Newbie Needs Advice on Sub Amp

[Ramblin 10+ year member]

Yes, I'm a self-professed newbie. Just found this forum last night, and had to join up. Before you bash me for asking my question, I did some research already. I've done about 2 hours of searches on the forum, but frankly just don't know enough about car audio in general to find the answer myself. I need your advice. So here goes....

I purchased my son a 2000 Silverado extended cab truck about a month ago, and it has a decent system in it. The component speakers are Kenwood driven by a RF P850.4 amp. The subs leave a lot to be desired. They are two Kicker 12's in a poorly-designed down-firing box powered by a second RF P850.4. We plan to leave the main part of the system alone for now and focus on improving the subs.

My plans are to raise his rear seat with 3" risers and build him a new under-seat enclosure that houses four JL 10W3V3-4's firing forward. I've already worked out all the math and can easily get 1.34 ft2 per side for the enclosure. The question becomes.....what should I drive them with? I'm not interested in building the enclosure with separate terminal boards for each sub and wiring each into the 4 channels of the RF P850. And I can't (I think) wire the subs 2 per side down to 2 ohms and attached them across the front and rear channels. The manual does not indicate that 2 ohms bridged is an option.

I'd really like to go with a class D amp, and I'd like to go with only one amp. The JL's want 300W RMS. But does a class D 2-channel amp exist? I believe I read somewhere that class D only comes in mono. If that is the case, and since I've already purchased the subs, can you guys give me a recommendation on a 1-ohm stable amp for say, under $400, that would make these subs perform?

I should also say up front that I do NOT like a mushy or distorted sound. I've been a musician all my life, and used to be heavy into home audio (20 years ago). I want the output to be clean but strong. My enclosure will not be ported. I'm not after shear volume. But I expect the subs to be very impressive.

If I have made any kind of mis-statement above or made a wrong assumption, please feel free to correct me. We am having a ball learning about car audio as fast as we can, and will not take offense to your efforts to educate me and my son. We are learning this together. If there are several options, or if you have a better idea on how to wire up the subs, please let me know. Also, please do NOT use acronyms or abbreviations for brands (even though I used RF above for Rockford Fosgate). I don't know all the brands that are out there, so you will literally need to "spell it out for me". We will learn them quickly. Thanks.

Keith

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[BASSINMYSUBS 10+ year member]

i would say go for a hifonics bxi1210d.. hifonics is1 channel but it is rated at 1200 rms at 1 ohm would be nice on the jl's

 

[jpexpc 10+ year member]

i would say go for a hifonics bxi1210d.. hifonics is1 channel but it is rated at 1200 rms at 1 ohm would be nice on the jl's

Agree. It will give you some upgrade room in the future to drop to a 1 ohm load and double your output if you get subs that can handle the power.

 

[Ramblin 10+ year member]

JPexpc, pardon me for being a little confused by your statement. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif I would wire the subs in pairs, + to + to terminal board + and negatives the same way. This brings the subs down to 2 ohms, right? Then wire each side of the enclosure to the two sets of inputs on the hifonics amp. Won't this take my 4 ohm subs down to a 1 ohm load?

Keith

 

[jpexpc 10+ year member]

The manual does not indicate that 2 ohms bridged is an option.

From reading this I assumed you were going for a final load of 2 ohms since you were curious to see if you're amp was 2 ohm stable. I don't see anywhere that actually mentions what subs you have nor what your voice coil configuration is. I based my post on the statement above.
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[jpexpc 10+ year member]

Bleh, I just read follow-up again. Are your subs SVC or DVC? If they are single your final load would be 2 ohms wired the way you described.

 

[jpexpc 10+ year member]

It appears you ninja-edited your original post. There's no way I missed that.

 

[Ramblin 10+ year member]

They are SVC. I spoke with a representative from JL Audio today, as I was considering using a 1000/1. A used one would fit within my budget. But he explained that I would need 8-ohm subs in my configuration. 8-to-4 in the enclosure and then down to 2 when attached to the amp in the same way I would connect to the Hifonics. That's why I thought my configuration would be 4-to-2-to-1 with the Hifonics.

Thanks for ther heads up. I know there are a LOT of JL haters on this forum, so please don't hijack this thread with stuff about their inept representative. I may not have explained myself to him properly.

Are there other amp options I should consider?

 

[jpexpc 10+ year member]

Ehh, you either added the model and total of the subs you are talking about or I missed it. The Hifonics would still be ideal. I thought we were talking about 2 subs, not four.

 

[Ramblin 10+ year member]

No problem. The original was a long post.....possibly hiding many ninjas. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[jpexpc 10+ year member]

Gotcha. The Hifonics would be great. If you don't mind giving them a little extra power you might consider a 1610d. The extra power I speak of would probably be around 50 watts each sub.