Dayton SA1000 Issue

[fan4fan1]

Hey guys, got this model amp recently to drive my new THT-LP. It's worked very well until tonight. I lost it (stopped outputting) after some extremely loud bass during the new Spidey movie, I cut it off for a couple seconds and when I turned it back on it was working again. For about 3 minutes--then it crapped out again. The blue power light stays on all the time, even when it stops putting out.

Using a Dayton RS 15" sub in a 74" inch THT-LP built by Rick Lee of Tennessee. I guess I'm overloading something, but with the high efficiency of the design is this supposed to happen? And if Parts Express's baddest-ass sub amp is this fragile, what should I be thinking about instead? Some kind of Crown monster?

Thanks for your help...

John

[CoronaOperator]

There could be a few causes of your troubles. How hot is the amp getting? If the amp overheats it will shut itself off until it cools down to protect itself. The amp will also shut itself off if it detects a short circuit or low impedance load ; AKA a blown voice coil or shorted speaker cables. It is a possibility (blown coil) because the amp you are using can put out twice the power that your speaker can handle. How loud were you listening to it?

Some other possibilities are a loose or shorted cable, both outside the cabinet (signal or speaker cable) or inside the cabinet (speaker cable or tinsel leads on the woofer itself). You may even have a bad amplifier.

If you can reproduce the problem take out a dmm and measure the AC voltage across your speaker terminals. That will let you know if its a problem with the amp or signal (no voltage) or further down the line (speaker).

[Radian]

If you can reproduce the problem take out a dmm and measure the AC voltage across your speaker terminals.

BIG +1

Must have a multimeter to set up a component amp correctly. It's not optional. Whether you had a Crown, QSC, or another Dayton....gotta use a meter.

Things to investigate:

-What input are you using on the back? L,R, or LFE
-What's the maximum voltage witnessed at the input of the amp when it exhibits shut-down?
-What's the DCR of the THT-LP as wired? Should be 2.8 Ohms at the leads, when disconnected from the amp.
-What's the "freq" knob set to? Should be set to some value well below 90 (11 o'clock)

Double check the switches on the back. They should be set to:

Subsonic Filter - OFF
Bass Boost - OFF
Remote Turn On - ON

[fan4fan1]

Thanks for all the advice everybody. The technical stuff is really appreciated but I may not have made myself clear, I'm not a builder, just a buyer. I have no idea how to measure the specs as suggested and I can't ask my builder to drive all the way over here to hold my hand (though I'm sure he would).

So I went ahead after experiencing the problem several more times and switched the SA1000 out for a Behringer A500 I had on hand. It's significantly lower in measured power specs than the Dayton but I wanted to try it out anyway. It worked perfectly, not a hiccup! Shook my HT like nobody's business on the Green Lantern movie with just an occasional red clipping light. Good thing my old lady was out of town! So the Dayton is going back next week and I think I'll just stay put with the A500 in place. I'll find something to use that extra $300 on, I'm certain.

Thanks again!

John

[Radian]

Shook my HT like nobody's business on the Green Lantern movie with just an occasional red clipping light.

The system is setup wrong.

This is bad, and is why the SA1000 is caching out.

It's clipping the line-level signal going into the subwoofer amp.

The system should not be clipping the input signal...ever . That is bad sound.

The A500 has visual meters to tell you this is happening. The SA1000, on the other hand, has a LED that will change color as this is happening. It's quick acting, masked by the blue light, and can be hard to see if you're not looking for it. If it exceeds its duty cycle, it will trip off to protect itself from getting fried.

It's purely a gain staging issue and is not related to the quality of the amplifiers you're choosing to use, or the specific type of speaker you're driving.

This isn't about being DIY, or a builder, or a buyer....or even this amp vs. that amp.

The system runs on electricity...so to make sure it's doing what it's supposed to do (what you paid for it to do) requires at a minimum the use of a multimeter.

[biggerrigger]

It clearly states in the manuals for both amps to not run them into clipping. If you do it may damage equipment as you have found out.
You need a multimeter to properly set up your sub and amp combo. You need to look in your set of plans that came with your sub to find the correct voltage limit or contact your builder for that info.

[subharmonic]

I think I'll just stay put with the A500 in place.

http://billfitzmaurice.info/forum/viewt ... 5&start=45

Same amp I am using, 67 volts is no joke. Are you bridging the outputs or just using one side? Either way that thing should be scary loud if you are clipping.

[fan4fan1]

PM sent to Radian