Single Driver Calhoun?
I've looked at the design posted here.
http://homepage.mac.com/tlinespeakers/FH/download/calhoun-1v0.pdf
There is a red line which goes horizontally halfway through double mouth BVR cabinet.
If I was to use one FR125S per speaker, could I cut the speaker in half, to have a single mouth BVR (similar to half chang, but as a half calhoun) and stay within the tuning parameters of this design?
Any opinions about pro/cons of doing this? I'd be planning to use these in a small-medium size room.
Thanks,
Cangaceiro
I've looked at the design posted here.
http://homepage.mac.com/tlinespeakers/FH/download/calhoun-1v0.pdf
There is a red line which goes horizontally halfway through double mouth BVR cabinet.
If I was to use one FR125S per speaker, could I cut the speaker in half, to have a single mouth BVR (similar to half chang, but as a half calhoun) and stay within the tuning parameters of this design?
Any opinions about pro/cons of doing this? I'd be planning to use these in a small-medium size room.
Thanks,
Cangaceiro
The red line is the centre line... i strongly suspect that you could indeed do that, Scott would have to confirm.
We were talking about reving that design (as it was the 1st MBVR). I may well have a helf-Calhoun in the stash.
dave
We were talking about reving that design (as it was the 1st MBVR). I may well have a helf-Calhoun in the stash.
dave
OK thanks Dave.
A few of the designs I have seen for FR125S seem to have cabinets around 10 - 13 litres in bass reflex design.
If I make a half calhoun, then the cabinet volume would be just over 11 litres, which falls within the capacity of these other examples.
I'm wondering if I keep the capacity of the low pass chamber to around 11 litres, but reduce the depth by 5cm and increase the height by 5 cm, will this affect the tuning adversely/significantly.
Basically I have some leaf veneer lying around that is 30.5cm x 2.4m and it would be much easier for me to use a single sheet than have to join two together. But if the tuning is affected adversely, maybe I won't go down this path.
ps. your phase plugs have "smoothed" some of the bite on my FE206E BLHs.
Thanks,
Cangaceiro
A few of the designs I have seen for FR125S seem to have cabinets around 10 - 13 litres in bass reflex design.
If I make a half calhoun, then the cabinet volume would be just over 11 litres, which falls within the capacity of these other examples.
I'm wondering if I keep the capacity of the low pass chamber to around 11 litres, but reduce the depth by 5cm and increase the height by 5 cm, will this affect the tuning adversely/significantly.
Basically I have some leaf veneer lying around that is 30.5cm x 2.4m and it would be much easier for me to use a single sheet than have to join two together. But if the tuning is affected adversely, maybe I won't go down this path.
ps. your phase plugs have "smoothed" some of the bite on my FE206E BLHs.
Thanks,
Cangaceiro
Hmmm...cangaceiro, if you keep the volume the same there won´t be any problems - but keeping the BR channel the same might be tricky.
Besides - I absobleepingly hate you antipodeans. You have access to wonderful woods and veneers that cost an arm and several legs over here.
Besides - I absobleepingly hate you antipodeans. You have access to wonderful woods and veneers that cost an arm and several legs over here.
Bugger, think I'll have to just go for a different design then. Maybe BR similar capacity.
Pit Hinder - What do you pay for veneer over there?
Dave, a version for those who are sq m underequipped might be very welcome. Footprint the same, OK, but if a She Whose Words Are Law wants them 1m high max...
cangaceiro, the problem with veneer hereabouts is quantity. You can´t get as little as you want, and buying a complete package for just one pair...
cangaceiro, the problem with veneer hereabouts is quantity. You can´t get as little as you want, and buying a complete package for just one pair...
Scott does the big ones. I do smaller ones. A set of uFonken will go a long way to keep SWWAL pleased.
dave
dave
OK then - that name is not yet protected...one smallish pair, and Sabine called them Kampfhamster (combat hamsters)
😱Yield not temptation, brother! I still have a 15 year old NOS pair of FE83Sigma around...and somehow there´s an urge to sniff sawdust...
Pit Hinder - We pay about $30 for pre-glued veneer (305mm x 2400mm). I'm pretty happy with the price as a couple of sheets are usually enough for small bookshelf speakers. I am terrible at joining veneer though, so I prefer to use veneer sheets larger than the surface I want to veneer. Got some nice blackwood veneer last weekend!
Looks like the half calhoun's are out for me. I went around to the father-in-laws place and he's after a pair of small bookshelves to fit in a cabinet he has (he lives in a small apartment). I wanted to make the planet 10 mini onkens, but the space constraints were slightly smaller than this, so I've gone for bass reflex around 11 litres.
I made one to have a quick listen and found that the FR125S still runs out of excursion pretty quick in BR. I had these in BIBs before and so I was familiar with the sound it makes when it does this. Anyway, I stuffed the ports and the box it's helped reduce the excursion quite a bit. I'm even starting to wonder if I shouldn't have gone sealed to start with. Will play around further with it this weekend.
Looks like the half calhoun's are out for me. I went around to the father-in-laws place and he's after a pair of small bookshelves to fit in a cabinet he has (he lives in a small apartment). I wanted to make the planet 10 mini onkens, but the space constraints were slightly smaller than this, so I've gone for bass reflex around 11 litres.
I made one to have a quick listen and found that the FR125S still runs out of excursion pretty quick in BR. I had these in BIBs before and so I was familiar with the sound it makes when it does this. Anyway, I stuffed the ports and the box it's helped reduce the excursion quite a bit. I'm even starting to wonder if I shouldn't have gone sealed to start with. Will play around further with it this weekend.
miniOnken was our very 1st box for FR125. I ended up needing a bit of assistance to push it more towards aperiodic (some open cel foam in the back of the port slots). Our recommendation now is 4.5-7 litre aperiodic
dave
You think if I kept the capacity (11 litre) but went fully stuffed and sealed it would be ok? From what I understand of aperiodic, it simulates similar to a larger sealed Box. So maybe 7 litre aperiodic might be close to 11 sealed? I'm finding the more stuffing I put in, the more the cone excursion is reduced so I cAn crank the volume a little more. The bass is fine even when box is stuffed. In fact I'm finding it a bit exagerated in a small room. Ie too boomy.
When I built the fr125s bibs, I had them in a huge room and the bass was fine with volume down, not boomy at all. I remember some posts by a number of people where it was mentioned how much the room can impact the sound. Now that I've moved house, I'm begnning to understand that much better.
When I built the fr125s bibs, I had them in a huge room and the bass was fine with volume down, not boomy at all. I remember some posts by a number of people where it was mentioned how much the room can impact the sound. Now that I've moved house, I'm begnning to understand that much better.
I'd not go much above 7 litres even sealed... some brcks, wooden blocksor similar can reduce the volume of the box you have. Then a big wad of wool or poly fluff in the port.
dave
dave
regarding stepped mouths (sachiko, spawn etc)
Hi!
Ive followed this thread with interest, and unfortunately my living conditions in the UK dont allow me to consider the whole horn concept in my living room-it simply isnt large enough!!!
However, on to the question, if i may:
Scottmoose, Dave: as i know you both work together in certain aspects of both of the BVR frugalhorn type designs, this may be more applicable to ask you two.
The LP effect of the 'stepping' of the flare at the mouth...How pronounced is it, in comparison with that of a smoothly contoured flare?
I ask this, as whilst im NOT about to build a horn design (or at least not an expanding one), im intrigued that this method of tapering may be beneficial to other designs topologies....
Hi!
Ive followed this thread with interest, and unfortunately my living conditions in the UK dont allow me to consider the whole horn concept in my living room-it simply isnt large enough!!!
However, on to the question, if i may:
Scottmoose, Dave: as i know you both work together in certain aspects of both of the BVR frugalhorn type designs, this may be more applicable to ask you two.
The LP effect of the 'stepping' of the flare at the mouth...How pronounced is it, in comparison with that of a smoothly contoured flare?
I ask this, as whilst im NOT about to build a horn design (or at least not an expanding one), im intrigued that this method of tapering may be beneficial to other designs topologies....
The steps in the mouth have only a small effect. In a duct, an expansion in the cross-section and subsequent reduction acts as a low pass. Because this is small in the steps the effect is small.
dave
dave
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