|
|
Post by soundmanjim on Mar 31, 2007 1:52:56 GMT 1
 I'm getting fed up with changing these tweeters. In my EV cabs i have, the right hand side tweeter blows about once every two months. Ive gone through Three now, and they arent cheap - £70 just for the diaphragms. Anyway after i noticed it had blown again (tonight) i climbed onto the stage to see what was happening. This all while dj was playing so i could get an idea. Now ive got limiters working, compression and such, and i had the mid-tops actually turned down a bit on the x-over BUT i was still seeing a clip light on the stage left channel. Turning the gain down until the thing stopped clipping made a noticeable difference to the overall level, so much so that i had to turn it back up again. Its just the one channel. I reckon ive got either a/ an impeadance mismatch somewhere B/ a bloody load of crap behringer amp that clips when it gets too hot c/something else? bad connection on the speaker line? Im reckoning that the amp is sub-standard and that its clipping when it gets hot (the other channels fine at the same level). I checked the x-over freqs and that didnt make any difference, input levels were the same and the desk was showing an equal level. so i dont know what to do. this is the third time its happened and i've only got two diaphragms left and i don't want to blow any more, they are very hard to get hold of nowadays. Its obvious to me the stage left channel on the berrringer is going down in heat - so im thinking of replacing it, so what would you let reccomend? I'm thinking CREST as a mate has a few going begging at 800w a side - or should i go mad and buy another QSC 2450? I already use 2450's on the monitors. Or theres powerlights BUT its not going to be moved so it doesnt matter how heavy it is, its an install. suggestions? 
|
|
shepz
Senior Engineer
Posts: 135
|
Post by shepz on Mar 31, 2007 11:18:00 GMT 1
My bets are with the amp jim.
Not sure if the RMX series have a clip limiter? I think they may do...
I know my PLX's certainly do and they're a great saviour!
|
|
|
|
Post by soundmanjim on Mar 31, 2007 14:54:44 GMT 1
the rmx's do have a clip limiter and 30/50hz cut. same as the behringer!!! Just now wondering if the clip lims on the behringer have been switched off though i doubt it.
|
|
|
|
Post by muppet on Mar 31, 2007 14:56:24 GMT 1
The RMX series does have a clip limiter but you have to enable it on the dip switches at the back of the unit. Its a good little amp though! if your amps are going into protect when its hot try getting a hover and cleaning out the filters if that fails try increasing the airflow.
|
|
|
|
Post by soundmanjim on Mar 31, 2007 15:00:42 GMT 1
ive got 2 sqc amps and one behringer ep2500 in the rack on the stage.
They all sit in a rack with front and back open.
the airflow is fine although it does get hot on the stage due to the par cans - i alleviated this problem by putting up a huge air shifter on the side of the stage and aiming it at the musicians and amp rack.
so really, cooling shouldnt be an issue - i have been using the ep2500 now for over a year with no problems but i have heard horror stories about them
(i had three, two were fine and one blew up on one channel, Behringer wouldnt help, no uk based fixer would touch so i sold to a drum and bass guy and he uses it in bridge mode to drive his subs - no problem)
Sooo i think i may just bite the bullet and buy another qsc - they will look lovely in the rack!!
|
|
|
|
Post by muppet on Mar 31, 2007 15:05:15 GMT 1
lol, yeah looks are awlays important and very often over looked! To be honest behringer gear gets the job done but it is built to a cost. i wouldnt be suprised if it is a design flaw in the amp itself, dont think you can go to far wrong with the QSC though
|
|
|
|
Post by muppet on Mar 31, 2007 15:17:53 GMT 1
just wondering what is the spec of your boxes and how you connect them? Tthe biggest tip i can give is when you spec your amp always try to over spec it slightly, believe it or not it is actually a lot healthier for your kit if you do
|
|
|
|
Post by soundmanjim on Mar 31, 2007 19:37:24 GMT 1
i did. the cabs are rated at about 500w, and the ep2500 runs at 500w at 8 ohms, so the amp shouldnt need to be flogged, but actually now thinking about it i probably need an amp that can provide a bit more so i dont have the thing cranked. im definalety going to get shot of the amp though.
|
|
Simon Ryder
Boss
Bringing out the best through sound
Posts: 212
|
Post by Simon Ryder on Apr 3, 2007 19:33:03 GMT 1
Could be a transistor on the way out in the output stage.
It could also be a wiring fault causing the amp to see far lower a load than it is expecting. On certain passive boxes or switchable active / passive boxes when run in passive mode you get a connection beteen pins 1 and 2 which if you use four core speaker cable presents a partial short circuit to the amplifier.
If this is so just disconnect 2+ and 2- inside the speakon connector at the speaker end (and mark the cable). Or get another cable.
Let me know if this works.
S
|
|
|
|
Post by soundmanjim on Apr 3, 2007 21:06:56 GMT 1
negative. the mid tops i use are ancient sloping EV MOTIVATOR II (Shuttlesound) and are fed by XLR's
|
|
|
|
Post by gingerbiscuit69 on Apr 5, 2007 19:37:37 GMT 1
id say its the amp, not the best for compression drivers, they are seriously sensitive and can break even when the amps not picking up clipping. I can make the thing clip JUST driving four of my big comp horns 1500hz up. they are big n loud tho lol.
on a serious note, the musical content of live music is much more demanding on the midtops than compressed and mastered audio tracks. you need just as much headroom as you would give the subwoofers. you can never have enough power, headroom sounds better, gives the amp an easier ride and the cleaner acoustic waves actually dont heat the motor/magnet as much as the equivilent waggage from a strained amp.
could always get beefier comps too...
|
|
|
|
Post by soundmanjim on Apr 6, 2007 1:17:07 GMT 1
indeed. i actually bought an AVC2 the other month (i know im still getting round to putting it in LOL) to keep a rein on high levels of row.
PS i have borrowed a CREST 600 amp and i couldnt believe my ears tonight - the sound was cleaner. It really was. Poxy behringer.
So im using the Crest until i can lay my mitts on another QSC or similar.
|
|
|
|
Post by muppet on Apr 6, 2007 14:25:10 GMT 1
go for something like an RMX 2450, Cheap but still reliable.
|
|
|
|
Post by soundmanjim on Apr 7, 2007 12:59:00 GMT 1
yep thats the kiddie i reckon. last night the sound was AWESOME. I can't believe (it's not butter) that just by changing an amp how much the sound improves. Crystal clear highs and great definition on the mids. (and no blown tweeters or burning smell). Good old crest. shame he wont sell me it. ah well! |
|
Simon Ryder
Boss
Bringing out the best through sound
Posts: 212
|
Post by Simon Ryder on Apr 7, 2007 13:34:59 GMT 1
Ebay my friend...... Ebay
Just bought a Crest amp myself to drive my Renkus Heinz monitors. Stunning sound quality.
|
|
