6" stock subs replaced by a 10" Jansen Sub

[alpac]

In a previous thread I explained how I installed a subwoofer amp and a separated subwoofer to my DSP audio system.
Here is the previous thread: http://www.xoutpost.com/showthread.php?t=5912

This time I went a step further and integrated a Jansen 10" sub in place of the stock 6" subs. I reused the stock enclosure in which I cut a hole to fit the 10" sub. As you can see in the pics below the result is pretty nice and neat and the sound is excellent.

[BMWX5man]

How it's sound? I have 10" 2 coils "Orion" sub with max power 400 watt and Xtreem mono amp 2 chanel with 500 watt max output just for sub. I mounted mine to cover with lot's of "Dyno..." and inside too, so I've created something like a box for a sub. Got boom booms now (joke), but it sounds much better then factory original stereo system.
Only problem is the heat. If I am listening music too loud both amp and sub getting warm. Maybe small cooling fan will help a bit.

[btrvalik]

Is the factory box fairly sturdy? What did you use to fill in the extra 1/2 hole from the old 6" sub? Anyone know if it can be purchased from BMW as a replacement part?

[alpac]

Yes the factory enclosure is sturdy. I actually tried first to build my own box but was not happy with the sound. It was better than with the factory subs but not what I was expecting. I then had the idea of reusing the stock enclosure.
I spent some time to study the exact place where to put the 10" sub before cutting the big 10" hole in the stock enclosure as there is not much room for error. As you can see in the picture below the 10'' sub fits pretty well and neatly in the stock enclosure. I filled up the few openings around the sub with insulation foam to seal the enclosure. The sound is great, much much better than with the 2x 6" subs.

[dkl]

Originally Posted by btrvalik

Is the factory box fairly sturdy? What did you use to fill in the extra 1/2 hole from the old 6" sub? Anyone know if it can be purchased from BMW as a replacement part?

You can get the factory box from BMW as a replacement part. The down side is that it will come with the two 6" subs attached for about $300 bucks. For that kind of money, mind as well get someone to build you a custom box!

[btrvalik]

There have been a number of other threads on this topic. A custom box from a local dealer will be over $1K. el_duderino is considering making an off-the-shelf box but it is not clear if/when it will be available. I'm not looking for earth shattering bass just want to fill out the bottom end. Do you know what the maximum depth is? JL audio has a 6" sub that might be a good replacement for what comes in the box...

http://mobile.jlaudio.com/products_s...p?series_id=23

Nominal Diameter Overall 6.5 in. / 165 mm
Diameter (A) Mounting Hole 6.86 in. / 174 mm
Diameter (B) Bolt Hole 5.625 in. / 143 mm
Circle (C) Magnet 6.125 in. / 156 mm
Diameter (D) Mounting 4.54 in. / 115 mm
Depth (E) 3.5 in. / 89 mm

Dimension (b) above is what the holes in the box needs to be. Coupled with a high quality amp this could produce some nice tight bass..

[alpac]

Originally Posted by btrvalik

There have been a number of other threads on this topic. A custom box from a local dealer will be over $1K. el_duderino is considering making an off-the-shelf box but it is not clear if/when it will be available. I'm not looking for earth shattering bass just want to fill out the bottom end. Do you know what the maximum depth is? JL audio has a 6" sub that might be a good replacement for what comes in the box...

http://mobile.jlaudio.com/products_s...p?series_id=23

Nominal Diameter Overall 6.5 in. / 165 mm
Diameter (A) Mounting Hole 6.86 in. / 174 mm
Diameter (B) Bolt Hole 5.625 in. / 143 mm
Circle (C) Magnet 6.125 in. / 156 mm
Diameter (D) Mounting 4.54 in. / 115 mm
Depth (E) 3.5 in. / 89 mm

Dimension (b) above is what the holes in the box needs to be. Coupled with a high quality amp this could produce some nice tight bass..

I did not check the depth of the box but these JL Audio subs are just 9mm deeper than the stock ones (80 vs 89mm) so that should work however you will never get the same profound bass from 2 x 6" (whatever good they are) as with a good single 10" sub. Also are you planning to add an amp or just replace the stock subwoofers with the JL Audio ones? These JL Audio subs are only 75w so I assume you are thinking about keeping the stock sub signal. Not sure you will hear much difference.

[btrvalik]

I don't have the DSP sound so I will be adding the sub and an amp. What are the stock speakers like.. anywhere near as beefy as these? Could you post or send a picture of the stock woofers? The amount of bass is going to be a function of the speaker motor (magnet and voice coil) and the surface area of the cone. I'm assuming these are much stronger motors than the stock speakers. The surface area would be 2x113 sq in. While that is smaller than 10" it is bigger than a 8". Do you know what the box volume is? I thought it was only something like .4-.5 ft^3 .. Seems like a 10" might be a bit much for that small of a box. I'm also planning to add something like a JL 250/1 which I assume is a much better amp than stock. I think 75 W of clean bass will be more than enough for this application. It takes a lot of money to get really good sub bass.. my home sub is about 4K.. I'm not looking for booming bass, and I don't think real sub-bass is possible without a bigger box... I'm just looking for fuller bass.

Thanks
Bruce

[alpac]

Here is a pic of the stock subs. Since you will have to build an enclosure for the subs anyway I really think you should go straight for a 10" inches rather than 2x 6". There is enough space to fit a 10" and its enclosure there. If you do not want it too booming you can tune the gain and crossover of the amp afterward but it is better to have too much potential than not enough...just my two cents.

[btrvalik]

Thanks for posting the picture... If I were to build a box I would definitely use an 8-10" sub based on how much volume I could get. bigger is not alway better if the box cannot be sized properly. I've built a lot of speakers in the past and I have the woodworking skills to build almost anything... but I have other woodworking projects in the queue.

I'm trying to avoid having to build a box. While the stock don't look as meaty as the JL units.. they really don't look that bad. Did the stock system sound that bad? Maybe I would go to the dealer to listen to one.. Maybe the stock sub with a good quality amp will get me enough bass .. and if not I could always go the route you did. Thanks for the help!