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Old 22nd November 2011, 07:29 PM   #1
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Talking Lecture me on what I'm not considering

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!
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Old 22nd November 2011, 07:56 PM   #2
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I think this is best answered here in Car Audio.
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Old 22nd November 2011, 10:59 PM   #3
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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.
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Old 23rd November 2011, 07:54 AM   #4
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Quote:
Originally Posted by Cal Weldon View Post
I think this is best answered here in Car Audio.
Thanks!

Quote:
Originally Posted by Perry Babin View Post
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.
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Old 23rd November 2011, 10:15 AM   #5
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You can get 20dB of boost (depending on the vehicle) at the bottom end of the spectrum from cabin gain.
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Old 23rd November 2011, 03:42 PM   #6
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Pioneers subwoofers are known to blow. Just saying.
I've blown about 15 sets on an under powered system.
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Old 24th November 2011, 02:48 AM   #7
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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!!!!!!
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Old 24th November 2011, 02:54 AM   #8
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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.
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Old 24th November 2011, 09:35 AM   #9
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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.
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Old 24th November 2011, 03:22 PM   #10
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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.
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