Hook up 2ohm sub bridged. Safe or not?

[kr15 5,000+ posts]

Listen to the expert because you've been told the correct advice from the beginning.

Car Audio Blog Author for Easy Way Electronics, Inc. - CDT Audio Dealer - pm me for a quote and system advice

gtfo, if this poor kid smoked his amp because of you, you should send him a new one

 

[keep_hope_alive Premium Member]

i will conceed that it may be possible to set the gain low enough to ensure the amp doesn't go into protect, even bridged at 2 ohms. but we didn't tell him what the gain should be set at to achieve this.

determining the voltage required out of the amp to safely run at 2 ohms mono requires solving simultaneous equations of ohms law (7th grade math). basically, you want the current out of the amp to be the same at 2 ohms bridged as it is at 4 ohms bridged. since the relationship is non-linear, the calculation is as follows:

P=I^2R

500W=I^2(4)

I = SQRT(500/4)=11.4A

V=IR

V=(11.4)(2) = 22.8 VAC

which gives

P=V^2/R

P=(22.8)^2 / (2)

P=260W

 

[keep_hope_alive Premium Member]

looks like we had the same idea at the same time!!

 

[trumpet 5,000+ posts]

please spend the 10 seconds looking up the amp to verify before posting incorrect information that can result in damaged gear.

My bad. I had looked up the amplifier but I missed the 4 Ohm bridged.

 

[keep_hope_alive Premium Member]

My bad. I had looked up the amplifier but I missed the 4 Ohm bridged.

no problem. that's why we work as a team! you know you're stuff. i've misspoke before. it happens.

 

[quackhead 10+ year member]

that KW would make a most excellent throw line weight down on the Ohio River......if u like to fish, that is....lol. Seriously, send that JL sub back and get what you paid for. It is not your fault they shipped you the wrong item. You designed a system and ordered the correct product, you should not have to suffer because of a retailer mistake..period.