Driver Reccomendation for 5 cubic Foot Enclosure. Home theater use

permo

Member
2011-12-07 4:21 pm
I got a little bored and started putting the cart before the horse. I chopped up a sheet of 3/4 pine plywood and built a subwoofer enclosure to fit a space in my basement. I know that the plywood is not the best. So, I then cut, screwed and glued 3/4 MDF to the outside so I now I have a 1.5 inch thick, 80 pound driverless box.


I already have my mind set on ported. I need a driver. I have 160 watts RMS via audio source amp 100 ready for this project, and a budged of $100 (willing to bend a bit). So efficiency is something to consider here, considering the low power available.

I would LOVE to get to 20 hz at F3 but I understand that this may not be possible. I have been looking at the dayton audio classic DVC 15 but not to happy with that sub in 5 Ft3.


My DIYAUDIO peeps have never let me down!
 
5ft³ = 141.58L
ready for this project, and a budged of $100 (willing to bend a bit)
I would LOVE to get to 20 hz at F3 but I understand that this may not be possible.
Hi permo,
All it's possible, but if you start by saying that you have a budget of $$$.00 not feasible then your beautiful project will vanish in thin air. So,
With a $170.00 driver you can get a beautiful 22.5mm Xmax and a horrendous ~60 or 65mm peak to peak and 43mm Xmech (one-way) from the data sheets.

With your project you will have F3=23 Hz in "free field" conditions and F3=18 Hz in your room with a Qtsb of 0.36. You can tune your port(s) to ~FB=18/19 Hz :cool:
Stereo integrity HT 15" Dual 2/4 Ohm subwoofer
Stereo Integrity HT 15" Subwoofer - Google Search
Thanks for waiting... :D
 

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permo

Member
2011-12-07 4:21 pm
picked up a 1260W for $49 shipped...that just seems wrong. So cheap. I am going to plug her into winisd tonight. I am going to reduce the volume of my enclosure to 4 cubic feet with blocking and see what happens in all likely hood. With an FS of 23hz I should be able to get an F3 near 20hz if I tune below FS......wish me luck.
 
sealed for a car looks sweet
Qtc .707
VB = 1.28 Ft3
fsb = 42.60 hz
F3 = 42.61 hz

Standard ported looks fine too, I'd use 2 in that 5ft3 enclosure.
vb 2.62 ft3
f3 24.68 hz
tune 24.33 hz

thats some serious 13mm xmax.
You'd need a HUGE port to prevent chuffing at higher volumes.
Use a shelf port so it isn't as long as a standard round port (8" diameter maybe by 36.8" long for 2 driver in shared box).

Nice pick of a driver though for the cash.
 

permo

Member
2011-12-07 4:21 pm
With bracing, driver displacement and port displacement I got my enclosure right at about 4 cubic feet. Here is what I came up with

4 cubic feet
Tuned to 23 hz
4 " port 13" long gives vent mach of .10. I will flare the port
F3 right at 20 hz.....

Not too shabby for a $49 dollar driver. I should have it up and running in a week. I am fairly confident it will sound pretty good.
 
well.............
at what power level ?

Their own paperwork has 1 driver in 2ft3 tuned to 32hz with a 4" port, and you can see the excursion isn't lessened very much at 300 watts. A larger port will lessen the excursion, and it will sound better.

You want to use 2 drivers and tune lower with a single 4" port ?

I don't consider my dual 15" with 8mm xmax (in single box) to have enough port area (4" diameter) for a 27hz tuning................
I've used dual 18's with 4.3mm xmax in a shared box with a 12" port for a 27hz tuning.

But it's up to you.
 

permo

Member
2011-12-07 4:21 pm
well.............
at what power level ?

Their own paperwork has 1 driver in 2ft3 tuned to 32hz with a 4" port, and you can see the excursion isn't lessened very much at 300 watts. A larger port will lessen the excursion, and it will sound better.

You want to use 2 drivers and tune lower with a single 4" port ?

I don't consider my dual 15" with 8mm xmax (in single box) to have enough port area (4" diameter) for a 27hz tuning................
I've used dual 18's with 4.3mm xmax in a shared box with a 12" port for a 27hz tuning.

But it's up to you.

I am using a single driver. I think the 4 inch port is adequate.
 
permo,

I built a pair of 1262W in 2.75 ft^3 boxes and used 18" long, 4" flared port kit (Fb=24 Hz)
There was no hint of port chuffing.
I powered it using a CV-900 amp so in theory 420 W/ channel into 2 ohms.
The HP filter (25Hz_4th order) was def. needed.
.
I finally went back to a sealed box with a bunch of stuffing and it requires no HP filter but falls off at 35 Hz or so, but that is what the extra subs are for.
.
Good sounding speaker, requires a very well braced box.

Dave
 
Short answer, they are no longer doing sub duty.

I built subwoofer cabs driven with a Crown Xti-1002 and have the 1262's low passed at 120 Hz to a pair of MMTMM's with no high pass filter at all, I just let them start to roll off at 40 Hz.
The subs fill in everything below 40 Hz or so and when the 1262's were ported they exhibited some single note boom, I very much dislike single note boom.
With them sealed, there is no single note boom, the group delay is much lower and they do not require a high pass filter.
With the CV-900 ( supposedly 420 W/2 ohm) they still only go to about 1/2 of Xmax (read that lower distortion) in the sealed box.
.
Out of context but, I am building a 5 element Bessel array to play around with which may replace the MMTMM's.

Dave

PS put the Infinity 1262W T/S specs in the HRSP file that TB posted and there is a bit of improvement but they cost almost twice as much.
I didn't realize that there was much difference at all between the 1260's and the 1262's except the single vs. dual coil.

Dave
 
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permo

Member
2011-12-07 4:21 pm
PS put the Infinity 1262W T/S specs in the HRSP file that TB posted and there is a bit of improvement but they cost almost twice as much.
I didn't realize that there was much difference at all between the 1260's and the 1262's except the single vs. dual coil.

Dave

The 1262 and the 1260 are, according to infinity the same driver with the only difference being the dual voice coil. According to my research, they are the same price as well. I could have gotten the 1262 for $50 shipped too.....I got the 1260 for ease of installation...straight 4 ohm.
 
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permo

Member
2011-12-07 4:21 pm
I built the box, after bracing, port displacement and driver displacement it was roughly 4.1 cubic feet. I used a four inch port 16 inches long to tune it to 23 hz. I stuffed it with 4 pounds of polyfill. I only have 150 watts rms going to it, but it sounds wonderfull and the cone barely has to move to provide substantial output. I think I need a much larger amp. This box is too heavy to move myself is one of the drawbacks tho.