subs

[e30maddog]

hey, currently in the boot of my cab is 2x 12'' subs, takin up lot of room!! im going to make a new box to give a lot more space in the boot and was thinkin of havin 1 sub in as normal and 1 with the arse end facing outwards. ive seen it many tiimes but never tried it myself, im not sure if i need to use 2 seperate boxes and do i reverse the the wires on the backwards sub (if you get my meaning) some advice would be great on the proper setup of the arse out sub

[chu346]

You would need to build the box as normal. If it's a sealed box you are making, it is commonly recommended to divide the box evenly so that each sub has it's own air space. Because if one sub blows it won't put pressure on the other and ruin it. You would need to wire the rearward sub the opposite way other wise the subs will be cancelling each other out.

What I would do is, go isobaric. This means you would only need half the box size of what it would take for one of the subs. For example, for your two subs you may need 4 cuft, for one sub 2 cuft, for two isobaric you would only need 1 cuft.

Best option would be to make your box ported and isobaric, if you want me to advice you on this let me know.

http://mobile.jlaudio.com/support_pages.php?page_id=152

[e30maddog]

nice, thanks for the reply. ive palyed with ported and unported boxes for these subs and unported is the way ahead, the ported box sounded crap. however, im not sure what a ported box would be like with the outwards sub. now the doin both subs isobaric would be geat coz it would free a lot of space up in the boot but what about sound? will they pounch as hard? and will they deliver the same bassline? would i need to make sure the boot is well sealed? the subs are jl's btw, cant remember what model off the top of my head, a few years old now

[chu346]

Having the sub facing outwards makes no difference to the sound.

Ported is better than sealed, but you need to make sure you've designed the box correctly and have correct subs. JL Audio subs can play in either type box well.

Because the two subs will act as one, it will be like you've only got one sub, so to counter this you need to make a ported box twice as big. This means it will need to be what the manufacture recommends for the box size for one of them, or bigger to get the same amount of output. I had 4 subs in this configuration and I found that the bass was not only loud and deep but very accurate. This is down to one sub being ontop of the other. A normal sub will wobble on the bass notes, but when isobaric the sub facing out reduces this wobble and keeps things under more control.

Making a sealed isboric box, will be like only having one sub that takes up half the box space of one sub.

I think you should give isobaric ported ago.

[chu346]

Also how did you design the ported box you tried?

[e30maddog]

i simply ported my existing box with a 10'' long (if i remember right) port tube with a 3.5''dia. at the time i did read into it.. but it didnt sound nerly as good so i blocked the port and stuck a power cap over it looking at the diff types of box design i think im pushed more toward the clamshell design. if i have room ofc, im just going over the dimentions now.. im looking to build so the box sits past the roof bit in boot as less as possible. which from rear seat to roof storage bit is 11''. and side to side is 37.5'' by 11'' high. its going to be tight but i rely dont want to loose a sub and settle for just the 1. 2x12'' subs+ bootspace in a cab is quite a challenge..

[Rav335uk]

2x12'' subs+ bootspace in a cab is quite a challenge..

Not really, I have 2 x 12" in an isobaric ported box, and with the bass on "0" it still is too loud, but I have 20 yr old Pioneer free air subs wired in opp.

[chu346]

You can't just put a port in a box and expect it to work. Find out the model of your subs and I will design you a nice ported box that you'll love.

[Rav335uk]

You can't just put a port in a box and expect it to work. Find out the model of your subs and I will design you a nice ported box that you'll love.

True, I had to "Borrow" the design of a good friend who had it built in his shop, went in there on day with a tape measure and the rest is in my boot.

Same subs though.

[TouringTash]

Its all to do with the z number iirc. Well that and a load more

An old sound engineer friend used to go on about Eminence (sp??) speakers from Maplins many years ago. Sounded good speakers to me and handled the sharp end of a 4K rig off of a Blaupunt head unit with no dramas.
Get the enclosure right and its all good maddog.
Get a quote from chu as its well worth doing right, as you don't want any more weight than necessary especially in a cabby

[e30maddog]

yh def, well the subs are jl audio i was wondering if this box setup would work
sorry for the noobness lol, but i have only ever had standard boxes
or maybe.............
idealy i would go for a vibe space but dont have the ££ kickin about for one

[Rav335uk]

This is similar to my set up

[FMH]

You can't just put a port in a box and expect it to work. Find out the model of your subs and I will design you a nice ported box that you'll love.

Any chance you could do this for me?

[chu346]

This will get you no gains=pointless and imo

idealy i would go for a vibe space but dont have the ££ kickin about for one

Not sure why you posted this pic, it's just a normal box with the subs facing the other way. I'd stick with the JL's if I was you. I need the model number of the subs and the max box size or I can't design a box for you.

This is similar to my set up

Looks like a 6th order bandpass, not a standard ported. Very difficult to design, but that is why you say it sounds good. Are you sure that's what you have?

You can't just put a port in a box and expect it to work. Find out the model of your subs and I will design you a nice ported box that you'll love.

Any chance you could do this for me?

Can do, post the type of subs you have and the max box size you want HxWxD

[FMH]

Just a single pioneer 12" for a cabby. 1000w RMS, 3000w peak. Powered by a VIBE BLACK BOX mono amp. 1250w RMS @ 1 ohm. 1000w RMS @ 2 ohm.

[Rav335uk]

[quote="chu346

This is similar to my set up

Looks like a 6th order bandpass, not a standard ported. Very difficult to design, but that is why you say it sounds good. Are you sure that's what you have?

[/quote]

That's exactly what I have in my boot, 2 sized ports on one side, one single sized port with the other sub, wired up + - - +, push pull,
But the size of the box takes over the boot.

[TouringTash]

You mean your one works?
I thought it was just ballast for the M30 donk

Checked out the dance music thread Rav

[Rav335uk]

You mean your one works?
I thought it was just ballast for the M30 donk

Checked out the dance music thread Rav

Jason, I've been borrowing music of that site, and was in the car yesterday on my way to Jim320i's, one track is 1hr 12 mins
, and i had to turn the bass down to -3

[TouringTash]

saucy.

Starting to get a craving for a system.
Would an E36 touring be a better idea for a hidden system.
just a little 3 way active set up

[Alex]

2x12'' subs+ bootspace in a cab is quite a challenge..

Not really, I have 2 x 12" in an isobaric ported box, and with the bass on "0" it still is too loud, but I have 20 yr old Pioneer free air subs wired in opp.

I like your sound system rav, its council as fook but sounds awsome

[Rav335uk]

saucy.

Starting to get a craving for a system.
Would an E36 touring be a better idea for a hidden system.
just a little 3 way active set up

I suppose you could, but how would you hide the system so you could still use the space??

2x12'' subs+ bootspace in a cab is quite a challenge..

Not really, I have 2 x 12" in an isobaric ported box, and with the bass on "0" it still is too loud, but I have 20 yr old Pioneer free air subs wired in opp.

I like your sound system rav, its council as fook but sounds awsome

Cheers ALex, but I think I did some damage to one of the rear JBL's

[TouringTash]

load cover for when the subs are needed but the rest outa sight.

How have you 'damaged' a speaker. If set up correctly nothing can blow.

[chu346]

Just a single pioneer 12" for a cabby. 1000w RMS, 3000w peak. Powered by a VIBE BLACK BOX mono amp. 1250w RMS @ 1 ohm. 1000w RMS @ 2 ohm.

Need to know the exact model so I can find out the T/S (list of numbers which determines the box size), also the how much boot space you have to play with.

[chu346]

How have you 'damaged' a speaker. If set up correctly nothing can blow.

JBL speakers can blow easily for no reason. JBL are only good for their subs.

[Rav335uk]

Everything has been set up correctly , it's been over 10years for the in car system, but the sub box is about 1 yr old.

[TouringTash]

How have you 'damaged' a speaker. If set up correctly nothing can blow.

JBL speakers can blow easily for no reason. JBL are only good for their subs.

A speaker blows for no reason, ouch. Will never use their stuff then.

[_Jay_]

Will get the type and model number for the subs im getting and measure up the size for how big a box I can in the back of the cab and would you be able to design me a box as well please? Will be able to make it all no problems, just not to sure of how big it needs to be etc.

[Rav335uk]

15" x 15" x 36" will be the biggest you can fit in the boot of a cab

[ImysE30]

^^^^ Not if you have an electric hood, i'm sure I only measured 11-12" in height in my bootlid

[Rav335uk]

That measurement is not under the hood cover, but in the largest space of the boot

[_Jay_]

I have a manual hood so whats my space under the hood section?

[ImysE30]

I would have thought you'd make a box to fit under the hood compartment so you still have some boot space?

[TouringTash]

and sacrifice sound quality

[ImysE30]

Not if you had the correct box and subs

[Rav335uk]

Not if you had the correct box and subs

But if you work out the box size, it would depend on you running either one sub or two.
No way are you ever going to get 2 x 12" subs in a box under the hood compartment.
My box was designed to hit a very wide Hz range too, most boxes are limited in what range they hit, that's why there are soo many different designs out there.