I've seen a number of threads proposing miniature LaScala -type 2 or 3-way horn speakers like below:
each one depending on the size of the enclosure has so many compromises that it almost makes it not worth attempting: the performance of the original article hardly inspiring, with a frequency range of 55Hz to 18kHz, reducing the bass bin makes it appreciably worse and many use stock Klipsch components to boot: the K400 mid horn is shouty and boxy sounding, owing to its 1" throat and long throw, while the K-77 tweeter and exponential lens that was used from the 60's into the 80's it sibilant and weak on its best day. Shrinking it all raises the LF cutoff as well as the transfer function of the bass enclosure, which in stock configuration, happens around 110Hz. "Why bother?" was my typical response.
However, I had a stack of wood in my workshop, some spare horns and drivers, going into a long winter without any projects; owing to the success I had with my passive radiating, La Scala-inspired 3-way that played from 20Hz to 20Khz left me wondering if I couldn't build a better mousetrap?
So I got out my calculator and settled a 80% scale version of the LS, measuring approximately 19-1/2" x 19-1/2" by approximately 34-36" tall, with the upper enclosure coupled to the doghouse of the bass bin with a pair of 6-1/2" alloy-cone passive radiators, for a cabinet displacement of 4.5 cubic feet. The objective is to tune the enclosure from 32Hz to 20kHz. Since it's an 80% scale enclosure, it's a simple matter to adapt my existing cut sheets to work. The plan is to build one enclosure as a proof of concept and
I've begun with the LF enclosure, starting with the doghouse:
the scaled down version will use a 12" 8Ω driver, as opposed to the 15" JBL2225H used in my large 3-way, with a cabinet volume between the doghouse woofer enclosure and the coupled upper enclosure going in at approximately 4.5 cu ft or 127L. I've made multiple motor boards for the upper enclosure, allowing for either a 2-way or 3-way alignment, with the PRV WG4550 mid horn and a P Audio/Lase BD-M750 for two-way, or the same wave guide and PRV's D2200Ph driver and an elliptical tweeter lens with a B&C DE-10 driver up top in 3-way configuration, both crossed over at 500Hz, as the large horn seems to lose directivity below 475Hz. and either a passive network, Dayton DSP-408 active crossover or a combination thereof:
each one depending on the size of the enclosure has so many compromises that it almost makes it not worth attempting: the performance of the original article hardly inspiring, with a frequency range of 55Hz to 18kHz, reducing the bass bin makes it appreciably worse and many use stock Klipsch components to boot: the K400 mid horn is shouty and boxy sounding, owing to its 1" throat and long throw, while the K-77 tweeter and exponential lens that was used from the 60's into the 80's it sibilant and weak on its best day. Shrinking it all raises the LF cutoff as well as the transfer function of the bass enclosure, which in stock configuration, happens around 110Hz. "Why bother?" was my typical response.
However, I had a stack of wood in my workshop, some spare horns and drivers, going into a long winter without any projects; owing to the success I had with my passive radiating, La Scala-inspired 3-way that played from 20Hz to 20Khz left me wondering if I couldn't build a better mousetrap?
So I got out my calculator and settled a 80% scale version of the LS, measuring approximately 19-1/2" x 19-1/2" by approximately 34-36" tall, with the upper enclosure coupled to the doghouse of the bass bin with a pair of 6-1/2" alloy-cone passive radiators, for a cabinet displacement of 4.5 cubic feet. The objective is to tune the enclosure from 32Hz to 20kHz. Since it's an 80% scale enclosure, it's a simple matter to adapt my existing cut sheets to work. The plan is to build one enclosure as a proof of concept and
I've begun with the LF enclosure, starting with the doghouse:
the scaled down version will use a 12" 8Ω driver, as opposed to the 15" JBL2225H used in my large 3-way, with a cabinet volume between the doghouse woofer enclosure and the coupled upper enclosure going in at approximately 4.5 cu ft or 127L. I've made multiple motor boards for the upper enclosure, allowing for either a 2-way or 3-way alignment, with the PRV WG4550 mid horn and a P Audio/Lase BD-M750 for two-way, or the same wave guide and PRV's D2200Ph driver and an elliptical tweeter lens with a B&C DE-10 driver up top in 3-way configuration, both crossed over at 500Hz, as the large horn seems to lose directivity below 475Hz. and either a passive network, Dayton DSP-408 active crossover or a combination thereof:
rough simulations in HornResp with a generic diver:
this leaves me with the challenge of a driver that will work well enough in a bass reflex enclosure with a 15 rear mounted passive to allow extension to 32Hz or so.
I began with my first driver sim, using the Eminence Delta Pro 12A, which I have on hand which is roughy equivalent to the Klipsch K28 and a 4" port in lieu of a passive:
with a roll-off at 40Hz, the performance isn't acceptable for my goals, but it forms a baseline for comparison.
ext up is the Dayton Audio Odeon 12N, which I had been favoring:
LF rollout begins at 38Hz, which would put it at roughly equivalent to the Klipsch Forte, which is broadly acceptable, but short of our goal of 22Hz.
next on deck is the Dayton Audio Odeon 12LF:
LF extension goes to 30Hz, which is great, but it also has a dip between 69Hz and the low frequency cutoff, and a rising rate after about 120Hz and is down 4.5dB in sensitivity compared to the Delta Pro 12a and 2dB below the Odeon 12N, which is sub optimal.
this leaves me with the challenge of a driver that will work well enough in a bass reflex enclosure with a 15 rear mounted passive to allow extension to 32Hz or so.
I began with my first driver sim, using the Eminence Delta Pro 12A, which I have on hand which is roughy equivalent to the Klipsch K28 and a 4" port in lieu of a passive:
ext up is the Dayton Audio Odeon 12N, which I had been favoring:
next on deck is the Dayton Audio Odeon 12LF:
LF extension goes to 30Hz, which is great, but it also has a dip between 69Hz and the low frequency cutoff, and a rising rate after about 120Hz and is down 4.5dB in sensitivity compared to the Delta Pro 12a and 2dB below the Odeon 12N, which is sub optimal.
A friend ran the Goldwood GW 1258. through HornRESP; it's currently on sale at just under $58. It's modeled in black, with the Dayton Odeon 12N in Gray.
As a pure horn diver, its performance evokes the Klipsch K-33 that is stock in the LaScala, Klipshorn & Cornwall, but as a base reflex driver, it's less than impressive:
I'm tempted to try it just the same, given P-E's generous return polices, but the T/S parameters are close enough to the classic Klipsch K-22, which is boomy and indistinct in a bass reflex enclosure, that I'd just as soon save the return shipping cost..
As a pure horn diver, its performance evokes the Klipsch K-33 that is stock in the LaScala, Klipshorn & Cornwall, but as a base reflex driver, it's less than impressive:
I'm tempted to try it just the same, given P-E's generous return polices, but the T/S parameters are close enough to the classic Klipsch K-22, which is boomy and indistinct in a bass reflex enclosure, that I'd just as soon save the return shipping cost..
I'd appreciate any additional recs for a 12" driver, preferably one that matches price (below $200) and performance
Given I've been using the JBL 2225H in my large 3-way horn as a benchmark, a @claudej12000 brought the JBL 2206 to my attention.
It simulates exceptionally well in a 127L vented enclosure. I just ordered one.
It simulates exceptionally well in a 127L vented enclosure. I just ordered one.
It’s on hold. The speaker I bought arrived in need of a recone itself. I’m negotiating with the seller to either get a partial refund to cover the cost of a cone kit or a complete refund entirely. In the meantime, I have my #2 selection arriving tomorrow, so as soon as I get the networks sorted on my beyond Heresy project, I’ll be able to move on to this one again. Hopefully later this week.
I brought the horn home yesterday for measurement:
After wiring up the innards, I threw a very hastily improvised network together:
and ran a sweep:
The 60Hz standing wave in my 10'x11' spare bedroom not withstanding, I'm pleasantly shocked that it measured as well as it did on my first try with a network that I literally threw together at the last minute.
The low frequency rolled off at the bottom in the mid 30's, without the benefit of corner loading! I put on Bela Fleck and Flecktones and every bit of Victor Wooten's baseline were there. While the bass wasn't as authoritative as my big horns, which extend to 20Hz, it had considerable presence.
I'll put together a proper network, clear out a corner and get more measurements, soon.
After wiring up the innards, I threw a very hastily improvised network together:
and ran a sweep:
The 60Hz standing wave in my 10'x11' spare bedroom not withstanding, I'm pleasantly shocked that it measured as well as it did on my first try with a network that I literally threw together at the last minute.
The low frequency rolled off at the bottom in the mid 30's, without the benefit of corner loading! I put on Bela Fleck and Flecktones and every bit of Victor Wooten's baseline were there. While the bass wasn't as authoritative as my big horns, which extend to 20Hz, it had considerable presence.
I'll put together a proper network, clear out a corner and get more measurements, soon.
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