EP2500 problem ?

[Tim]

Hi guys,

I think i have a problem with my EP2500

It just dosent seem as loud as it was when it was new. Could it be possible to damage an amp yet it still works only slightly quieter?

I could get 110db at 20Hz when it was new with 4 TC2+ 12" subs. Now i can only manage 100db

Could it be the amp? Or the subs?

Is there any way to test eather to see if there is a problem?

Thanks for any help.

[ThomasW]

Without more definitive info it's impossible to diagnose.

If the amp is still under warranty take it in and get it checked out. I doubt that it's a function of overdriving the amp, it has enough power to destroy those drivers.

I could get 110db at 20Hz when it was new with 4 TC2+ 12" subs. Now i can only manage 100db

Unless you have absolutely the same test conditions (note this includes barametric pressure, temperature) and are using a high end calibrated mic, the test comparisons probably aren't valid.

What to you mean it can only manage? Is the amp at full output and the drivers being driven to Xmax? At what distance are these measurements being taken?

[Tim]

What to you mean it can only manage? Is the amp at full output and the drivers being driven to Xmax? At what distance are these measurements being taken?

Thanks for the reply Thomas,

What i mean is at the exact same amp/receiver settings it is about 8 to 10db down than the last time i measured it. The amp can manage more but i don't want to push the subs too hard just in case.

When you say is the amp at full output dose that mean the gains on the EP2500 are at full power and the AV receiver is also at full volume? If that's the case then my answer is no, Its not at full power.

I am measuring at a distance of about 11 foot. That is where my seat is.

I don't think the subs are reaching Xmax. How would i know if they where? I only ever watch movies so i am not really looking at the subs. I have never heard them bottom out though.

I have the subs in pairs wired in series. The amp is in duel parallel mode and at a 4ohm load on each amp channel is putting out about 650W into each pair of subs. That's about all the subs can take i think. The gains on the amp are set to 30. The sub level in my AV receiver is at MAX which is +10.

I used to have the amp gains set to 24 and the AV receiver to +3 and it sounded louder and more punchy back then. Now it just seems to have lost that crisp impact it used to have. And i find myself turning up the gains to get that impact back again.

Maybe the subs have broken in and loosened up. And that's why they don't sound as tight? Could that be it?

I am also using a Behringer Ultra Curve Pro, like a BFD. Only the Ultra Curve has a real PEQ and RTA. I have boosted one of the overall gains in this by +4db and that seems to have the volume back to what it used to sound like.

Oh, by the way. I am a little confused about the little dip switches on the back of the EP2500. Regarding the low pass switches, or high pass, whatever they are i cant remember. Anyway, to turn that feature off do the switches go to the left or the right? In the instructions they show a picture where OFF is to the right. But on the back of the amp, the OFF markings are to the left

So which way is correct? I have tried both and notice no difference. Makes no sense to me.

[peted]

Tim:

Regarding the dip switches, from the building guide, page 2:

"Special note to those using Behringer EP-1500/2500 amps

PLEASE NOTE: The big DIP switch on the back of the EP-1500/2500 amps have +/- marks molded into plastic housing. These molded in markings are opposite the settings that are screened in white paint on the back of the amp. Follow the +/- white painted on the graphics, DO NOT use the markings molded into the plastic on the switch itself.

If you're using one of these amps and you don't think you're getting enough low frequency output CHECK THE POSITION of the selector switches."

[ThomasW]

As drivers break in they play a bit lower. Sometimes the efficiency actually goes up ever so slightly as the suspension softens up.

You check Xamx by looking at the drivers to see how much they're moving. If you didn't do this when you first set up the IB, then you have no basis of comparison for the current operation.

As long as you can get the output levels you want, by increasing either amp or sub out settings, and you aren't clipping the amp or overdriving the speakers, go ahead and turn it up.

If you're using the RS meter that may actually maybe the problem. They really aren't all that accurate. And unless you've made no changes in the room (furniture, wall treatments etc), and have the meter in exactly the same position, and the exact same output levels, you're going to get differences in output levels.

If the amp is failing it will continue to do so. Watch the output settings, if you need to add more and more power to get the same levels then you need to get the amp checked out. Time it so there's still some warranty left or you'll get stuck with a repair bill that's equal to the cost of a new amp.

[Tim]

Thanks for the tips guys.

Regarding the DIP switches again. I am talking about the little tiny ones. Not the big one ( i dont think mine even has a big one )

There is about 8 or 10 of these little white switches in a row. There are NO + or - markings at all. Just ON and OFF markings. Maybe the Australian version is diffrent than the US version?

Thomas, I am not using a RS SPL meter. I am using a Behringer 8000 mic with my Behringer Ultra Curve Pro. It has a db meter built in to it.

I honestly can't see why you all are using a BFD? The Ultra Curve Pro is a far better and easyer to use maching plus it has the db meter built in. With a RTA and graphic PEQ why bother with the BFD ?

[ThomasW]

The +/- is referring the the molded in on/off markings on the DIP switch. Those are to be ignored. Follow the printed graph on the chassis

1/3 octave spacing isn't accurate enough to EQ a sub. One should use no less than 1/6th octave measurements for accuracy.

Here's an example from Ken B. The spike at 45Hz wouldn't be seen with 1/3rd octave testing.



And if one takes this to the extreme, here's that same spike with 1Hz spaced testing.

[Tim]

With Ultra Curve i can EQ down to 1/10 octave measurements and everywhere in between to 6 octave and see a graphic display of my curves in the parametric EQ mode.

[peted]

I can think of 200 reasons ($) why many would prefer to use the BFD, even if it takes a little more work. Once you are set up, you have saved the money.

[ThomasW]

With Ultra Curve i can EQ down to 1/10 octave measurements and everywhere in between to 6 octave and see a graphic display of my curves in the parametric EQ mode.

Okay that's cool. I've used a PC and software much longer than the UltraPro has been on the market. I (erroneously) assumed that it was limited to 1/3rd octave RTA testing. After looking closely it's obvious that it's test capacity is quite nice.....

Now if the screen were only 10 times bigger .......

[Tim]

Yeah its a nice little piece of kit. If you have the extra money i think it is well worth it

www.behringer.com/DEQ2496/index.cfm?lang=ENG

[poppabirdy]

This unit looks easy to operate and a nice alternative to the SMS-1, which is pricey. I noticed that the latest version of software for the DEQ2496 allows low and high cut filters to be set in the PEQ.

Tim, do you know how low the high pass filter goes?

Thanks, Poppabirdy

[Tim]

I wouldent have a clue as i dont have the new software installd in mine.