don't just double up on the drivers without checking the math- you'll likely be changing some of the variables used in the enclosure design
I gather they're not Fostex drivers, so it would probably be well worth the time to check with Dave / Scott as to their suitability to this design.
Unless your amp has a really tough time with the 16ohm load, or sensitivity is extremely low, you might very well get better sound with the single driver.
I gather they're not Fostex drivers, so it would probably be well worth the time to check with Dave / Scott as to their suitability to this design.
Unless your amp has a really tough time with the 16ohm load, or sensitivity is extremely low, you might very well get better sound with the single driver.
There is another version...
that uses a Karlson on both the end of the internal divider (as shown in the attachment) and also on the back panel at the mouth end of the horn. I was unable to attach a copy of this but you can search the web to find the Dutch web site, just Google "De Waddenhoorn".
that uses a Karlson on both the end of the internal divider (as shown in the attachment) and also on the back panel at the mouth end of the horn. I was unable to attach a copy of this but you can search the web to find the Dutch web site, just Google "De Waddenhoorn".
Thanks for the input Chris. I do actually have the plans worked out for 2 x drivers = 2x mouth area. I would opt for a single driver except I just happen to have 2 pr of CSS WR125ST's to use.
Pop
Pop
Got one. I have them from a bipole project Dave set up fo me: the WR125ST's, the Apex Jr tweet and cap/crossover. Can't seem to get real happy with the bipoles so looking for something else.
Has anybody tried this with a Fostex FE127e?
This could be more practical than the original BIB.
Thanks.
This could be more practical than the original BIB.
Thanks.
alexg said:
A bipole? Yes (Giovanni has done sealed bipoles, and i have a set of diy FR ref ML-TL bipoles in my living room)
or the iBIBk? also yes, JohninCR
dave
The i in iBIBk is inverted -- the intention here to both provide greater bass loading for the shorter BIB and to provide a closer to optimum driver height.
The k = Karlson slot is intended to smooth out the peaky nature of the BIB -- something i heard in the one set of BIBs i have auditioned and something i could not live with long term,
Whether it works or not is still an unkown. John says his are good, but he has not had a comparison to a "normal" BIB with the same driver.
dave
The k = Karlson slot is intended to smooth out the peaky nature of the BIB -- something i heard in the one set of BIBs i have auditioned and something i could not live with long term,
Whether it works or not is still an unkown. John says his are good, but he has not had a comparison to a "normal" BIB with the same driver.
dave
johninCR said:
Can you please tell me how is the bass of your iBIBk speakers?
What was the result of your lift height experiments?
Thanks.
planet10 said:
Thanks for the information.
I will try this design, instead of the normal BIB.
I find the iBiBk design to be very interesting. Has there been any refinement to the design presented by Planet10 in post #5?
Reflector Needed?
I wonder if the less than expected bass performance of the 126/127 BIB (and other relatively short BIBs) noted by some is in part due to the distance from the pipe/horn terminus to the ceiling. The shorter BIBs terminate a little too far from the ceiling for effective loading.
If this design has now been built, has an impedance curve been run? It just looks like the abrupt termination of the pipe would encourage resonance development, more so than in the upright BIBs. Perhaps a reflector would help. Also, a built in vertical 'v' divider like those used in the Austin horns.
Just a suggestion and a query as to the current status of the design and any feedback on how it sounds.
Regards,
Bob
I wonder if the less than expected bass performance of the 126/127 BIB (and other relatively short BIBs) noted by some is in part due to the distance from the pipe/horn terminus to the ceiling. The shorter BIBs terminate a little too far from the ceiling for effective loading.
If this design has now been built, has an impedance curve been run? It just looks like the abrupt termination of the pipe would encourage resonance development, more so than in the upright BIBs. Perhaps a reflector would help. Also, a built in vertical 'v' divider like those used in the Austin horns.
Just a suggestion and a query as to the current status of the design and any feedback on how it sounds.
Regards,
Bob
Re: Reflector Needed?
= Naturally, and why if one is desired for a driver with an Fs of over, say, 65Hz, I always recommend the inverted variation. You can tap the driver into the horn at a more desireable location too.
= Naturally, and why if one is desired for a driver with an Fs of over, say, 65Hz, I always recommend the inverted variation. You can tap the driver into the horn at a more desireable location too.
planet10 said:
Heads are interesting things. So much can happen inside of them, yet so little comes out (in my case anyway). 😀
Thanks for the update.
I've been working on a cutting list for a pair of these babys. Looks like they require two sheets of 4x8 material. If all goes well (i.e. I'm able to steel time away from the family.), I'll be next to build a pair.
Hi all - - I have built a rough pair of BIBs for the 126e, and am enjoying them in my living room with some equalization from my computer. I am now interested by the iBiBk or some variant (doctor says I need to inhale a certain amount of plywood dust each day to stay healthy).
A couple of references to the Zd, or driver position, being better in the iBiBk than in the original BiB. Was this determined using one of the spreadsheets? If so, can someone explain to me why it is better than the original published Zd of 20" or so? Just in general terms.
Also, does the BIB get any of its qualities from the fold in the middle, or is this purely a practical measure? I understand that a straight pipe for one of the bigger drivers would be impractically large, but am wondering about the idea of straightening out the 127" line length for the 126e. I would place a 45 degree jog just above the driver to shorten the vertical height to within a foot or so of the ceiling. This would also push the driver out into the room, while leaving the pipe mouth pushed against the wall.
Something like:
\ |
\ \
\ |
\|
(Because my wife takes up a large portion of the living room with her sewing hobby, yes, I am free to install 7 foot thunderbolts beside the TV. 😉 )
Thanks!
A couple of references to the Zd, or driver position, being better in the iBiBk than in the original BiB. Was this determined using one of the spreadsheets? If so, can someone explain to me why it is better than the original published Zd of 20" or so? Just in general terms.
Also, does the BIB get any of its qualities from the fold in the middle, or is this purely a practical measure? I understand that a straight pipe for one of the bigger drivers would be impractically large, but am wondering about the idea of straightening out the 127" line length for the 126e. I would place a 45 degree jog just above the driver to shorten the vertical height to within a foot or so of the ceiling. This would also push the driver out into the room, while leaving the pipe mouth pushed against the wall.
Something like:
\ |
\ \
\ |
\|
(Because my wife takes up a large portion of the living room with her sewing hobby, yes, I am free to install 7 foot thunderbolts beside the TV. 😉 )
Thanks!
ilewis33 said:
To keep the driver at a reasonable height in the non-inverted orientation, a 2nd best choise for Zd is chosen. in the iBIBk the inverted orientation allowed Scott to choose a better driver location.
The fold is useful at helping to keep HF out of the mouth output.
dave
I replaced my Harvey's (original design) with a pair of slightly over sized bib's with a false bottom. The false bottom was made to raise the driver to 45" and to get the terminus closer to the ceiling. I like my drivers high, I listen standing up most of the time. They are running with fe-126 drivers.
To my ears the bib's sound better in almost every way. The only problem they have is they some times make a weird sound, which I think is due to not enough pressure behind the cone. It sounds like a form of distortion, though I do not really hear it any longer since I am used to it.
My impression of bib's may be biased due to my room having perfect corners for them, it is a long and narrow room with the corners being just about the right width apart. I am going to build a pair of Austin 126's next, I want a compression chamber behind the driver and hear good things about them.
To my ears the bib's sound better in almost every way. The only problem they have is they some times make a weird sound, which I think is due to not enough pressure behind the cone. It sounds like a form of distortion, though I do not really hear it any longer since I am used to it.
My impression of bib's may be biased due to my room having perfect corners for them, it is a long and narrow room with the corners being just about the right width apart. I am going to build a pair of Austin 126's next, I want a compression chamber behind the driver and hear good things about them.
Saburro Response
I am ready to pick up a pair of the FE126-en drivers. I am considering the Saburo, however the response appears a bit rough, is this audible in room? I have noticed that the BVR designs appear to have a smoother response but I don't really want anything between the amp and the 126, are their any other recommendations? I am reading good things about the curvy Chang, but no designs for the 126 currently, will/can a curvy Chang be designed for the 126?
I am in a small room (10.5'x12.5') and will be using a factory modded JoLida 102B to drive them. I am currently running a GR Research OB series MTM crossed at 200HZ to a Hawthorne Augie in an OB alignment but miss the single driver (insert favorite single driver description of sound here). I am looking for that single driver magic mid range.
Thanks,
Ed
I am ready to pick up a pair of the FE126-en drivers. I am considering the Saburo, however the response appears a bit rough, is this audible in room? I have noticed that the BVR designs appear to have a smoother response but I don't really want anything between the amp and the 126, are their any other recommendations? I am reading good things about the curvy Chang, but no designs for the 126 currently, will/can a curvy Chang be designed for the 126?
I am in a small room (10.5'x12.5') and will be using a factory modded JoLida 102B to drive them. I am currently running a GR Research OB series MTM crossed at 200HZ to a Hawthorne Augie in an OB alignment but miss the single driver (insert favorite single driver description of sound here). I am looking for that single driver magic mid range.
Thanks,
Ed
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