Blown bass speaker...

[spiker82]

Hi.

 

I could do with some advice regarding live PA system set up/compatiblity.

I'm far from an expert in this field but am a working professional musician. Really need some help here.

 

A band I play with have recently (August 2010) purchased a new set up: we are running a Dynacord Powermate 1600 mark 2 (with 4 ohm output each side) connecting to EV TX1181 (500 watt, 8 ohm) bass bins and from them to EV ZX390 (600 watt, 8ohm), tops. Both are passive.

We also run two powered monitors from the Aux 3/4 outputs.

 

So, we are running poweramp to bass bin to top on either side with the monitor on seperate aux 3/4 channels.

 

The bass bins have blown on the third gig.

 

The maximum we have put through the system is 4 vocals, Sax, Acoustic Guitar DI, Keys, Lead Guitar DI, Bass DI and Kick Drum DI and have never pushed the mixer near the 0db mark.

 

Any advice or comments would be greatly appreciated.

 

Thanks,

 

Michael

[dboomer]

The 0 dB mark probably has nothing to do with anything (unless the system has been calibrated). Short answer is you've exceeded the power the speakers can handle ... either thermal or mechanical/excursion.

 

Does your amp have limiters? Are they engaged? Do you have high pass filters set up?

 

Take a look at this ... http://www.peavey.com/support/technotes/po..._MUCH_POWER.pdf

[audiomik]

Michael

have to agree with Don Boomer on this - a quick look at the spec sheet for your EV TX1181 cabinets states that a 30Hz high-pass filter should be used and your powered mixer, whilst the block diagram shows a high-pass filter in it, probably doesn't meet the EV specification.

 

To try to explain in simple terms, a Bass Reflex loudspeaker below the port frequencies has very little control of the air loading for the loudspeaker cone and I suspect that you may have exceeded it's excursion limit without the filter to cut low frequencies as recommended by EV.

There is some useful information from EV, as well as that from Don at:

http://www.electro-voice.com/faq.php#8

 

Hope this assists, plus the addition of a good High-pass filter at a minimum of 30Hz, together with a limiter should do much to resolve future problems.

Something like the Behringer DEQ2496 might be of interest to you as it has both filtering, EQ and compressor/limiter functions in the one unit:

http://www.behringer.com/EN/Products/DEQ2496.aspx

I use one of the earlier Ultra Curve Pro versions of these myself with good results.

 

By the way, welcome to the Blue Room - I see this is your first post

Mik

[paulears]

4 vocals, Sax, Acoustic Guitar DI, Keys, Lead Guitar DI, Bass DI and Kick Drum DI

 

This, to me is the key. This band is going to be loud, irrespective of what type of music you play. You're putting the lot through a system that is very underpowered for a band of this size. You've probably got hardly any headroom at all, and although you're certain you're not overdriving it, you are probably running it very, very close to it's limit and it's just getting tired very quickly.

The kick and bass together are probably quite loud on stage in real terms, and putting these into the speaker system are going to stress it quite significantly if you're trying to get levels up. As the others have said, the split between cabinets also means the bass end is not just doing the 'duh' bit of the kit, but actually trying to produce recognisable notes from the bass. I've got some smaller HK subs that I don't use much now that are quite good at bass that goes up a bit - but not much cop at producing the very bottom end. These work quite well with plastic box type tops when you tweak the crossover, but no matter what you do, they can't do much with a kick drum. In fact, using them with any top with a proper full range spec is entirely pointless. I guess the important thing for you is that you've destroyed one - and even though I suspect you didn't abuse it on purpose, it's a good indication that either the person mixing didn't hear it screaming in agony, or the overall volume was so high, the death screams were buried in the overall sound.

 

Either way - what you're asking the system to do is beyond it's capability - which is a bit odd, as it's not a bad system, just perhaps a little disadvantaged by your expectations?

[spiker82]

The 0 dB mark probably has nothing to do with anything (unless the system has been calibrated). Short answer is you've exceeded the power the speakers can handle ... either thermal or mechanical/excursion.

 

Does your amp have limiters? Are they engaged? Do you have high pass filters set up?

 

Take a look at this ... http://www.peavey.com/support/technotes/po..._MUCH_POWER.pdf

 

 

Thanks Don, very useful document you posted a link to.

Michael

 

A concurrent post has been automatically merged from this point on.

 

Thanks folks. This is all very useful info and I'm pretty sure has resolved the issue. Will pass it on to the rest of the guys. Great forum.

All the best for now.

 

Michael