Drive Unit Recomendations to acheive < 30Hz Sealed

[pow216]

Hello, I'd like some suggestions for drive units to go into a DIY sub.

The design aim is <30Hz, but <=25Hz ideally. Sensitivity is not so important I have plenty of large monoblocks about! Extension is more important to me than SPL. And I don't want anything other than a sealed box.

I have space to accommodate an enclosure up to 130 litres and that space would fit up to two 12" drive units in. I'd consider using any arrangement of drive units from a single 10" to a single 12" to two 12"s but a single 12" would be my preferred choice.

So . . .

 

[Richard Ellis]

How about the Tang-Band WQ-1858 12" sub.
Modeled on winISD beta , I get -3DB@31.47 Hz(Qtc, .71)....in a very small 79.3 liter enclosure, sealed???



___________________________________________________Rick.........

 

[Richard Ellis]

I've found if you "force" these drivers that are more suited to sealed designs....& you port them they will go way down in frequency response....trouble is the size of the enclosure your willing to deal with..........
This being the case, "forcing" this TB driver into a ported enclosure of 166.9 liters gets you -3.04Db at 16.7 Hz!! Fb of 17.88, port, 102mm by 376mm long.



_____________________________________________________Rick.......

 

[pow216]

WQ-1858 is a serious contender, thanks!

Any others?

 

[pow216]

Your post #3 I certainly agree with, and for some that might be a great solution. I don't mind the additional box size, and could bring it down with a different design, but using the same principle.

But I have promised my self it must be sealed !

 

[Richard Ellis]

Just find some listings of TS parameters, I found this one right off the bat on PartsExpress. Do the EBP, looking for a value less than fifty, Fs over Qes....when you get some, run them thru the sims & see if the size vs. performance match up with what your seeking.

Doing that "sealed type driver into a ported enclosure" doesn't work all the time. I have a pair of 12" DVC subs I modeled as a ported design(They were best as a sealed).......the response curve went "berserk"....all over the place, no go.


____________________________________________________Rick.........

 

[Inductor]

The design aim is <30Hz, but <=25Hz ideally.

Do you mean you want your F3 lower than that (response with 3dB attenuation/roll-off) or passband/response range of the speaker/sub usually -10dB?
Only the discontinued THIEL TSW 12.1 could go there to that territory (F3 29Hz).
Similarly the Pioneer TS-W303R 12" can replicate (28Hz) the low extension with a Q of 0.8.
Then you have with 30Hz and up
Dayton Audio UM12-22 12" Ultimax DVC Subwoofer 2 ohms Per Co | 295-512 good Q, F3 31.4 Hz
Tang Band WQ-1858 12" Aluminum Subwoofer | 264-897 with low Q (0.6) and F3 35 Hz
MaxSpeakers PV-1230 w/Q 0.9 and F3 32.0 Hz.
Wavecor SW310WA01 w/good Q (0.7) and F3 35 Hz
SB Acoustics SB34NRX75-6 12" Q 0.7 and F3 35 Hz
Dayton Audio RSS315HFA-8 12" Reference HF Subwoofer 8 Ohm | 295-445 low Q (like the TB WQ-1858), F3 36 Hz
In this category I would go with the Dayton Audio UM12-22 12" Ultimax DVC Subwoofer, for you to choose.

 

[Bob Richards]

I put top of the line Peerless 12 inch drivers in smallish closed boxes, and then drove them with active EQ and 4 pole active crossover (ahead of the power amps). They measure acoustically flat +/- 3dB from 20HZ to 100HZ at my chair.

If I had it to do again, I'd do the same thing, but instead of a single 12 inch on each side, I'd build woofer towers, mabe 4 ft. tall, with at least two 8 inch Peerless nomex cone drivers in each cabinet. I'd isolate internally each driver from the other (not sure that matters, but it won't hurt), and one driver would be very near the floor, and the other would be very near the top of the tower cabinet. I have a theory that this would work even better with room acoustics. The idea is to illuminate the room on all three axis, so cancellation areas will be less severe.

 

[pow216]

Thanks for all the replies it gives me lots to look at. Maybe I'll need to EQ.

Well I thought I'd be able to improve on the last sub I built, it was a Sony XS-L121P5S in 70 litres. -3dB @ 32 Hz. Maybe it won't be as easy as I thought!
Sony XS-L121P5S

 

[pow216]

#7, Yes -3dB.

 

[tinitus]

woofer with 20hz Fs, 0.40 Qts
box, 0.5-0.6 Qtc

 

[myleslewis]

Apologies, not trying to hijack the thread but thought it would be pointless to start a whole new thread when I could discuss the same thing as the OP in this one . I too am looking for a drive unit that can be put into a box of 150L MAX. Smaller would be better but have an upper limit of 150L. Driver size can be up to 12" ideally. Box can be either sealed of vented.

Main purpose is the same as OP's, low end extension, would like it to play down to < 25hz but just finding it hard to find the drivers for it !

Is what I'm wanting even possible ? Price isn't too much of an issue, would be happy paying £200-220 for drivers.

Thanks,

Myles.

 

[tinitus]

topic is sealed box for as long as the OP wants it to be

if you expect full output below 25hz you will need vented box
or lots of EQ, and amp power
try search threads with vented subs

 

[sine143]

If you are going sealed.... just find a good driver for a sealed box and eq it flat to taste (and then add more boxes to increas the spl because sealed boxes are not about efficiency).

 

[tinitus]

If you are going sealed.... just find a good driver for a sealed box ...

Hello, I'd like some suggestions for drive units to go into a DIY sub ...

... sorry, I just thought that was funny

 

[Richard Ellis]

Apologies, not trying to hijack the thread but thought it would be pointless to start a whole new thread when I could discuss the same thing as the OP in this one . I too am looking for a drive unit that can be put into a box of 150L MAX. Smaller would be better but have an upper limit of 150L. Driver size can be up to 12" ideally. Box can be either sealed of vented.

Main purpose is the same as OP's, low end extension, would like it to play down to < 25hz but just finding it hard to find the drivers for it !

Is what I'm wanting even possible ? Price isn't too much of an issue, would be happy paying £200-220 for drivers.

Thanks,

That Tang-band I mentioned will do just find, reworking the simulation to 145 liters, it will still run in the mid-high teens for an F3, ported.

________________________________________________Rick.........

Myles.

 

[tb46]

Series Tuning Capacitor

Hi pow216,

Your Sony based subwoofer (Post #9) should be a nice subwoofer. How about using two of these 12" in a 100L box, and using a series resistor/capacitor combination to give you the <30Hz response your are looking for? This tuning method should also work w/ your existing subwoofer, so you could give this a try if you can find appropriate capacitors/resistors to set up a test. Hornresp does a good job @ simulating this.

Using google translate I found this:

https://www.lautsprechershop.de/ind...ww.lautsprechershop.de/hifi/aka_tief_c_en.htm

Regards,

 

[norman bates]

I put top of the line Peerless 12 inch drivers in smallish closed boxes, and then drove them with active EQ and 4 pole active crossover (ahead of the power amps). They measure acoustically flat +/- 3dB from 20HZ to 100HZ at my chair.

If I had it to do again, I'd do the same thing, but instead of a single 12 inch on each side, I'd build woofer towers, mabe 4 ft. tall, with at least two 8 inch Peerless nomex cone drivers in each cabinet. I'd isolate internally each driver from the other (not sure that matters, but it won't hurt), and one driver would be very near the floor, and the other would be very near the top of the tower cabinet. I have a theory that this would work even better with room acoustics. The idea is to illuminate the room on all three axis, so cancellation areas will be less severe.

Yea, my double 15 box loads better up and down compared to both 15's on the floor.

 

[Shadydave]

Tinitus said

if you expect full output below 25hz you will need vented box
or lots of EQ

I managed to get an honest 35 Hz with no port, no EQ but concrete walls.
I built a 73 liter Baltic Birch box, that needed allot of after the fact bracing and houses an Infinity 1262W car subwoofer.
I am feeding it about 400 Watts (Cerwin Vega CV-900 into 2 ohms).
It has a rising response down to about 35 Hz. (about 8 Db higher at 35 Hz than 100 Hz on same sweep).
But it drops like a rock below 35 Hz.
Minus 15 Db by 25 Hz
I don't know if you could get another 5 to 10 Hz lower by doubling the box size but maybe you might want to simulate it.
I will say that I believe I have a hefty dose of room gain as the speaker boxes are in a concrete room.
However, all I can say is wow. I am so glad I took out the port which made it go down to 20 Hz but with allot of single note boom and delay.

Dave

 

[bjorno]

Hi pow216,

Your Sony based subwoofer (Post #9) should be a nice subwoofer. How about using two of these 12" in a 100L box, and using a series resistor/capacitor combination to give you the <30Hz response your are looking for? This tuning method should also work w/ your existing subwoofer, so you could give this a try if you can find appropriate capacitors/resistors to set up a test. Hornresp does a good job @ simulating this.

Using google translate I found this:

https://www.lautsprechershop.de/ind...ww.lautsprechershop.de/hifi/aka_tief_c_en.htm

Regards,

Hi Oliver
Agree completely and the info that is provided at lautsprechershop is good too so I made a quick picture as usual to further illustrate an Capacitor-assisted Closed Box design using the OP Speaker Driver.

b