Lecture me on what I'm not considering

[CaptEditor]

I have wanted to put a subwoofer in my car for years. So long, in fact, that I've gone through many cars in that time. Right now I have a 2004 Subaru Outback Wagon which I plan to keep forever until it turns into dust.

So here is my idea. I would like to put a subwoofer in the spare tire well and mount my spare tire on a swing out carrier on the back of the wagon. The subwoofer will be oriented upward. I have not physically measured the volume of the tire well but I can estimate that a box around 5 cubic feet is possible considering that the full size spare is 27 inches in diameter and 9 inches wide.

The candidate I am looking at is the Pioneer TS-W309D4 (or another driver for less than $100)

Specifications: • Power handling: 400 watts RMS/1,400 watts max • Impedance: Dual 4 ohms • Re: Dual 3.2 ohms • Le: 3.76 mH (8 ohm)/1.30 mH (2 ohm) • Frequency response: 20-180 Hz • Magnet weight: 83 oz. • Fs: 34.5 Hz • Sensitivity: 92 dB 1W/1m • Vas: 1.22 cu. ft. • Qms: 16.43 • Qes: 0.65 • Qts: 0.62 • Xmax: 10.3 mm • Dimensions: Overall diameter: 12-7/8", Cutout diameter: 11", Overall depth: 6-3/4", Mounting depth: 6".

I was thinking about a 5 cubic foot ported box tuned to 22 hertz. The manufacturer recommended volumes are 0.85-1.75 cubic feet sealed or 1.25-1.65 cubic feet ported.

I can't get any box modeling programs to function on my computer so I'm using the one at LinearTeam and I don't know how accurate it is.

What am I not considering? Tell my why my idea is terrible! Don't be afraid to tell me I'm an idiot just enlighten me as to why!

Oh and btw I want this subwoofer to really pound out the super low notes yet still sound good. I will most likely cross it at 50-60 hertz and listen to it at very reasonable volume levels most of the time. I know it is a massive compromise to ask for good response down to 20 hertz and excellent sound quality all for less than $100 but hey, that's why I'm asking you guys for input!

 

[Cal Weldon]

I think this is best answered here in Car Audio.

 

[Perry Babin]

Car subwoofers are designed to be used in smaller enclosures. They can work in small enclosures because the vehicle produces significant cabin gain at low frequencies.

You probably wouldn't want to tune it that low. In a small enclosure, that would require a very long port. If the tuning could extend the low end response down the the 20-25HZ range, it may be excessive in the vehicle.

I think Pioneer's recommended enclosure is tuned to about 40Hz.

 

[CaptEditor]

I think this is best answered here in Car Audio.

Thanks!

Car subwoofers are designed to be used in smaller enclosures. They can work in small enclosures because the vehicle produces significant cabin gain at low frequencies.

You probably wouldn't want to tune it that low. In a small enclosure, that would require a very long port. If the tuning could extend the low end response down the the 20-25HZ range, it may be excessive in the vehicle.

I think Pioneer's recommended enclosure is tuned to about 40Hz.

So the cabin gain can really be that significant. I have heard that car audio is tricky because the acoustics in a car are unpredictable. Perhaps I will consider a sealed box instead because of the shallower roll off and I will also have room for the amplifier with adequate ventilation under the false floor.

 

[Perry Babin]

You can get 20dB of boost (depending on the vehicle) at the bottom end of the spectrum from cabin gain.

 

[carshateme]

Pioneers subwoofers are known to blow. Just saying.
I've blown about 15 sets on an under powered system.

 

[mike49504]

Any sub will blow if you clip the amp no matter if you run 25 watts or 50 million watts to it ..

If you clip the amp the sub will blow!!!!!!

 

[Perry Babin]

That's not true. 25watts, no matter how clipped it is, won't blow a speaker designed to handle significantly higher power. A speaker that could handle 50W RMS 'continuous' power probably couldn't be blown by a 25 watt amp producing a full square wave output.

 

[CaptEditor]

Thanks for the input. I am also aware of the potential damage that clipping can cause. I will make sure to get an appropriately powered amp and set the gain correctly to avoid this type of failure.

carshateme, did they fail from mechanical damage or electrical? I'll look into the reliability of the newer Pioneers.

I spoke with a friend this evening we looked at a few other drivers in the 300-400 watt range while keeping SQ and low pricing in mind. I may decide to go with a 300 Watt CDT if I can find an amp to match it for a reasonable price.

 

[carshateme]

Yeah, they all died from mechanical damage. I mean some where "Purposely" blown...but they don't handle the amount of RMS they say they do...mostly a good 100-200 rms less. The new pioneer subs I cannot rag on, but from what I hear...they're pretty reliable especially the Pioneer Champion Pro Series.

 

[TheBaronGroog]

The Pioneer in a ported box will need a huge port, "old school" subs will work better in that volume, need a smaller port, cost lesss and have a higher sens-so if you want to go ported that's the direction I'd head. For SQ build a big ported box, tune as low as possible and the EQ down the bump you'll get from cabin gain.

Alternatively you could follow my route and use the cabin gain:

I'm running a 10" in a sealed 0.126cf box. F3 is about 76Hz, sub plays from 63Hz and down and is near flat to 30Hz-but my car is a mini and the sub is in the footwell. So quasi linkwitz transform, no need for an electronic EQ to do the work when the car is a great mechanical one. Pics below show box model, with and without cabin gain factored in. RTA is of white noise with no EQ/TA, I literally just fitted the stereo, left gains at zero and tried it out. Will EQ out the bump and dip, but considering it's totally untuned I'm prety happy with the results!