Best Position for Sub?

[Gester]

Just wondering what'd be the best position to put a 12" Sub in. Facing the back seats? Right up against them? Facing the boot lid upwards? Or facing to the back rear of the car?

What would give the best loudest sound? It'll be in a enclosed box as well.

[Knat]

I have a single 12" sub in my R33 and I face it towards the end of the car.... Sounds good! I've had a sub pointed into the car in my R31 when i could fold the seats down and almost sit it inside the cabin, but there's not as much bass as being faced the other way and as an enclosed unit (boot)

[BOoStEr]

Just looking at my R32 it seems logical to mount a sub in a sealed box through the plate behind the back seat.(see my posts #18 &

#22 " Where's the bass? " this forum). I've run this idea past a few installers and most have recommended something else for one reason or another. One guy quoted a couple of articles on bass loading in CSA magazine. I found these articles (issues #5 & #9) and I must say that in these tests the forward facing mounting position had the lowest SPL and very uneven frequency response. The main difference between my idea and their setup is that my cabin will be sealed from the boot and their's fires through an open ski-port.

[BigDatto]

Gester,

The answer to your question is "none of the above"

Try standing in the middle of a room (of any given size) and speak at a normal level. Now go to a corner, face the wall and repeat...

This is why manufacturers of Hi-Fi speakers ALWAYS recommend positioning at least 40-50cm from a side wall - The bass response would lift considerably and "muddy" the soundstage. In a car where you WANT lift face the driver toward the rearmost corner in your boot. You won't win any fashion contests doing this, but you will optimize bass response using the natural acoustics of your car.

Let me know if it makes a difference !

[Frosty]

hey gester

depending if it is in a sealed box but if not face it towards the tail gate were the real lights are. bounces the sound of the corner and makes it louder and deeper

[KamikazeR33]

hey guys im not sure on how this design would work, but it looks good to me anyway, and pretty neat

i know ill be getting soemthin done like this

[Sumo]

Kamikaze: I had a audio workshop try and convince me to do the same setup.

Sumo

[KamikazeR33]

any good?

its got further to travel across than it does front to back

[predator]

wow... almost looks like there is some boot space left there with that setup!

My 12" sub should be ariving any day now.. Will be interesting to see what i can do as well. I don't want to lose too much boot, but i know that i will in one way or another.

With bass, low frequencies are a lot more omni directional than higher frequencies, therefore staging is not as important in general in a sub. If you think about it, higher frequencies have less area and therefore bounce around more and are affected more by where it is positioned - so its important to get that part right.

That is why most home theatre applications they generally say you can position the sub most of time where it fits when there is all these theories of where you should be positioning all your other speakers.

I think where you position the sub is not as important as the enclosure (where it develops most of its sound) and the mounting itself (not loose). The key is to make sure there is no non-harmonic vibration or "buzzing" developed. I wonder whether adding sound insulation into the wells and other "open" spaces in there is going to help aswell so less sound can escape?

There is probably a massive art to getting it all perfectly right and requires many complex tools that us peeps probably don't have access to. I'd say unless you do something really stupid its going to sound pretty good - and bass in the end is only part of the equation (for me anyway!)

[predator]

btw: I don't think that side setup would be that optimal, as really there is really little room for proper resonation behind the speaker, other than the side wells (which are pretty small really and not that effectively shaped)... however you would have good resonation from the front of the speaker, as there is no box filling the rest of the boot. I still think the former is more important though.

I'd say while more practical, you would be sacrificing some volume and quality there.

[KamikazeR33]

aparently there is soundproofing behind it (i think) but there is soundproofing in the boot

[zanda]

Originally posted by predator666

With bass, low frequencies are a lot more omni directional than higher frequencies, therefore staging is not as important in general in a sub. If you think about it, higher frequencies have less area and therefore bounce around more and are affected more by where it is positioned - so its important to get that part right.  

That is why most home theatre applications they generally say you can position the sub most of time where it fits when there is all these theories of where you should be positioning all your other speakers.  

you are partly right predator.

in terms of a room, with a large air volume and semi-infinite space, the location of a sub is not "as essential". However, within a car, the primary governance in terms of the effectiveness of bass drivers is the relationship between active and passive wave cancellation.

wavelengths for bass travel are typically in the order of 3m. as governed by c=f x lambda (assuming c=3.3, and f=80 Hz mean). for the best amplitude response, the listener should be positioned at the anti-node of the source. in terms of a woofer driver, this amounts to a multiple of the wavelength.

In short, the MOST CONSISTENT way of acheiving this is to direct the driver toards the back f the trunk. this allows reflecion of the sound wave off rear boot surface (approximately 0.5m) and then travel from the boot to the front of the vehicle cabin (about 2.5m, depending on the car).

this method typically produces best resullts for single driver setups in sedan sized vehicles in terms of SPL. some experimentation may be necessary to determine whether the sound is better when the driver is facced into the LH or RH corner or directly backwards.

[KamikazeR33]

gordo

im not 100% sure on if it in enclosed in a box or not... im about to ask the guy

if it is i would assume it may be an alright design

[Frosty]

yeah thats not a bad install, im having mine mounted in the floor in a clear perspex completely sealed

should be good

taking the spare wheel and that out if ya know what i mean

[BOoStEr]

Frosty Have you had your sub installed yet? What did you do about the little tower thingy in the middle of the wheelwell?

[Frosty]

nah havent had it done yet booster

just leave it there

when you put the box in you need that space filler faom to fill it up

you just ignore that plus im puttin 2 mite even go 3 12s now not sure

ill keep ya posted on what i do

[Gester]

Has anyone managed to put the Sub in the compartment with the battery?

[BOoStEr]

Gester I'm still undecided as to whether to put the sub behind the seat or in the wheelwell. I don't see it being too difficult to go behind the seat once you've relocated the battery though. I'm still toying with the idea of facing it foward through the arm rest hole but if I do this I can only fit one 10". If i face it backwards I can fit 2 x 12"s easily.

[Darker]

Has anyone managed to put the Sub in the compartment with the battery?

Yep, done it. Single 10" drivers side, facing into the boot, and currently working on the second once I have relocated the battery. 12"s would fit no problem, provided they arent going to be too deep. You can always bring the false wall forward to compensate though, just means less boot space (tis why I have 10") All I need to do now if buy decent 10"s rather than the Sony's I was given

[NO_RSPECT]

I got mine like the pic above with the driver facing the left suspension tower roughly. Its a solobaric L7 square so the box is absolutely small and the sound is mad for such a small driver in such a miniscule box. also get some brown bread deadener and deaden the boot lid and anywhere else you can fit some if there is any left exspecially the boot floor.

perfect