I may soon be aquiring a second pair of KEF B-139 bass drivers, does any-one have plans or a link to a design using pairs of B-139's in parallel??
I do not have much floor space so would prefer to go tall rather than wide, midrange will be Vifa I have a quad of P-11 and I will Bi-amp these, assuming I ever get time to build that is.
Sealed or transmission line is what I am thinking
Regards Ted
I do not have much floor space so would prefer to go tall rather than wide, midrange will be Vifa I have a quad of P-11 and I will Bi-amp these, assuming I ever get time to build that is.
Sealed or transmission line is what I am thinking
Regards Ted
OK; here is the question; do I try and design a dual T-line box with seperate lines or do I combine both drivers in one box using Vas X 2?? As I do not like low impedance loads I would consider running another set of compatible drivers in series in seperate sealed box/boxes.
What about a pair of 8 inch 8R woofers in series before the KEF's, or a pair of 6.5 inch 4R-mid-woofers or a single largish 4R sub wired after them?? I have several pictures in my head but I am having trouble getting them down on paper.
For those Aussies out there I do have some of Jaycar's little carbon fibre 165mm mid woofer but as these have a fairly smooth top-end it seems a waste to cross them over so low ( 250-400 Hz)
Is the thought of sittng a pair of B-139's on top of a 12 or 15inch sub box a little over the top?
Visaton have some cheapish 8inch woofers that may do the job in series
http://www.soundlabsgroup.com.au/p/V-9029-W200S/W+200+S+-+4+Ohm
Wired in series -parallel this would/should be an easy amplifier load and reasonable power handling
What about a pair of 8 inch 8R woofers in series before the KEF's, or a pair of 6.5 inch 4R-mid-woofers or a single largish 4R sub wired after them?? I have several pictures in my head but I am having trouble getting them down on paper.
For those Aussies out there I do have some of Jaycar's little carbon fibre 165mm mid woofer but as these have a fairly smooth top-end it seems a waste to cross them over so low ( 250-400 Hz)
Is the thought of sittng a pair of B-139's on top of a 12 or 15inch sub box a little over the top?
Visaton have some cheapish 8inch woofers that may do the job in series
http://www.soundlabsgroup.com.au/p/V-9029-W200S/W+200+S+-+4+Ohm
Wired in series -parallel this would/should be an easy amplifier load and reasonable power handling
Dave the web-site has been down for days, it was the first place I went looking, I have seen the pix of Andy's Manhattan tower and GeeVee has sent me the plans for the Bailey clone but I was thinking of something bigger.
But heck I still haven't finished the "Tardis" front and back subbie yet, I get sidetracked into new projects all the time.
I was thinking about a simple folded line but we only have 8 foot ceilings here.
Performance of the B-139 in a simple sealed box is still reasonable but when I was a younger man in England I went to the audio show at Heathrow and still remember hearing IMF studio monitors for the first time, we have access to much better mid-range drivers and tweeters now, but it is my memories ot the bass of that particular speaker I rememer most vividly.
From what i have read and heard it is the long term power handling of the KEF/ELAC driver that is the biggest drawback, which is why I was considering multiple drivers.
I would even consider giving these the front and back treatment but using the additional woofers in seperate sealed boxes as a base, I have 8 1/2 foot ceilings, and the room is small but 'L' shaped and all walls have drapes and heavy wall hangings floor is polished and the ceiling is untreated plaster board.
These speakers are going to have to do double duty as music and HT mains L&R
All comments and advice appreciated
But heck I still haven't finished the "Tardis" front and back subbie yet, I get sidetracked into new projects all the time.
I was thinking about a simple folded line but we only have 8 foot ceilings here.
Performance of the B-139 in a simple sealed box is still reasonable but when I was a younger man in England I went to the audio show at Heathrow and still remember hearing IMF studio monitors for the first time, we have access to much better mid-range drivers and tweeters now, but it is my memories ot the bass of that particular speaker I rememer most vividly.
From what i have read and heard it is the long term power handling of the KEF/ELAC driver that is the biggest drawback, which is why I was considering multiple drivers.
I would even consider giving these the front and back treatment but using the additional woofers in seperate sealed boxes as a base, I have 8 1/2 foot ceilings, and the room is small but 'L' shaped and all walls have drapes and heavy wall hangings floor is polished and the ceiling is untreated plaster board.
These speakers are going to have to do double duty as music and HT mains L&R
All comments and advice appreciated
Moondog55 said:
OK i fixed that. Earlier in the week it was maintenance where i host my pictures, today it was my server.
The B139 box isn't up anywhere yet. Here is the single Triangulated line -- a TTL won't work for your ap.
http://p10hifi.net/planet10/TLS/downloads/B139-TTL-map-100707.pdf
dave
I wish I had a second pair. I seem to remember seeing a tiny H frame OB design that used a pair somewhere here or on the web, German design IIRC, they had so little wood involved it might be fun just to knock up a pair and see how they sound.
If you search for my thread on the B139, Scott posted an interesting MLTL that was a bit smaller than Dave's true TL and might be an alternative. I still haven't decided which to build.
If you search for my thread on the B139, Scott posted an interesting MLTL that was a bit smaller than Dave's true TL and might be an alternative. I still haven't decided which to build.
Dave, I think you might be right.
Oh, and the PDF for that dipole sub is availble from here:
http://www.tech-diy.com/LS_Articles.htm
Oh, and the PDF for that dipole sub is availble from here:
http://www.tech-diy.com/LS_Articles.htm
The mid & tweeter cabinet could be designed to sit on the angled face....
http://p10hifi.net/planet10/TLS/downloads/PushPush-B139-TL-map-041107.pdf
dave
http://p10hifi.net/planet10/TLS/downloads/PushPush-B139-TL-map-041107.pdf
dave
Attachments
I like the look of those, how much clearance above the open throat do you need ??
Also is there a program that can simulate the effect of a first order high pass at 25Hz (ie woofer resonance ) in TL's
I am beginning to think that a Q equals 1 sealed box using that system may give me what I need in this room
Also is there a program that can simulate the effect of a first order high pass at 25Hz (ie woofer resonance ) in TL's
I am beginning to think that a Q equals 1 sealed box using that system may give me what I need in this room
Cheap price does not mean cheap sound quality but I take your meaning,
How do I stack 2 folded lines in one tower??
Do I plan to port to the rear or the front??
Given that I want to use mid-range drivers that I have in store and the transmission from a medium size driver to a 4inch is smoother ( at least in my limited experience) is there a driver of similar quality and performance avaliable here in Australia
Perhas these
http://www.soundlabsgroup.com.au/p/V-1307-AL170A/AL+170+A+-+8+Ohm
or these
http://www.jaycar.com.au/productVie...&pageNumber=&priceMin=&priceMax=&SUBCATID=383
How do I stack 2 folded lines in one tower??
Do I plan to port to the rear or the front??
Given that I want to use mid-range drivers that I have in store and the transmission from a medium size driver to a 4inch is smoother ( at least in my limited experience) is there a driver of similar quality and performance avaliable here in Australia
Perhas these
http://www.soundlabsgroup.com.au/p/V-1307-AL170A/AL+170+A+-+8+Ohm
or these
http://www.jaycar.com.au/productVie...&pageNumber=&priceMin=&priceMax=&SUBCATID=383
Midrange drivers
I have some Vifa M11 dedicated mid-ranges rewired to 16 Ohm as I intended to use MTM configuration and wanted the lowest distortion from my amp, in discussion with Andy Graddon ( whose opinion I respect highly) no lower than 375hz as their resonant frequency is a little high at 110 hz and probably crossed to the Vifa neo tweeter at 3000 or higher.I have heard comments that 375/400 is a little high to cross the B-139's.
I could go 4way using the KEF's below 100, I have a couple of good amps avaliable and I have a Behringer cross0over avalable to experiment with.
I have some Vifa M11 dedicated mid-ranges rewired to 16 Ohm as I intended to use MTM configuration and wanted the lowest distortion from my amp, in discussion with Andy Graddon ( whose opinion I respect highly) no lower than 375hz as their resonant frequency is a little high at 110 hz and probably crossed to the Vifa neo tweeter at 3000 or higher.I have heard comments that 375/400 is a little high to cross the B-139's.
I could go 4way using the KEF's below 100, I have a couple of good amps avaliable and I have a Behringer cross0over avalable to experiment with.
I have been unable to find any information about the speaker i remember from England.
In my head I have a memory of a B-139 with an 8inch KEF ( B200 ) before the 4inch, I cannot remember the model, I thought it was IMF but found nothing in the archive and now that site is defunct.
I was thinking of 100/120 Hz as being the limit myself, maybe I need to rethink things and look at a better mid-range match, I have always liked Vifa P13's, it's just that I have the little ones here and paid for
In my head I have a memory of a B-139 with an 8inch KEF ( B200 ) before the 4inch, I cannot remember the model, I thought it was IMF but found nothing in the archive and now that site is defunct.
I was thinking of 100/120 Hz as being the limit myself, maybe I need to rethink things and look at a better mid-range match, I have always liked Vifa P13's, it's just that I have the little ones here and paid for
…Impressive, do I read that right -3dB @30hz?
With my test gear and some moderate room gain I estimated a -3dB response below 25 Hz, I recall the speaker sounded ‘bottomless’ and it was impossible to keep the gramophone in the same room as the speakers when playing at higher levels.
…Did you build as a 3-way?…
Yes at first, before I modified the speakers to better sounding 4-way’s and the above posted simulation is an reconstruction using MJK: s software of an old sketch I still have in my possession. The only question mark is how much mineral wool was put in the TLs.
The inside walls (LDF) were covered with 2 .5 cm dense Roockwool and the rest with fluffy itchy yellow mineral wool as seen in the small picture but I never estimated the weight or density or took notes of any numbers.
I remember having a hard time to make both speaker measure equal at the low crossover point and iterated the component values of the 12 dB LP-filter (no HP-filter for the B200) and the stuffing over a long time period of until I was satisfied with the result.
My notes reveal the use of a rather lossy 1.8-Ohm inductor, 6.2 mH and a 100uF capacitor.
I don’t recall the dip seen in the simulation at about 115 Hz, but that is probably because I at that time only had a homebrew of test equipments, a gated dial tone generator system including a calibrated microphone hooked up to an oscilloscope and a DIY true analogue RMS meter.
The weak point of this design was the need for a low crossover point between the B200 and any tweeter.
At the finishing end, the best-achieved results show up when using 2 Peerless 122MF midranges in parallel placed side by side with the lower B200 driver below a Decca Ribbon look-alike tweeter, the Gamma VLD12.
b
With my test gear and some moderate room gain I estimated a -3dB response below 25 Hz, I recall the speaker sounded ‘bottomless’ and it was impossible to keep the gramophone in the same room as the speakers when playing at higher levels.
…Did you build as a 3-way?…
Yes at first, before I modified the speakers to better sounding 4-way’s and the above posted simulation is an reconstruction using MJK: s software of an old sketch I still have in my possession. The only question mark is how much mineral wool was put in the TLs.
The inside walls (LDF) were covered with 2 .5 cm dense Roockwool and the rest with fluffy itchy yellow mineral wool as seen in the small picture but I never estimated the weight or density or took notes of any numbers.
I remember having a hard time to make both speaker measure equal at the low crossover point and iterated the component values of the 12 dB LP-filter (no HP-filter for the B200) and the stuffing over a long time period of until I was satisfied with the result.
My notes reveal the use of a rather lossy 1.8-Ohm inductor, 6.2 mH and a 100uF capacitor.
I don’t recall the dip seen in the simulation at about 115 Hz, but that is probably because I at that time only had a homebrew of test equipments, a gated dial tone generator system including a calibrated microphone hooked up to an oscilloscope and a DIY true analogue RMS meter.
The weak point of this design was the need for a low crossover point between the B200 and any tweeter.
At the finishing end, the best-achieved results show up when using 2 Peerless 122MF midranges in parallel placed side by side with the lower B200 driver below a Decca Ribbon look-alike tweeter, the Gamma VLD12.
b
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