Karaoke Forums

----Power Amp of course?

Currently I'm using a Yamaha EMX512 which at 8ohms is pushing 350watts per side into 2 15" speakers. I LOVE the system but admit it's limited to the "clean volume" I can create. I'm looking into rebuilding my system into one with EXTRA CLEAN OOMPH when I need it. Going with the premise you can never have too much power what is ENOUGH power for most Karaoke Gigs of medium size.
For arguments sake not talking about powering any SUB ( another topic later)

Just to power 2 15" quality speakers like a Yamaha SV115 or equiv.
at 8ohms
500watts x 2?
600watts x 2 ?
1000 watts x 2?

To power my system, I use 3 Behringer EP2500 amps. One for the subs, one for the mains, and one for the monitors. Each has a power rating of 2400 watts, running in mono at 4 ohms ( I think thats correct) The monitors never get turned up very loud, but it's nice to know that if I ever had a problem, I actually have that amp as a spare to use. I am looking at purchasing the new Behringer EP4000 for the subs. I agree totally,,,,you can NEVER have too much power.

I see the ep2500 rated at 450watts x 2 @8ohms ? - So Is it correct to say your mains are running 450watts x 2 ?

My mains are rated at 800 peak, if i am not mistaken. But rarely do I push them to the top. Actually, to perfectly honest, I would have to get down on my hands and knees to see exactly how the amps are set up, I wasn't the one flipping the switches. I just trusted the guy who I bought them from to do the right setting for my application. All I know, it's VERY loud and VERY clear!!

The S115V only need 500W at 8 ohms, so the EP2500 (QSC RMX2450 clone) works just fine. If you have that kind of power into those speakers, you can get a lot of volume, more than enough for most any karaoke show. Any more power would be best used in a sub.

(By the way, the EP4000 is really not any more powerful than the EP2500. The 4000 number is peak.)

_________________
[color=#ffff55]Mickey J.[/color]
Alas for those who never sing, but die with all their music in them.
-- Oliver Wendell Holmes, Sr.

The rule of thumb to insure your speaker receives good clean power would be to multiply your speakers rating by 1.5 to 2. So ideally your Yamaha S115V's should have an amp capable of producing 750 to 1000 watts @ 8 ohms per side if you are running in stereo. Of course, if you are running in mono you may be able to bridge the amp. Doing it this way your amp would only have to be able to produce 750 to 1000 watts @ 4 ohms.
Re: How Big is yours?
Posted: Fri Jul 24, 2009 10:41 am

--------------------------------------------------------------------------------



If he is running in stereo or parallel mode the answer would be yes. If he is running in bridged mode he would be pushing 2400 Watts into 4 ohms (two 8 ohm speakers in parallel). The quickest way for Mrscott to find out is to look at the back of his amp. If switch's number 6 and 7 are engaged (slid to the right) and he only has a speaker cable connected to the two center binding posts, then he is running bridged.

_________________
Quickness of mind will deceive the eye

My understanding was double the continuous rating, or halve the peak rating. This is what they call "program". Has this thinking changed either in the conventional wisdom or on your part?

_________________
[color=#ffff55]Mickey J.[/color]
Alas for those who never sing, but die with all their music in them.
-- Oliver Wendell Holmes, Sr.

Here are my amps:

Yamaha P5000S - 500 watts/ch. @ 8 ohms runs my lows (Peavey SP5s)
Crown XLS602 - 380 watts/ch. @ 8 ohms runs my mids/highs (Peavey PR12s)
ART SLA1 - 260 watts @ 8 ohms bridged runs my monitor (Yamaha BR12)
I also have one DB Technologies SUB12 powered sub (400 watts)

So I have a 2420 watt @8 ohm system.

Rock and f'n Roll!!

_________________
C Mc
KJ, FL

Sorry for the lil hijack Jam, just a little clarification.

My bad, I never even noticed the S115V had a RMS spec. As most people don't just send a sine wave to their speakers for a prolonged period of time I've never really thought much about RMS (continuous) ratings as they really don't have a bearing on what a speaker is actually producing during playback. There are those that that also believe "program power" is also archaic. For these reasons, To be honest, when I do my calculations I look at the peak, cut it in half and work from there. Using the 1.5 rule from there gets us to 750 watts and you know I always believe in error to the high side. It has kept me out of trouble for many years.

_________________
Quickness of mind will deceive the eye

I currently run
Carvin DCM600 for the high frequency
Carvin DCM1000 for the 15" drivers
QSC RMX1450 bridged to 1 4 ohm 18" Peavey sub - if you add up all continuous watts per channel approx 2500 watts total.

I will be replacing the sub amp (which blew up a few weeks ago) with a DCM2000L pushing 2000 watts @ 4ohms.
The DCM1000 will be replaced with a DCM3000L @ 550 watts per channel for the 15"
The DCM600 will be replaced with the DCM1000 from the current lineup which only pushes 225 watts per channel for the high frequency. This will bump total wattage to about 4000.

Since this will all cost a little bit, I was going to replace the speakers as well, but will most likely just replace the drivers & possibly crossovers to refresh the entire system. Can't afford the Yorkvilles I was looking at right now. Am also going to get a Driverack to replace the current crossovers as well.

_________________
LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

My standard configuration is two PV215 speakers driven by a QSC 2450 Amp. From this I run bridged mono to each speaker. Speakers rated at 700w program @4ohms, while the amp produces 750w to each @ 4ohms (Bridged)

I have other configurations, using other equipment, for larger and smaller venues, but what I've outlined is my mainstay and seems to work quite well for me in most places.

_________________
EveningStar Entertainment & Events
JR & Michele LaPorte
Peoria, AZ

You can't bridge that amp to 2 4 ohm speakers. It would drop the load to 2 ohms. It does push 750 watts PER channel into 4 ohms, but this is not a bridged configuration.
In bridge mode the load can only be 4 ohms & the amp would actually push 2400 watts into 4 ohms.

_________________
LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

So ya made me go back to my manual eh?

You are correct sir.

I misspoke.

I use the bridge mono on my QSC 1850's for each sub (when I require them). For the 2450 I should have said "PARALLEL INPUT MODE". This mode is just like Stereo mode, except that the inputs for Channel 1 and Channel 2 are internally connected together. A signal into any input jack will therefore drive both channels directly. Each channel's gain control still functions as usual, and each channel feeds its own speaker load. You can patch the input signal on to additional amplifiers by using any of the remaining input jacks.

Example: One mono signal driving both channels, with independent gain control for each speaker system.

My purpose for this is that I wanted to get away from the effects of stereo when using multiplex discs. This way I don't have to lose a speaker under those operating conditions.

_________________
EveningStar Entertainment & Events
JR & Michele LaPorte
Peoria, AZ

Well I've got an AB1100A that at 8 ohms is pushing 600 Watts to each of my Mackie S215's. When I bring in subs, it's a pair of SRS1500's which are both 600 Watts as well. So the total if I run the full rig is 2400 Watts. Rarely do I need the subs though. The S215's can get pretty low and I don't play much hip-hop or rap that has frequencies they can't reproduce. Only for the largest venues (which are usually private parties) do I bring out the subs.

_________________
DJ Tony
Let It Rip Karaoke

I run mono also, just set it so at the mixer instead of the amp. No point in running stereo in most clubs as the entire club in most situations aren't going to benefit from stereo anyway.

_________________
LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

When shopping for my amp, it's what all stores said to me, multiply the speaker rating by 1.5, so I guess it's not just him

Are you sure these two amps (EP2500-RMX2450) are not made at the same factory? They're both made in China and I wouldn't be surprised to know they're the same amp I don't think QSC built this one, same for Behringer, of course

Current system in main room is a pair of Yorkville E2204s

http://www.yorkville.com/products.asp?c ... e=71&id=17

powered by a QSC PLX 2402

and triple 18" custom subs powered by a Yamaha P7000s.

Total power is - I dunno - 2500 watts or so but I'm hardly using it all. Limiters are engaged on the PLX but very seldom do they even flicker. Those Yorkies are very efficient. The subs are the same situation. We're just cruisin' and not pushin'.

If you mean the S115V, as I recall that's about a 300w RMS 8ohm box. There are many inexpensive amps that are suitable. Here are my picks:

Crown XTi 2000 (check PSW Marketplace, Silas is selling two @ $450 right now)
will bridge into 4 ohms, has DSP if you want to eliminate out-board GEQ, light-weight and pretty efficient. Not a good amp for subs though.

QSC RMX2450
similar power to the XTi 2000, but good on tops & subs. heavy at around 50 pounds. No DSP or other fancy bells & whistles.

Behringer EP2500/EP4000
cheap, similar power to the previous two, good on tops & subs. about 35 pounds. No DSP or other stuff.

QSC GX5
cheap, but won't bridge or run 2 ohm stereo loads. mid-weight around 25 pounds. No DSP but has a useful built-in 100Hz cross-over if you want to use it for both tops and subs in the future without an out-board cross-over.


And since you asked I currently own XTi 2000s, EP2500s, and an RMX2450. I no longer use the XTi amps for subs (they suck at it) and I bought the RMX2450 for subs (because it's too damn heavy to use for anything else!) The Behringers are pretty much all-purpose. I am getting an EPX3000 as soon as they can ship one, but I suspect it will be useless for subs too and will just free up an XTi from top-duty.

_________________
Jeff Wheeler, moonlight DJ/KJ

The S115V should have an amp at least 500 watts per channel (750 at the 1.5 times rating).

_________________
LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!