10" Blaupunkt subwoofer install (trying for no footwell space loss)

**johnsylora** · 02-11-2006, 20:11

Hello everyone,

I have a 2005 Red NSX in which I installed an 8" Polk Audio subwoofer (4.5" deep without the box, >6" deep with the box) in the passenger footwell. http://www.nsxprime.com/forums/showt...ght=polk+audio The sound is good, but the footwell space loss is not acceptable. I have searched for subwoofers less deep than the original factory Bose subwoofer (3.5" deep) and have chosen the 10" Blaupunkt Overdrive ODW1000 (2.2" deep).

Here are pictures of the 8" Polk Audio installation showing the loss of footwell space and wrinkling of the carpet which is not acceptable in an NSX!! The first two pictures are with the floormat in place and the last 3 show the wrinkled carpet under the floormat.

**johnsylora** · 02-11-2006, 20:17

The Blaupunkt speaker was purchased at Stereo 1 in Rancho Cucamonga (909-484-1005) for $225 including tax. I tried to bid twice on Ebay up to $120 + $30 shipping, and I could not win. At least I get a local store in case of problems and a warranty for the higher price.

Here are pictures of the very flat Blaupunkt subwoofer (2.2" deep) compared to the original Bose subwoofer which is also very flat (3.5" deep).

**johnsylora** · 02-11-2006, 20:22

Here are more pictures of the 10" Blaupunkt subwoofer which appears like a film reel in design! Notice the beautiful aluminum speaker grille. This grille adds about 1" to the thickness of the speaker so it will not be used since space is a premium in the NSX.

**johnsylora** · 02-11-2006, 20:32

The installation of the Blaupunkt subwoofer will be done at Audio eXtreme in San Bernardino (909-383-3636). The original Bose subwoofer was used as a template to trace an outline onto the 3/4" Birch wood (Home Depot $15 for 2ft x 4ft sheet). Birch was chosen instead of MDF because birch is lighter and has better acoustic properties. The outline of the Bose subwoofer was cut out using a Bosch jigsaw. This wooden plate will serve as the top plate of the Blaupunkt box. A circle is drawn on this top plate using the Blaupunkt speaker grille as a template. That is all for now.

Here are pictures of the process.

**johnsylora** · 02-11-2006, 20:35

Here are additional pictures of the Blaupunkt speaker with the packaging.

**ediddynsx** · 02-11-2006, 21:01

Good stuff let us know how it goes and sounds when you are done.

**nbovelle** · 02-13-2006, 12:37

Is it your plan to put it in the stock location without any decrease in leg room?

Also, what will be the volume of the box?

Nate in DC

**Vega$ NSX** · 02-13-2006, 12:50

Awesome write up so far! Please keep it up!

I considered this option when first doing my system, but I had a hard time find a vendor that sold this sub. I thought it was ideal for preserving footwell space, though I was a bit worried how it would sound. I ended up going with the SOS sub box and am very happy with the results, but (even though it isn't that bad) I do miss some of the foot space I used to have. But depending on what you say about how it sounds, I'll still consider going this route.

**Shaun Ray** · 02-13-2006, 15:48

Good luck with the experiment. I too used a toolbox, but wanted more leg room so made a rough enclosure using a 10" Earthquake SWS. The box has approx. 0.2 cu. ft. internal volume and sounds okay. I think a larger enclosure would improve low freq. response, but good for a 1st try.

I tried to do the same for the passenger side, but that leg room is still a premium. By the way, I'm 5'-8" and have plenty of leg room for the driver's side. Still hopeful to have a solution.

Keep us posted!

Shaun

**johnsylora** · 02-13-2006, 17:23

Hello everyone,

I'm glad there is so much interest in installing a subwoofer without footwell space loss in the NSX. Well, I had some degree of success with the work of Audio eXtreme in San Bernardino. Originally our plan was to use the original Bose subwoofer as a template top plate for a box. But Troy (proprietor of Audio eXtreme) saw the metal plate that covers the Bose subwoofer as a better and larger template to use as the top plate. The metal cover plate was traced onto the birch plywood then the outline removed with jigsaws.

Here are pictures of the top plate and the creation of a wooden template using 3/4" birch plywood. The last picture shows the Bosch jigsaw with the larger blade used to cut the straight areas and a narrower scroll blade to cut the rounded and right angle edges.

**johnsylora** · 02-13-2006, 18:18

These next pictures show the wooden plate which has the same shape as the metal cover plate over the Bose subwoofer. A 9.1" circle is traced and removed allowing mounting of the Blaupunkt speaker which has an outer diameter of 10.2". A Porter Cable router with a perfectCircle attachment is used to removed the circle.

**johnsylora** · 02-13-2006, 18:30

These next pictures show the Blaupunkt positioned behind the 3/4" birch wooden plate. The edges of the plate were filleted using a router (1/2" round bit) then sanded with a DeWalt Random Orbit Palm Sander for a smoother finish.

**johnsylora** · 02-13-2006, 18:34

These pictures show further sanding of the edges of the hole using an air driven sander followed by mounting of the Blaupunkt speaker to the back of the wooden plate using screws.

**johnsylora** · 02-13-2006, 18:40

An expanded metal grille was cut out using the wooden plate as a template. This will be used to protect the speaker. The following pictures show the metal grille being cut with an air driven cutting wheel. The 4th picture shows Troy on the right with one of his talented employees cutting the metal grille.

**Malibu Rapper** · 02-13-2006, 18:43

Originally Posted by Shaun Ray

Good luck with the experiment. I too used a toolbox, but wanted more leg room so made a rough enclosure using a 10" Earthquake SWS. The box has approx. 0.2 cu. ft. internal volume and sounds okay. I think a larger enclosure would improve low freq. response, but good for a 1st try.

Shaun Ray, you should try the horn loaded enclosure to get more output. I think minimum recommended box size for that sub is .25 cubic feet. I can get the SWS for pretty cheap now if anyone is interested, PM me.

**johnsylora** · 02-13-2006, 18:58

A line was drawn along the passenger floor using the original metal plate over the Bose subwoofer as a guide. This line will serve as a reference showing the original border of the metal plate covering the Bose subwoofer. If the wooden front plate of our Blaupunkt subwoofer stays along this line we will have negligible loss of footwell space.

These next pictures show positioning of the Blaupunkt speaker in the car's footwell. The first picture shows the wooden plate is aligned fairly well with our reference line which is the factory location of the metal plate covering the Bose subwoofer. The original screw mounting brackets (2 below and 1 above) are used to screw the Blaupunkt speaker down. The carpet is folded over the system showing a factory appearance with little visible wrinkling!

**dave22** · 02-13-2006, 19:08

Very impressive.

Now how does it sound?

**johnsylora** · 02-13-2006, 19:11

At this point I was still thinking we could fiberglass the back and sides. However, Troy felt there was basically no room to do this and doing so would create a box with very little (<.3cf) of airspace producing a weak subwoofer. So we opted for a free air application. After a good listen I decided the system sounded fairly good in free air so we left it so.

When compared to the 8" Polk in a sealed box the 10" Blaupunkt in free air appears to hit many of the lower frequencies (car and body vibrating slightly) that the 8" Polk could not produce. However, the low end is definitely not overwheming (ie rear view mirror vibrating, body of driver and car rattling etc).

These pictures show the carpet over the Blaupunkt speaker with essentially the same passenger footspace as the factory setup. The last picture shows the carpet rolled back with the sound deadening foam underneath which ends just before the Blaupunkt speaker.

**johnsylora** · 02-13-2006, 19:19

Here are more pictures showing the position of the Blaupunkt subwoofer in the passenger footwell. The third picture shows the small wooden tab at the top of the wooden plate which allows mounting of the wood to the factory screw hole which is where the original metal plate covering the Bose subwoofer was mounted.

**johnsylora** · 02-13-2006, 19:34

These last pictures show the carpet and floormat returned to their original positions over the Blaupunkt subwoofer. The wrinkling and poor fit of the carpet which was present with the 8" Polk installation is resolved!

Overall, I'm very satisfied with this solution. The 10" Blaupunkt in free air is producing medium sounding bass. I'm not sure if an attempt at a fiberglass sealed enclosure would strengthen or weaken the sound. When the stereo is playing you can see the excursion on the 10" Blaupunkt speaker (about .2") and you can feel the bass through the passenger footwell carpet. It feels like a foot massage! When compared to my previous 8" Polk sealed box the Blaupunkt appears to be weaker in volume, but it appears to be hitting lower frequencies than the Polk which your body can feel. Overall, I'm very satisfied with this 10" Blaupunkt subwoofer installation and solution to the loss of footwell space in the passenger area. Thanks for your attention and good luck to you all in your pursuit of high quality sound for the NSX!

**D'Ecosse** · 02-13-2006, 21:44

John, got your pm & responded but only reading this thread after I responded to your questions.
Your low volume is without doubt your free-air install (which I didn't realize until reading this thread) .

See the notes in the manual which point out the limitations of free-air application.

(from Blaupunkt subwoofer manual)

INFINITE BAFFLE (a.k.a. “Free-air”) is simply a woofer installed in the back shelf of the car that uses the trunk as the enclosure.
Advantages: simple installation and adequate performance;
Disadvantages: only moderate sound pressure levels and poor power handling

Infinite baffles are simply a piece of wood holding up the woofer to the back deck of a car.
If you chose this installation (which is generally a poor performer) you must take great care in sealing/caulking all holes that vent into the back seat for proper bass response.

Free-air & infinite baffle are often interchanged in terminology but are really quite different in how they are applied.
Infinite baffle is really a misnomer which suggests a speaker mounted on a plate which has infinite size allowing no direct path for the sound waves from those created by the rear movement of the cone on the reverse side, to come around to the front . It does mean that the speaker is not enclosed (free-air) but the platform is such that the face inhibits this effect - not truly "infinite" of course, but effectively large enough to create such effect.
Please note that you don't even have 'infinite' (sic) baffle which is typically a parcel shelf or similar - you only have a small mounting platform barely bigger than the speaker diameter allowing the sound waves to come around the front and cancel themsleves out. The illustration below is again taken directly from the Blaupunkt manual & is an excellent illustration to show the mechanism.

Please consider a sealed box, even one of moderate volume - you'll be much more satisfied with the result.

**Gansan** · 02-13-2006, 23:19

D'Ecosse is absolutely right. There is no doubt that the reason you are seeing mediocre bass from a fairly large driver is the lack of a back side to the enclosure. Even a tiny airspace is better than free-air, because the enclosure would block the inverted pressure waves coming from the back of the woofer. I was following this thread with intense intrest until you said you had no back side to the speaker!

**Shaun Ray** · 02-14-2006, 05:21

Bradley,

Thanks for the hint about the 10-SWS. I got mine from ebay for about $160. I thought about the horn load but wanted to go sealed first. Some articles on the SWS suggested sealed was better.

Output is definetly not the problem. My amp is rolled way back as I have power to spare. The enclosure is more than loud enough, just lacking in the lower frequencies. I've compensated somewhat with an EQ, but more enclosure volume is the key.

This was just a first attempt at an enclosure and it was a success in my opinion. The next one will be better. I'd like to work with fiberglass, but just not motiviated enough to learn. Just a matter of time (and good climate).

My next enclosure might include a wider box with a front loaded SWS that includes a ported opening firing downward. That might improve low frequency. (or a horn port as you mentioned). With the enclosure resting on the seat rails, I can fire downward and have some airspace for the ports to breathe.

Sorry John......I'm just realizing I'm stepping over you great posting. I'll start another thread if I get further on this endeavor!

Cheers!