You're welcome!
Don't keep up with small woofers, 8" was my lower limit for traditional 'sub' duty (< 60 Hz), so no clue if such exists except as low Xmax, ~wide/full range drivers.
Don't keep up with small woofers, 8" was my lower limit for traditional 'sub' duty (< 60 Hz), so no clue if such exists except as low Xmax, ~wide/full range drivers.
If you’re going to approach a quad driver design, since you have the motor strength and box volume, I’d sug a sealed alignment with each driver having its own sealed chamber.
You don’t need an f3 of 30hz, and f10 will do with room and boundary gain lifting the response to near flat. The sealed enclosure will dig deeper below the bandpass of the ported design. Sealed enclosures have far better impulse/step response and your bass will be cleaner. You will need a driver with higher xmax though and I would suggest 8” as a minimum diameter. These aren’t going to be inexpensive exactly but that’s the advantage to a DIY effort……a well executed pair of 8” bass arrays would retail for over $10k
You don’t need an f3 of 30hz, and f10 will do with room and boundary gain lifting the response to near flat. The sealed enclosure will dig deeper below the bandpass of the ported design. Sealed enclosures have far better impulse/step response and your bass will be cleaner. You will need a driver with higher xmax though and I would suggest 8” as a minimum diameter. These aren’t going to be inexpensive exactly but that’s the advantage to a DIY effort……a well executed pair of 8” bass arrays would retail for over $10k
Hi,
used to build such tall and thin dipole bass towers with 8" and 6.5" drivers to accompany with my ESL panels.
The footprint of the towers is tiny, just less than the area of a DINA5 piece of paper for the 6.5" version.
I eventually omitted with the 8" version, because it became obvious that in the large rooms the system would play, the dipole simply couldn't fill the room properly in the lowest register.
As the need for a dedicated CB sub playing from 50Hz down (*) became apparent the smaller 6.5" version fitted the bill better, sounding 'faster', more precise and with considerably more attack in the kickbass region.
In small rooms and wo a dedicated sub the towers may be equed down to 35Hz, delivering very precise low bass but wo the slam down below.
The second best but simpler solution I think would be CB towers at the cost of increased size and/or massive equing of the drivers.
From 6 drivers on up You will have enough reserves in dynamic range even for large rooms.
Then just remains the question of how the CB bass triggers the room modes, how it will sound.
jauu
Calvin
* preferably the sub would play below the lowest room mode, just pressurising the room, with the associated rise in SPL, which would be quite efficient, also allowing for quite small drivers to be used. The combination of the monopole sub and the dipole tower shows less tendency to booming and combines powerful slam at the lowest notes with precision and speed at the bass and upper kickbass.
used to build such tall and thin dipole bass towers with 8" and 6.5" drivers to accompany with my ESL panels.
The footprint of the towers is tiny, just less than the area of a DINA5 piece of paper for the 6.5" version.
I eventually omitted with the 8" version, because it became obvious that in the large rooms the system would play, the dipole simply couldn't fill the room properly in the lowest register.
As the need for a dedicated CB sub playing from 50Hz down (*) became apparent the smaller 6.5" version fitted the bill better, sounding 'faster', more precise and with considerably more attack in the kickbass region.
In small rooms and wo a dedicated sub the towers may be equed down to 35Hz, delivering very precise low bass but wo the slam down below.
The second best but simpler solution I think would be CB towers at the cost of increased size and/or massive equing of the drivers.
From 6 drivers on up You will have enough reserves in dynamic range even for large rooms.
Then just remains the question of how the CB bass triggers the room modes, how it will sound.
jauu
Calvin
* preferably the sub would play below the lowest room mode, just pressurising the room, with the associated rise in SPL, which would be quite efficient, also allowing for quite small drivers to be used. The combination of the monopole sub and the dipole tower shows less tendency to booming and combines powerful slam at the lowest notes with precision and speed at the bass and upper kickbass.
Hrm, good point, thanks. I actually do very much like the idea of a sealed enclosure with series of drivers in each. I'm starting to want to migrate this from "sub" to simply a full range tower speaker (using a full range woofer and a subwoofer with a very simple crossover doing a highpass/lowpass and crossing over higher). The idea of a sealed one is starting to sound nice. Also much easier to build and can't get anything "inside."
Very best,
There is a problem with this approach, of using many smaller drivers to make a subwoofer: smaller drivers have more distortion at lower frequencies compared to larger ones, in general. IMHO it is a bad idea to use 6.5 drivers for a "subwoofer" (to me this means operating only below 100Hz max and should be able to do something useful at 20Hz). Also, Fs of smaller drivers will typically be too high to make them useful as a subwoofer.
Unfortunately, physics is working against the success of this concept.
Just like @mayhem13 mentions, sealed subs using multiple 10" (or larger) drivers is a better approach. The drivers do not necessarily need to be exotic but it is useful to try and vet them (look for online measurements) and not just buy something because it is cheap. A 10" driver does not need a huge enclosure, maybe 25L to 30L. You can EQ the response of a closed box sub to match your room's low frequency gain using an Linkwitz Transform. I am using the approach with four 12" per side, each in about 45 liters sealed, stacked on top of each other on the front the wall.
Unfortunately, physics is working against the success of this concept.
Just like @mayhem13 mentions, sealed subs using multiple 10" (or larger) drivers is a better approach. The drivers do not necessarily need to be exotic but it is useful to try and vet them (look for online measurements) and not just buy something because it is cheap. A 10" driver does not need a huge enclosure, maybe 25L to 30L. You can EQ the response of a closed box sub to match your room's low frequency gain using an Linkwitz Transform. I am using the approach with four 12" per side, each in about 45 liters sealed, stacked on top of each other on the front the wall.
Hi,
Oh yes, bigger drivers in a bigger enclosure of course is going to do this job better. But, this is about minimizing foot print and compromising things to allow for a skinny tower that can hit 30hz without necessarily building a tall TL or something (though that is totally an option too). I realize it's not ideal to use smaller drivers and the compromises that come with it. Instead of being strictly a sub, I'm thinking more to move towards a full range tower in general with the ability to dig to 30hz in room. I realized that saving floor space also includes reducing the cabinet count, why do 2.1 when you can do it with 2!
Very best,
Oh yes, bigger drivers in a bigger enclosure of course is going to do this job better. But, this is about minimizing foot print and compromising things to allow for a skinny tower that can hit 30hz without necessarily building a tall TL or something (though that is totally an option too). I realize it's not ideal to use smaller drivers and the compromises that come with it. Instead of being strictly a sub, I'm thinking more to move towards a full range tower in general with the ability to dig to 30hz in room. I realized that saving floor space also includes reducing the cabinet count, why do 2.1 when you can do it with 2!
Very best,
Dave Hi
Which of the above plans give fullrngae I mean with deep bass. I dont want to have a sepearet subwoofer just a full line arrray / colum of mark audio drivers
I ended up doing something different.
I did a tower with 4 x 12" drivers.
And now I'm doing a tower with 8 x 12" drivers (hahaha). This one isn't done, I'm currently on hold due to the hurricanes here in Florida. But the manifold and baffle are done. 4 x 12" drivers on each side, cone to cone, squeezing out of slots.
As soon as the storms are done, I'll have a build thread on this one.
Very best,
I used 4 x JBL CX1200's in the tower above. I like it. I use it near field and it packs a lot of punch for pennies (very inexpensive).
I had to stop here due to microphone clipping limitations. It had plenty more room to keep going up. But my mic was clipping in that 112db range. I easily get 130db from this thing. Currently using a Crown XLS1002 with it, bridged. I use a MiniDSP HD2x4 and it's on one of its channels for EQ/DSP.
The octa-sub baffle is using GRS 12SW-4 drivers, inexpensive as well, just lots of them.
It's not done yet so I cannot show measurements, but my prototypes were successful.
More info on my prototypes with 2 drivers, that I'm scaling to 8 drivers here:
And better prototype here with measurements to compression:
Update, new prototype finished. Measured.
21" wide, 13.5" tall, 13.5" deep. Internally about 1.6 ft^3 displaced. W-frame slot loaded open baffle
GRS12SW-4 x 2 ($31 each) wired in series (7.7 ohm)
DATS to see Fb and baffle resonance, noted the 225~240hz spike expected from the slot cavity resonance.
The crude form:
Measurements:
Ground plane 1 meter
First, I took my jig out and took them to peak to peak xmax over 16mm, and they were still...
21" wide, 13.5" tall, 13.5" deep. Internally about 1.6 ft^3 displaced. W-frame slot loaded open baffle
GRS12SW-4 x 2 ($31 each) wired in series (7.7 ohm)
DATS to see Fb and baffle resonance, noted the 225~240hz spike expected from the slot cavity resonance.
The crude form:
Measurements:
Ground plane 1 meter
First, I took my jig out and took them to peak to peak xmax over 16mm, and they were still...
Very best,
The only thing I would do differently on my 4 x 12" tower above, is I wish I did quad opposed, 2 drivers facing forward, 2 drivers facing rear, in phase, so that the tower wouldn't shake. As it is, when I get those 4 drivers pushing hard into infrasonic, things on top of the tower walk off the side of it. So I have to blue tack everything down on there. It's fine for just listening, but the tower shakes enough to make things walk off the top which is annoying. In an opposed alignment, it would have the same output and all but kill the cabinet vibration.
So I did that on the next sub, dual opposed with 12's. And now I'm doing the 3rd iteration which is an octa-sub with 8 x 12's and they're in quad opposed pairs, so 8 drivers, cone to cone, in phase, to cancel out most of the cabinet/baffle vibrations so that these taller towers on their smaller footprints with mass don't shake.
Very best,
So I did that on the next sub, dual opposed with 12's. And now I'm doing the 3rd iteration which is an octa-sub with 8 x 12's and they're in quad opposed pairs, so 8 drivers, cone to cone, in phase, to cancel out most of the cabinet/baffle vibrations so that these taller towers on their smaller footprints with mass don't shake.
Very best,
I took heavy inspiration from a couple of these SLOB configuration loud speakers, but applied it to a larger open baffle w-frame slot loaded subwoofer in my case using 8 x 12" drivers. I thought about going even bigger on the drivers, but the cavity peak resonance is relative to the cavity side/area, so the frequency was lower and it heavily influences the working bandwidth to keep the peak an octave away from the working bandwidth, so stayed with the 12" driver to keep the cavities small enough to keep the peak resonance frequencies higher in the 200+ hz area, so my working bandwidth can be 10~100hz. With big 15~18" drivers, that drops closer to 100~150zh range and then my working bandwidth is closer to 60~80hz at the top end. And with 18" or larger drivers, it's lower, then I'm looking at 40hz as the highest range which is more like what people do with infinite baffle manifolds.
Very best,
https://www.parts-express.com/Epiqu...G-Subwoofer-4-Ohm-per-Coil-295-104?quantity=1
I wonder if this has shelved/dethroned the tangband as the little thumper that could?
I wonder if this has shelved/dethroned the tangband as the little thumper that could?
I ended up doing an 8 driver open baffle w-frame sub. It's flat to 27hz then rolls off. This is with 8 x 12" drivers. It's 50" tall, 21" total wide, 12.5" deep. Occupies very little space on the floor. Slot loaded on the front (4 slots).
Natural response with the cavity's peak resonance in the >200hz range. Flat to about 27hz (fundamental A1). Zero EQ here. Zero smoothing.
And here's a low pass filter and a negative notch on 165~240hz range to sink it low. No other EQ or filtering.
The slam is fantastic. Great tactile response.
Very best,
Natural response with the cavity's peak resonance in the >200hz range. Flat to about 27hz (fundamental A1). Zero EQ here. Zero smoothing.
And here's a low pass filter and a negative notch on 165~240hz range to sink it low. No other EQ or filtering.
The slam is fantastic. Great tactile response.
Very best,
That was just a quick sweep and a quick low pass. I just got the drivers installed last night waiting for my power to go out in the storms (Florida). I still have more work to do on it, but wanted to do something other than think about the hurricane and tornadoes.
Those sweeps were near field, near the wall.
I will be doing ground plane measurements soon outside to get a good measurement and will make a build thread about this particular enclosure soon.
Very best,