Normal 6.5" or shallow mount 8" woofer

[oreo]

Hi all,

I am trying to complete a stealth-upgrade of the ICE in my BMW 1-series and thus I intend to use the stock locations for the front speakers (i.e. DLS IR1 tweeters + MB Quart QM100MX 4" in the doors + woofers underneath front seats) and fibreglass a 20l ported enclosure for a 10" woofer in the rear (Phoenix Gold Octane R10). HU is a Nakamichi CD400 linked to an Alpine H701. Tweeters + Mids are powered by a Genesis Q90X amp, mid-woofers (planned for 70-130 Hz) by a Genesis Stereo 100 and the sub by a bridged Genesis Dual Mono.

I have yet not completely decided on the mid-woofers to mount underneath the front seats. They will be able to play in a box of approximately 20 dm3 (liter) and it is possible to fit a speaker with a mounting depth of about 70mm. It is thus possible to select among a few 6.5" woofers, but as the stock location also allows mounting a shallow mount 8" woofer (such as the Earthquake SWS or PL Aliante) I am looking for input on how you think that these will compare. Any input is useful - thanks!

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[Warbleed 10+ year member]

Well, in looking for a shallow mount 8, make sure that you are looking for one intended for the frequency ranges its going to be playing, as many shallow mount 8" drivers are intended purely as subwoofers, and might not offer adequate extension above 80Hz or so.

Ideally you're gonna want one with a fairly low inductance, and since you are dealing with what is likely a fairly small cabinet, I'd opt for a driver with a fairly low Qts.

 

[oreo]

Thanks for your quick input!

Ideally you're gonna want one with a fairly low inductance, and since you are dealing with what is likely a fairly small cabinet, I'd opt for a driver with a fairly low Qts.

The cabinet is somewhere between 0.5-1 ft3, which should not be that small I think (or?). Thus, I thought that I would not have to find the drivers with the lowest Qts...

Well, in looking for a shallow mount 8, make sure that you are looking for one intended for the frequency ranges its going to be playing, as many shallow mount 8" drivers are intended purely as subwoofers, and might not offer adequate extension above 80Hz or so.

How would I know this? Would the parameters parameters for the speakers tell you anything, like:

SWS 8:

Fo:30.4 (Hz)

Sd:22.0 (msqM)

BL: 6.21 ™

Qms: 3.987

Qes: 0.804

Qts: 0.669

SPLo: 86.7 (dB)

Vas: 27.83 (l)

Xmax: 23 (mm)

Recommended sealed box (in manual): 5l

or Aliante 8 SI

Fs: 54

Qes: 0.89

Qms: 5.48

Qts: 0.77

Vas: 8.7

Xmax: 5 (mm)

Recommended sealed box: > 12l

 

[Warbleed 10+ year member]

The EQ isnt too impressive looking. Quite a bit of xmax for that size driver, but a VERY weak motor, and I'm wagering a fairly high inductance as well.

The Aliante is a bit more musically oriented, but isn't going to have a great deal of low frequency extension with a 54Hz Fs.

I don't know that I like the motors of either driver, as they are both extremely weak, which makes them ill suited for small sealed boxes. They are both more suited to a free air/large sealed environment, IMO.

Of those two drivers I'd definitely take the Aliante, as it's definitely the more musically oriented driver of the two.

Personally I'd just use a beefy 6.5 sub like this:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=264-832

Low inductance, fairly strong motor, and good displacement. I think they look cool too.

 

[oreo]

Valuable input - thanks!

One of the problems I have with using the original mount is that the total height of the element cannot exceed 75 mm, which excludes most 8" woofers and also many 6.5" ones (including the one you link to). One option I have considered is to make a small fibre-glass box instead of the original mount. I have heard lots of good things about the JL6W0 in a 5 liter sealed box:

Qes: 0.503

Qms: 9.028

Qts: 0.477

Vas: 0.342 ft3

Xmax: 0.298 in

Sd: 20.9 in2

Re: 3.42

Any thoughts on this one?