• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

740 Installing jl audio 12" sub (help)

Slimssousa

New member
Joined
Mar 12, 2017
Location
California
Planning on installing a JL monster 12 inch sub with a JL Amp. Has anyone installed subs on a 740? I'm asking for tips and tricks.
 
Douchnozzle has it right, just a couple of things. You are going to want to add a 150-200 amp fuse in the power cable, as close as possible to the battery. You are also going to want to ground everything in the audio system to the same point, to eliminate whining with rpm increases. lastly, look up how to properly tune a sub, to keep your system efficient. You may need one of the denso 100 amp alts if yours is getting long in the tooth. Finally, capacitors are mostly a band aid for a bad battery/electrical system, if you need one to stop your lights dimming, there is something else wrong
 
I want to use the amp I have, it's a JL audio 250 amp. Thanks for Giving me some info though. it will definitely help b/c not everyone does subs in a classic Volvo and I need all the tips I can get haha
 
I had really good luck with a single 12 in a small sealed box (whatever is recommended for the sub) under the rear deck, pointing backwards at the taillights. Kept the trunk space useable but when the trunk was empty it was like a really nice bandpass enclosure and it pounded so hard my pantlegs would visibly move. Nothing too high end either, just a PPI amp and an Infinity Perfect sub.
 
Where are you planning to mount the amp?

If you do it under a seat, I'd mount it under the passenger seat, run the power along the left side of the car and RCA cables under the center console. If you mount the amp in the trunk or cargo area of a wagon, I'd run the RCA cables down the right side instead of down the middle.

Ultimately, amp/sub installs are pretty straightforward, usually the most difficult part is finding a nice hole in the firewall to run the power cable.


edit: forgot that 740 batteries were on the driver's side
 
You are also going to want to ground everything in the audio system to the same point, to eliminate whining with rpm increases.

Yeah, no.

Fortunately the OP doesn't actually have any audio equipment and hasn't been able to formulate an actual question yet, though this won't slow or stop the bad advice on this forum.
 
Again. What specific advice are you looking for?
Did u happen to install subs on a 200/700/900 series Volvo? If so. Id love to get all the info I can, no specifics. I've never installed a sub before. Lmk what I should buy for the install since all I have is a sub and amp. All I know is that the amp I have is perfect for that sub. And that if installed correctly, it shall bump. And again. I have no specific questions. Just need some good info so I don't hit a bunch of problems.
 
Did u happen to install subs on a 200/700/900 series Volvo? If so. Id love to get all the info I can, no specifics. I've never installed a sub before. Lmk what I should buy for the install since all I have is a sub and amp. All I know is that the amp I have is perfect for that sub. And that if installed correctly, it shall bump. And again. I have no specific questions. Just need some good info so I don't hit a bunch of problems.

Teach yourself.
 
You can look in the Showroom subforum for examples of what others have done to 740's.

As far as what do I need and how do I do it, there are better places on the interwebs for that info, it isn't Volvo specific.

The trouble with car audio discussions in general is that everyone who has ever helped their cousin put some flea market subs in his truck and also has an internet connection is now a self professed expert in the field. A lot of bad information ends up thrown around in car forums, including this one. Better to learn the basics from a better source imo.
 
Last edited:
Back
Top