest of these is the Behringer Ultradrive which can be had new for £165. I know i go on about them here but they are incredible pieces of kit for the money and can replace a lot of your other rack processing gear in the process.

[shellsteven 0]

Chaps, took your advice and bought myself an MDX-2600. http://www.dj-forum.co.uk/html//emoticons/biggrin.gif http://www.dj-forum.co.uk/html//emoticons/biggrin.gif http://www.dj-forum.co.uk/html//emoticons/biggrin.gif In all honesty, trying to find the time to set everything up right is a task in it's own right, but have set the basics... enough not to get another amp rendered U/S by a drunkard wannabe DJ! I've printed off Gary's guide to the Pro-XL, and shall have myself a few minutes on friday before bursting some kids ear drums!

 

Ever set your gains and levels perfectly, only to find that the next CD you play is quieter or louder, and you find yourself playing with knobs during your disco? Well that problem's now solved, just need to get it sounding good. Shall report back!

 

Have to admit, been hovering around the sound business since the sixth form (about eight years) but only ever used compressor/limiters for mic application. Didn't even think to use it for my disco! http://www.dj-forum.co.uk/html//emoticons/wallbash.gif Well, I know now!

 

 

[YourBigEvent 0]

Can you not buy blanking panels that are designed for this purpose, set the amp levels, connect blanking panel and you are sorted, the DJ could take the panel off to get to the amp, but that is the only way, another option is to get an amp with gain controls on the rear, rack mount it against a wall so he can't get to the rear, or buy a lockable rack case, adjust levels, lock case, sorted !