Big_T

My car is quite heavy (jaguar xj8) and appears to have lot of sound deadening material built into the build. For instance when I first got the car I put a powered 8 inch tube in the trunk (this worked perfectly in my Honda civic) in the Jaguar I could not hear it at all even turned all the way up. Open the trunk and bass poured out.

So I put a 12inch infinity reference in a sealed box powered by 2 bridged channels off a Phoenix gold octane amp giving 125 watts rms. The rest of the speakers are powered off a 120 watt rms PPi 4 channel amp. There seems to be an adequate amount of bass but it seems a bit boomy and biased towards the lower frequencies. I played with the crossover frequencies (raising the crossover point) but it didn't seem to help very much. When I listen to the sub from the trunk it seems to be punchy enough, but in the cabin it looses the higher bass frequencies.

In mid bass, there seems to be some frequencies missing, and I have a feeling it's because the bass is getting muddied by fact that it has to pound throughout the frame of the car instead of vibrating thought the back seat as in normal cases.I'm getting a nice rich low bass from the 12 but missing the bright punch of kicks and the high part of bass notes is not there.


I though about switching to one or two 10 inch subs but I think it may be still boomy due to the build of the car. Also I do enjoy the lows the 12 hits when they are required.

I'm considering putting a single 6 inch sub/box or even bazooka somewhere in the interior of the car.

I'm looking more for sound quality (with a bit of bass rumble for good measure) .

Do you think a 6inch in the interior (bandpassed to mid bass) is a good idea? Will it phase cancel?

or if not I'm open to ideas!!

Dukk

You are on the right track. The nature of the car is killing the higher bass frequencies. The solution is better/more midbass. Whether you accomplish this through better front speakers or adding a woofer up front is your choice.

Mr.DatSubishi

^^^seconds on that. You can also tune your enclosure for specific midbass output.

Big_T

thanks guys. I was wondering though what would be the best way to bandpass the frequencies to mid woofer? Is there a particular full range crossover because most I see are high pass and low pass. I was thinking maybe a passive system Capacitors and resistors but it's not very tunable?

About tuning the enclosure, thanks I'm going to try to implement that as well.

Dukk

The Coustic XM-5 and XM-6 both have a bandpass output (true 3way crossover) and are great reliable pieces. Audio Control and others make them as well.

derekj

What year is your XJ? I always remember the trunks being sealed from the interior due to the gas tank being behind the rear seats. Jag uses lots of sound damping material - that's what makes it a Jag. Try venting the trunk into the cabin and see if it makes a difference in the sound of the system.

dbs

could you make an enclosure in the glove box ???

Big_T

"The Coustic XM-5 and XM-6 both have a bandpass output (true 3way crossover) a"

Thanks I'm now looking into getting one of those.


"What year is your XJ? I always remember the trunks being sealed from the interior due to the gas tank being behind the rear seats. Jag uses lots of sound damping material - that's what makes it a Jag. Try venting the trunk into the cabin and see if it makes a difference in the sound of the system."


Yeah My first instinct was to vent which I tried at the 8inch sub stage, I ported though a gap where an upgradable 7inch sub could go on higher models on the rear parcel shelf. It seemed to have little to no effect? (and I made a messy hole on the rear parcel shelf ) The car is a 2001, yes you are correct, the gas tank is there between the trunk and rear seat.



could you make an enclosure in the glove box ???


Well I don't ever use the glove box so it could be possible, I'm not sure there is enough space and won't it rattle the all the front paneling? I'm thinking to put a small custom enclosure in the front passenger seat footwell, and hope I don't have many tall passengers.