Simple Sub Question

**MikeSomething** · 08-30-2006, 04:51 PM

If I underload my sub, will I blow it? I'm getting a 300w x 1 RMS @ 4ohm Fosgate amp... I'm gonna run a Eclipse 10" Sub thats rated at 500w RMS @ 4ohms w/ dual voice coils...now because the RMS is diff will the constant low power going to the sub make it blow?

**MikeSomething** · 08-30-2006, 05:12 PM

Originally Posted by Kages99

Personally i would go with 400w-500w @4 ohms amp to push the Eclips 10". But that's just me......

Well, LS1's aren't the cheapest things to mod, I'm lucky I had enough to buy the 300w...

I dunno tho, my friend sounded pretty convinced that underloading them can be just as dangerous. Just wanna play it safe and ask you guys!

**White Rascal** · 08-30-2006, 06:19 PM

As long as the amp's gain is set correctly you have nothing to worry about. If you use it as a volume control and set it too high you may run into problems.

**StangKiller615** · 08-31-2006, 12:16 PM

Underpowering a sub will blow just as easy as overpowering it. You allways wanna run a sub at 75% of the rms rating. So if you have a sub rated at 500 watts, you will want to take a look at a amp in thr range of 375-500 watts.

**MikeSomething** · 08-31-2006, 12:22 PM

Originally Posted by StangKiller615

Underpowering a sub will blow just as easy as overpowering it. You allways wanna run a sub at 75% of the rms rating. So if you have a sub rated at 500 watts, you will want to take a look at a amp in thr range of 375-500 watts.

Now it's you and my friend vs. the rest of the world. Why doesn't anyone else tell me this?

**White Rascal** · 08-31-2006, 05:16 PM

Recommended power is only a guideline. They are not set in stone rules. If a sub is rated at 300 watts it won't blow just because you sent 301 watts to it. Like I already said, if you set the gain properly and are not sending the amp into hard clipping there is nothing to worry about. Regardless of whether it's a 300 watt amp or a 1000 watt amp. That 75% of recommened power rule is a lot of nonsense.

**Wulfe13** · 09-01-2006, 09:02 AM

Originally Posted by MikeSomething

Now it's you and my friend vs. the rest of the world. Why doesn't anyone else tell me this?

He's right, underpowering is actually more likely to blow a sub than overpowering it.... within reason of course. You get more distortion with less power because the sub is trying to work to hard to get the power it needs. The more power you have the more control over the sub you have. Now if you're talking 300w sub being powered by a 1500w amp then obviously, that'll blow the hell out of it.

Now in your situation, I'd say just set the gain high but not high enough that you get distortion when the volume is at the level you prefer, and you should be ok. It might not rattle the teeth out of your head but it should sound pretty good.

**White Rascal** · 09-01-2006, 09:20 AM

OMG! Where on earth do you people get this stuff?

The sub doesn't do any "work" at all to "get the power it needs".

I give up. Believe what you want.

**StangKiller615** · 09-01-2006, 11:52 AM

Underpowering a sub, and the resulting clipping of the amp to get the subs to perform as desired, overheats and burns coils.

Try this little test. Take a 4 ohm door speaker rated at 40-50 watts and hook it up to an automotive 12v battery... and let it sit for a while. that is only 36 watts of energy.. but see how the speaker likes it.

the less watts you add to a speaker the higher the gains and volume, resulting in higher clipping and the result is burnt v/c's.

**MikeSomething** · 09-01-2006, 12:46 PM

And the verdict is:

I'll beef up my mids w/ this smaller rated amp and buy one rated the same RMS as my sub... I think some nice Infinity's and my stealthbox w/ a Eclipse Comp 500w rms sub should sound ok... Thanks for the advice guys!

**StangKiller615** · 09-01-2006, 12:49 PM

Originally Posted by MikeSomething

And the verdict is:

I'll beef up my mids w/ this smaller rated amp and buy one rated the same RMS as my sub... I think some nice Infinity's and my stealthbox w/ a Eclipse Comp 500w rms sub should sound ok... Thanks for the advice guys!

Go with a mono amplifire for your subwoofers.

**MikeSomething** · 09-01-2006, 02:02 PM

Originally Posted by StangKiller615

Go with a mono amplifire for your subwoofers.

Ok... Fosgate?

**StangKiller615** · 09-05-2006, 07:38 AM

Originally Posted by MikeSomething

Ok... Fosgate?

Yes, Fosgate and MTX make some of the nicest amps.

**MikeSomething** · 09-05-2006, 05:15 PM

Sub came in the mail. Eclipse 10" 500w RMS...

I've got Fosgate 6.5" 50w Mids coming soon. Already got the Fosgate amp for the Mids, just ordered the Fosgate 500w x1 RMS amp for the sub. hopefully it'll sound pretty good. I was just wondering about getting a cap tho. You think I'll need one for the sub's amp?

**StangKiller615** · 09-06-2006, 08:46 AM

Originally Posted by MikeSomething

Sub came in the mail. Eclipse 10" 500w RMS...

I've got Fosgate 6.5" 50w Mids coming soon. Already got the Fosgate amp for the Mids, just ordered the Fosgate 500w x1 RMS amp for the sub. hopefully it'll sound pretty good. I was just wondering about getting a cap tho. You think I'll need one for the sub's amp?

Your sub looks alot like the the MTX 8000's, I used to have. Nice size magnet. It will sound awesome. Some people do not use caps, and will tell you that they are usless. I disagree though, I used a 1 fared digital cap on my system. They recommend that you need a 1 fared cap for every 1000 watts your stereo puts out. If you are going to be running 1000 or more watts, then yes I would recommend you get a cap, anything less and you will be fine. Here is what a cap will do for you. Your car amplifier is just one of several components competing for the available power in your vehicle. For this reason, we suggest adding a stiffening capacitor to your car's electrical system. A capacitor (cap) is like a power reservoir delivering current upon demand. A cap is recommended for all medium-to-high power systems. If you dont wanna bother with a cap, then you may be interested in upgrading your alternator with one with more amps.

**daveb91** · 09-06-2006, 04:27 PM

Pretty much distortion kills speakers not underpowering them. That is all good night.

**Wulfe13** · 09-07-2006, 07:18 PM

Originally Posted by daveb91

Pretty much distortion kills speakers not underpowering them. That is all good night.

Underpowering a speaker CAUSES distortion! If you have a 250w speaker and a 100w amp, it will distort alot sooner than a 100w speaker with a 250w amp. That is a FACT... I sold Home and Car audio for 6 years.

**StangKiller615** · 09-08-2006, 05:51 AM

Originally Posted by Wulfe13

Underpowering a speaker CAUSES distortion! If you have a 250w speaker and a 100w amp, it will distort alot sooner than a 100w speaker with a 250w amp. That is a FACT... I sold Home and Car audio for 6 years.

Well said Wulfe.

**White Rascal** · 09-08-2006, 07:18 AM

Under powering does NOT cause distortion. Pushing an amp (or HU for that matter) beyond it's voltage swing capabilities is what causes distortion.

**StangKiller615** · 09-08-2006, 07:26 AM

Originally Posted by White Rascal

Under powering does NOT cause distortion. Pushing an amp (or HU for that matter) beyond it's voltage swing capabilities is what causes distortion.

It causes clipping, which is caused by underpowering. Clipping kills subs.