My new amp and sub are going in very soon (I know I say that a lot) and I was reading in this forum about how to wirethem and can across this..

https://blazerforum.com/m_34483/tm.htm

In there it says "A sub should only have one ohms rating, (1,2,4,6,8,10...) the most common ohms rating for a sub is 2 or 4... Wile an amp can have more than one ohms rating. It is very important to know what your lowest ohms rating is on your amp. For example, If your amp’s lowest ratting is 4 ohms, and your sub configuration is lower than 4 ohms, (worst case scenario) you can blow your amp, (best case scenario) or your amp will cute out."

I am having trouble understanding if this system of mine will blow accroding to this ^^^^^
My system:
Alpine SWS 1042D 10" sub (4 ohms)
http://www.crutchfield.com/S-KaKMDYy...p;I=500SWS1042
Alpine MRP M450 Class D Mono Amplifier-I'm wiring it at 2 ohms-400 watts (You can wire it at 4 ohms-220 watts)
http://www.crutchfield.com/S-KaKMDYy...p;i=500MRPM450
Alpine head unit, speakers...

The thing that is tripping me up is how the ohms are different, basically am I over/under powering the sub by having the amp at 2 ohms when the sub is at 4 ohms?

Anything else bad that could happen? I hope not.

BTW it's a sealed box real close to the optimal volume of 1cubic foot.

 

you cannot have the sub at 4 ohms and the amp at 2 ohms. The sub sees the load from the sub and then powers accordingly. if you have a single 4 ohm VC sub, then you only have the option of running your system at 4 ohms. Now, if you had a sub with Dual 4 ohm VC's, then yes, you could get 2 ohms.

 

It says thatthe subis a dual voice coil (4 ohm each) so I guess it's doable. Now on another page it says that the RMS power range is 50-300 watts and the peak power handling is 900 watts, is 400 watts safe? I'm learning all of the jargon.

Congrats on mod status by the way!!

 

Yes, wire all the positives together and to the amp, and all the negatives together and to the amp. The power will be fine. Do you have access to a digital multi-meter?? if so, set your gain with it, so you dont smoke your sub.

If you do, turn all bass enhancements off on HU, set everything to 0. turn up volume to 3/4. put test leads of DMM(with meter set on Volts) into the speaker leads on the amp. turn up gain until you reach your majic number of 28.3 volts. then you are set.

And thanks about the mod thing.been a while

 

I gota DMM for this purpose! You've been a big help, thanks a lot!

 

no problem brah. thats what this forum is for

 

I have that exact same sub, and it's been running at 350 watts RMS without a hitch... It occaisionally distorts at max volume... but that's probably because of the box, and the fact that I tuned the gain by ear, lol.

*bows and tips an imaginary hat to hillbilly* Imma go take a DMM to my amp soon as the truck is warm, lol

 

drperry - your magic number (target voltage) is 26.5 volts

 

Sweet! Thanks!

Hopefully I'll still be able to turn the volume up to 100% without distorting, lol

 

I have two subs that seperately have a nominal impedance of dual 4 ohms for one sub. Then I have a Rockford Fosgate amplifier that is 4 ohms. I have my subs wired up to 2 ohms and I was wondering because on my amp I have protect mode and thermal mode. Will my amp go into protect if somethings wrong or will it not because of the wiring?