Back in the mid-Naughties, I had 4 of the Radio Shack 40-1197 drivers, and spent many a happy hour checking out speakers that used them. The BD-Pipe always appealed to me. Folded pipe, with a 45-degree rear facing driver for added spatial neat-o-ness. But I never built anything.
So, now, a decade, a divorce, and a lot of livin' later, I am once again seated in front of a computer, looking at small full-range speaker designs. And I still like the ideas in the BD-Pipe design.
So, are there current designs that are similar? 4" - 4.5" FR drivers, compact tower, easy build, easy load for low-powered amplification, and with that angled, (or upward-facing,) psuedo-omni driver. Corner placement is a must in my tiny, weirdly shaped living room. and it's an upstairs apartment in an old house, so lotsa bass isn't a goal.
--Shannon
So, now, a decade, a divorce, and a lot of livin' later, I am once again seated in front of a computer, looking at small full-range speaker designs. And I still like the ideas in the BD-Pipe design.
So, are there current designs that are similar? 4" - 4.5" FR drivers, compact tower, easy build, easy load for low-powered amplification, and with that angled, (or upward-facing,) psuedo-omni driver. Corner placement is a must in my tiny, weirdly shaped living room. and it's an upstairs apartment in an old house, so lotsa bass isn't a goal.
--Shannon
BD-Pipes with 40-1197 were our 1st couple builds.
They are ML-Voigts. Bert lucked the design a bit, originally too big for the original 1-driver version, the 2nd driver made for a more appropriate pipe size, and the (average) driver position with 2 drivers moves closer to the optimal 50% point typical of an ML-Voigt.
Today you would find a Metronome or ML-Voigt for a driver you are interested in, double it into a bipole and fold it. Fold it like a these monoliths and you can mount one of the drivers on the top. Experiments done with the BD-Pipes, pipes, in particular microTower bipoles with push-push driver placement, flat top placement, top but sloping backwards and forwards, have us prefering up or slightly forward.
Do note that for many ML-Voigts one can come up with a ML-TL with much the same response. An ML-TL can also be pushed more towards compact if needed.
Check out the microTower. From the sounds of your application i woud consider a castle microTower.
dave
They are ML-Voigts. Bert lucked the design a bit, originally too big for the original 1-driver version, the 2nd driver made for a more appropriate pipe size, and the (average) driver position with 2 drivers moves closer to the optimal 50% point typical of an ML-Voigt.
Today you would find a Metronome or ML-Voigt for a driver you are interested in, double it into a bipole and fold it. Fold it like a these monoliths and you can mount one of the drivers on the top. Experiments done with the BD-Pipes, pipes, in particular microTower bipoles with push-push driver placement, flat top placement, top but sloping backwards and forwards, have us prefering up or slightly forward.
Do note that for many ML-Voigts one can come up with a ML-TL with much the same response. An ML-TL can also be pushed more towards compact if needed.
Check out the microTower. From the sounds of your application i woud consider a castle microTower.
dave
I saw the microTowers
And was intrigued.
What were the differences y'all noticed with the different angles of the "ambience" driver? Intuitively, straight up would be the most pseudo-omni-ish.
Power-wise, I'd think that the 8-ish watt amps (likely either an Amp Camp Amp or an Elekit TU-8200 SEUL) that I can afford to build would be plenty, given corner loading and a itty-bitty space... Driver spec looks to make about 89-ish dB/W @ 8 ohms in series, which shouldn't be a problem unless the drivers are nastily reactive.
All in all, this looks like it might be the one. My previous thought was the Madisound BK-12Ms, but these might be a better fit to my room and listening style. (Which is mostly not in-the-sweet-spot audio nerdery, although that does happen.)
It's not like I'm on a short schedule... If I'm listening to my new system on New Year's Eve, I'll be hella stoked.
--Shannon
And was intrigued.
What were the differences y'all noticed with the different angles of the "ambience" driver? Intuitively, straight up would be the most pseudo-omni-ish.
Power-wise, I'd think that the 8-ish watt amps (likely either an Amp Camp Amp or an Elekit TU-8200 SEUL) that I can afford to build would be plenty, given corner loading and a itty-bitty space... Driver spec looks to make about 89-ish dB/W @ 8 ohms in series, which shouldn't be a problem unless the drivers are nastily reactive.
All in all, this looks like it might be the one. My previous thought was the Madisound BK-12Ms, but these might be a better fit to my room and listening style. (Which is mostly not in-the-sweet-spot audio nerdery, although that does happen.)
It's not like I'm on a short schedule... If I'm listening to my new system on New Year's Eve, I'll be hella stoked.
--Shannon
Castle, BK-12, Frugel-Horn are all from the same design team.
BK12 is a custom design to give Madisound a horn option for the FE126 in the same vien as the larger BK horns for FE166 & FE206. While the small one is a modern horn and the bigger ones are antiques, it is a very good box given its remit. The other boxes with drivers different than FE126 are better (for most people). By not going with FE126 one gives up rated sensitivity, but finds that it is much easier (and more likely) to have bass. But even FE126 works better in FH3 than BK-12 in most respects for most people.
8w is probably more power than you think, and importantly, both the ACA and Elekit perform gracefully as they push into clipping and seem to have more power than they do.
dave
BK12 is a custom design to give Madisound a horn option for the FE126 in the same vien as the larger BK horns for FE166 & FE206. While the small one is a modern horn and the bigger ones are antiques, it is a very good box given its remit. The other boxes with drivers different than FE126 are better (for most people). By not going with FE126 one gives up rated sensitivity, but finds that it is much easier (and more likely) to have bass. But even FE126 works better in FH3 than BK-12 in most respects for most people.
8w is probably more power than you think, and importantly, both the ACA and Elekit perform gracefully as they push into clipping and seem to have more power than they do.
dave
Shannon, re your question regarding angle of top facing driver on the Castle variation of the microTowers, I’ve built several pairs and found 10dg forward to be a good balance of reflections from rear wall & ceiling - assuming standard 8” /horizontal- and direct output from vertically oriented drivers.
Of course, there’s more than enough variety of room sizes/shapes that endorsement of any particular enclosure style / driver configuration is tricky business.
Of course, there’s more than enough variety of room sizes/shapes that endorsement of any particular enclosure style / driver configuration is tricky business.
That's what I thought I'd learned in my reading... hella cudos to the crew... Y'all rule.
It was the sensitivity issue that kept me thinking about the BK-12M, plus the existence of flat-packs. But the more I thought about it, the more I realized that I probably didn't need it as much as I thought I did. First, the 2-driver setup puts the actual, in-room sensitivity close enough to the FE126 to not really matter. The clipping behavior of single-ended amplifiers is one of my favorite things about them. They don't really "clip", so much as they just stop getting louder. Heck, I drove Paradigm Century 600i (88 dB, 8 ohms) to satisfying levels in a much bigger room with 2A3 Paramours back then, and I'm an old metalhead. And, if I don't care as much about rated sensitivity, I can trade it off for much cleaner-looking treble behavior and more uniform dispersion.
--Shannon
Just had a thought while proofreading... why is it that smooth frequency response seems to be inverse to sensitivity, especially with 4" fullrangers?
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BD-Pipes experiment
I have been interested in this type of cabinet for two reasons: easy to move around during placements and storage, and no BSC/crossovers, leaving the drivers "el natural".
However, to experiment would possibly require over $200 for 4 FE103's at current prices. I would like to try with less expensive drivers in foam core and see if then I could build in wood with better drivers.
Course there are many good 3" and 4", but which ones to try and or change the BD Pipe cabinet to use with alternative drivers.
Choices could be the Faital Pro 4FE35-16s in parallel, TC9FD's, TB W3-2141's, find 4 good RS 40-1197's off of fleabay and take a chance, etc.
Then all the rules for TQWP alignments.....
I think the BD-Pipes would be an interesting experiment to get in to bipole cabinet design without too much expense.
I hope that I'm not the only guy who would need help for current drivers in this cabinet......
I have been interested in this type of cabinet for two reasons: easy to move around during placements and storage, and no BSC/crossovers, leaving the drivers "el natural".
However, to experiment would possibly require over $200 for 4 FE103's at current prices. I would like to try with less expensive drivers in foam core and see if then I could build in wood with better drivers.
Course there are many good 3" and 4", but which ones to try and or change the BD Pipe cabinet to use with alternative drivers.
Choices could be the Faital Pro 4FE35-16s in parallel, TC9FD's, TB W3-2141's, find 4 good RS 40-1197's off of fleabay and take a chance, etc.
Then all the rules for TQWP alignments.....
I think the BD-Pipes would be an interesting experiment to get in to bipole cabinet design without too much expense.
I hope that I'm not the only guy who would need help for current drivers in this cabinet......
BD-Pipe is an ML-Voigt with dual drivers, nicely folded to get te up/back firing driver.
Any ML-V should be bendable into such a configuration. But do start with a proper box, stuffing driers in random wboxes does not work that well.
I might still have 4 RS 40-1197 which do fit into a BD-Pipe (they came out of one, replaced with official FE103), that could get you going on the cheap.
dave
Any ML-V should be bendable into such a configuration. But do start with a proper box, stuffing driers in random wboxes does not work that well.
I might still have 4 RS 40-1197 which do fit into a BD-Pipe (they came out of one, replaced with official FE103), that could get you going on the cheap.
dave
All that said, having built quite a few pairs of each -with a span of well over a decade between? - I’d not be surprised if the Castle configuration of Planet10 microtower didn’t surpass the BD pipes. My 88yr old mom is loving her pair of MTs with CHN70s, and the CHR70 is another proven winner in that enclosure.
Mind you, I don’t remember ever making that comparison, and while a bi-pole pipe of sorts, it’s not a folded ML-Voigt.
Mind you, I don’t remember ever making that comparison, and while a bi-pole pipe of sorts, it’s not a folded ML-Voigt.
Just to make sure I'm following, are you referring to the microtowers that are designed for the CHR/EL 70?
Thanks,
Mike
Originally done for CHR/EL70, but new drivers have been added, the latest to create news were a couple pair with Pluvia 7HD.
dave
dave
Mike, to follow up on Dave’s post above, I’ve built several iterations of the CMTs; so far all with some flavour of MA drivers - including one with CHBW70 and ERT26(?) soft dome tweeter. Passive XO by DaveR, I think.
While I don’t want to speak for the actual designers, I’d suspect that rather line the FH family, this topology would easily lend itself to alternate tunings for a range of 3 & 4” drivers.
Just a personal taste thing, but I quite preferred the version with up-firing second driver - either flat or with forward angles of up to 10dg IIRC - to the straight bi-pole.
While I don’t want to speak for the actual designers, I’d suspect that rather line the FH family, this topology would easily lend itself to alternate tunings for a range of 3 & 4” drivers.
Just a personal taste thing, but I quite preferred the version with up-firing second driver - either flat or with forward angles of up to 10dg IIRC - to the straight bi-pole.
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Thanks Chris and Dave,
I have four of the RS drivers mentioned earlier. I wouldn't mind trying them in something. I've never done anything dipole. So that sounds even more interesting.
I have four of the RS drivers mentioned earlier. I wouldn't mind trying them in something. I've never done anything dipole. So that sounds even more interesting.
With those drivers i would do the BD-Pipe. Th egreate rvolume and longer length will extract more bottom out of those i’d think.
dave
dave
Mike, the rear facing panel on which the second driver is mounted is rather close fitting; after several builds, I found it easiest to cut that blank slightly over twice the finished length before cutting the driver holes and chamfering the rear side, then cut to finished size.