10 Inch subwoofer box

[spongee]

Hey guys, pretty new to subwoofers. I got a small subwoofer from a friend for cheap, jbl gt3-10 220rms.
I was wondering if putting it in a bigger box would help reach lower frequencies, because my stock door speakers can reach about 50hz
and the subs lowest is like 40hz but very quiet at that point, and it also plays loudest at 45-50hz, so when certain songs play the bass is either really loud or really quiet.
So is it worth doing anything about the box? I want to learn more and I dont want to try to make a box that wouldnt make a difference

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[RobGMN 5,000+ posts]

Hey guys, pretty new to subwoofers. I got a small subwoofer from a friend for cheap, jbl gt3-10 220rms.
I was wondering if putting it in a bigger box would help reach lower frequencies, because my stock door speakers can reach about 50hz
and the subs lowest is like 40hz but very quiet at that point, and it also plays loudest at 45-50hz, so when certain songs play the bass is either really loud or really quiet.
So is it worth doing anything about the box? I want to learn more and I dont want to try to make a box that wouldnt make a difference

Depends on the box you have it in now.
Sealed? Ported? How big?

Based on available specs (and who knows if they are accurate), you want an internal volume of 11.5 cubic feet.
It'll be only 3 dB down at 39 Hz. A port will make it louder at whatever freq you tune it for.

 

[Jimi77 5,000+ posts]

Ported will help with low end. What are the specs of the current enclosure?

 

[spongee]

Depends on the box you have it in now.
Sealed? Ported? How big?

Based on available specs (and who knows if they are accurate), you want an internal volume of 11.5 cubic feet.
It'll be only 3 dB down at 39 Hz. A port will make it louder at whatever freq you tune it for.

Sorry, I dont really know the specs or dimensions of the box, it is ported though, ill attach a photo here for estimation, i can measure it if that helps?

 

[RobGMN 5,000+ posts]

Sorry, I dont really know the specs or dimensions of the box, it is ported though, ill attach a photo here for estimation, i can measure it if that helps17View attachment 65945

A very rough guess would put the externals on that box at 20x20x6, which is 2400 cubic inches. A cubic foot is 1728, so your box (minus the woofer) is about 1.2 cubic feet.

Get measurements if you can, but I'd say the box is WAY small if the specs on that woofer are correct.

 

[spongee]

A very rough guess would put the externals on that box at 20x20x6, which is 2400 cubic inches. A cubic foot is 1728, so your box (minus the woofer) is about 1.2 cubic feet.

Get measurements if you can, but I'd say the box is WAY small if the specs on that woofer are correct.

Heres the only woofer specs I could find on the official site, no photos there but im guessing these are the right ones
Frequency Response 35Hz – 3kHz
Sensitivity (1 watt @ 1 meter) 88dB
Nominal Impedance 4 ohms
Voice-Coil Diameter 50mm
Vas 40.17 liter
Qts 0.43
Fs 35Hz
Qes 0.47
Qms 4.99
Sealed Enclosure (vol) 20L

 

[RobGMN 5,000+ posts]

Heres the only woofer specs I could find on the official site, no photos there but im guessing these are the right ones
Frequency Response 35Hz – 3kHz
Sensitivity (1 watt @ 1 meter) 88dB
Nominal Impedance 4 ohms
Voice-Coil Diameter 50mm
Vas 40.17 liter
Qts 0.43
Fs 35Hz
Qes 0.47
Qms 4.99
Sealed Enclosure (vol) 20L

OK. So the specs I found were way off.

If they are recommending 20L, you may not be that far out of the game.
Get us the measurements of the box and the port, and we can see how close you are.

 

[Jimi77 5,000+ posts]

Sounds like a peaky enclosure tuned around 45hz. First thing I'd try is moving the sub as far to the rear as possible. It should be rear firing. That will reduce cancelation to a minimum.
If that doesn't help, then I try building a new enclosure. It's guesswork without TS specs. If you don't have TS specs, then I'd go for ~1.25cuft net tuned to ~35hz.

 

[Mitchell Fosgate III]

Connected to any amplifier? Subwoofer. Or connected to the back of the radio. I don’t see any wires in the back. No pictures of the front. Are there any music? If no, no. That won’t help.

 

[spongee]

OK. So the specs I found were way off.

If they are recommending 20L, you may not be that far out of the game.
Get us the measurements of the box and the port, and we can see how close you are.

Alright, since the back is slanted I found it easier to show it in a photo lol hope this is okay
port is round, 7.5cm wide 11.5cm long

 

[RobGMN 5,000+ posts]

Alright, since the back is slanted I found it easier to show it in a photo lol hope this is okay
port is round, 7.5cm wide 11.5cm long

Assuming the wood is 1.25cm thick, and the driver takes up 10% of the box volume, you are right at about 31,000 cc for that box. If those #s are accurte, the port tuning would be dang close to what Jimi said, at around 50Hz.
You could experiment with lengthening the port (to 20cm for 40Hz tuning), but don't expect miracualous changes.

So, it doesn't seem like the box and port are off the mark.

Let's talk about the rest of the system setup. Jimi already mentioned experiemtning with box placement. Tell us about your head unit, the amp settings, how it's connected to the system, etc.