Power amp Query

8k2q1gfcz9s5d4

Hi all,

Over the last few years ive built up a ok knowledge base on mixers and speakers for live sound, but ive always over looked poweramps .

any way, long story short, im in a new band and were after buying a second hand pa system. Were running it as a 2 way system, and one of our power amps has seen better days to say the least. its a t.amp power amp it was broken when we got it, got it patched up in joe o niell's but its not able to power our tops or bins well enough. we tried out our pa at a practice, cranked the power amps, very little sound, couldnt hear vocals over the drums. Tried our monitor power amp on our pa speakers, worked perfectly, and we didnt have to crank it too much (our monitor power amp is 700watts a side, the t.amo is 1350 watts a side!)

anyway, looking to get a good quality power amp, without breaking the bank :rolleyes: nearly broke after buying the PA! budget is around 600-700
looking at some of these, but to be honest kinda lost.

http://www.thomann.de/ie/db_technologies_hpa_2800.htm
http://www.thomann.de/ie/dynacord_sl1800.htm
http://www.thomann.de/ie/ev_q99.htm

these are the bins and tops we have

Bit of a noob question, but, lets take the dynacord amp, which gives 900 watts a side, would it be good enough to power our bins? would it be better to put a good quality dynacord amp, which is a little low in power, than a higher powered cheaper amp?

thanks in advance for all the help!

Frank

Savman

http://www.martin-audio.com/products/F215+.asp

Your tops need 600W-1200W of amp power, according to the manufacturer. I'd tend to shoot for the highest figure possible here for headroom.

http://www.martin-audio.com/products/S218+.asp

These beasts require 1000-2500W of amp power.

Both boxes are 4ohms so make sure you are reading the poweramps output at 4ohms (not 8 or 2). And don't try slave 2 boxes off the same amp channel, all but the tour grade amps will fail, and even some of those won't do it as you'll be running at a 2ohm load and trouble will be in the post.

So you need a pair of beefy amps running one speaker per amp channel.

BTW the EV and Dynacord amps you linked to are much the same unit, perhaps not sonically, but EV and Dynacord share so many components the differences are negligible IMHO.

The amps seem a fine match for your tops power requirements, but for Subs I'd most definitely be looking at something larger. You need a whole lot of power to push out a pair of dual 18" drivers, underpowering here will not do your system any benefit. Even if you landed in or around the RMS/AES figure this would be ideal.

markwho

Having the same problem. Know very little about power amps, how they work and their circuitry. Anyone know of some decent books, or decent articles online that can help?

8k2q1gfcz9s5d4

Savman wrote: »

http://www.martin-audio.com/products/F215+.asp

Your tops need 600W-1200W of amp power, according to the manufacturer. I'd tend to shoot for the highest figure possible here for headroom.

http://www.martin-audio.com/products/S218+.asp

These beasts require 1000-2500W of amp power.

Both boxes are 4ohms so make sure you are reading the poweramps output at 4ohms (not 8 or 2). And don't try slave 2 boxes off the same amp channel, all but the tour grade amps will fail, and even some of those won't do it as you'll be running at a 2ohm load and trouble will be in the post.

So you need a pair of beefy amps running one speaker per amp channel.

BTW the EV and Dynacord amps you linked to are much the same unit, perhaps not sonically, but EV and Dynacord share so many components the differences are negligible IMHO.

The amps seem a fine match for your tops power requirements, but for Subs I'd most definitely be looking at something larger. You need a whole lot of power to push out a pair of dual 18" drivers, underpowering here will not do your system any benefit. Even if you landed in or around the RMS/AES figure this would be ideal.

Thanks for the help!

We have a HK audio power amp powering the bins at the moment, i think its 1200 watts a side, cant remember exactly, but i think its on the way out as well :mad:

markwho

Genesis Long Silverware wrote: »

I might get given out to for this, but Power amps have become a lot cheaper over the years. You could get a new cheap 1200watt amp for what it would cost to repair a crown etc.
I used to have a crown and if it broke, it broke the bank. Big bucks. But if you had a €200 1200 watt and it goes, its cheap to replace.

There a loads of reason cheap power amps are cheap and expensive power amps are expensive.

First of all cheap power amps are not very efficient, some cheap brands are only up to 20% efficient, whereas the more expensive brands can be up in th 50/60% range, even up to 75% in some cases.

Also, Cheap power amps break far far more often, if you're gigging a lot you could look at replacing them 2/3 times a year. They just can't handle the workload at all. Whereas if you have nice upper range dynacord/hk audio power amp, they're built to last years. Only thing bad to happen those are loose connections, which is usually caused by bad care of the amps, and is easily fixed also.

And then there's features that the more expensive power amps come with. Limiters, fade ins. Things that stop the power amp blowing your speakers. Which with cheap ****e power amps, it can be very easy to blow your speakers. And if you got expensive speakers, its far more of an annoyance to get those fixed

So, really in my experience, the extra 7/8 hundred euros is money well well spent.

PaulBrewer

There's also the issue of sound ?

Savman

PaulBrewer wrote: »

There's also the issue of sound ?

GTFO.

noodle650

Genesis Long Silverware wrote: »

I might get given out to for this, but Power amps have become a lot cheaper over the years. You could get a new cheap 1200watt amp for what it would cost to repair a crown etc.
I used to have a crown and if it broke, it broke the bank. Big bucks. But if you had a €200 1200 watt and it goes, its cheap to replace.

the sound quality of a Thomann amp, or any other cheap branded amp, even Peaveys will not have the sonic Clarity of Crest, Crown, QSC, BSS, good Yamaha, Dynacord or Matrix. Tried my subs through my thomann monitor amp, then through my matrix Str 1200 and the difference was incredible