box building

[robcento]

im thinking of mounting two 10" subs into the boot of a cinquecento. first of all would this be a wise idea? eg. rattle etc. or would it just be a case of soundproofing the thing adequately?
onto the question, im hoping to fibreglass the subboxes, but unsure as to sizing, is there a certain size the box should be for the sub? a specific shape? volume? as ive said the subs would be 10", would the power of the subs make a difference? also would the thickness of the fibreglass be important and how think should it be made? as for structural options, i was thinking a mdf frame built up with mesh and fibreglassed over, would this give enough strength and/or support?
the subs would be mounted at either side of the car so a twin box isnt what im after. i want to get away from the mdf boxes and make something a little different... try to mount the subs into the car on either side (does that make sense ) and therefore maximise the little boot space already there. amps would be fitted to either rear of seats or floor, well decide that after
sorry to ask so many questions but i figured it would be worth looking into before commiting myself to anything that going to turn out ****
thanks for any amount of help i can be given

 

[paulbfd]

You can do something like this:

http://www.autoacoustics.co.uk/sbo-fs983.htm

I'll be doing something similar to what your talking about, but with just one 10".

 

[chaos]

im thinking of mounting two 10" subs into the boot of a cinquecento. first of all would this be a wise idea? eg. rattle etc. or would it just be a case of soundproofing the thing adequately?
onto the question, im hoping to fibreglass the subboxes, but unsure as to sizing, is there a certain size the box should be for the sub? a specific shape? volume? as ive said the subs would be 10", would the power of the subs make a difference? also would the thickness of the fibreglass be important and how think should it be made? as for structural options, i was thinking a mdf frame built up with mesh and fibreglassed over, would this give enough strength and/or support?
the subs would be mounted at either side of the car so a twin box isnt what im after. i want to get away from the mdf boxes and make something a little different... try to mount the subs into the car on either side (does that make sense ) and therefore maximise the little boot space already there. amps would be fitted to either rear of seats or floor, well decide that after
sorry to ask so many questions but i figured it would be worth looking into before commiting myself to anything that going to turn out ****
thanks for any amount of help i can be given

The volume of the boxes would be dependant on the subs. The thickness of the material is important - you wouldn't want to damage the enclosures cos it isn't up to the vibrations caused by the subs. IMO they should be 3/4 inch thick.
I would have thought that you could build a fibreglass enclosure the way you've described, but I would add internal bracing to be safe. It would make the box more solid. In fact, I would brace any enclosure. Saying that, there may be a better way of doing a fibreglass enclosure, as I have only built mdf ones. You would need to fibreglass the wheelarches if you were to fit them over the arches.

Don't worry about asking lots of questions, that's what the Forum is here for

HTH

 

[robcento]

cheers.. yeah, thats the kind thing i was thinking of :thumbs: would internal bracing not intefere with anything? i dont fully understand how the sub works, i know its air movement but it it the air inside or outside of the box??

 

[chaos]

cheers.. yeah, thats the kind thing i was thinking of :thumbs: would internal bracing not intefere with anything? i dont fully understand how the sub works, i know its air movement but it it the air inside or outside of the box??

Bracing attaches to 2/3 adjacent sides inside the enclosure. As long as it doesn't touch the sub, and that you factor in the volume of air that the braces take up when determining the dimensions of your enclosure, then you'll be fine

Take a look at

http://www.crutchfieldadvisor.com/r.../build_box.html

for building an enclosure and

http://www.jlaudio.com/tutorials/bracing/

for bracing

HTH

 

[Neo-The Matrix]

As said already, the volume is sub dependant, usually you will have it written on the instruction sheet of the sub or else find some program on the net (many free good programs) that you enter the thiele parameters of the sub and they give out the best enclosure volume according to what frequency they are most effective.

If you need to gain some more space in the enclosure do like I did - muchos damping foam and mount the subs inverted.

MDF should not be less than 3/4 at most (since you are coating them with fibreglass) you can get away with maybe 1/2.

I have a Pioneer 12" 1K watts in my punto I built the box using 1/2 mdf with loads of wood glue and sealant on the joins and edges.

For your vibration concears you will need to sound proof the boot. You can either buy something like dynamat or if you want to keep costs down go to shops where they sell airconditioning part and they should have sound reducing foam mats which are very cheap and as durable as the expensive dynamat.

 

[robcento]

thanks for the help, wil take a look into the subs i want and come back if i need any more help! cheers.

 

[chaos]

As said already, the volume is sub dependant, usually you will have it written on the instruction sheet of the sub or else find some program on the net (many free good programs) that you enter the thiele parameters of the sub and they give out the best enclosure volume according to what frequency they are most effective.

If you need to gain some more space in the enclosure do like I did - muchos damping foam and mount the subs inverted.

MDF should not be less than 3/4 at most (since you are coating them with fibreglass) you can get away with maybe 1/2.

I have a Pioneer 12" 1K watts in my punto I built the box using 1/2 mdf with loads of wood glue and sealant on the joins and edges.

For your vibration concears you will need to sound proof the boot. You can either buy something like dynamat or if you want to keep costs down go to shops where they sell airconditioning part and they should have sound reducing foam mats which are very cheap and as durable as the expensive dynamat.

Another point - make sure the enclosure is completely airtight!!!

Using the A/C foam mats to reduce vibrations - good idea Neo!

 

[robcento]

i found the subs i'm going to get, the various forums i visit have hinted that its one of the best subs out there for the price, so this is it http://www.soundmasterscotland.com/jbl_gt4_10_subwoofer_i013740.aspx any opinions on it/anyone here currently using them or had experience with them? also what would i bee looking at to power two of these? and also a pair of 6x9's? as for components up front, would a headunit provide enough power?
sorry for the questions but im a noob when it comes to ICE, engines and bodywork i can cope with as i've helped out dad when he's done stuff, never done this kind of thing before :O

 

[chaos]

i found the subs i'm going to get, the various forums i visit have hinted that its one of the best subs out there for the price, so this is it http://www.soundmasterscotland.com/jbl_gt4_10_subwoofer_i013740.aspx any opinions on it/anyone here currently using them or had experience with them? also what would i bee looking at to power two of these? and also a pair of 6x9's? as for components up front, would a headunit provide enough power?
sorry for the questions but im a noob when it comes to ICE, engines and bodywork i can cope with as i've helped out dad when he's done stuff, never done this kind of thing before :O

Good sub!!!! I got one. Can't fault it. GT4-10 kicks out 250W RMS.
Personally I wouldn't have the 6x9s. Just have the components up front. You can run em off the HU but using an amp would give better sound quality.

One point though - Motorworld do them for 30 quid.

 

[paulbfd]

Personally I wouldn't have the 6x9s. Just have the components up front. You can run em off the HU but using an amp would give better sound quality.

Couldn't agree more

Get a decent 4 channel amp, bridge 2 channels to the sub and use the others for your components (check the cinq / sei section, there's been talk about door speakers recently). It'll kick arse and sound great.

Mount the sub one side and the amp the other and still have a useable (if that's possible in a Cinq!) boot.

 

[robcento]

i was planning on a sub each side... haha, who needs a boot? would sound be ok with no real speakers in the abck, maybe components rather than 6x9's in the rear doorcards? and would a 4channel amp still be ok for this? i really have no idea and the link i used was just the first i found that had details of the sub, would shop around first

 

[robcento]

also, with this sub what kind of size would i be looking at for the box? i've had a quick look on google but couldnt find what i needed. anyone that can find out or provide a link would be great. dont pick up the car until early next week, then the bits will come and have them fitted

 

[paulbfd]

0.75ft3 sealed.

For the best SQ, the sub in boot, comps in front and nowt else.

 

[chaos]

0.75ft3 sealed.

For the best SQ, the sub in boot, comps in front and nowt else.

Bang on
No speakers in the back!!! (except for the sub of course)

 

[robcento]

okie doke, saves me the money of buying more than i need so glad i asked will be bck when it comes to wiring up
thanks again for the help

 

[chaos]

okie doke, saves me the money of buying more than i need so glad i asked will be bck when it comes to wiring up
thanks again for the help

that's OK, let us know how you get on

 

[robcento]

rightee, im back again lol. ive decided on getting two jbl gt4 10" subs, and also components for up front and an amp to power it all. someone said a 4 channel amp would be enough for this, this still ok? and also can someone point me in the right direction of what i should get? would rather the whole system was JBL, i ahte thigns not matching... everything has to be symetrical etc. or it looks odd anywho... so im looking for jbl components and also 4 channel amp. also minidisk headunit. currently have cd but i use minidisks more so want to change it. again jbl thanks in advance

if i ramble on too much let me know and i'll try and get straight to the point!

 

[chaos]

rightee, im back again lol. ive decided on getting two jbl gt4 10" subs, and also components for up front and an amp to power it all. someone said a 4 channel amp would be enough for this, this still ok? and also can someone point me in the right direction of what i should get? would rather the whole system was JBL, i ahte thigns not matching... everything has to be symetrical etc. or it looks odd anywho... so im looking for jbl components and also 4 channel amp. also minidisk headunit. currently have cd but i use minidisks more so want to change it. again jbl thanks in advance

if i ramble on too much let me know and i'll try and get straight to the point!

I have never seen a JBL HU.

Any ideas on what amps you want to buy?

 

[chrisunoman]

If you want to power the components off the amp then you will need a six channel amp.

Or a four channel for the subs, and a separate two channel amp for the components.

You could, in theory, run the two subs off two channels of a four channel amp but they would be very underpowered (or the amp would blow the components)

Seeing as 6-channel amps are very expensive (£400 at least) and generally just having 2 higher powered channels for a sub, i think this would be your best option (seeing as you want to stick with jbl)

This 4 channel for the subs
http://caraudiosecurity.com/shop/product/products_id/2911.html

This 2 channel for the components
http://caraudiosecurity.com/shop/product/products_id/2910.html

This way you would probably have more control over the sound too.

Hope this helps.