New Alpine amp and 8"JL aUDIO SUB

[danny-p]

Hi All,
I've just travelled the other side of the country to get an 8" JL Audio sub and Alpine Amp installed into my car...
The reason is i have an Audi Quattro which i didn't want to hack to bits so i was having someone install it for me hiding the amp behind the rear speaker cover etc and keeping the new sub enclosed in the hidden side compartment in the boot leaving 100% boot space.
The system has worked fine for 3 days then all of a sudden no bass???
I found the fuse in the back of the amp blown and replaced the 30amp fuse and the system sounds a bit distorted....
At first i thought that the distortion noise was only because of the car having half its interior stripped out to mount the amp but it remained once the interior was re-clipped back into place.
After several other interior parts removed i gained access to the JL-8W0-4 Sub/box and removed the box.
With box removed i tried it again and distortion was just as bad so i removed the sub from its housing and this smell hit me..(it was like a chemical burning smell as if a motor has burnt out)...
the sub seems fine visually but could what ever caused the fuse to blow of damaged the sub??
That smell surely can't be normal....the noise is almost like the speaker has a tear in it but it hasn't.
Thanks for reading this and look forward to your replies

Danny-p

[lynx]

It's possible the voice coil in the sub has burned out.This could be the cause of your reported symptoms. Have you also checked for stray wires touching each other either at the amp end or the sub connector end ?

Can you connect another speaker on to the end of the amped signal to establish if the amp is ok ?

[danny-p]

Hi,
I will try connecting another speaker to it tomorrow as for the wiring connector block i found the "remote on" lead had dislodged itself from the Audi loom which i'm presuming had blown the v-coil as you suggested.
I'm hoping that the Amp is ok
Thanks again
Danny

[lynx]

Originally posted by danny-p
as for the wiring connector block i found the "remote on" lead had dislodged itself from the Audi loom which i'm presuming had blown the v-coil as you suggested.

The remote lead becoming detached would leave the amp without a switching signal therfore the likely symtom of this would be the amp not starting up as you power on the head unit.I can't see how this would cause damage to the voice coils.Reconnect the signal (remote on) to the amp and establich if the amp is still functional and test with a different speaker.Can you return the JL for service ?

[danny-p]

I dont have any other speakers to test the amp with....Would it be out of the question to take thw amp down to halfords and ask them to connect it to a speaker and try it....All i'm worried about is that the amp blows one of their speakers
Stuck
Thanks
Danny-p

[lynx]

You could try however i suspect the answer will be they are not permitted to do that. Do you have an old hi-fi speaker or even somthing off an old mini system to try the amp with ? Since it appears to be the speaker which is damaged are you able to get it tested under warranty ?

[danny-p]

Originally posted by lynx
You could try however i suspect the answer will be they are not permitted to do that. Do you have an old hi-fi speaker or even somthing off an old mini system to try the amp with ? Since it appears to be the speaker which is damaged are you able to get it tested under warranty ?

Managed to try another speaker using the Alpine t505 Amp and speaker worked fine.
Rang around various I.C.E installers via the yellow pages and all said same as you regarding the voice coil.
But they also said that although JL Audio are awesome speakers for the money because the bose stereo is only 2-Ohms imp (runs @ 1.5) and the JL-8W0-4 sub is 4-Ohms then the distortion from the higher impedance sub with single voice coil only has caused the speaker to fail blowing the 30Amp fuse.
He recommended using the JL 8w3v2-d4 which is a duel 4-Ohm sub which this guy said could wire up to produce a lower impedance?

Searching the net i found this jl sub....
**
.
Click to enlarge
Brand: JL Audio
Model: JL-8W3V2D2
Availability: Not Available Online
List Price: £149.99
Our Price: £134.99
To Order Call ***********
click here to add to system list
be the first to review this product






Nominal Diameter: 8 inches (200 mm)
Continuous Power Handling: 125 Watts
Voice Coil: 1.43" diameter, 4-layer, Kapton former
Configuration: Dual 2 ohm
Xmax (one-way, linear): 0.38" (9.5 mm)
Sealed Enclosure Range: 0.30-0.50 cu.ft. (8.5-14.0 liters)
Ported Enclosure Range: 0.60-0.90 cu.ft. (17.0-25.5 liters)
VRC™ Technology: YES
Elevated Frame Technology: No

Since their introduction in 1998, JL Audio W3 subwoofers have earned a reputation for outstanding performance and reliability. The introduction of this next generation, the W3v2 models, signals the arrival of some significant upgrades to these already impressive drivers:

In addition to JL Audio’s patented VRC™ technology, the 10W3v2 and 12W3v2 also incorporate our patented Elevated Frame cooling technology for enhanced thermal dissipation and 20% more power handling than the original 10W3 and 12W3. Cosmetic upgrades include a new powder-coated silver frame finish, a new dished cone/dust-cap design and a rubber mounting flange gasket that accepts grille mesh inserts directly (these grille inserts are sold separately).

The W3v2 subwoofer drivers deliver exceptional tonal balance and impressive output in compact enclosures and are ideal for moderate to high power applications.


**
Would this sub be better to fit using the same amp and as its 2-Ohms (same as bose) therefore minimising v-coil distortion?
Thanks in advance

Danny-p

[lynx]

First things first, you've lost me a little. What does Bose have to do with the problem ? My understanding is the factory fit sounds may have been Bose however the part of the equation is purely the Alpine amp driving the JL sub. Is this correct.If so the amp should be fine driving a 4ohm load (though i assume the fitter has configured the two channel amp to run in bridged mode to now drive a 2 ohm load ?).I'd be inclined to take this up with JL as a potential warranty issue.

[danny-p]

Originally posted by lynx
First things first, you've lost me a little. What does Bose have to do with the problem ? My understanding is the factory fit sounds may have been Bose however the part of the equation is purely the Alpine amp driving the JL sub. Is this correct.If so the amp should be fine driving a 4ohm load (though i assume the fitter has configured the two channel amp to run in bridged mode to now drive a 2 ohm load ?).I'd be inclined to take this up with JL as a potential warranty issue.

Nothing to do with the problem but it had been pointed out to me that one of the reasons the not that powerful bose systems are so clear at high volumes is because they are a low resistance 2-ohms...May be wrong but the I.C.E.installer i spoke to said i should try a more powerful sub with dual voice coil.
The JL sub i have/had was 75watts with single v-coil and i was recommended a 125watt JL with stronger dual voice coil.
What do you reckon bearing in mind the enclosure is pretty small (24"x11"approx) to fit in the compaertment so maybe the small enclosure had some affect on the cause of the coil blowing?
Cheers
Danny

[lynx]

I am not an expert in subwoofers however my understanding of dual voice coil setups is to allow a greater degree of flexibility when used in multiple sub setups and or to achieve low impedance loads when paired with a suitible amp. In your situation my gut feeling is the speaker was substandard for some reason. I would be inclined to stick to another single coil setup as i don't feel that in your case a dvc sub will be of benefit ie your amp is being presented with a suitible load when fitted 'normaly', hope that makes sense.Did the original dealer recommend the setup you are using, and if so can you go back for help in resolving this issue ?
Perhaps somone with experience of installing these could offer specific advice.I seem to recall somone posting that they had many years experience carrying out installations.

[danny-p]

Originally posted by lynx
I am not an expert in subwoofers however my understanding of dual voice coil setups is to allow a greater degree of flexibility when used in multiple sub setups and or to achieve low impedance loads when paired with a suitible amp. In your situation my gut feeling is the speaker was substandard for some reason. I would be inclined to stick to another single coil setup as i don't feel that in your case a dvc sub will be of benefit ie your amp is being presented with a suitible load when fitted 'normaly', hope that makes sense.Did the original dealer recommend the setup you are using, and if so can you go back for help in resolving this issue ?
Perhaps somone with experience of installing these could offer specific advice.I seem to recall somone posting that they had many years experience carrying out installations.

Cheers for that,
The install was carried out some 300 miles away by someone i'd contacted from another forum....His reaction is "wierd" "thats strange that is" "i can't understand how thats happened" and so on so i'm not getting anywhere.
From the other forum he's apparently done this bose sub upgrade on several other peoples cars and all seem okay??
Which sounds like i'd been given a dodgy sub in the first place but even more strange is how its ran for 3-4 days perfectly then it blows the Amps 30 amp fuse then once fuse replaced sounded horrible?
Parts were sourced via ebay also which makes matters even worse.
Yeah if anyone with good experience regarding sub installs could help me out that would be great.
Thanks again
Danny-p

hmmmmmmmmmmm.. put the car infront of me.. or any other good ice installer and they could find the problem.. over the net help is difficult. a distored sound leading to a blown fuse i have seen in the past to be caused by a screw through the speaker wire coming from the amp to the speaker. also not enough power being supplied to the amp. without seeing exactly how the amp and sub have been wire up i cant give an accurate opinion

hope this helps :/

if you want to speak to someone in the know ring SQ +( www.sqplus.com ).. experts in the very top end of car audio installs

[danny-p]

Originally posted by Zoidy
hmmmmmmmmmmm.. put the car infront of me.. or any other good ice installer and they could find the problem.. over the net help is difficult. a distored sound leading to a blown fuse i have seen in the past to be caused by a screw through the speaker wire coming from the amp to the speaker. also not enough power being supplied to the amp. without seeing exactly how the amp and sub have been wire up i cant give an accurate opinion

hope this helps :/

if you want to speak to someone in the know ring SQ +( www.sqplus.com ).. experts in the very top end of car audio installs

Cheers for that mate but we've ruled that out on the first day as the Amp is bridged @ 300 watts straight to the sub and the whole L/S of the car is stripped out revealing all wiring from the main loom right up to the amp then upto the sub and all wiring is fine??
All the Bose cabin speakers are still perfectly clear after the 30 amper blew in the back of the Amp, so this tells me that the fault is from the amp to the sub.
Just the v- coil blew in the sub presumeably blowing the 30 amper.
The JL Audio that blew was 4-0hm and only a 75 watt single voice coil and i've ordered the 2-ohm 125 watt with dual coils so instead of wiring the 2 channel amp bridged going into the 75 watt sub i was going to wire it up as 2 channel going in to each v-coil at 150 watts each minimising stress on the coils but giving me the same 300 watts to the speaker.
What do you reckon, bearing in mind as sub enclosure space is limited so i'm limited to a pretty small enclosure for this 8" driver within the boots side compartment.
Cheers
Danny=p

[lynx]

Originally posted by danny-p
The JL Audio that blew was 4-0hm and only a 75 watt single voice coil and i've ordered the 2-ohm 125 watt with dual coils so instead of wiring the 2 channel amp bridged going into the 75 watt sub i was going to wire it up as 2 channel going in to each v-coil at 150 watts each minimising stress on the coils but giving me the same 300 watts to the speaker.

I would advise against this.JL Audio also advise not to do this :http://www.jlaudio.com/tutorials/dvc/diffsignals.html.
Connect the coils in series and then connect to the amp.

[danny-p]

Originally posted by lynx
I would advise against this.JL Audio also advise not to do this :http://www.jlaudio.com/tutorials/dvc/diffsignals.html.
Connect the coils in series and then connect to the amp.

Hi Lynx,
I still don't see the problem with wiring the system up the " independent " route.
From the link it said " Parallel " would half the resistance..." series would double it and " independant " went on about house amps etc?
See below:- What is the advantage of dual voice coils?

The primary advantage of the dual voice coil speaker is wiring flexibility. A single dual voice coil driver offers the user three hookup choices...parallel, series and independent. In a parallel hook-up the drivers impedance will be half that of each individual coil (a dual 4 ohm speaker would be a 2 ohm speaker in parallel.) A series hook-up results in twice the impedance of each single coil (a dual 4 ohm speaker results in 8 ohms if its coils are wired in series.) Finally, you can wire each voice coil to a separate channel of your amplifier, which can be useful if your amplifier is not mono-bridgeable or if you are bridging a four channel amplifier down to two channels to run your sub.

The independent wiring application is the one that brought about the need for dual voice coil speakers in home audio. Unlike most good car amplifiers, home amplifiers and receivers are typically not mono-bridgeable. For this reason, dual voice coil woofers were developed so that a subwoofer or center speaker could be driven from the left and right channels of the average stereo home amp/receiver. Since sub-bass frequencies are hard to localize, the dual voice coil subwoofer allowed sub-bass reinforcement within one cabinet and one speaker. This cabinet could be placed inconspicuously in a corner or along a wall of the listening room, with the obvious benefits being space-efficiency and lower cost than two independent bass cabinets or a larger cabinet with two subs in it. Many popular home subwoofer / satellite speaker systems still use this basic configuration.