Need Advice/Help on blowing Subwoofer's

[Ksan 10+ year member]

Ok, guys I'm not sure if it is natural, a run of bad luck or something I'm doing wrong. Wanted to get some opinions before I buy another Subwoofer though. I've had two Image Dynamic IDQ 12" in a sealed box running on a Image dynamics 1200.1 amp for around 5 years and finally they blew a couple weeks ago. A friend I know had a Sundown SA-15 sub and I sat in his truck and listened to it and it sounded fine and played good. I bought it from him for $100 and built a Box for it. A 3.2^ tuned to 32Hrz. It is a dual 4-Ohm sub and I could only wire it to a 2-Ohm load on my amp but today the sub blew.

It was getting around 800 watts at 2-Ohm and my Gain is set to around 64% and my Bass Boost is turned off. I had it wired + coil 1 to + coil 2 to and - coil 1 to - coil 2 and then one coil + to amp + and other coil - to amp - . If I still remember right that would be a 2-Ohm load on a 4-Ohm dual voice coil sub?

I am simply not sure why I've blown those sub's. Maybe the IDQ's were just getting old and had been played a long time and maybe the Sundown already had something wrong with it being second hand? Could be why he sold it to me in the first place but the thing is the Sundown played fine for several days before blowing. I'm going to be ordering new sub's and I'm pretty Set on either 2-Incriminator 12's or 15's, 1-Xcon 18" or 2-Digital Design Subs' 12's or 15's but before I buy I wanted to ask you guys if you think something else could be wrong, did I do something wrong or was it just a run of bad luck? Thanks for the help and I will give any more info you may need.

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[Mitch86 5,000+ posts]

Google "gain setting tutorial." Get a DMM and follow the instructions. More than likely your gain is set too high causing clipping and blowing the subwoofers.

 

[hispls 5,000+ posts]

You sure that Sundown was D4? I'd think you'd have to really be abusing SA 15 to blow it up on 800W or less. You certainly should have at least smelled it getting hot and angry and had a chance to turn it down before it failed.

 

[Ksan 10+ year member]

You sure that Sundown was D4? I'd think you'd have to really be abusing SA 15 to blow it up on 800W or less. You certainly should have at least smelled it getting hot and angry and had a chance to turn it down before it failed.

See that is exactly what I was thinking. No way it blew on 800 Watt's but it just started playing fuzzy and lost 90% output. Never smelled anything so it has me thinking I did something wrong and it wasn't the subwoofer but a problem that I need to fix in my install. I don't want to buy more subs and then screw them up too. I need to figure out what went wrong on this and fix it.

The guy I bought it from told me it was a D4 I ask like 3 times. I'm going to pull the sub and meter it to see what the coils are.

 

[i2ain2thunder 10+ year member]

No such thing as bad luck, only lack of knowledge, or experience. Set gains properly, use no boosts, (bass boost, eq boost, subwoofer level boost, all bad). Subs gain a ton of heat if they are not used properly and heat will fry your coil.

 

[fasfocus00 5,000+ posts]

gain at 64%, that's really specific and rather high unless your head unit is a 1v output. i bet you were clipping the $hit out of both setups. just having 2 coils handing the clipping would make it last longer than a single coil. doesn't matter power if signal is clipped. a clipped signal is pretty much the same as just heating up the coils with a lighter.

 

[Ksan 10+ year member]

Yea, there is no doubt it is something I did wrong. I set the gain using my ear which I know isn't good but was the best I had. I used a 34Hrz test tone and started with everything set to off and turned the gain until I could hear the tone change and then backed it off. 64% is a rough guess but I would bet money it is VERY close to 64%, At least as well as I can figure.

My head unit is a 4V. So what I need to do is go to a shop and have my gain set the right way with a scope? I'm being lazy on my day off and have not pulled the sub yet to meter the coils but will soon. Thanks very much guys for all of the help you're giving to a idiot like me. Live and learn I guess but I should know better by now.

 

[blazian87 10+ year member]

Yea, there is no doubt it is something I did wrong. I set the gain using my ear which I know isn't good but was the best I had. I used a 34Hrz test tone and started with everything set to off and turned the gain until I could hear the tone change and then backed it off. 64% is a rough guess but I would bet money it is VERY close to 64%, At least as well as I can figure.
My head unit is a 4V. So what I need to do is go to a shop and have my gain set the right way with a scope? I'm being lazy on my day off and have not pulled the sub yet to meter the coils but will soon. Thanks very much guys for all of the help you're giving to a idiot like me. Live and learn I guess but I should know better by now.

Instead of going to the shop to set gains correctly, just do it yourself with a digital multimeter and save money. I use the SMD DD-1 which is a simple easy to use device to detect where you clip at within minutes. It is a bit pricey but much cheaper than an oscope. BTW if your preout voltage is 4v, then most of the time the gain should be around 25%. 2v would need like 50% usually.

Here's some tutorial videos on how to set gains properly

 

[wew lad 5,000+ posts]

the dd-1 is not cheaper than an oscope. you can buy a dso nano v3 off amazon for half the price of a dd-1 and it's much more useful in other situations as well

 

[Ksan 10+ year member]

Well, I just pulled the Subwoofer and metered it. Both coils Ready 2.3 so that would mean it is a dual 2-Ohm and not a Dual 4-Ohm? Also if the coils still read 2.3 then they should be good?

 

[blazian87 10+ year member]

the dd-1 is not cheaper than an oscope. you can buy a dso nano v3 off amazon for half the price of a dd-1 and it's much more useful in other situations as well

Hmm.. didn't know how cheap oscopes were.. I always thought they were in the several hundreds.

 

[Jeffdachef 5,000+ posts]

Well, I just pulled the Subwoofer and metered it. Both coils Ready 2.3 so that would mean it is a dual 2-Ohm and not a Dual 4-Ohm? Also if the coils still read 2.3 then they should be good?

a little worn but still should be good. Check if you burned any softparts and check the coil. Play the sub free air too.

 

[Ksan 10+ year member]

OK sub is now wired to a 4-Ohm amp load and it is playing and sounding nice. What are the odd's it keeps playing with out problems after my stupid @$$ didn't check the coils, when I had a meter in the tool box right beside me and played it at 1-Ohm for like a week? Guess I will find out. Thank you all very much for the help.

 

[Ksan 10+ year member]

Well the sub is done, the guy had said it was a D4 but it isn't his fault, it is mine, I should have checked it to make sure. It would have only taken a few minutes to check. It started knocking pretty hard on the lows and now it has lost all out put. At least now I know where I went wrong at. I can move on with a hard lesson learned. Thanks guys.

 

[Tripn88]

Well it's only 50 bucks for a recone so your still on top if you want that sub.