spl 7250 2U poweramp...

[cm]

Hey there,

I am using the spl 7250 to drive two floor monitors that are 65 watts/8 ohms each. And it just isn't very loud, at all. On the back, the amp says, "250 watts/4 ohm minimum load per channel" for two quarter-inch jacks. It also has two "banana" plugs that say, "450 watts/8 ohm minimum load". So how do I calculate the ohm load? And what does the "bridging" function actually do?

Any insight or info is appreciated...

[Don T.]

Hello:
 What they are talking about is that each channel of the amp can handle a 4ohm load. The bridged outputs are simply the "hot" of each channel going to the speaker with channel 2 (or B) putting out an inverted signal so the speaker actually sees the difference between 1 & 2. It doubles the voltage out. The transformer however "sees" 1 & 2 in series so 8ohms bridged is all it can handle. HOWEVER!!!!! somthing isn't right cuz 185 watts (dual channel 8ohms) is still pretty loud unless you don't have enough drive to push the amp into clip. Another thing is those pesky speaker ratings. Back in the 70's we rated them at RMS power (say 65watts) then in the early 80's manufacturers began rating at program power (now that same speaker is 130watts) and later they began rating in peak power so that same speaker is now 260watts. I think they did this cuz it sounded like you get more bang for the buck. Some say that program power better represented what actually arrived at the speaker in PA or stereo use and peak power tells you the amp size you should buy. Oh well. One last thing. If you are using an EQ maybe you are sucking the life out of the signal when eliminating feedback (real common with 10 band graphic EQ's). Hope this helps.
Don T.

[cm]

Thanks for the response. I decided to see if I could drive the amp a little louder at the input, so I turned the monitor output from "0db" up to "+10db" on my old Peavey Mark III mixer. It got condsiderably louder. Before, I was just afraid to crank the monitor output lest the signal distorted. But it sounds OK even though we're "in the red" on the output meter. I guess there's some headroom built into the mixer. I think I'll save some money and NOT switch to the banan plugs.

Thanks again, Don T.

cm