As of yesterday I managed to melt the voice coil of my second sub, and im trying to replace it with something that will last longer than a month.

I initially bought a dvc (4+4) infinity perfect 10 rated at 350 rms.

But than I found a really good price on a mtx 600.1 amp. The power sheet on the amp rates it at 714w RMS @ 2 ohm (14.4v)

So i decided to try and wire the infinity to it despite the power overload and planned to turn down the gain. Amp was wired at 2 ohm and needless to say melted after three weeks.

Then I replaced it with a pioneer premier 10" dvc (4+4) rated at 750rms and 2500 max. It was also wired at 2 ohms and ran great, for 3 weeks at which point it melted last night


So here's my question, im gonna abandon my single sub apporach and likely get 2 10" alpine Type R's (DVC: 2 + 2ohms) and run the two subs at a total load of 2 ohms. They're rated at 500w rms each.

Will this survive ??? is there anything else i should consider ?

 

consider getting extended warranty wherever you get these subs... cuz apparently you are running these mad hot so no matter what sub you get it may eventually go. Extra $20-30 at circuit city for extended warranty covers you 2 years no matter how much you blow them and can eventually get your money back (gift card form).

 

so where did you set our gain at? What type of input is the amp getting also?

 

the gain was set at about 75-80% of max but with the infinity i used to also have the remote gain controller connected and that was also set to about 75-80%

With the pioneer the remote gain controller was disconnected.


For the feeds im using the actual amplified rear speaker lines (amp to speakers) and then using the amps internal cross over to get the low freq. The car is a 2007 sedan with studio on wheels. Would it make a difference to tap the headunit outputs (between h/u and amp) instead?

Is there any benifit in using ported versus sealed boxes in terms of heat disipation? I was using a sealed fiberglass enclosure.

 

stop getting a 2ohm setup and get a bigger mono amp like a 1000.1

 

i dont see how this would help ? running a 4 ohm load or a 2 ohm load only changes the strain on the amp and not the subs.

if I run a 4 ohm setup off a 1000.1 amp, less current will be drawn and the amp will run cooler, but the watts delivered to the subs will still be equal (or similar) ... unless im missing something

 

I think you should look into how to adjust your gains properly. If your amp wattage is close to the max recommended power for the sub, you can easily send some horribly clipped signals to the sub and trash it. And no, I don't care what people say, you can't HEAR clipping unless it is EXTREMELY bad.

If you want to adjust gains correctly, do this:

1 Get a mutli-meter with V-AC readout capability.
2 Make a test tone CD with 50Hz (or 80Hz) sine wave non attenuated test tone. . .make it like 10 minutes. (you can download these MP3s all over the web.)
3 disconnect all the other speakers (or get ear plugs)
4 hook the voltmeter up to the +/- output that the subs are on. Unless you have an amp with a switching power rail, you'll have to keep the subs hooked up. (I doubt the MTX has switching power rails.)
5 Figure out how many V-AC your desired wattage is at your current resistance. . .Sqrt(Ohms times Desired Power). . .For you, desired power is what power you want going to your sub(s)
6 Since you're using the factory deck, set your BASS to what you are going to listen to it at (like bass = 3)
7 Set the gain to FULL OFF and set the volume on the head unit to 75%
8 Start the test tone
9 SLOWLY turn up the gain until it reaches your desired Voltage.
10 Done. Enjoy listening to your stereo KNOWING that you have clean bass at 75% volume that will not "melt" your voice coils.

My system example:
NINe.1 and 4 7kV2's: 200W per sub x 4 subs: desired 800W at 2Ohms.
V-AC for gain: SQURT(800*2) = 40VAC. I have it set slightly lower than that (39.5VAC) just for a little extra protection.

There are similar methods for setting crossover points. . .but that's another story.

Hope this helps a bit!

-andrew

 

What do you do?

Simple....

TURN DAT MAWFAWKER DOWN!

 

if you have to push your amp that high you need a bigger amp

 

JL Audio FTMW!

 

Quit getting dvc subs. Get a single 4 ohm coil and run the amp at 4 ohms.

The amp will run cooler at 4 ohms mainly because it is creating less power (and because it operates more efficiently under a bigger load). Less power means less strain on the sub.

I've never heard of clipping caused by too much amp output power. Clipping is caused when the input signal is higher then the amp can handle. This causes the amp to reach max output before the input signal is maxed out, causing a 'plateau' effect on the output signal.

Remember, gains are not volume controls. The point of the gain is to match the output of your head unit with the input of your amp - thus preventing clipping.

 

Interesting math here. I'm assuming you meant 20VAC, as sqrt(400) = 20, not 40!

 

I think this is your problem. You are sending speaker level signals into the low level input of your amp. You may be clipping the signal going into the amp before it gets to the amp and it may be amplified to clipping again.

Try using a LOC. Or better yet, do as you suggested and tap into the audio signal before it goes into the OEM amp. It the SOW is anything like the Bose amps, it adds it's own equalization that may not be of benefit.

 

I fixed it above. LOL SQRT(800 [desired power]*2 [impedance]) = 40 VAC

thanks for the catch!

 

I'm not married to a Math teacher for nothing!