Hi,
Looking again at the Onken Double implementation from Artec: http://www.artec-france.com/etudes/reference/AR8170H5.jpg
I was thinking of single driver version of it with a 12"er, but the front horn of the Onken would be Conical (no curves)... Is there any merit to this concept?
-If the conical horn needs to be deeper, would it be a detriment to performance because the ports would be longer as a consequence of the deep flare rate?
-If the "horn chambers" inside the onken box are left unsealed (for tube electronics), are there cons to this arrangement as there are multiple ports used? http://www.artec-france.com/etudes/reference/plan2AR8170H.gif
Maybe it would help HF and Lower Mid integration/coherence especially if the HF cd would be xo'd in its most linear region. The HF horn would most probably be conical too. I'm far from being knowledgable on speaker design, so please be kind. Thanks.
fred
Looking again at the Onken Double implementation from Artec: http://www.artec-france.com/etudes/reference/AR8170H5.jpg
I was thinking of single driver version of it with a 12"er, but the front horn of the Onken would be Conical (no curves)... Is there any merit to this concept?
-If the conical horn needs to be deeper, would it be a detriment to performance because the ports would be longer as a consequence of the deep flare rate?
-If the "horn chambers" inside the onken box are left unsealed (for tube electronics), are there cons to this arrangement as there are multiple ports used? http://www.artec-france.com/etudes/reference/plan2AR8170H.gif
Maybe it would help HF and Lower Mid integration/coherence especially if the HF cd would be xo'd in its most linear region. The HF horn would most probably be conical too. I'm far from being knowledgable on speaker design, so please be kind. Thanks.
fred
Hi GM,
I have these Japanese 60's 8" coaxs that are designed for these enclosures:
http://pic4.picturetrail.com/VOL706/2663514/5316039/93893985.jpg
Obviously the BR design is before the T/S era and. Published FR of driver is 30-25k. What improvements on the cabs can you suggest based on the limited measured T/S I gathered here:
Re: 7.8 Ohms
Fo: 30-45Hz
Fs: 99.9Hz
Qms: 4.33
Qes: 1.15
Qts: 0.91
Qo: 0.45 (40Hz)
94dB
I currently use the drivers in OB and sound very good in them, but I'd like to try the stock BR design too. However, based on some vintage BR designs I've heard Im a bit hesitant because of the muddy bass and midbass dip. I don't mind if the LF BW is truncated to some extent, just as long as the bass isn't ill defined or boomy and retains good efficiency. Thanks.
fred
I have these Japanese 60's 8" coaxs that are designed for these enclosures:
http://pic4.picturetrail.com/VOL706/2663514/5316039/93893985.jpg
Obviously the BR design is before the T/S era and. Published FR of driver is 30-25k. What improvements on the cabs can you suggest based on the limited measured T/S I gathered here:
Re: 7.8 Ohms
Fo: 30-45Hz
Fs: 99.9Hz
Qms: 4.33
Qes: 1.15
Qts: 0.91
Qo: 0.45 (40Hz)
94dB
I currently use the drivers in OB and sound very good in them, but I'd like to try the stock BR design too. However, based on some vintage BR designs I've heard Im a bit hesitant because of the muddy bass and midbass dip. I don't mind if the LF BW is truncated to some extent, just as long as the bass isn't ill defined or boomy and retains good efficiency. Thanks.
fred
Greets!
You can horn load any driver and get some sort of response, but you will have to design from scratch to get something useful unless you are very lucky. Using a WG on the woofer to better match its polar (power) response to the mid/HF horn is a good plan though, but to get it to load down into the LF also will require it to be very long so the port system couldn't be a function of horn depth.
GM
You can horn load any driver and get some sort of response, but you will have to design from scratch to get something useful unless you are very lucky. Using a WG on the woofer to better match its polar (power) response to the mid/HF horn is a good plan though, but to get it to load down into the LF also will require it to be very long so the port system couldn't be a function of horn depth.
GM
Greets!
My answer hasn't changed since you posted these 'specs' on the BIB thread awhile back:
These numbers don't jive, Neither Fs/F0 or Qts/Q0 will have such a large spread. I don't remember who/where/when someone asked me this before except with just the Q0 values/this cab and I arrived at specs that unfortunately run counter to your description, with a 40 Hz Fs, 0.58511 Qts, and 5.6 ft^3 Vas.
GM
My answer hasn't changed since you posted these 'specs' on the BIB thread awhile back:
These numbers don't jive, Neither Fs/F0 or Qts/Q0 will have such a large spread. I don't remember who/where/when someone asked me this before except with just the Q0 values/this cab and I arrived at specs that unfortunately run counter to your description, with a 40 Hz Fs, 0.58511 Qts, and 5.6 ft^3 Vas.
GM
GM said:
Hi GM,
Thanks for the reply. Yes, a design from the ground up is what I had in mind. I was just thinking out loud if a Conical WG is theoretically feasible w/ an Onken type cab especially when used in a narrow room where the cabs would be placed very near side walls (w/ wome toe-in). I haven't seen a reflex basscab with front conical WG as most are exponential or tractrix.
fred
GM said:
Yeah.. Some of the T/S data like Fs, Qts, Qms, Qes where measured/taken from my 16ohm driver version. These I now suspect are inaccurate.. The only published useful spec from a brochure is the Qo (which was uploaded by someone at the old FR forum pic gallery), BUT, it was for the 8ohm version of these drivers with a different looking paper cone material w/ no annular rings.
I'm not sure if different impedance versions of the same driver can have different T/S specs by a wide degree. BTW, I must have missed your reply on the BiB thread WRT this. I aplogize that the post is a bit redundant. Thanks again.
fred
PS - 40 Hz Fs, 0.58511 Qts, and 5.6 ft^3 Vas.
If the above data you gathered is adequate enough to come up w/ BIB dims, I would surely appreciate it if it could be mentioned at the BIB thread.
But if not adequate, thank you still for making me understand the "doesn't jive" thing.
Here is my new Onken based system. I'm pretty pleased overall with the performance.
It was quite a lot of work, but I think I even got the basic box tuning right. I won't have to open them again for a while.
I'm not totally used to the CD mid horns yet which is what I have now got, dispersion patterns are quite a bit different than most horns and indeed most direct radiators.
I'm less and less convinced that the 2402H is essentially similar in sonic signature to the 075 - it seems not to have quite the high frequency extension. I'm thinking Fostex T900 or T925 alnico bullet horn tweeter in the fall.. LOL
The mid and tweeter horns are entirely separate from the Onken boxes to allow me to try other horn/driver combinations.. The x-over is external for the same reason.
Another conclusion is that amplifiers with high source impedances interact with the more complex x-over and drivers in ways that I don't yet fully understand. Average amplifier power output is a couple of mW typically, the 300B with fixed bias and regulated supplies does a good job, my more traditional 2A3 amplifier with direct coupled driver stage and polyprop in oil cathode bypasses doesn't cut it. (And the problem is not in the bass! The mid horn hates that amp or vice versa.)
It was quite a lot of work, but I think I even got the basic box tuning right. I won't have to open them again for a while.
I'm not totally used to the CD mid horns yet which is what I have now got, dispersion patterns are quite a bit different than most horns and indeed most direct radiators.
I'm less and less convinced that the 2402H is essentially similar in sonic signature to the 075 - it seems not to have quite the high frequency extension. I'm thinking Fostex T900 or T925 alnico bullet horn tweeter in the fall.. LOL
The mid and tweeter horns are entirely separate from the Onken boxes to allow me to try other horn/driver combinations.. The x-over is external for the same reason.
Another conclusion is that amplifiers with high source impedances interact with the more complex x-over and drivers in ways that I don't yet fully understand. Average amplifier power output is a couple of mW typically, the 300B with fixed bias and regulated supplies does a good job, my more traditional 2A3 amplifier with direct coupled driver stage and polyprop in oil cathode bypasses doesn't cut it. (And the problem is not in the bass! The mid horn hates that amp or vice versa.)
Attachments
Nice Kevin! Congratulations on getting them working. If they sound as good as they look, you'll be a happy man.
That's a great listening room you've got there. You can watch the o'scope, get high on solder fumes and listen to great tunes all at the same time. Add a few adult beverages and we'll have to call you "Ali-Baba."
Nice that you seem to have gotten the box tuning right. Won't the drivers change as they break in? Lower FS and such? Let us know how that goes.
Tell us a little about the mid horn. I never heard a CD horn I liked. Good, but never great - but they were all in P.A. or cinema use. What have you got going there? Is it JBL?
Onkens rule!!
That's a great listening room you've got there. You can watch the o'scope, get high on solder fumes and listen to great tunes all at the same time.
Add a few adult beverages and we'll have to call you "Ali-Baba."Nice that you seem to have gotten the box tuning right. Won't the drivers change as they break in? Lower FS and such? Let us know how that goes.
Tell us a little about the mid horn. I never heard a CD horn I liked. Good, but never great - but they were all in P.A. or cinema use. What have you got going there? Is it JBL?
Onkens rule!!
Hi Mike,
They're definitely a lot of fun and I had a little time to crank them up a bit more tonight, my room is probably a little too small.. There is a lot of bass, and it seems quite well controlled, I do expect though that the extension will improve as the drivers break in. Some tuning may then be required.
Eventually I might tri-amp this system, and at that point I think modifying the amplifiers I would use on the low end for variable damping factor might be interesting.
The mid range horn is JBL 4333, the compression driver is a 2420 which has a honking great alnico magnet, currently 16 ohm vc with titanium diaphragm. All "unauthorized mods" by previous owner have been removed.. LOL I doubt the diaphragms are oem, but sound reasonable. (not broken in yet) The horns are 2312, and the diffusers are aftermarket clones of the 2308. They are quite interesting sounding, but I need to do some measurements to see if they are crossed over properly - they sound like no cone mid I have ever heard, both good and bad. They are a little directional even with the diffusers installed.
The tweeters are 2402H annular ring tweeters with ferrite magnets and I don't think they are as good sounding as the older alnico versions but I'm not quite sure..
Ali baba..
They're definitely a lot of fun and I had a little time to crank them up a bit more tonight, my room is probably a little too small.. There is a lot of bass, and it seems quite well controlled, I do expect though that the extension will improve as the drivers break in. Some tuning may then be required.
Eventually I might tri-amp this system, and at that point I think modifying the amplifiers I would use on the low end for variable damping factor might be interesting.
The mid range horn is JBL 4333, the compression driver is a 2420 which has a honking great alnico magnet, currently 16 ohm vc with titanium diaphragm. All "unauthorized mods" by previous owner have been removed.. LOL I doubt the diaphragms are oem, but sound reasonable. (not broken in yet) The horns are 2312, and the diffusers are aftermarket clones of the 2308. They are quite interesting sounding, but I need to do some measurements to see if they are crossed over properly - they sound like no cone mid I have ever heard, both good and bad. They are a little directional even with the diffusers installed.
The tweeters are 2402H annular ring tweeters with ferrite magnets and I don't think they are as good sounding as the older alnico versions but I'm not quite sure..
Ali baba..
They look great kevinkr and I'm pleased for you that they they sound good too. Be interesting to see how they are in a few weeks time as you get more used to them. Probably sound better in a larger room too I think. This is the sort of speaker system I had in mind when I started to thread and hope to be able to do a little later. Will probably make the mid horns too. I am looking at open baffle for the mids and highs too.
jamikl
jamikl
I made an interesting discovery last night, I definitely had the mid horns phase reversed. Swapping the phase as required by my cross-over design greatly improved mid range dispersion and eliminated an audible hole in the frequency response and dispersion pattern, and also interestingly resulted in much more coherent highs as well.
The difference was so noticeable that I almost fell out of my chair.. (And it wasn't bad before despite what must have been large holes at 800Hz and 8kHz - the cross-over points.)
Matching levels between the drivers masked the problem to some extent as the mids and tweeters are about 8dB more efficient than the bass cabinets, tonally I thought there was a hole in the lowest registers of the mid-range at any level setting. Now that is gone and the overall levels required from the horns is much lower. Dispersion now seems much less position dependent, and the tonal balance sounds right as well. Ah, the benefits of tweaking..
The Onkens move a lot of air at low frequencies, this is more than audible - you can feel it.
Still need to get set up to do measurements so that I can tweak things and also gather enough information for eventual tri-amplification.
The difference was so noticeable that I almost fell out of my chair..
(And it wasn't bad before despite what must have been large holes at 800Hz and 8kHz - the cross-over points.)Matching levels between the drivers masked the problem to some extent as the mids and tweeters are about 8dB more efficient than the bass cabinets, tonally I thought there was a hole in the lowest registers of the mid-range at any level setting. Now that is gone and the overall levels required from the horns is much lower. Dispersion now seems much less position dependent, and the tonal balance sounds right as well. Ah, the benefits of tweaking..
The Onkens move a lot of air at low frequencies, this is more than audible - you can feel it.
Still need to get set up to do measurements so that I can tweak things and also gather enough information for eventual tri-amplification.
Hey Mike,
Further listening indicates some tuning will be happening in the future..
I determined last night that the ports are a whopping 7/8" too long, so I will at some point be cutting a little material off of the ends of the internal port dividers (left/right) on each side to fix this. I was a little bummed initially, but I realized that with a small plunge router and a fence fastened to each divider this will not be hard to accomplish.
I also think that I will take the opportunity to add some additional bracing in key locations. I don't hear any rattles or buzzes, but I do think I possibly hear a cabinet resonance.. Additional rigidity cannot hurt.. LOL
I don't plan to move fast on these realizations as there may be other causes, and I won't do anything until I can measure the results. I think things are pretty good as they are and I want the tweaks to fix "real" not "imaginery" shortcomings.
The measurement hardware will be in house within a month, courtesy of my significant other who recently asked me for links to the stuff I want for my birthday. She supports my hobby with bemused puzzlement, but has also given me a very nice playroom.. All I will need to do is build or buy a low noise mic pre-amplifier with phantom power. Due to expense I am thinking of designing and building the pre, although I really want an m-audio dpm3.. LOL
Off Topic: To those unfamiliar with Jean Hiraga and his role in bringing awareness of early Western audio technology (particularly SE triodes, and high efficiency speaker systems) back to the West, his influence is now pervasive and impossible to value properly. The Hiraga book that turned me on to the Japanese way of Audio was the French language version of "Initiation into Tube Amplifiers" A very literal translation of the title I'll admit, perhaps more correctly translated as "An Introduction To Tube Amplifiers." It is really a shame that this has not been translated into English, although I have no trouble with it in French for the most part. Sadder still is the wealth of tube articles in MJ which will never see the light of day in English. Many of the designs, speakers, amplifiers, etc are very interesting - if not always entirely original. The passion Japanese feel for DIYAudio is fascinating, and inspiring. The level of quality of execution for diy efforts is sometimes mind boggling. I wish we had a little more of that here. AudioExpress, although good, and its brethren are a faint shadow by comparison.
The relevance of this in regards to the Onken bass cabinet, is Japanese audiophiles resurrected the old Jensen Ultraflex design, made it new and interesting again. It works well, perhaps in a perfect world it is not the ultimate solution, but properly executed there is no question it can be very good. In conjunction with the Iconic driver I choose there is no question it can move a lot of air very efficiently and with very low distortion. I am sure it will only get better with time (woofer break in) and tweaking.
Ali Baba
Further listening indicates some tuning will be happening in the future..
I determined last night that the ports are a whopping 7/8" too long, so I will at some point be cutting a little material off of the ends of the internal port dividers (left/right) on each side to fix this. I was a little bummed initially, but I realized that with a small plunge router and a fence fastened to each divider this will not be hard to accomplish.
I also think that I will take the opportunity to add some additional bracing in key locations. I don't hear any rattles or buzzes, but I do think I possibly hear a cabinet resonance.. Additional rigidity cannot hurt.. LOL
I don't plan to move fast on these realizations as there may be other causes, and I won't do anything until I can measure the results. I think things are pretty good as they are and I want the tweaks to fix "real" not "imaginery" shortcomings.
The measurement hardware will be in house within a month, courtesy of my significant other who recently asked me for links to the stuff I want for my birthday. She supports my hobby with bemused puzzlement, but has also given me a very nice playroom.. All I will need to do is build or buy a low noise mic pre-amplifier with phantom power. Due to expense I am thinking of designing and building the pre, although I really want an m-audio dpm3.. LOL
Off Topic: To those unfamiliar with Jean Hiraga and his role in bringing awareness of early Western audio technology (particularly SE triodes, and high efficiency speaker systems) back to the West, his influence is now pervasive and impossible to value properly. The Hiraga book that turned me on to the Japanese way of Audio was the French language version of "Initiation into Tube Amplifiers" A very literal translation of the title I'll admit, perhaps more correctly translated as "An Introduction To Tube Amplifiers." It is really a shame that this has not been translated into English, although I have no trouble with it in French for the most part. Sadder still is the wealth of tube articles in MJ which will never see the light of day in English. Many of the designs, speakers, amplifiers, etc are very interesting - if not always entirely original. The passion Japanese feel for DIYAudio is fascinating, and inspiring. The level of quality of execution for diy efforts is sometimes mind boggling. I wish we had a little more of that here. AudioExpress, although good, and its brethren are a faint shadow by comparison.
The relevance of this in regards to the Onken bass cabinet, is Japanese audiophiles resurrected the old Jensen Ultraflex design, made it new and interesting again. It works well, perhaps in a perfect world it is not the ultimate solution, but properly executed there is no question it can be very good. In conjunction with the Iconic driver I choose there is no question it can move a lot of air very efficiently and with very low distortion. I am sure it will only get better with time (woofer break in) and tweaking.
Ali Baba
So Kevin,
Measure before you mod, eh? Very wise.
If you are looking for a mic, why not try the one that Mr. Linkwitz uses?
Linkwitz mic project
You could hook that right up to your sound card for measurements. Remember to measure only one speaker at a time - comb filtering!
You are right about Mr. Hiraga and his influence on Hi-Fi in the West. He is well known in the East, too. It seems to be only the English speaking world that does not know his work, even tho they have benefited by it. Most of what I know about Hi-Fi, I learned from Jean Hiraga, his books and revues. A good bit of what I know about pro sound too.
An English translation of the French audio stuff would be a great gift to the audio world. I did some translation for Hiraga and crew many years ago, too bad I don't have the time for this massive project.
I'll have to check out the Japanese stuff. Seen it, but can't read it!
Enjoy the cavern, Mr. Baba.
Measure before you mod, eh? Very wise.
If you are looking for a mic, why not try the one that Mr. Linkwitz uses?
Linkwitz mic project
You could hook that right up to your sound card for measurements. Remember to measure only one speaker at a time - comb filtering!
You are right about Mr. Hiraga and his influence on Hi-Fi in the West. He is well known in the East, too. It seems to be only the English speaking world that does not know his work, even tho they have benefited by it. Most of what I know about Hi-Fi, I learned from Jean Hiraga, his books and revues. A good bit of what I know about pro sound too.
An English translation of the French audio stuff would be a great gift to the audio world. I did some translation for Hiraga and crew many years ago, too bad I don't have the time for this massive project.
I'll have to check out the Japanese stuff. Seen it, but can't read it!
Enjoy the cavern, Mr. Baba.
Cool to see Hiraga still going strong..
I looked at the linkwitz mic project some months ago, but decided this was one aspect of diy I wanted to avoid. I am planning on using the Behringer ECM8000 mic which is both inexpensive, and based on prior experience has a relatively flat response. It's not as good as a B&K, but can be had for about $40 which seems like a relative bargain..
Stand, clip and cables will come to less than $80, I just have to cobble up a high gain low noise mic pre-amp.. Hopefully the notorious birthday elf will leave these on the patio table come birthday day..
(My running joke with my spouse to be.. LOL)
I looked at the linkwitz mic project some months ago, but decided this was one aspect of diy I wanted to avoid. I am planning on using the Behringer ECM8000 mic which is both inexpensive, and based on prior experience has a relatively flat response. It's not as good as a B&K, but can be had for about $40 which seems like a relative bargain..
Stand, clip and cables will come to less than $80, I just have to cobble up a high gain low noise mic pre-amp.. Hopefully the notorious birthday elf will leave these on the patio table come birthday day..
(My running joke with my spouse to be.. LOL)
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