2nd Eclipse sub fried with Diamond amp

Ok, here's a quick run down. I have a Diamond Audio 1200.1 wired powering 2-10" Eclipse 7104 DVC's wired to 1 Ohm. The amp gain is turned up 75% and before toasting  the sub I was getting some distortion when turning the music up to a moderately loud level. The box the subs are in is below spec for air space if that makes a difference. This is the second sub I've gone through. Probably only reason it hasn't been more is because the car has been garaged during the winter. With the distortion I obviously have a problem some-where. I was told by the installer that it is my amp throwing DC into the subs which would do the trick. The amp is practically new and have my doubts about that scenario. Don't think its the subs at all either. I'm thinking possibly the wiring, but can't find a diagram for the 1200.1 to look at and check. Subs are wired right, already checked that. The amp is buried, so I didn't have time to unhook it all and check it.  Probably take me half a day to  test everything out. I know a local contact that did have a spare 1200.1 that I could try out, but lost his number. So Dave if you're reading this please PM me if you get a chance. Any and all suggestions are appreciated. The installer and I are not on good terms so I can't take anything he says as being truthful. He would never admit doing anything wrong if that is the case. All I know is that from day one the system has not sounded good or worked correctly. Thanks again for the help.

Sounds like your amplifier is clipping, probably because the gain is WAY too high.  Plus your amplifier wired to one ohm will produce 1200 watts, and your speakers are only rated for 400 watts, so you are also overpowering them.  Either condition will fry a voice coil, both together are pretty much guaranteed to do so.

-------------
Support the12volt.com

I agree, too high a gain and too small a box. Your overall level of output is going to be determined by the box. Get it too small and 99.99% of the people work the gain control and overall output levels wrong trying to make the sub do something that it can't. Fix the box, give each sub about 1.25 cu.ft. gross sealed volume and your response is going to come alive. Turn the gain down, an amp makes the same amount of power regardless of where the gain is. All you are doing is matching the output level of the headunit to the input level of the amp, get it wrong and clippity clip clip poof. The amount of power you have on tap can run a sub all day long, provided that you do not take the level and keep it sustained, this does not allow the subs to cool which in turn will melt the coils / former.

-------------
Top Secret, I can tell you but then my wife will kill me.

When you clip an amp, it produces a 'square wave' which means that the 'squared' portion of the wave is clipped and is sent to your sub as DC current.  This is BAD!

With a multimeter you can properly set your gain.  I wish I knew the steps offhand - can anyone help?

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

So I'm back to the box too small problem again...which he denies up and down. He says it is built to spec. Wish I had a picture, you guys would honestly laugh. That was my main point to him and he denies that it is out of spec at all. He's wrong, and like I said, he'll never admit otherwise. I do understand the clipping issue, but didn't think the amp was turned up too high. Looks like I'll be hunting for another sub...again. Woofersetc gave me a pretty good deal last time. I'm going to take pics of the inside of the box measurements and post them and let you guys flame. I think its a good .5 cu ft too small which is huge.

A "too small" enclosure will not cause your woofer to blow.  It is the act of turning the amp up too much trying to compensate for the lack of boom from too small an enclosure that s the problem.  How did yu set the gain?

-------------
Support the12volt.com

Thats exactly right!  I have a 1200w amp pushing my 750w eclipse titanium.  Just make sure you set it correctly.  Over compensation is the enemy.

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

I didn't set the gains myself actually. I checked how the gains were set and put them back in almost the exact same position. Wish they were top mounted, quite the task just to adjust gains and frequencies on my amp the way it sits. The fact is, there is a total lack of "boom" from the system, which I complained about. He turned around and bumped up the gains to satisfy me for the time being. I understand what you guys are saying and agree that the subs are not being allowed to cool properly and the voice coils are frying due to the amp being set to high for the sub/enclosure setup. Where the gain is set now requires a much larger box, probably double what I have now. I need to start searching for a sub right now so I can work on this asap. Its just frustrating. I told the installer I wanted .75 cu ft each sub and he just does it to "spec" from what he says was in the manual. I think he ended up building a little over 1 cu ft for the two without the subs installed. Not nearly enough space. He did this because he didn't want to glass the spare tire well. He ended up building a rectangular wood box instead to save time.

OK, two issues.  First you should set your gain to match the output level of your head unit ONCE and LEAVE IT THERE.  It is a one-time adjustment.  Do a search on this forum if you do not know how to do this and set it correctly or you will continue to blow speakers no matter what you do.

Second, I can't find the proper enclosure size for that woofer, but from the (really marginal) specs listed on the Eclipse web site, it looks like you need at least 1 cuft for each of those woofers; 1.75 cuft sealed looks like best performance... like forbidden suggested.  He is an Eclipse dealer and he cares about good system performance, so he would know.  Listen to him!!  By the way what does the owner's manual suggest?

-------------
Support the12volt.com

First of all, set the gain correctly as stated above. Secondly, I would highly suggest rewiring the amp to a 4 ohm load. I had my 600.1 doing 1 ohm and it was getting hot real fast and clipping a bit. Ended up asking about it and rewiring to 4 ohm and it gets louder and sounds so much cleaner even with half the power, and it never even feels warm to the touch any more.

-------------
2003 Chevrolet Silverado Standard Cab ~ Alpine CDA-9851
Diamond Audio D3600.1 ~ 2x Diamond Audio TM310D4
Diamond Audio D3400.4 ~ Diamond Audio Hex S600s
AstroStart RS5204 Remote Start/Alarm

Owners manual actually says .6 cu ft each sealed enclosure, but it has been posted many times that .75 or higher is needed. I have considered re-wiring to a 4 Ohm load also. Probably order a new sub from woofersetc today to get the ball rolling. Thanks guys for all the input. I think I'm better off tuning everything in myself than trying to take it back to the shop. I have read how to match it with the head unit several times and don't think that will be a problem.

You'll also be better off buying your speakers from a local authorized dealer rather than ordering from a place like woofersetc.  That way you'll have access to the manufacturer's warranty.

Amplifiers run better at higher impedance loading.  I highly recommend building a 4-ohm load, especially with a good SQ amp like a Diamond.  And again, those speakers model in WinISD needing 1.75 cuft sealed EACH.....

-------------
Support the12volt.com

Well, in my case, even if I had the warranty its no good on burnt voice coils from what I've been told. I might call and see what their price is anyways though. thanks.