Hi everyone,
Sorry for getting theoretical here. I'm kicking around an idea in my head for next year, when my cards are paid off. I have a pair of 2-way speakers on stands. I am thinking of adding a bass section to fit below them.
The existing speakers use Revelator 18W/4531 and are about 12" wide. They're rather large due to the BR.
The plan is to seal them and run the upper section from around 200 to 300 Hz up. The bass section should be simple (sealed or BR) and will incorporate a 3-way Hypex plate amp. I'll be converting the passive speakers to fully active.
The bass section should be about 10" wide. I could see a pair of 8" woofers, or a pair of side mounted 10" drivers...
Bass should be solid, convincing but not looking to spend ultimate dollars. Also, plan on fully leveraging the EQ capability of the plate amp for room integration. Thoughts?
Sorry for getting theoretical here. I'm kicking around an idea in my head for next year, when my cards are paid off. I have a pair of 2-way speakers on stands. I am thinking of adding a bass section to fit below them.
The existing speakers use Revelator 18W/4531 and are about 12" wide. They're rather large due to the BR.
The plan is to seal them and run the upper section from around 200 to 300 Hz up. The bass section should be simple (sealed or BR) and will incorporate a 3-way Hypex plate amp. I'll be converting the passive speakers to fully active.
The bass section should be about 10" wide. I could see a pair of 8" woofers, or a pair of side mounted 10" drivers...
Bass should be solid, convincing but not looking to spend ultimate dollars. Also, plan on fully leveraging the EQ capability of the plate amp for room integration. Thoughts?
I did a directivity study here on side firing woofers:
https://www.htguide.com/forum/missi...0-in-floorstander-designs?p=926319#post926319
https://www.htguide.com/forum/forum...1359-directivity-study-woofers-and-subwoofers
And some measurements of quad 8” woofers, 2 each on each side panel-
If you wanted side mounted woofers, then XO should be 150Hz or less.
18W can easily handle that.
Dual opposed would greatly reduce vibration
I speak from experience: having twin 12” woofers in 13.75” wide cabinets, and at 92dB/2.83V, they have at least 6dB more headroom than I have ever used.
Twin 10” sealed or triple woofers 8 vented woofers would give enough SPL for me. I’m planning the downsize…
https://www.htguide.com/forum/missi...0-in-floorstander-designs?p=926319#post926319
https://www.htguide.com/forum/forum...1359-directivity-study-woofers-and-subwoofers
And some measurements of quad 8” woofers, 2 each on each side panel-
Here is some more data on a prototype of a twin dual opposed cabinet. (2 x 8" woofers on opposite sides of the cabinet- 4 in total)
Hor 0 is the blue line; Hor 180 is the red line:
If we rotate the cabinet 90 degrees we see the two other 8" woofers, and the cables on the back of the cabinet.
When the mic is placed here, and the cabinet is in this position, it is thus Hor 90-
Hor 0 to -90 in 10 degree steps...
Hor 0 is the blue line; Hor 180 is the red line:
If we rotate the cabinet 90 degrees we see the two other 8" woofers, and the cables on the back of the cabinet.
When the mic is placed here, and the cabinet is in this position, it is thus Hor 90-
Hor 0 to -90 in 10 degree steps...
If you wanted side mounted woofers, then XO should be 150Hz or less.
18W can easily handle that.
Dual opposed would greatly reduce vibration
I speak from experience: having twin 12” woofers in 13.75” wide cabinets, and at 92dB/2.83V, they have at least 6dB more headroom than I have ever used.
Twin 10” sealed or triple woofers 8 vented woofers would give enough SPL for me. I’m planning the downsize…
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Don’t mix the modal range (80hz on down) with midbass through 1 driver if you can avoid it. Keep your two ways as they are. Build three freestanding subs….place one in between the two mains and feed it left and right signal. Then place the remaining two outboard of the mains and feed them left and right respectively. Use DSP to smooth response…..done.
@tktran303 - That's interesting, and a lot lower than I would have expected given the wavelength to driver diamter.
Yea the cabinet dimensions matter.
If you are able to use 3D CAD like AKABAK or other, you can manage/control directivity based on your come diameter and cabinet width AND depth.
A few subwoofers of different sizes around the room is an option, as mayhem13 suggested.
I did not do this because I designed this system around a midrange that has limited x-max (~1mm) and Fs ~ 200Hz.. and is best crossed over ~400Hz…
If you are able to use 3D CAD like AKABAK or other, you can manage/control directivity based on your come diameter and cabinet width AND depth.
A few subwoofers of different sizes around the room is an option, as mayhem13 suggested.
I did not do this because I designed this system around a midrange that has limited x-max (~1mm) and Fs ~ 200Hz.. and is best crossed over ~400Hz…
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I made a sealed basscabinet with a Scanspeak 26W8534G00, and that works very well to a limited volume (xmax is limited) crossed at 300Hz. But there are a lot of possibilities. But i would use a bigger driver (sidmounted or not), the scanspeak is an 7" midwoofer, and using bigger drivers mostly fit such an midwoofer than using small (almost similar size) 8" subs. So you probally should sidemount (and use dual opposed if you do that). But that requires a lower cross over point. If you want to stay higher, i would at least use a 10" (or more than one) per side, like the 26W.
The other way is making a few subs that are not your speaker stand and spread them in the room. It often helps to reduce room modes and so make the sub more even accross the room. That is what Floyd Toole propagates for the best subbass. Those can be smaller drivers, but you will have to cross at least below 100Hz to make that work.
The other way is making a few subs that are not your speaker stand and spread them in the room. It often helps to reduce room modes and so make the sub more even accross the room. That is what Floyd Toole propagates for the best subbass. Those can be smaller drivers, but you will have to cross at least below 100Hz to make that work.
The point some are missing is that increasing the overall speaker footprint is not an option. absolutely do not want to add separate subs.
Also want to convert to fully powered with minimal wiring and devices. A bass cabinet with 3 channel plate amp is the primary requirement for this project
Also want to convert to fully powered with minimal wiring and devices. A bass cabinet with 3 channel plate amp is the primary requirement for this project
Then 2x a 10" woofer per cabinet in dual opposides will be the best solution i think. How big can the cabinet be (in litre and how low do you want it at what volume. A pair of Scanspeak 26W4558T00's in a 85L (for both) enclosure can easely be tuned to 30Hz (as example) or even lower if you make the box bigger. They will also fit dual opposite in a 12" (30cm) wide cabinet without blocking the air vents, you got 3cm spare between them if mounted flush from the front. But you best cross to the midbass at arround 100Hz or lower.
I'm not a huge fan of many small woofers. I don't believe they will outperform large surface areas, but for my needs, and ease of manufacture, I am thinking the SS 8" woofers could be perfect, and certainly affordable at $130US each. I could do two forward facing drivers in a cabinet the exact width of the current studio monitors.
https://www.madisoundspeakerstore.com/approx-8-woofers/scanspeak-22w/8534g-discovery-8-woofer/
Thoughts?
https://www.madisoundspeakerstore.com/approx-8-woofers/scanspeak-22w/8534g-discovery-8-woofer/
Thoughts?
Go triple and you won’t look back. Besides the Hypex amps can handle 2 ohms…