power amp shutting down/off

valleybass94 · #1 03-04-2013, 10:36 PM

i have recently purchased a bmax pre-amp and have a crown xls1500 running an enclosure wtih a 15" 600watt 4ohm carvin speaker. it worked fantastic for a few gigs but a month later it seems like i have to raise the volume a bit more. my gain on the bmax was at 5 and my volume knob between 2 and 3, but now i have it at 3 and my crown begins peaking and shortly after it cuts off? i need advice :/ i plan to get the ampeg hlf410 but will that be a solution or am i just doing something wrong? and i must add that i do have to compete with my guitar player that insists on raising his volume every other song and thats where my problems begin, please help.. thanks guys

*dumbandconfused*

B-string · #2 03-04-2013, 10:39 PM

You are probably burning your one and only speaker, the amp may be going into protect?

lowfreq33 · #3 03-04-2013, 10:44 PM

Are you running the Crown in Bridge mode?

valleybass94 · #4 03-04-2013, 10:51 PM

yea i have it on protect mode b-string 2, and no lowfreq33 im running my speaker from channel one only.

B-string · #5 03-04-2013, 11:00 PM

I suspect the multiple driver cab will solve your problem. Can you borrow a cab just to be sure?
Carvin likes to list "continuous" power ratings and I really think that 15" is being hurt.

BogeyBass · #6 03-04-2013, 11:05 PM

As far as needing more sound pressure to keep up with your guitar player. You need more speaker area to keep up with him.

So yes the 410 will have more output than a single 15"

or you could simply add another 15" speaker to the other channel.

Crown claims that amp to be 2ohm stable so you could run another 4 ohm 15 on just one channel.

the problem is it keeps cutting out, does this mean your amp is shutting off/ going into protection mode.

Either there is a problem with the amp or its overheating with just a 4ohm load. Its a 2ohm stable amp, so it must be getting really hot. Most likely your rack or however you have the amp mounted is not letting enough air flow to stay cool. And is making it overheat and shut down.

The second channel has a no load condition, but that should not be a problem. Unless for some reason the amp does not like no load conditions.

Or there is a voltage drop on your AC power and the amp is pulling more current to put out the rated power. Which again is causing it to overheat.

Or cutting out you mean the speaker is clicking or farting out, that is no surprise a single carvin/eminence 4ohm 15" aint gonna handle that much power before giving out

B-string · #7 03-04-2013, 11:14 PM

My concern is over current from a dying speaker could be interpreted as a fault by the amp forcing a shutdown.
http://www.crownaudio.com/media/pdf/amps/138022.pdf

The current sense affects the peak limiter as well would be my guess.

valleybass94 · #8 03-05-2013, 07:04 AM

yea bogeybass, i should have worded that better, it is going into protection mode. as soon as i begin to turn up my volume, of course thats when the clipping begins then i begin to smell the "heat" coming from my amp and shortly after, off and seconds later, back on.
and b-string 2, let me check out that site.

john m · #9 03-05-2013, 07:16 AM

You need more speakers to achieve volume AND

be sure there is "breathing room" in your rack.

Adding a fan would help. I used to do a lot of outdoor gigs in the summer with an AB 1100 power amp running 4 monitors (2 ohms) on one side and 2-18 subs (4 ohms), on the other side. That thing ran very hot and the side with the subs would often shut down. We added a 4 1/2 inch fan to the rack and used an 18" window fan for outdoor gigs. That kept it out of thermal shutdown. You could actually touch the case without getting burned. That amp is still going strong after 20 years, though it is used for a rehearsal PA only.

valleybass94 · #10 03-05-2013, 08:40 AM

thanks all for your wisdom....let me see wut results once i get my ampeg hlf410. couldnt find anyone with a 410 cab to test out first.

Stone Soup · #11 03-05-2013, 12:56 PM

Quote:

Originally Posted by valleybass94

as soon as i begin to turn up my volume, of course thats when the clipping begins then i begin to smell the "heat"

I have a XLS 1500 driving two 4 ohm multi-driver PA cabinets. The amp barely gets warm. The heat thing would worry me.

Is the clip light on the amp lighting up? Are you sure you don't have the preamp set too hot?

john m · #12 03-05-2013, 04:13 PM

Quote:

Originally Posted by Stone Soup

I have a XLS 1500 driving two 4 ohm multi-driver PA cabinets. The amp barely gets warm. The heat thing would worry me.

Is the clip light on the amp lighting up? Are you sure you don't have the preamp set too hot?

Produce more heat.

seamonkey · #13 03-05-2013, 04:52 PM

"Smell the heat" is not good.
You might have the one in a million case where something is wrong with the Crown.
They usually self protect well before anything gets hot enough to smell.

Stone Soup · #14 03-05-2013, 05:21 PM

Quote:

Originally Posted by john m

Produce more heat.

The bass and the kick drum are going through the amp, as well as the keyboards. I'm producing as much heat as could be expected. The amp works great and runs cool. They aren't what you might be used to.

john m · #15 03-05-2013, 08:15 PM

Quote:

Originally Posted by Stone Soup

The bass and the kick drum are going through the amp, as well as the keyboards. I'm producing as much heat as could be expected. The amp works great and runs cool. They aren't what you might be used to.

And crank it till it sounds like thunder--- it will get hot.

valleybass94 · #16 03-07-2013, 03:22 PM

Quote:

Originally Posted by Stone Soup

I have a XLS 1500 driving two 4 ohm multi-driver PA cabinets. The amp barely gets warm. The heat thing would worry me.

Is the clip light on the amp lighting up? Are you sure you don't have the preamp set too hot?

yeah the clip/red light begins to light up