[FullRangeMan]

I should not use multiple woofers to avoid too low or too hi impedance, just one 15'' woofer in BR will be suffice and made a lot of bass.

[Woodsage]

I should not use multiple woofers to avoid too low or too hi impedance, just one 15'' woofer in BR will be suffice and made a lot of bass.

I have been referencing my OB speaker not a BR so apples to oranges I think.

My Oris 200 systems produced some of the driest, fastest, most detailed bass I have ever heard with one (active) 15" woofer.

That being said there are plenty of good BR that use multiple 15's as well.

[Russell Dawkins]

Mike, in that other thread where you post photos of your beautiful open baffle columns you mention using a grill cloth to hide the colour of the Fast 8 cones.
I know you were reticent to widen the middle driver hole to accomodate the 10" Crystal, but were you aware of another driver Lii Audio had replaced the Fast 10 with? From their description the Fast 10B sounds like an improvement over the Fast 10 in a couple of ways yet it is just over half the price of the Crystal 10. Its fs is 10 Hz lower than the Fast 8 (37 vs 47 Hz) and sensitivity is 1.5 dB higher, the whizzer had been changed to resemble those on the Crystal10 and Fast 8 and the main cone is now black, even if the whizzer is still beige.
At $550/pr you might think it worth enlarging the mounting holes in your baffles to accommodate them.
https://www.lii-audio.com/product/one-pair-10-inch-hifi-speaker-driver-for-tube-amplifier-total-full-range-and-exquisite-sound-fast-10b-black/

[Woodsage]

Mike, in that other thread where you post photos of your beautiful open baffle columns you mention using a grill cloth to hide the colour of the Fast 8 cones.
I know you were reticent to widen the middle driver hole to accomodate the 10" Crystal, but were you aware of another driver Lii Audio had replaced the Fast 10 with? From their description the Fast 10B sounds like an improvement over the Fast 10 in a couple of ways yet it is just over half the price of the Crystal 10. Its fs is 10 Hz lower than the Fast 8 (37 vs 47 Hz) and sensitivity is 1.5 dB higher, the whizzer had been changed to resemble those on the Crystal10 and Fast 8 and the main cone is now black, even if the whizzer is still beige.
At $550/pr you might think it worth enlarging the mounting holes in your baffles to accommodate them.
https://www.lii-audio.com/product/one-pair-10-inch-hifi-speaker-driver-for-tube-amplifier-total-full-range-and-exquisite-sound-fast-10b-black/

Thanks for the heads up on that driver Russell. It looks good for sure but, having retired pretty early, my disposable income wasn't what it once was. And I have a lot more freedom than I used to have so I tend to spend my money and time on different things these days like travel or converting my mountain bike to an e-bike so I can spend more time up in the hills riding.

That being said I have been keeping my eye out for any of the Lii 10" drivers coming up for sale used. If I find a bargain it would be enough to motivate me to enlarge the baffle cut out to accommodate the larger driver.

Building speakers is no longer convenient for me but if it were I would make the shift back to large format drivers. I'd go for a Lii 15" full range with two of their new 15" woofers per side with active bass.  Open baffle of course. Maybe someday if my pot stocks ever recover.....

Mike

[FullRangeMan]

That being said there are plenty of good BR that use multiple 15's as well.
Certainly there is with impedance correction or full xover.
Three 4Ω woofers in serial=12Ω in parallel=1.3Ω
Three 8Ω woofers in serial=24Ω in parallel=2.6Ω
Serial are avoided by builders due the sound and no gain in SPL so choice seem to be 2.6Ω and Zobel.

[Woodsage]

That being said there are plenty of good BR that use multiple 15's as well.
Certainly there is with impedance correction or full xover.
Three 4Ω woofers in serial=12Ω in parallel=1.3Ω
Three 8Ω woofers in serial=24Ω in parallel=2.6Ω
Serial are avoided by builders due the sound and no gain in SPL so choice seem to be 2.6Ω and Zobel.

Yes I understand these wiring options but I always run active bass so I’m not too worried about impedance and certainly not a Zobel network.

On these particular speakers I have wired the bass both in series / parallel and in parallel. In series / parallel the four woofers came in around 8 ohms and I drove them easily with two class AB plate amps. They are currently wired in parallel for about a 2 ohm load which is easily driven with a Crown XLS 1000.

Both the plate amps and the Crown are driven off the speaker binding posts of my tube amp that drives the Lii audio drivers.

Additionally some woofer manufactures make high impedance versions (16 ohm) specifically for multiple woofer setups.

Mike

[LostInPA]

Thanks to those of you who have already done the experimentation.   I have done some trials with my electronic crossover, and have settled on 160 Hz, along with a bit less gain on the low frequency side.   There is now better bass definition, and better integration with the Fast 8.   This all still falls in to the site stated definition of full range single driver, with 3 octaves to the powered subs and 7 octaves to the fast 8.     

[LostInPA]

I was ultimately not satisfied with the performance as a wide range single driver application in the cabinets that I had made.   

Cabinets re-purposed, and posted here   https://www.audiocircle.com/index.php?topic=76975.new#new

I do have  other plans for the Fast 8 drivers in a full range application, to be posted here at some future time.