GM, if you have the free time could you run a frequency response simulation (i believe they're made using the MJK charts but I need to buy access to his worksheets soon).
Below are the stock specs, except the actual QTS when taking my amps output impedance into consideration is 0.69.
www.madisoundspeakerstore.com/images/Alpair-7P-Gen1-specs.jpg
From the v2 calculator I got this:
73.41 (FS)
5.56 (VAS)
0.69 (QTS)
69.30 (VB)
In
91.71 (line length)
19.90 (zdriver)
92.23 (sm)
0.71 (wood thickness)
0.71
Below are the stock specs, except the actual QTS when taking my amps output impedance into consideration is 0.69.
www.madisoundspeakerstore.com/images/Alpair-7P-Gen1-specs.jpg
From the v2 calculator I got this:
73.41 (FS)
5.56 (VAS)
0.69 (QTS)
69.30 (VB)
In
91.71 (line length)
19.90 (zdriver)
92.23 (sm)
0.71 (wood thickness)
0.71
How high are your ceilings? If not too high you may be better off with ceiling firing cabs. I have built both and prefer the regular version, assuming you get boundary loading from the ceiling and back wall.
I think the BIB will excel at the music you like. At those low spl's you could probably lower the tuning enough to get close to the ceilings without risking damage to your drivers. Let's see what the experts say though!
I think the BIB will excel at the music you like. At those low spl's you could probably lower the tuning enough to get close to the ceilings without risking damage to your drivers. Let's see what the experts say though!
The folded height would only be 4 feet tall, ceilings are about 10 feet.
Floor loading is the only real option.
Floor loading is the only real option.
I made made my small BiBs unfolded and had the pointy side up like a Voigt. I made the mouth rear-firing, experimenting with placement (in or out of the corner) to get the loading right. I agree inverted is probably best in your situation, but you can be creative with the style and placement of the mouth.
I only have Hornresp loaded, plus don't have his later ones that include room loading, so others will have to do them if anyone wants that level of simming accuracy.
Anyway, as I've periodically noted on any speaker design thread that warranted it, my 'broken record', 'knee jerk' response will always be 'BIB rules' and especially where a 'weak' [high Qt] motor is concerned since it needs all the acoustical loading it can get, so combined with your modest power requirements........ manipulating the specs to create the proper height ceiling loading with the largest footprint one can tolerate is what I'd do and it's performance is what it is, though movies with a lot of <40 Hz output [just about all modern movies] will probably need some form of high pass filter [TT 'rumble' filter].
GM
So you're suggesting I tune the iBiB to FS*.707, or even lower?
Sounds like this would work best if I high pass the iBiB and use a sub to cover the bass.
Sounds like this would work best if I high pass the iBiB and use a sub to cover the bass.
No, I said if was me I'd design a BIB to fit the room height and whatever tuning it takes is what it is, which for sure will be a tuning well below Fs and as I noted, we're in 'unchartered waters', so suggest building one out of some cheap insulation board or similar to get an idea whether the driver can handle it and just be sure it's airtight with some scrap wood or similar clamped/taped to the baffle and front sides where most of the high pressure is.
GM
GM
GM, with the BIB I wonder if it may be the best overall to load at the floor in or near room corners, and design for that rather than the ceiling? So I'm wondering if the whole BIB cab idea should be rethought to be used inverted rather than up firing instead where possible? Reason being is for most drivers used in a BIB, you can have more control over driver location up to a more appropriate ear height, and also have more control on the loading, rather than build up or elongate the pipe to reach near to an optimum ceiling height etc. Dunno? Terry Cains inverted BIB's seem to make a lot of sense to me rather than the ceiling loaded kind, however I am just speculating at an overall possible good compromise for the design, rather than being a designer etc.
You may get the smoothest response with them fairly tight in the corners. That has been my experience with the one pair I built.
Best,
Benjamin
Ah, the 'circle of life' has finally been fulfilled! 😀 The correspondence between me and Terry is forever lost AFAIK, but swap my name for his in your post and it pretty much sums up my initial response to him when he PM'd me for my thoughts on the design.
Note though that his ceiling was a lot higher than the horn plus he planned to have them out in the room, so also told him the horn needed to be either a lot longer, larger to go low [a full WL] and/or wall and preferably corner, loaded.
Anyway, lots of iBIB [floor loaded] posts, designs here.
Re ceiling loaded, I've done dual corner loaded with driver at the floor corner, vent at ceiling corner as well as a 1/2 WL open pipe version after being exposed to them by a coworker's father who also hooked me on cardboard tube construction with small radio, etc., drivers.
Driving a whole corner where the ceiling is loaded only over a narrow LF BW works well as it's just ''bottom'/'rumble', but had some concerns about 2+ octaves up into the lower mids, but Terry made them anyway and the rest is history, which a lot folks really like, even with the [super] long time delay offsets, so what do I know other than it's become obvious we don't hear very well down below ~300 Hz, which we already knew at least intuitively, otherwise we wouldn't be able to tolerate all the butchering of the sonic event a room does to it.
GM
Full Wavelength BIB
Hi everyone,
I have a pair of Fostex FE206ES-R loudspeakers that I've had in Sachiko cabinets for a very long time. I love them to bits but my wife and I have always found them a bit lacking in the bass department. My wife is a bit of a bass head but is very supportive of my audio hobby and would love me to use the Fostex drivers in a cabinet that will provide us with some "lovely, lovely bass" as she puts it.
Here's some info on the Fostex:
http://www.einklang-audio.com/treiber/fostex/fe206esr.pdf
The obvious choice would be a BIB however I'm not keen on sacrificing the amazing depth and imaging that I'm currently getting with the Sachikos.
The potential solution I have come up with would be to build a "full wavelength" BIB.
I did a search in the thread and only found one mention of such a thing but no examples. What I was thinking would be to have the first half of the BIB be "normal" but instead of opening upwards towards the ceiling it would open to the side (to the right on the right speaker and vice versa on the left) with the correct 10 X 14 inch terminus dimensions going into the second half, which would be "sideways" (viewed from the front the divider inside the horn is edge on) with the ceiling corner loaded terminus being 14 by 20 inches. The dimensions of the cabinet would end up being roughly 42 wide by 16 deep by 82 inches high. I'd be using them in a room with an 8' ceiling. If we place the drivers close to the inside of each speaker baffle this hopefully solves the issue of having the drivers close to the side wall. I want to put them on the short wall of the room which is 13' wide so the drivers would end up being about six to seven feet apart.
So the line would be twice as long and the terminus would be twice the area of a standard BIB (keeping the conical profile) and the horn opening would be right in the corner of the ceiling but the drivers would be in well away from the side walls.
Would this work or is it a really boneheaded idea?
😕
Hi everyone,
I have a pair of Fostex FE206ES-R loudspeakers that I've had in Sachiko cabinets for a very long time. I love them to bits but my wife and I have always found them a bit lacking in the bass department. My wife is a bit of a bass head but is very supportive of my audio hobby and would love me to use the Fostex drivers in a cabinet that will provide us with some "lovely, lovely bass" as she puts it.
Here's some info on the Fostex:
http://www.einklang-audio.com/treiber/fostex/fe206esr.pdf
The obvious choice would be a BIB however I'm not keen on sacrificing the amazing depth and imaging that I'm currently getting with the Sachikos.
The potential solution I have come up with would be to build a "full wavelength" BIB.
I did a search in the thread and only found one mention of such a thing but no examples. What I was thinking would be to have the first half of the BIB be "normal" but instead of opening upwards towards the ceiling it would open to the side (to the right on the right speaker and vice versa on the left) with the correct 10 X 14 inch terminus dimensions going into the second half, which would be "sideways" (viewed from the front the divider inside the horn is edge on) with the ceiling corner loaded terminus being 14 by 20 inches. The dimensions of the cabinet would end up being roughly 42 wide by 16 deep by 82 inches high. I'd be using them in a room with an 8' ceiling. If we place the drivers close to the inside of each speaker baffle this hopefully solves the issue of having the drivers close to the side wall. I want to put them on the short wall of the room which is 13' wide so the drivers would end up being about six to seven feet apart.
So the line would be twice as long and the terminus would be twice the area of a standard BIB (keeping the conical profile) and the horn opening would be right in the corner of the ceiling but the drivers would be in well away from the side walls.
Would this work or is it a really boneheaded idea?
😕
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For bass apps with a separate amp, digital time delay, don't see a problem, but this much delay with a 'FR' driver will require ~complete damping of the horn's upper harmonics, negating a significant amount of available bass, but may still be enough in room. For sure it will have extension, but so will a separate IB.
The other concern is that the driver will in theory need to be further down the pipe, making it too low, so again not a big deal with a sub or multiway, but a 'FR'..........
GM
The other concern is that the driver will in theory need to be further down the pipe, making it too low, so again not a big deal with a sub or multiway, but a 'FR'..........
GM
Thanks for the reply. I figured the driver placement in the cabinet might nix it. Oh well.
I do have a couple of FE208E Sigmas and had thought about putting them into BIB subs and then use the ES-R drivers in Dallas II horns. The sigmas would be fast enough to keep up with the ES-Rs and I bet that would get us some serious bass. 😛
I do have a couple of FE208E Sigmas and had thought about putting them into BIB subs and then use the ES-R drivers in Dallas II horns. The sigmas would be fast enough to keep up with the ES-Rs and I bet that would get us some serious bass. 😛
Your perception of depth and imaging will change when changing the frequency response of the system. You will hear some things more and some things less. Some sounds will get a better balance and others worse. I think overall it changes for the better (it gets more natural and as intended), but it depends on taste. I mean that if you are taking steps to extend the bass range, changes will occur whether you go with a BiB, a separate subwoofer, design a new backloaded horn with more extended response etc. IMO, this is not a reason to avoid a BiB.
While a BiB is a pretty simple design and your Sachikos have a higher level of technical refinement, the BiB as such will not necessarily and immediately be a step back from the Sachikos. The BiB is a comfortable platform for a fullrange driver and it helps out right where you need it most, bass extension. And it does so without extra boxes littering the room.
I am looking into a new BiB design. I wanted to build a second one of the 12" version I have now and attach enclosures for mid/high to them. A mock up of those enclosures didn work well at all, protrudes far too much into the room.
I am very much considering going back to the 8" equivalent Tangband W69-1042 units, one per side, in a W-fold BiB.
Again using the standard boards available at my DIY-store, that works out quite favourably. Each half has the right ratio in the bend section, the volume is a bit over-sized for the driver. Internal width is slightly more than panel thickness, so bracing is limited to the the wide front and rear panel. No angled cuts etc.
It would make a BiB that's 60 cm wide and about 23.5 cm deep (panels of 20 cm width and the thickness of the wide panels), which is about half the depth of the current 12" BiB turned on its side. And I could either mount mid/high enclosures on it, or make a double front baffle to incorporate those enclosures into that. Regardless, similar extension, based on hornresp higher max SPL, a more friendly form factor.
I'm having some trouble deciding where to put the driver down the length. It all looks horrible in hornresp. I think I will just stick to ~0.42. It's not the end result won't look different than the sim anyway.
I'll show a picture one of these days.
I am very much considering going back to the 8" equivalent Tangband W69-1042 units, one per side, in a W-fold BiB.
Again using the standard boards available at my DIY-store, that works out quite favourably. Each half has the right ratio in the bend section, the volume is a bit over-sized for the driver. Internal width is slightly more than panel thickness, so bracing is limited to the the wide front and rear panel. No angled cuts etc.
It would make a BiB that's 60 cm wide and about 23.5 cm deep (panels of 20 cm width and the thickness of the wide panels), which is about half the depth of the current 12" BiB turned on its side. And I could either mount mid/high enclosures on it, or make a double front baffle to incorporate those enclosures into that. Regardless, similar extension, based on hornresp higher max SPL, a more friendly form factor.
I'm having some trouble deciding where to put the driver down the length. It all looks horrible in hornresp. I think I will just stick to ~0.42. It's not the end result won't look different than the sim anyway.
I'll show a picture one of these days.
Thanks for the advice Ivo. I really should put the ES-R drivers into BIBs and try it out someday. I use the Sachikos upstairs at the moment but I have a fairly modest but acoustically optimal basement room and have toyed with the idea of four 208E sigma BIB subs (one for each corner) and the ES-R drivers in either BIB's themselves up front against the wall or in Dallas horns. With the subs in the corners there wouldn't be much in the way of standing waves. I have the drivers so it wouldn't be a big deal to put together but I would have to get a sub amp. I currently run the ES-Rs with a Korneff 45 amp and they play plenty loud at 98db efficient.
I've also thought of doing something nuts like putting the four pi loudspeaker design into a BIB. They're meant to be used in a corner angled in at a 45 degree angle and it'd give me a chance to try Wayne Parham's CD horn design philosophy and see what it's about. With the CD horn and crossing at 1.2KHz the speakers have controlled directivity that prevents early wall reflections and supposedly results in better imaging and a wide sweet spot. I bet the JBL 2226H would go pretty deep in a BIB as well. They'd be big though.
I've also thought of doing something nuts like putting the four pi loudspeaker design into a BIB. They're meant to be used in a corner angled in at a 45 degree angle and it'd give me a chance to try Wayne Parham's CD horn design philosophy and see what it's about. With the CD horn and crossing at 1.2KHz the speakers have controlled directivity that prevents early wall reflections and supposedly results in better imaging and a wide sweet spot. I bet the JBL 2226H would go pretty deep in a BIB as well. They'd be big though.
I've known Wayne many years, heard a lot of his speakers. Got to hear the 7Pi last May at LSAF. It was very nice. Been wanting to hear his corner horns for a while, was not disappointed. If you really want corner horns, just go there with the 7Pi.... A BIB with the JBL 2226H would be huge, like telephone booth size, for those who remember them....
I've never met Wayne but haven't heard anyone with a negative word to say about him and he's always helpful to others on his forum.
I've thought about the 7pi horns and have a pair of hard to find JBL 2012H midrange drivers to put into them. The nice thing about building the 4pi speakers is that they have the same drivers that are used in the 7pi so they'd get re-used if I decided to go the whole hog. I envy you having heard the 7pi I just wish I could hear them before shelling out the cash. My living room has a great set of corners so it's very tempting.
I've thought about the 7pi horns and have a pair of hard to find JBL 2012H midrange drivers to put into them. The nice thing about building the 4pi speakers is that they have the same drivers that are used in the 7pi so they'd get re-used if I decided to go the whole hog. I envy you having heard the 7pi I just wish I could hear them before shelling out the cash. My living room has a great set of corners so it's very tempting.