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Sub positioning

1K views 33 replies 6 participants last post by  essexgte 
#1 ·
Due to the size of my sub boxes, which are made the right dimensions for my subs, i only have 3 choices of postioning. Which would be best?

1) back to back to subs pointing to each side of the car
2) on theyre back so both subs pointing upwards at shelf (metal as its a saloon)
3) facing each other (subs would only be about 15 inces apart)

Any info appreciated. They are vented boxes if this makes any difference.

Also i will be sound proofing the boot tomorrow/tuesday. Any tips on this? Is strips, squares, triangles the best or just to cover as much as possible.

Cheers
 
#4 ·
each position will give a different effect/sound. simply try all three and stick with the one you prefer,(each different position will require the amps to be tweaked).

i would imagine that the most likely position you end up with will be number 3, followed by number 2.

with regard deadening go with whatever is easier,(it's simply mass loading to prevent resonating, as long as you cover as much as possible, you will hear a difference). with your car being a saloon i would avoid deadening the shelf area.

HTH mate.
 
#6 ·
i would deaden;

boot floor inc the wheel well, both boot sides & wheel arches, boot lid, rear panel holding the number plate, also around the rear light area's, in fact the only two places i wouldn't do would be the underside of the rear shelf and the back of the rear seats,(this is where you want the sound to penetrate into the cabin).

by having the subs firing into each other the cones will be loading one another, this effect will allow you to increase the input power from the amp. cancellation issues occur when using two or more different types/sizes of speaker to reproduce the same frequencies.

i don't know what subs you have or what amp/amps you will be driving them with, so i can only offer a broad opinion on how they may react. if, however, your after a more musical output, having them firing upward may well be your best option.

trying to explain the effect of loading on a subs cone is a little difficult, when your boot is shut and your subs are playing, each outward movement of the cone will produce a pressure wave, this same pressure wave will bounce back and have some effect on the subs cone movement, you are fitting two subs, so each sub,(no matter which way its firing), will have some effect on itself and the other one. this is why your subs will sound different if your boot is open or closed. now your running ported enclosures, so each inward movement of the cone will produce a pressure wave out of the port, again this will have an effect on both subs.

sorry, this is getting a little too involvedlmao , lets just say that when your boot is closed, pressure waves generated by each sub and its port will affect the response of itself and its neighbour, even if one sub is in the boot and one sub is on the front passenger seat, the trick is, to make it work in your favour.

follow the link and have a look at some vids, this will give you an idea of how sound pressure can affect solid objects.

http://www.realmofexcursion.com/videos.html

HTH
 
#7 ·
Well I have to JL W6 V2's and the boxes are built to the exact dimensions JL recommend running off JL 500/1 amp. Ive been told to fire them at each other by people but some others have said it will cancel them out. Ill point them towards each other and see what happens. TBH it would be easier for Amp positioning this way too!
 
#10 ·
Got this sent to me today:

CarMedia said:
Spoke to paul and hes recomends that you dont try facing the subs outwards but one of the other 2 options would be worth tryin.
But remember if you face the subs at each other you would have to reverse the polarity of one sub box or you would suffer from phase cancelation.
As for sound deadening you need to cover as much as you can afford ;)
remember to start on the largest flatest panels as these would resonate the most, then just fill in any gaps afterwards with what ever you have left over (ie. small corners would be last as they are the strongest points in the boot well)
Hope this helps if not give us a call
Dan
Car Media
 
#11 ·
I agree dont face the subs directly towards each other, if they do need to face each other then they should be slightly angled away from each other. Not being funny but 2 w6's running off a 500/1 your going to get loads of bass no matter which way they are arranged in the boot
 
#13 ·
tbh your going to suffer because your using a saloon car.

how have you wired them?

have you tried them firing upward?

you seem to be using a single 500/1 amp, i personally would have gone with a 1000/1.

as an experiment try a single sub firing toward the rear seatback, get it so it's fairly close to start of with,(this will load the cone), play a track your familiar with and gradually move the sub rearwards until your happy with the sound,(remember to listen from the drivers seat with the boot shut, but a window open slightly, improves output in the car).

with regard phasing issues when directing subs at each other, try it wired both ways,(both the same polarity, then one at 180 degrees, reversed polarity).
 
#14 ·
I bought a 500/1 as i will be having a second one so they can have one amp per sub...
Tomorrow i will be soundproofing the boot and then trying them out. Currently they are back to back, but ill try them upwards tomorrow. To try a single sub ill have to take it out the box again and connect the jumper lead back up. I may do it, i may not. Ill see how i feel lmao
In response to how theyre wired:

Vc1- to Vc2+ on each sub, then both sub + to amp + and both sub - to amp -
 
#18 ·
Ill have to leave them like that too as the 500/1 cant do 1 ohm, lowest it can take is 1.5 ohm, so the way i have them wired results in 4 ohm. I might try the on sub method though see what its like until i can get a second 500/1
 
#19 ·
The JL 500/1 is a great amp & if you read the manual it has some clever circuitry to provide the most power without the need to bring the resistance of the speakers to 1 ohm etc.

I did this install on My fiancee's brothers' clio for him last year, great little amp on a pair of 12's, I haven't got a final piccy after the cover panel for the M44 went in. Just remember to get the base cube dial...







Regarding the position of the subs, the best way to have them is facing horizontally or at least some way horizontally at a slight angle, bass frequencies are less directional than the higher frequencies which must be angled towards the listener as much as possible to create a decent sound stage.

Placing subs facing up is the less ideal position for them, try & keep them facing horizontally & not directly facing each other where you could create standing waves.

Dynamat everywhere, double it where you can & where you can't add it to a flat surface use spray on souind deadening.
 
#20 ·
i personally would go with a single sub until you can obtain either a second 500/1 or a single 1000/1.

these subs are happy to run at 500 watts rms continuously without any issues, and the only way they will see that kind of input power from the amp will be whilst playing test tones recorded at 0dB.

without knowing the wiring specs of your power supply or the condition of your charging circuit, i would hazard a guess that whilst playing music your probably getting around 100watts rms to 130watts rms output power from your amp into each sub,(200 to 260 watts rms overall, assuming your gain control is set correctly). put this same output power through a sub with higher sensitivity,(these subs are in the mid 80's), and the volume increase will be obvious,(higher sensitivity, higher output).

theoretically a pair of 12" subs recieving 100watts rms each will be louder,(spl), than a single 12" sub recieving 200watts rms,(more cone area), but by running a single sub you will be less likely to overdo the gain control.

but, when setup and running enough power, this kit will be crackin mate, you should get high output coupled with very good sound quality.:beer: :beer: :D
 
#21 ·
That clio install looks good. Ive just got home after soundproofing the boot. Good lord what a difference! I only did one layer round the well, in the well and inside the boot lid. No more rattles! Best £15 i spent really. I have laid them on theyre back with the subs pointing upwards as thats all i can really do with out having them facing each other or back to back. The boxes are that big! Ive left them at 4ohm as the supplier said they are only capable of 1.5ohm and wiring the subs differently would bring a load of 1ohm so no good. Ill try to get a second 500/1 ASAP then i should be flying!
Ill just need someone to set it up for me as i have so many different knobs not only on the amp but also on my AVIC!
So you recommend to get the external bass controller too?
 
#22 ·
Cheers for that Drizz, It took a while to fibreglass the box shape, worth it in the end though.

I assume you are putting 2 12" subs in the boot of your Vectra saloon right?, how big are the boxes you have exactly? A 12" sub shouldn't really use more than 1.25 - 1.5 ft2 per speaker, have you worked out the internal capacity of yours?

In the Vectra, you have a ski hatch right?

I have previously installed 4 x 12" JL subs in a vectra where they all directed into the cabin throught the ski hatch hole, so 2 will be more than easily achieved.

& yes, get the base cube control, it's a cheap way of boosting the bass, not the best pure audiophile quality, but does allow you to have the extra kick when needed.
 
#23 ·
They are built according to the manual that came with the subs. They arent shaped, they are rectangular, but the exact measurements JL say in the manual. I do have a hatch yes and ill open it later, put it up before i left earlier and forgot to put it down again.
Yes they are 2 12s. Ill look into the external controller, Yet more wires into the car lmao
 
#25 ·
Yeah, sorry it's not a Vauxhall, but hey, it's his first car so I can forgive him. I even did it all for free, I guess thats what family is for eh?

It's a relatively simple but time consuming process, lots of waiting for fibreglass to go off, layering more on & on & on etc... you get the idea.

Here are the door pods:



Start off doing something like that then move up to the bass boxes, same process just more fibreglass!
 
#28 ·
How heavy are fibreglass pods? i know there supported by wood and glassed over but with regarding my boot install i want it to be as light as possible. May be a stupid question but is fibreglassing it heavier than say normal sub enclosures? due to all the wooden supports?
 
#30 ·
No it's lighter, you only need about 6mm of fibreglass when comparing to 18mm mdf to get the same sort of strength.

The boxes I made for the clio were mdf backed with fibreglass fronts, but you can make all fibreglass boxes with some kind of metal mesh bonded in the fibreglass to give it extra rigidity.
 
#32 ·
I used to when I was younger, did the whole competition scene, but now I'm a CAD Techie now, much easier way of making money.

As Hattori Hanzo vowed never to make another sword I did the same with stereo installs however I broke my oath & made another install for the Brother inlaw last year...
 
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