How do you fit a subwoofer under the R33 shelf?

[Fhrx]

I’ve had numerous people asking me over PM’s how we manage to fit a subwoofer under the R33 shelf next to the battery. This is one example of how it’s done. This R33 belongs to a certain member here.

[Nav2k]

nice dude (:

now tell me how do u fit a sub in the shelf of an s14? (:

wanting to invert a 13inch in there not much room...anyway, install starts in june holidays only so got some time for planning.

[Fhrx]

This is how we did our old demo car:

This is another option for a 12":

[Nav2k]

looks very nice, but the step is only accomodating the magnets of the sub right? i mean..the full face of the subs wont fit in it? dun worry, ill figure some crap out hehe

ur installs r awesome mate (: wish i lived nearby.

[Fhrx]

Well the entire sub does just fit in but they're 8's remember.

That is why I though I should put up an image of how we fit the larger ones in.

[Nav2k]

hehe cool, thanks for that (:

[zzsprade]

I’ve had numerous people asking me over PM’s how we manage to fit a subwoofer under the R33 shelf next to the battery. This is one example of how it’s done. This R33 belongs to a certain member here.

Fhrx,

Out of curiousity, what size is that sub under the parcel shelf. Would it happen to be 8" and if so what is the quality like out of such a set up and 8" subs in general? Ie. What kind of sound does it have?

After seeing such an example you may have helped me find a solution for putting a realistic sub into my boot... so as always cheers and thank you for your contributions!

-Alex

[Fhrx]

It's a JL Audio 10W0-4 (10")

[zzsprade]

It's a JL Audio 10W0-4 (10")

And how is the general sound quality (even your best guess) from having a 10" sub in such a location under the parcel shelf? Also any ideas on the best type of enclosure/direction placement for such a location Fhrx?

Cheers again!

-Alex

[EJ]

i would say dont because it would rattle the s**t out of the boot and the parcel shelf

[zzsprade]

i would say dont because it would rattle the s**t out of the boot and the parcel shelf

Any suggestions on how to overcome this, as I quite like the suggestion. Sound deadening mat? Smaller 8" sub?

-Alex

[sliksilvia]

some Flash take from bunning will prevent the rattles even some liguid nails between were the metal sheets join works really well

[cooks44]

You can do it the same way I am - bandpass box.

Find a good sub that uses a smallish volume sealed bandpass box and run the port (the sub's only audible exit) straight through the parcel shelf. Great for SQ, not great for marios - you wont hear any bass in the boot anymore!

I was originally sizing up an old Cerwin-Vega AI series 10" for the job, CV's recommended bandpass box is 2.6ft³ though.... Infinity's Kappa Perfect 10.1 (10") recommends a 0.95ft³ box - easily fits under the parcel shelf!

My box is currently in R&D stages (the box is together and I've tested it in position - quite a nice sound!), but it's out again for me to install the rest of the job. Will take pics once it's finished.

[Fhrx]

Be careful though, remember the physics of the bass.

The biggest single issue with bandpass enclosures though is exacltly as their name suggests. Their bass reproduction is restricted to a particular tuned band. Unfortunately you cannot get a bandpass enclosure to acurately reproduce the entire subbass spectrum. You can tune it low and allow some serious front end speakers to dip deep into subbass territory but the other types are better. The order of quality bass goes:

1. Free-air

2. Sealed

3. Ported

4. Bandpass

Although sealed and ported is a never eneding argument, free-air definately sound best (sound though, they don't thump hard at all) and bandpass is not so much worse, it's more a specialised enclosure used in specific application.

[Fhrx]

i would say dont because it would rattle the s**t out of the boot and the parcel shelf

With bass waves measuring up to 25 meters peak-to-peak it is going to rattle the car not matter where it is.

[HoeTrain]

1. Free-air

2. Sealed

3. Ported

4. Bandpass

Don't forget Passive Radiator.

[Fhrx]

But it's not really an enclosure design in it's own right though? It's more a technique, like the use of aperiodic membranes. It simply allows sealed boxes more bass below the subs resonant frequency.

Like saying that tranmisson line porting is another one. It's still a ported enclosure after all.

[HoeTrain]

Very true, I only mentioned it cause I saw a nifty design where the radiator cones were place in the parcel tray using a single sub and a really well designed cabinet.

[cooks44]

Passive radiator.... oh no!

Of course you're right about the tuning restrictions of a bandpass box... Mine is meant to be tuned to 52Hz, still plays up to 100Hz quite well which is where my high-pass crossovers start dropping off.

The resulting drop in dB as it gets down towards 20Hz is definately noticable when testing it outside the vehicle, once inside the vehicle's acoustics flatten this drop out quite well. Still playing around with spectrum analyser software to test this properly though!

So yes, given the right application a bandpass box can be great - only problem is the box volumes and port dimensions are absolutely CRITICAL as they not only tune/shape the sub's bottom end (the bass you want) but also tune it's top end creating a fixed frequency band for that subwoofer. If it suits your vehicle/application and can be tuned to the rest of the stereo well, great!

But if you find out it doesn't fit in with the rest of your system you've got to start your box again from scratch. Not much fun!

Personally, if you want a good result from your stereo you have to consult a specialist. There are many programs that can tell you what box a specific subwoofer needs, some even allow you to tailor the box to your requirements. But they can't tell you whether the box/sub combination is going to blend properly with your existing speaker combination or whether your amplifier is up to the task. (Hey Fhrx...?)

[Fhrx]

Yeah, you're spot on there cooks.

I would never say bandpass enclosures are 'bad'. In fact they're designed for very specific applications. Many quality home theatres utilise bandpox enclosures but cars are a totally different scenario.

I find you tend to tune bandpass quite low and use a serious front end like a three way active system etc...

Quality sound is all about planning, planning and more planning.