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View Full Version : Reduced amp output, why?



Shawn
02-01-2009, 08:56 PM
once upon a day (about 6 weeks ago) i had a daewoo nubera (economy sized sedan) and my audio setup could shake things up three cars back, then i rolled the car and got my '98 magna solara. i transfered my car audio set-up across (head unit, amp and subs) and replaced the magna's factory speakers. how ever, the output of the amp/subs seemed to be alot lower than pre-roll. i could hardly feel it in my back. initially i thought the amp had taken a knock in the roll and was at fault, so i swapped it with my sisters old amp, which is better. the output has improved but its still weak compaired to the daewoo.

i'm thinking it might be due to the fact that the magna is a larger car, and the back seat has more padding, there for more insulation but i realised that the power cable for the amp is slightly thinner than the daewoo's (due to the damage i wasnt able to get it from the daewoo). in the daewoo it was a 9mm diametre cable where now its a 5mm. is this the problem?

i'd really like to resolve this so i can get back to pissing off the nabours with my subs...

oh, also, while i'm picking brains, where is the cheapest place to get rolls of that rubber insulation stuff. JB HIFI wanted $50 per square metre when i did the daewoo and i'm gonna need alot more for the magna.

http://img262.imageshack.us/img262/9350/p211108132301kl0.th.jpg (http://img262.imageshack.us/my.php?image=p211108132301kl0.jpg)

http://img352.imageshack.us/img352/6298/p0512081720fx4.th.jpg (http://img352.imageshack.us/my.php?image=p0512081720fx4.jpg)

Ers
02-01-2009, 09:09 PM
Bingo.

Magna is a lot larger car, different acoustics, and better insulation from factory, including that massive back seat.

Power cable, possibly - if you have a multimeter, or access to one, measure the volts your amp see's. Should be seeing ~ 13.5V at the amp.

Cable size does determine voltage drop, larger cables dont drop voltage as much, however, in your scenario - its the larger car, not the cable thats the issue.

If you really want a loud sub, invest in something like a soundstream tarantula (SPL sub) with a good amp behind it. 1 of those 12" subs will do a lot more than those two kenwoods.

Mr İharisma
03-01-2009, 08:06 PM
Could be many things.

If you are running the kenwood subs like in your picture you are best to rear load them in a Magna - i.e aim them toward the rear tail lights. Size of the car wont matter that much ( with some tuning ) only that the phase from the subs will be very different car to car and from the positioning of the woofers. The resonate Hz will change as well which will require tuning to tame any peaks or fix and troughs. Use the swap over to adjust all your gains correctly.

Cheap is not always good. Dynamat xtreme will set you back about $30 / sheet.

Shawn
04-01-2009, 09:03 AM
Cheap is not always good. Dynamat xtreme will set you back about $30 / sheet.

Where from? JB HIFI wanted $50 per sheet.

Nick
04-01-2009, 10:47 AM
Where from? JB HIFI wanted $50 per sheet.


Try ebay! Or FHRX studios.. Not that Charisma knows about it because FHRX did his Bora install :P:P

Lucifer
04-01-2009, 11:02 AM
Try ebay! Or FHRX studios.. Not that Charisma knows about it because FHRX did his Bora install :P:P
They did? Who ever would have guessed lol

Shawn
04-01-2009, 11:05 AM
wow, the postage charges for dynomat on ebay is massave. i'll check autobarn and maroochy car audio, hopefully they will have a better price.

Mr İharisma
04-01-2009, 05:31 PM
Try ebay! Or FHRX studios.. Not that Charisma knows about it because FHRX did his Bora install :P:P

:D Yeah not at all. Fire an email to Marty at www.fhrxstudios.com and he will give you a decent price.