5" subs / woofers in backdoors (?) Advice appreciated!

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Hi all

I am currently working on improving the sound in my Peugeot 206 station wagon. The Radio is a Kenwood kdc bt 61u of around 250 euro, 280 dollar. In previous cars, it sounds decent to my ears. Now I am thinking of what speakers to purchase. In previous cars, I have always been very happy with Focal composites speakers. So I am thinking in the front a set of those for around 200 euro / 230 dollars. The aim is to have a nice sound, incredibly loud not needed. I am thinking however how to support the bass of those speakers. In other cars I used to have a focal bus powered subwoofer under a chair. Sounded great. This car is a lot smaller though, and easier to break in, therefor I am thinking of ways to keep it more out of sight and still leave some room for people to sit in the back. Oh and by the way, there is no room for a spare wheel and I got often two very destructive dogs in the back, so a sub in the boot is not an option either. So I was thinking: what if I found a pair of sub /woofers that would fit in the back doors... And I think I did: Tang Band W5 1138SM.
A 5"subwoofer that would fit in the back doors of my car.

1. Could a backdoor be transformed into a holder for such a subwoofer? And if so, what kind of treatment would it take?
2. should I use two as "real" subwoofers (sub output on radio, mono and let's say 120Hz down) or should I use them in stereo as two woofers (rear speakers output filtered from let's say from 300-500 Hz down)?
3. Is there other / better possibilities to consider?

I am looking at a bass solution somewhere between 200-300 euro.

Input highly appreciated!


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If you do go with these, ensure they operate as subwoofer only.

If you cross them over at 300Hz, wavelength = 1m. So you'll get weird interference effects with differences in distance of ~20cm between sources (ie, front and rear speakers).
At 100Hz, you can't tell where the sound's coming from, which is perfect for subwoofers.

Those particular woofers will need a proper enclosure (built from wood or fibreglass) to sound their best, but will probably do more bass than the previous speakers if you drop them straight in.
Just remember that it'll be difficult to mount them behind a grill due to the silly excursion the Tang Band mini-subs can do.

Sounds logic enough to me... a few additional questions though:

1. do rearspeakers in the door always interfere with the front speakers? Only in the lower frequencies?
2. do you think the door needs extra dampening inside when used as a subwoofer enclosure to prevent it from vibrating too much?
3. Would something like this be enough to drive both speakers?
1 - yes, according to measurements.
For higher frequencies, you hear the rear speakers with a time delay which your brain processes as a different source. You either want full-range or sub-only for the rear speakers, IMO.
2 - yeah, that'd help to prevent things vibrating. Other members will be able to advise on which sort to use
3 - yes, if the 150w/ch rating is accurate. Just be careful though - if you turn it up so that amplifier is clipping, the speakers won't last too long.

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