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First HT DIY Subwoofer for a noob on a budget..

31695 Views 99 Replies 7 Participants Last post by  jeffrobinson
Good evening gentlemen,
I'm a noob who bought a pair of Phoenix Gold Ti15d's from Sonic years ago planning to stuff them in a suv. Fast forward 9 years, they were never installed. Want to build a home theater sub for the kid and I need the right box the first time due to a state employee budget. Picked up a Bash 300w amp at partsexpress for one Benjamin. Phoenix recommended a sealed 1.5ft for sq, or a 3.5ft ported w two 4x9.75in ports. Are these still the best choices? Those were speced for car use and that was a long time ago. I have bassbox pro 6 and cant figure it out. Everybody says go low for home theater and I'm stumped. Anybody up for a little bench racing? Specs are:
Fs: 26.21HZ
Re: 1.75 Ohms
Qms: 9.26
Qes: 0.594
Qts: 0.558
Vas: 114.63 liters
Mms: 283.15 grams
Cms: 130uM/Newton
BL: 10.89 Telsa-m
SPL(1w/1m): 88 db
Sd: 792 sq cm
Xmax(field): 36.2mm p-p
Size of enclosure is dosent matter, its in my living room. I want low, right? My front mains go to 65hz, receiver is Yamaha with YPAO room eq, room is 15 by 20 or so with 12ft ceilings and hardwood floors. Use will be 95% movies, 5% metal. Anybody feeling like helping out?:huh: Thank yall in advance, Jeff.
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MikeP, I think I figured out my crossover question. The upper bass from the 15s from 60-120hz will be as good or better than anything the little Polk can do, why cross it out. High pass the Polk to lose the chuffing, leave the big boys alone. Is that the reasoning? Have I used up all my MikeP time?
Sorry for the delay, I've been swamped. Yes, that is the reasoning. The 15's will produce the full spectrum of bass down to 20 hz, hi-pass the Polk and let it contribute what it can.
Cool! If ya get caught up and feel like peeking at my post #79 it would be most appreciated. Stuffing and feet stuff.
Some people say lining a ported sub has no effect, others say it does.I always do with an open cell egg crate foam a couple inches thick. Walmart pillows is another option, I personally haven't done that. I have no idea what is inside of them, I imagine some kind of poly stuffing. Here is a a read on it.


I don't see any issue with using caster wheels.
MikeP, she's killing me!! I've now been told that unless I can make them multi purpose, then forget it.:explode: Our 6yr old will be doing homework soon enough. I did some research and found that I can mock the left and right side drawer cabinets of a desk into a pair of 4ft^3 boxes tuned to 21hz. With a 27in. chair space in between, and a 62in. wide top over them, I can create a desk the same dimensions of an accepted, commercially available model. I guessed based on your winisd modeling that a 2ft^3 reduction in volume required a 1hz addition in tuning frequency. 10ft-18hz, 8ft-19hz, 6ft-20hz=4ft-21hz? Do I ever reach a point where I'd be better off with one box at at 10 or 8ft^3 than two boxes at half the size?
The bigger the box the better so find out what you can get away with and we'll take it from there.
Going with what we designed. This is a fight I'm willing to have. They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety. Ben Franklin.
Well, my build has hit a little snag. My father-in-law (with all the woodworking tools and experience) took a fall from his 10ft stepladder while trimming trees in the front yard. Broken arm, broken ego, and the inability to bass fish has left him unwilling to teach for a while. This gives me some time to scheme a little. I've been required to find a way for a pair of 6ft^3 subwoofers to have a wife-worthy, secondary purpose. A desk it will be. A sub at each end, with a desktop above. To create the floor space required for a full size desk in the living room, I will need a tall, narrow cabinet rack for components and htpc. Is there a forum here for DIY furniture of this type? I'd love to see some home brewed racks with tricks like cooling fans and prewiring etc. Ideas anybody? I did find one incredible thread here:
but I'm looking for more, maybe a little more rookie oriented.
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You may have an interesting time dealing with nulls if you have a set location for your bass desk. I imagine you wouldn't get much WAF if you had to have the desk in the corner because that was the best placement :)
I'm afraid I do have a set location for the desk, but I think I can change the subs facing direction under the desktop if necessary. Does the direction they face address null problems?
It depends the most where the center of the driver is. Quarter spaces along the walls is where they would handle room modes, which quarters and which walls is the tricky part.
After a brief wiki of the terminology in that response Doug, I am reminded how little I know.....Thank you just the same :)
Bumping my very old thread. Absence makes the heart grow fonder. Well it's been a long while, but I'm still in this. Mike P. did a work up for me using a 300 watt bash as my power for the P.G. 15's I'm hoarding. Since then I've picked up a QSC 1450 & Art Cleanbox Pro. This will be feeding the subs 700w rms each. Is there going to be any trouble with that in a 6' 20hz slot ported cab? If, of course you guys forgive me for my work ethic. ?
Noice! I don't have an answer to your question unfortunately, but good on you for resurrecting your thread, and with a nice amp too! I'm looking forward to you working on this!
Thanks, Cap! I did a lil snooping and it would appear Mike P. hasn't posted since 2014. He was a soldier, and I'm sure sorely missed. I know there are still lots of super smart folks here, my self not included. That said, I look forward to moving ahead on these cabinets, and I promised I'd be posting my progress in pictures. I might have a question or two along the way. Thanks for having me back!
Johnnysubs are huge. Wifeshockingly huge.


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Im 5'9" and fat as Santa Claus. This box is 6' at 19hz slot port and big as a clothes dryer.
Laminate on!! First cab done minus driver mounting and wiring. :)


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Well the Johnnysub twins are done and two movies later I realize I need more front stage...?


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