what happened??!!

schroedes · Post by **schroedes** » Sun Apr 11, 2010 1:31 pm

Ya the one sub is still running fine, sides for the other sub are capped off, I guess I didn't check to make sure they were both dual 4 ohm, I will though, if it was amp how could I test that? Would the amp be ruined?

Post by **Eric D** » Sun Apr 11, 2010 6:09 pm

Put a DMM across the output of the amp in DC mode and check that. You should read much less than 1V. Also put the (-) lead on the DMM on your amps (-) input source and touch the (+) of the DMM to each speaker output in DC mode. This will confirm if your amp has the DC offset output like many Class D amps do.

schroedes · Post by **schroedes** » Sun Apr 11, 2010 7:01 pm

OK, I will try that, thanks a lot man

schroedes · Post by **schroedes** » Mon Apr 12, 2010 1:48 pm

OK, pulled the amp out and took back off, didn't see anything fried or anything on circuit board, also the other rsdc I had that didn't fry has a slight smell to it, normal?? Tried to hook up the good rsdc and good Atlas to see if it would work, both dual 4 ohm, amp went into protect mode right away, but with just the one good Atlas everything seems to work fine, if I test the amp with my dmm, what is DC mode?? And what exactly am I looking for?? Thanks

schroedes · Post by **schroedes** » Mon Apr 12, 2010 1:57 pm

What exactly is the DC offset mode?? And how would the amp send out a DC signal?

gridracer · Post by **gridracer** » Mon Apr 12, 2010 2:16 pm

schroedes wrote:if I test the amp with my dmm, what is DC mode?? And what exactly am I looking for?? Thanks

That would mean set your DMM to DC (direct current) and if you get a reading in DC volts from your amps outputs you have a problem with your amp.

Post by **Eric D** » Mon Apr 12, 2010 2:19 pm

If you put the DMM in DC mode as stated, then put it across the terminals of the amp (output terminals), you should read very little DC voltage. If you are getting high DC voltage, then the amp has a problem.

What size fuse is on the amp? You may wish to install a smaller fuse, say 15A, and see if it blows. If it does blow (no speakers connected), then your amp really has a problem.

schroedes · Post by **schroedes** » Mon Apr 12, 2010 3:39 pm

LOL, thought you were talking bout DC mode on amp, thinking wtf, OK ill do that and let ya know, amp is Brutus 1610 with 2 70 amp fuses, what would make an amp send out a dc Signal ?

schroedes · Post by **schroedes** » Mon Apr 12, 2010 3:40 pm

And I don't need load connected to do this test right?

Post by **Eric D** » Mon Apr 12, 2010 7:24 pm

No load. No RCAs needed either. Just power (B+), (B-), and remote.

If any of the output transistors short on an amp it will output DC (at the rail voltage). Class D amps often have a output relay to help protect the speakers, but if a transistor is shorted and the amp has no method to detect this, it will still close the relay and fry the speaker connected to it.

oldskoolmseriesfan · Post by **oldskoolmseriesfan** » Mon Apr 12, 2010 9:19 pm

Wow,this is a long tutorial, but I think its very informative and in the future if anyone has this same problem, we could just direct him to this thread.
Thank you to ERIC D for having the patience to lay it out in laymens terms and for being very thourough, schroedes, just follow and you will learn the jedi ways. Im just waiting to see where this ends up, I hope its an easy fix for you schroedes.

Im not sure if I want to ask you this but where did online ID "SCHROEDES" come from?

schroedes · Post by **schroedes** » Tue Apr 13, 2010 7:38 am

Haha, thanks a lot man, ya I hope to figure this out, gotta send it back to sonic and they are gonna test the sub and send me a new one, still waiting to get my meter, out of town right now, name just comes from my last name

schroedes · Post by **schroedes** » Sat Apr 17, 2010 3:55 pm

OK, I did what you said, read about 6 millivolts, on the outputs, from the input to each output was 12.4 volts, so I'm thinking the amp is fine??

reallyxxxxxxloud · Post by **reallyxxxxxxloud** » Sun Apr 18, 2010 12:55 am

Not fine if its an intermittent short. Would a short in the winding of the Transformer cause this maybe? I have seen it a heap in the PG 9001D Transformer... It was the same amp as the Fusion FP-9001D.

dontlookatme · Post by **dontlookatme** » Sun Apr 18, 2010 1:24 am

maybe one was able to just handle it and the other wasnt. who knows why good things break down for no reason. but that could just be the only answer u have. ur options are limited, send the sub back to where u got it, send the amp back or both. or put another 2 new subs and see if u blow them. i had an amp blow some speakers and both on the same channel months apart. once day the amp just stop working

vingasoline · Post by **vingasoline** » Sun Apr 18, 2010 9:07 am

[quote="schroedes"] Tried to hook up the good rsdc and good Atlas to see if it would work, both dual 4 ohm, amp went into protect mode right away.

The amp is broken. I'm guessing when the rail voltage switches to compensate for the 1 ohm load it causes a problem with another component and sends the voltage right to the subs.. Just cause their wired parallel doesn't mean they should both be wrecked.. The amp could go into protect before damage to both woofers occur. Also, if they were wired out of phase, you would only damage one woofer.

and if you can unintentionally fry 2 subwoofers with the same amp, it's either user error, or the amp..

dontlookatme · Post by **dontlookatme** » Sun Apr 18, 2010 9:40 am

schroedes · Post by **schroedes** » Mon Apr 26, 2010 12:35 pm

Well sonic is sending me another new sub, how could I know if its the amp? I really don't wanna hook it up and blow my new subs again, any ideas?? Would it be safer to just wire em for 4 ohms instead of 1?? Thanks guys

schroedes · Post by **schroedes** » Tue Apr 27, 2010 4:34 pm

???? Anyone?

Post by **Eric D** » Tue Apr 27, 2010 6:03 pm

Hook the amp up without any speakers first and then see if it works by seeing if it will output a signal into your DMM.

schroedes · Post by **schroedes** » Wed Apr 28, 2010 10:52 am

Ya I did that, refer to above, 12 volts at input and very small voltage at outputs, I just don't wanna blow a brand new sub again ya know LOL, amp is nearly brand new as well

Post by **stipud** » Wed Apr 28, 2010 10:58 am

schroedes wrote:Ya I did that, refer to above, 12 volts at input and very small voltage at outputs, I just don't wanna blow a brand new sub again ya know LOL, amp is nearly brand new as well

How small of a voltage are we talking here?

How have you set the gains? I highly recommend you try this method to set them:
http://phoenixphorum.com/gain-setting-w ... vt280.html

You shouldn't be reading much, if any DC with the gains set properly like this.

schroedes · Post by **schroedes** » Wed Apr 28, 2010 11:09 am

Less than a volt at outputs, I still have a rsdc I could sacrifice to to test the amp somehow? Like I said the amp ran the one new Atlas fine just kind of lost

schroedes · Post by **schroedes** » Wed Apr 28, 2010 11:16 am

I'm just kind of lost I meant, really don't wanna blow new Atlas again, pain in the ass to return last one

Post by **stipud** » Wed Apr 28, 2010 11:38 am

If you don't want to blow subs then make sure your amp doesn't clip. If you don't want your amp to clip you have to set the gains properly. One of the ways to do that is set them with a multimeter and test tone.

All you need to do is play a 60Hz tone at 3/4 deck volume, all equalization disabled, and with no speakers connected. Then measure for sqrt(1200*4) = 69.28 volts A/C at the amp outputs. Leave bass boost off, forever. Odds are that this will be much quieter than where you set them previously. Benefit is, if you crank your bass music, you won't blow anything.