NAF

I recently installed a sub into the boot of my 99 impreza...
However despite having a 1x280w amp driving it
it sounds rather muffled at lowish volumes ,so I have been driving at times with one of the split rear seats folded down which allows the bass to penetrate a lot easier....
Anyone got any ideas on how to vent the bass
in any way from the boot & allow me to keep the seats closed???
would Dynamating the boot make any difference????

Thanks,

Niall Foster

longun

Is the box sealed or ported??

iain atkins

I'ver got a MY97. I'm using an isobarik pair of Infinity perfect 10's and a phoenix gold amp. I also had the same problem and ended up dynamatting the boot and also took out the rear speakers - difference was worth losing the rear fill in the back, believe me

NAF

The Box is ported Longun....Its a 10" JBL sub..
The difference with the seat folded down is huge...but its a bit of a nusiance as you can well imagine ...not very practicle at times...
Iain,
your suggestion seems very interesting....too be honest when I fade to the rear speakers fully & have a good listen to them I have to admit I'm not too impressed with the sound quality ....very muffled ...2 be honest I wouldnt be too bothered about losing these.....'sides I never have too sit in the back anyway ..
As well as that it sounds like another good excuse to get meself a nice new set of fronts
===
Niall

p.s Chiark...if u r about..whats your opinion on removing the rear speakers???




[This message has been edited by NAF (edited 30 October 2000).]

longun

OK. Did you make the box or was the box pre made and is the port big enough??

The other problem I have encountered is when you put the port in it should only go so far in to the box. If it goes in too far you loose sound quality for really low bass.

Other that that take it back to the shop if thats where you got it from and tell them it don't sound good..

NAF

Longun,
The box was pre-made.....the whole lot came together as a package...the port is quite big in it.. 2 b honest....it sounds fairly good ...its just at low volume its not all that easy to hear ,unless I fold one of the rear seats down in which case its fine...
Might give removing the rear speakers a go & see what it sounds like then ..
Regards
Niall

chiark

Rear speakers: I've got em, but they're faded out so far that they're bugger all use. Keeps the passengers happy though.

Dynamat/Accumat/whatever is a definite route to follow. Removing the rear speakers works in practical experience from one member, and is a quick fix so may be worth a try.

Someone once suggested drilling holes in the back of my seats, which I personally wouldn't recommend unless you're confident that you're not weakening anything!

Some schools of thought would recommend running the ports through the rear speaker holes. Given that a port is designed to re-inforce the speaker output at the front of the speaker, I don't know if this would work.

Adam M reported a while back that a bandpass box from Audio Images (?) in Bradford gave shedloads of bass and I think it hung from the rear shelf... Perhaps that's worth investigating...

NAF

Dont think I fancy buying a new box Chi .....think If I'm gonna spend a few bob I might as well spend it on some Dynamat or something similar.. ..Reckon I'll Dynamat the boot then remove the rears ,get myself a new pair of fronts & see how it goes!
Thanks for the help guys!
Regards
Niall Foster

NAF

Actually....just thought of something..
What about drilling holes underneath the rear parcel shelf (i.e in the metal shelf )
Do you reckon that would make much difference?

Niall

RonaldoH

I have seen a WRX with a port installed into the rear shelf. Sounded absolutely pap to say the least. If your venting the air created by the sub into a larger area of air in the car the whole thing becomes one large boot of bass. Quiet un-bareable to listen to, especially when using big subs and big amps. Your gonna need loud and clear front speakers and some ampage to produce the clarity that your ears require from your fav cds.

You also have the negative side of porting the bass in that the rear speakers will be drowned out by the low frequencys that are produced by the subs over the top of that of the mids/6'9''s, what ever is your preference.

280watts....Juts a quick question, what amp and what sub? 10''/12''? Have you got the crossovers set up correctly and perhaps a coil on the sub, depending on the amp. I guess that the sub is new, remember these things require breaking in....try a bass cd for 20 mins on a frequency that produces a deep warm bassy sound and you may notice a slight difference once the voicecoil on the sub has been given a workout at that frequency. This is sometimes the cause of a tight sub.

Where are you based naf? I would have no worries showing you my setup. Its crystal and sounds lovely all day long



[This message has been edited by RonaldoH (edited 30 October 2000).]

NAF

Ronnie,
The amp I'm using is I think is a Pioneer Gmx-602 (off the top of my head)
The Sub is a JBL 10" in a premade JBL enclosure with 1 large port....Sound quite good as I say but not very noticable at low volume...folding down one of the split rear seats makes a fair difference ....makes the bass a lot more ambient..
As for the crossovers.....I tried a lot of different settings with them until I found what I thought sounded best....didnt want to have the gain up too far as I thought I might damage the sub......the amp also has a bass boost switch on it which I have switched on..
I have the sub for almost a year now so chances are its probably well broken in ???
As a matter of interest Ronnie,
What sort of speaker/amp setup have you got in your car ???

rockin'Ru

Well,I'm a serious do-it-yourselfer and ran across this problem in a Camerey,and in the end[heheh] we wound up taking the rear deck apart and cutting a large hole in it.Then we used a grinder to cut slits in the deck cover[being careful not to slice the covering]and it worked great.Plus he kept his rear fill.
Just an idea that works.

chiark

NAF,

If you're ever in this part of the world (North of England) drop me a line and you can have a listen.

There's already a hole in the rear shelf that's about 2 inches in diameter. Dunno what it's for.

Rockin': Sounds serious

Bajie

I've got 2 JBL 10s run individually powered by Rockford Fosgate amps.
Upgraded two way speakers on back shelf
Sounds good to me

Bajie

Sorry, they're 12" .

RonaldoH

naf.

Pleasure mate.

I run a pair of JL 12'' subs in the rear, powered by a lightning cap (keeps the volts at 12 volts constant to avoid dips in bass and performance) and rockford fosgate 4 channel amp. Up the front I am running a pair of MB Quartz components that are co-axles (these have the tweeter in the middle and also have crossover) I also have the same 16cm speakers in the rear shelf.
I run these off the head unit which is a new alpine on the market. CD player with BBE (Barkus Berry Electronic device found on some stereos other than alpine...don't really use the function to be honest...distorts bass at low end through mids), has crossovers built in to the head unit. LPF/HPF (Low pass filter and High pass filter) is variable and is also adjustable by changing the frequency to each of the filters in hertz. Long winded version of bass and treble on most units but can improve sounds massively! Also has sub control and 65x4 watts (not likely to be a true 65 watts per channel) but all the same hits 35 on volume without distorting. However the subs take a massive pasting and make the spolier resonate!

It does the job and sounds sweet. I installed it all myself and love various music so its all about the ears that need pleasing. Mine are happy all day long when I am in my scoob

Ron

[This message has been edited by RonaldoH (edited 31 October 2000).]

NAF

Thanks for the offers of listening to yer setups lads.....Next time I'm in the UK I'll look ye up!!
Seems to me like nearly everybody is running a pair of Subs........kinda makes me feel a little inadequate with my little 10 incher.....lol ....
Took the rears out today.....nice job to do in between dodging torrential showers .......bass is definitely more noticable now thats theres two nice big holes for it to escape tru..
Not sure if I miss the rears just yet....didnt get much of a chance really to have a proper listen today........but just in case I do ,I was thinking of fitting a pair of 13 cm co axials in the rear doors....just to please the passengers if nothing else!! ..anyone ever seen this done ???
Btw...
Ronnie........you still thinking of paying us a visit in Ireland in the new year??

regards,
Niall


[This message has been edited by NAF (edited 31 October 2000).]

Richard Gledhill

I definitely found a big difference removing the rear speakers (probably me you were thinking of Chiark...). I have a Rockford Fosgate Punch 400a4 amp (4x100W) running Xtants at the front (expensive component speakers) and bridged across a Rockford Fosgate Power DVC 10" in the boot, in a custom box. Looking at designing a new, ported, box at the moment, but for now I'm quite happy.

I'm also looking at replacing my head unit with the expensive Alpine one - I think the one you're talking about Ronaldo?

Fun this sound stuff isn't it

Richard

Scooby Doc

Fun - Damn right

I have a MY00 and am progressively upgrading the sounds. Need to decide what to do with the subs. The kit I've got are 2 old 8" Denons - stuck in an acoustic rear shelf from my old Golf. These are probably cactus and will go in the bin. Blank sheet of paper. What do you reckon, 1x10" or 2x10" and what sort of enclosure - local ICE shop sells boxes but don't know much about them. Amp at the moment is a Denon DCA 800 - needs upgrading but will have to save up first.

Any thoughts about the subs?

Martin

NAF

martin
I have a single JBL 10" sub in the boot of my car which I have trouble hearing at times...
Most of the other guys seem to run 2x 10"
or 2x 12" subs..which they find perfectly ok soundwise n that...
Seems to me running 2 subs is the way to go...
I'm sure the rest of the guys will be able to fill you in a lot better..

Regards
Niall


[This message has been edited by NAF (edited 05 November 2000).]

Scooby Doc

Niall

How are you getting on

I have had my DCA 800 installed running infinity kappa 6.5" components in the front. The amp is runnng bridged in mono into a 10" infinity referenc sub.

In my 4 days of experience the sub sounds good when idling but inevitably as road noise increases it becomes less distinct. I have a MY00 - stupid question - do the rear grilles just pull off. I had a rather half hearted attempt at the weekend when it was going dark butgot sore fingers - I take the do just pull off. Areyou still running wiht your rear speakers out?

I also find that at mway speed it can be a little difficult to hear higher frequencies such as vocals but cymbals (?spelling) are OK. I suppose this is due to road noise. Where did you stick your dynamat? Has this made a difference. The infinity components sound pretty good most of the time - they made me smile! Its just that most of my mileage at present is on mway and I arrived home rather deaf tonight!

Any thoughts?

chiark

The rear grilles, in my experience, don't pull off and I thought that you had to remove the back seats, side panels and back shelf to get into there.

However, someone put a message somewhere telling me that it is possible to get the grilles off.

I'll try to find it and let you know. In the meantime, see

chiark

Found it...
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>
I beg to differ !
I removed the grilles by 'popping' them off with a medium flat-blade
screwdriver. As I remember, the trick was to lever them just by the mounting
lugs, of which I think there are five.
Regards

Carl<HR></BLOCKQUOTE>

An email from a member of the importingimprezas group...

Not tried it, so caveat emptor etc...

Scooby Doc

Nick

Your are a fountain of knowledge! I think I asked the grill question again in one of the other sections just before I read this.

Cheers

Martin

(Not so deaf today!)

Richard Gledhill

To remove the rear speakers you need to do all the seat removal stuff (I think), but the grilles should come out ok.

As for 1 or 2 subs - it depends on the sub to some extent. If you have 2 subs, you may well find you get more boom and less tuneful bass. I changed from 2x10" cheapish subs to one expensive 10" sub and the difference is noticeable - much tighter and cleaner bass than before, and plenty enough to make your hairs stand on end on the back of your neck None of the boxes have so far been ported, but Rockford Fosgate are kind enough to post ideal dimensions for a vented bass box, so I might try it myself

Richard