I want to build a tapped horn in a 12"x18"x60" (30cm x 45cm x 150cm) space below my headboard with the opening on one of the small ends.
Could it do 25hz-120 with one bend? Is it long enough? Would it sound smooth?
What drivers would you recommend??
Ive never built a sub before but ive done plenty of woodworking and electronics. I was thinking of osb and pl premium.
Could it do 25hz-120 with one bend? Is it long enough? Would it sound smooth?
What drivers would you recommend??
Ive never built a sub before but ive done plenty of woodworking and electronics. I was thinking of osb and pl premium.
Single bend in a 150cm (60") will have a low corner above 30 Hz.
It could have smooth response.
Driver recommendations are many, helps to know where you are located.
William Cohan has made subs similar (but longer) than what you are after:
Tapped Horn Experiments
My "Tub Sub" worked well with cheap drivers, but is larger than your requested dimensions, it is 57" x 12.5" x 30". You can see details of it in post #8:
$500 DIY Subwoofer Challenge!
It could have smooth response.
Driver recommendations are many, helps to know where you are located.
William Cohan has made subs similar (but longer) than what you are after:
Tapped Horn Experiments
My "Tub Sub" worked well with cheap drivers, but is larger than your requested dimensions, it is 57" x 12.5" x 30". You can see details of it in post #8:
$500 DIY Subwoofer Challenge!
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Art, your Tub Sub is the PERFECT example of how simple a TH can be! Very stealthy! Are you still using it today?
The hot tub, Tub Sub, and over a dozen other speakers were included in the house/property sale around 5 years ago, don't know if the current owner still uses them.
Located in Connecticut.
I can make the length 64". 30hz is great for music but i wonder if i will gain something watching movies if i can go lower? I might just build a tapped horn for simplicity. Curious, would a series 6th order bandpass go lower in my dimensions without killing the effciency too much?
I can make the length 64". 30hz is great for music but i wonder if i will gain something watching movies if i can go lower? I might just build a tapped horn for simplicity. Curious, would a series 6th order bandpass go lower in my dimensions without killing the effciency too much?
30 Hz is pretty all round for music and movies, 20 Hz is more of a specialty thing for specific movies and songs that drop that low intentionally.
1) There are another two octaves or so below 30Hz in some movie soundtracks (and music tracks), so you could gain some "shake" sensation. Costs a lot in size and/or power to go that low at loud levels.
2) Not a whole lot of difference in efficiency between the two.
Deciding on the cost, maximum dimensions, build complexity, and the SPL at low frequencies you desire will narrow down what designs and drivers would be your best choices.
The dimensions are set, ballpark how much power would i need for movies w a 30hz TH?
How would i fold a 20hz horn w my dimensions and the mouth on the end?
How would i fold a 20hz horn w my dimensions and the mouth on the end?
How loud you want to listen or feel is a personal choice, not a need.
Given the enclosed volume restrictions, sensitivity for 30 Hz response would be somewhere around 88 dB 1watt one meter half space. If the exit is one meter from your ears, 1 watt does 88dB, 10w, 98dB, 100w 118dB, 500w 121dB. Excursion limitations may occur well below power limits.
A 20Hz TH horn would require over a 14 foot path length, requiring a triple fold. Output would be roughly 6 dB less than a 30 Hz horn.
Given the enclosed volume restrictions, sensitivity for 30 Hz response would be somewhere around 88 dB 1watt one meter half space. If the exit is one meter from your ears, 1 watt does 88dB, 10w, 98dB, 100w 118dB, 500w 121dB. Excursion limitations may occur well below power limits.
A 20Hz TH horn would require over a 14 foot path length, requiring a triple fold. Output would be roughly 6 dB less than a 30 Hz horn.
By the math you would have won that $500 subwoofer chalenge if you shrunk your box alot and added one off those diy rotary woofer that are based off rc helicopter hubs for extension to 1hz. Lotsa half octaves below that bose.
I would use a 12", although depending on how much output you are willing to sacrifice you could shrink that down all the way to a 6".
The relationship between power and SPL is logarithmic, so it should be:
1W - 88dB
10W - 98dB
100W - 108dB etc, assuming the system is well out of power compression etc.
I assume it was just a finger slip on Art's part.
1W - 88dB
10W - 98dB
100W - 108dB etc, assuming the system is well out of power compression etc.
I assume it was just a finger slip on Art's part.
I did screw up the math previously, should have wrote:
1 watt does 88dB, 10w, 98dB, 100w 108dB, 1000 watt 118dB.
For a cabinet volume limited to your dimensions of 12"x18"x60" (30cm x 45cm x 150cm), net volume for a 20-30 Hz Fb TH would be so little that it's unlikely to achieve sensitivity at 30 Hz more than 88 dB 1watt one meter half space. A passive radiator or sealed system would likely work/sound better than an undersized low tuned TH.
With a cabinet below your headboard, taking room modes, and distance to your head into account, who knows what SPL will be at your ears or toes 😉.
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Update. Ive decided to build it and divide it into two boxes with a a jbl gtx1200 on each end. The ends will be 60" apart with one end near a corner and the other one down the wall.
My amp is 50+ watts per channel and has dsp. Im thinking i might be able to help some room modes in mid and upper bass with mutisuboptimizer? At 20hz they should be mutually coupling because of the long wavelengths?
Sealed they model individually as 100db at 20hz in quarter space and much higher at 30hz. With room gain and coupling probably 110db at 20 h and higher at 30hz? I can get +5db at 20hz with a 4" ports if i have to add them.
I figure i should have 10db headroom above my DML mains but i haven't built them yet, the exciters were on backorder. Cant model those.
My amp is 50+ watts per channel and has dsp. Im thinking i might be able to help some room modes in mid and upper bass with mutisuboptimizer? At 20hz they should be mutually coupling because of the long wavelengths?
Sealed they model individually as 100db at 20hz in quarter space and much higher at 30hz. With room gain and coupling probably 110db at 20 h and higher at 30hz? I can get +5db at 20hz with a 4" ports if i have to add them.
I figure i should have 10db headroom above my DML mains but i haven't built them yet, the exciters were on backorder. Cant model those.
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Pretty sure all these go down to 20 Hz with enough gain to justify it and quite a few down to ~10 Hz: The Ultimate List of BASS in Movies w/ Frequency Charts | AVS Forum