Help! I'm blowin subs like crazy!

[bangin camery]

I need help wiring my Hollywood Edge 12-12d sub to my AUTO-TEK SX2300 amp. The sub has dual 4Ohm voice coils with 800rms and 2400 peak. I heard that if you parallel wire the two 4Ohm voice coils it reduces the sub down to 2Ohms, is that true? My amp is a two channel amp, but pushes 800 watts at 2Ohms when it is bridged, I think it is 1Ohm stable but I'm not sure. After I break the sub in and turn up the power on the amp it only takes about 3 weeks to a month for thing to blow. Please help on how to wire it up. Thanks!

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[helotaxi 5,000+ posts]

A few questions:

1) Are your gains set correctly?

2) Are you cooking the coils, or is the sub coming apart?

3) What type of enclosure is the sub in?

 

[bangin camery]

The power on my amp is turned all the way up and the bass thrust is turned down a little. I think that I am cooking the coils because when I tap the cone it sounds like there is sumthin loose in the sub. The sub is in a 1.1 cubic foot sealed box. Any other questions? PS does anyone know if the amp is 1Ohm stable or not?

 

[LBX2G 10+ year member]

yep ur amp is clipping. Those new autoteks tend to do that. Turn Gain way down like, all the way, then adjust it from there. DO not go nomore that halfway.

 

[bangin camery]

Thx for the advice ill have to try it, but the amp is not brand new. it just started doing this when i got the Hollywood. Do you know much about Hollywoods? they are popular where i'm from.

 

[helotaxi 5,000+ posts]

Your first order of business is to learn what a gain control is for. It is not a volume knob. It is not a power level control. Its sole purpose is to match the output level of the previous component in the signal chain (EQ, crossover, headunit, etc...) to the input stage of the amp. The reason it is needed is every component has a different output voltage level. The gain control ensures compatability. Every amplification stage in every component has a maximum voltage that it can output. It also has a fixed amplification ratio. For example that ratio of your output stage on your amp is 12. The preamp stage feeds a 1 volt input to the output stage and you get 12 volts from the outputs. Say you still have the 12 ratio and a maximum voltage of 24. The input stage feeds a 2.5V signal to the output stage which tries to output 30V (12*2.5V) but since it can only produce 24V, everything beyond 24V is "clipped" off. This clipping produces distortion and generates a lot of heat in both the amp and the speaker. It is usually the heat from clipping, not excess power that blows sub voicecoils. The moral here is set your gains to match the level of you HU outputs. Half-way is usually more than enough. Set it too high and the amp will start to clip at low volume settings. Set it too low and you won't get full power out of the amp which in my opinion is much better than toasting subs on a regular basis.

The other way to blow a sub is to give it too much power for the enclosure that it is in. What this brings about is the sub reaching its mechanical limits and literally beating itself to death. Sub manufacturers are generally pretty good at telling you what the displacement limited power handling of their subs are. Most will be able to give you an enclosure size and the max power that you can feed the sub in that enclosure. Try contacting Hollywood.

 

[bangin camery]

Thx for the advice but i dont think that there is a Gain knob, but i know what you are talking about. There is a power, bass thrust and a couple others but not a gain. which one would i need to turn down.

 

[somekook 10+ year member]

the gain might say input or level... look through your manual.im thinking that the "power knob" is actually your gain

 

[helotaxi 5,000+ posts]

Well, the gain CAN be used to control power levels and can be used as a volume control.

But can only limit power not make more.

Clipping doesn't technically generate a lot of heat (generates MORE heat), because instead of having a single peak in power like you would with an unclipped signal, you have a plateau where the amplifier is hitting peak power for a longer duration of time.

Exceed the capacity of the amp and sub to dissapate heat for any extended period of time and you quickly have a lot of heat. Clipping is one of the quickest ways to do this. Basically, you exceed the max duty cycle of the output device; not a recipe for its long life.

 

[helotaxi 5,000+ posts]

True, inside the amplifier it does. However, an insanely clipped signal from the lowest of the low Pyramid amplifiers isn't going to phase a Kicker SoloX //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Also, a clipped signal before the input stage of the amplifier may not push the amplifier past its limits ...

The lowest of the low Pyramid amps probably won't even move the cone on a SOLO-X //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif not that the amp would survive long enough at a horrendously clipped setting to even think of warming the sub up. Clipping before the input stage will not necessarily hurt an amp, no. Clipping the output of an amp may not hurt the amp either. On the other hand, either also may. The only way to find out is to clip the amp and see what happens (or sit down with the exact specs and schematics of the amp and all the components in it and a calculus book and calculator). I'll pass on the smoke check on my amp, thank you. I would much rather under power a speaker by a few watts (that I likely wouldn't hear anyway) than risk cooking my amps or speakers.