Hey Ali-Baba,
Sounds like things are shaking down there in the "cavern."
Thanks for the report on the sound of the different amps. A good DHT SET amp can be very dynamic, indeed!
I might not hurt to play around with SS amps on the low end. In the big systems I heard in France, and read about in Japan, there is often a SS amp on the bottom. It's not so much a question of power (I think) as how the amp handles the drivers. As you have been hearing.
On most of the "big" systems I know, the Triode amp is used for mids and highs only, the bass drivers are usually done with SS amps. The full range triode is reserved for smaller systems with fullrange type drivers.
It seems that you have plenty of volume, so no worries there. But if you get the chance to try SS on the bottom, it would be nice to learn of your results.
Sounds like things are shaking down there in the "cavern."
Thanks for the report on the sound of the different amps. A good DHT SET amp can be very dynamic, indeed!
I might not hurt to play around with SS amps on the low end. In the big systems I heard in France, and read about in Japan, there is often a SS amp on the bottom. It's not so much a question of power (I think) as how the amp handles the drivers. As you have been hearing.
On most of the "big" systems I know, the Triode amp is used for mids and highs only, the bass drivers are usually done with SS amps. The full range triode is reserved for smaller systems with fullrange type drivers.
It seems that you have plenty of volume, so no worries there. But if you get the chance to try SS on the bottom, it would be nice to learn of your results.
Yup, things are shaking down in the cavern... (Or should that be bat cave?) LOL I have an old Dyna ST-120 I am in the process of rehabing for speaker measurements, once that is done I will try it on the bottom end. (It's nearly 40 so I don't trust it with my drivers.)
So far the SE amplifier sounds the best even on the bottom because its 3 ohm source impedance (neglecting the R of the cross-over coil) is close to what I designed for. I suspect an SS amplifier will require a resistor for padding.
My ultimate evil plan was to add subwoofers of some description run by the ST-120 to fill in between say 25Hz - 40Hz. So far that doesn't seem exactly necessary..
Ali-Baba
So far the SE amplifier sounds the best even on the bottom because its 3 ohm source impedance (neglecting the R of the cross-over coil) is close to what I designed for. I suspect an SS amplifier will require a resistor for padding.
My ultimate evil plan was to add subwoofers of some description run by the ST-120 to fill in between say 25Hz - 40Hz. So far that doesn't seem exactly necessary..
Ali-Baba
Well here is the latest update from the bat cave..
I recently designed and built a microphone pre-amplifier with calibrated gains based on the AD SSM2019 pre-amplifier IC. Checked it out with my AP at work and seems to work as expected. I am using this with a Behringer ECM8000 mic.
Initially I thought to use it with my licensed copy of AudioTester, but after several frustrating days of trying trial measurements and getting results that were often non-sensical and the consistent lock up after a certain number of FFT's were run convinced me to try something else. Asio support in AudioTester is very buggy and that is the environment I was attempting to run it in. The conventional audio dll did not seem to work at all..
Anyway last night I downloaded Arta and installed it. Wow, what a difference. No crashes and measurements that look reasonable if somewhat disappointing.. Once I am comfortable with Arta I plan to purchase it.. Not cheap, but still a bargain. Until registered I can not save the acquisitions made, however any screen capture utility will work.
Currently I am experimenting mainly with system measurements, and the results convince me that eventually a new cross-over design should be attempted..
I looked at the direct radiated output of the woofer, then the port, midrange horn and tweeter.
The direct radiated nearfield output (mic flush with baffle, centered) of the woofer is amazingly flat right out to the 800Hz cross-over point. I would say from about 60Hz to almost 700Hz the output is flat within +/- 1.5dB, at 50Hz and 800Hz it is down roughly -3dB.
So far so good..
Now here comes the interesting part, I measured the output at one of the ports. (Slightly inside <1cm) You would think this would be quite band limited and follow the usual BR port response wouldn't you? Well it doesn't quite, as some of you may recall I noted that through a minor miscommunication the port length is about an inch longer than it should be, I planned to fix this later once I understood what was actually going on..
The first peak as expected is low, and in this case is right around 30Hz which may actually be extending the low end bass response - easily moved to the intended 40Hz tuning with a plunge router later if I want to. The next peak appears at around 190Hz and is MUCH greater, probably no surprise either, here is what really confuses me - the response continues out with several ripples right to 1KHz! I expected it to crash right after the 190Hz peak.. Now this in no way seems to detract from the sound, oddly enough...
This discovery makes me believe one of four things, one I haven't damped the interior of the cabinet sufficiently, two I made an egregious mistake in the cabinet design, or three the Onken actually should not be run with anything approaching a full range driver, or four, as our friends across the pond might say, my measurement was utter rubbish.
The cabinet has a judicious amount of acoustical fiberglass installed on the bottom, one side of the port dividers and the entire rear panel.
Ok, moving on I found that the overall system response (mono, 1 channel only) from the listening position is typically flat to within +/-5dB from 40Hz - 15kHz in repeated measurements using both AudioTester and Arta.
I also determined that I have a broad low q rise in response between 1 - 3kHz of several dB and another between 8 - 10kHz which if smoothed out would whack the system response error to something like +/-2dB. The horns are somewhat directional and careful placement of the mic is necessary to get a valid response measurement, careful placement results in a 1 - 2dB improvement in response flatness. Careful tweaking of the mid and tweeter level controls can reduce the error considerably, but I like it better the way I set it through extended listening. The room is not treated so I am not too surprised.
The x-over is a calculated design and is based on assumptions from manufacturer data and not measurements. I did not expect it to be right, but it is not too far off either. The next gen design which will be based on response and impedance measurements will fix these issues.
Incidentally notwithstanding the comments above the system has never sounded better. I have never measured a system on my own in a room and this room response is a single point measurement so I can't decide if it is good or not. This is my first solo since leaving the eville audio empire years ago, but it definitely sounds ok, and has a very high audiophile acceptance factor in critical listening tests so far.
Anyway it is a lot of fun...
I recently designed and built a microphone pre-amplifier with calibrated gains based on the AD SSM2019 pre-amplifier IC. Checked it out with my AP at work and seems to work as expected. I am using this with a Behringer ECM8000 mic.
Initially I thought to use it with my licensed copy of AudioTester, but after several frustrating days of trying trial measurements and getting results that were often non-sensical and the consistent lock up after a certain number of FFT's were run convinced me to try something else. Asio support in AudioTester is very buggy and that is the environment I was attempting to run it in. The conventional audio dll did not seem to work at all..
Anyway last night I downloaded Arta and installed it. Wow, what a difference. No crashes and measurements that look reasonable if somewhat disappointing..
Once I am comfortable with Arta I plan to purchase it.. Not cheap, but still a bargain. Until registered I can not save the acquisitions made, however any screen capture utility will work.Currently I am experimenting mainly with system measurements, and the results convince me that eventually a new cross-over design should be attempted..
I looked at the direct radiated output of the woofer, then the port, midrange horn and tweeter.
The direct radiated nearfield output (mic flush with baffle, centered) of the woofer is amazingly flat right out to the 800Hz cross-over point. I would say from about 60Hz to almost 700Hz the output is flat within +/- 1.5dB, at 50Hz and 800Hz it is down roughly -3dB.
So far so good..
Now here comes the interesting part, I measured the output at one of the ports. (Slightly inside <1cm) You would think this would be quite band limited and follow the usual BR port response wouldn't you?
Well it doesn't quite, as some of you may recall I noted that through a minor miscommunication the port length is about an inch longer than it should be, I planned to fix this later once I understood what was actually going on.. The first peak as expected is low, and in this case is right around 30Hz which may actually be extending the low end bass response - easily moved to the intended 40Hz tuning with a plunge router later if I want to. The next peak appears at around 190Hz and is MUCH greater, probably no surprise either, here is what really confuses me - the response continues out with several ripples right to 1KHz! I expected it to crash right after the 190Hz peak.. Now this in no way seems to detract from the sound, oddly enough...
This discovery makes me believe one of four things, one I haven't damped the interior of the cabinet sufficiently, two I made an egregious mistake in the cabinet design, or three the Onken actually should not be run with anything approaching a full range driver, or four, as our friends across the pond might say, my measurement was utter rubbish.
The cabinet has a judicious amount of acoustical fiberglass installed on the bottom, one side of the port dividers and the entire rear panel.
Ok, moving on I found that the overall system response (mono, 1 channel only) from the listening position is typically flat to within +/-5dB from 40Hz - 15kHz in repeated measurements using both AudioTester and Arta.
I also determined that I have a broad low q rise in response between 1 - 3kHz of several dB and another between 8 - 10kHz which if smoothed out would whack the system response error to something like +/-2dB. The horns are somewhat directional and careful placement of the mic is necessary to get a valid response measurement, careful placement results in a 1 - 2dB improvement in response flatness. Careful tweaking of the mid and tweeter level controls can reduce the error considerably, but I like it better the way I set it through extended listening. The room is not treated so I am not too surprised.
The x-over is a calculated design and is based on assumptions from manufacturer data and not measurements. I did not expect it to be right, but it is not too far off either. The next gen design which will be based on response and impedance measurements will fix these issues.
Incidentally notwithstanding the comments above the system has never sounded better. I have never measured a system on my own in a room and this room response is a single point measurement so I can't decide if it is good or not. This is my first solo since leaving the eville audio empire years ago, but it definitely sounds ok, and has a very high audiophile acceptance factor in critical listening tests so far.
Anyway it is a lot of fun...
The last post was so long I thought I would just make a couple of additional comments in a new post rather than edit the last one..
The bass extension has improved considerably and the early, peaky bass resonance I complained about seems to have gone away. Note that I don't really measure anything that would account for the peak I used to hear either.
They are in a quasi corner placement and so get some help on the extreme bottom end that way. I am not sure yet whether or not I am going to need BSC or not, but I suspect I don't based on preliminary measurements.
They go down pretty far and despite the tuning, or possibly due to the inadvertant "EB" port tuning there is usable output well below 40Hz. This is bass you can feel, and the hyped up bass in some hip hop recordings can be a little scary at times. (I guess they don't mix for Onkens.. LOL) And all that on 7Wrms of 0 fdbk 300B triode power per channel..
The mids and highs are detailed, and seem well balanced. The mid horn and tweeter integrate as one and generally you are not aware that they are separate drivers.
My impression is that the Iconic 165-8G dominates though and the "color" of the system is the color of this driver, and probably because I cross it over at 800Hz. Fortunately this is a great driver out to 1kHz anyway and I can't recommend it enough. I have heard my share of Altec 416 series drivers, not to mention JBL D130, etc. This would probably equal or better any of them. It was expensive, vintage A416 go for roughly the same price, however here you know exactly what you are getting..
The midrange is a JBL 4333 and in cursory bench measurements with a current source it exhibited a peak in output in the 1KHz - 3kHz range and a rising impedance and falling output above this. I doubt that the diaphragms are genie JBL, but am hesitant to purchase new ones from JBL as they are so expensive. ($225 each) They sound good and some judicious x-over design would probably do it.
I have not really investigated the tweeters except to make sure that they function correctly. They aren't useful much above 15kHz which with my ears may be just fine.. or not.. I have access to some Fostex alnico horn drivers like the T900 and will evaluate them sometime in the coming months.
The bass extension has improved considerably and the early, peaky bass resonance I complained about seems to have gone away. Note that I don't really measure anything that would account for the peak I used to hear either.
They are in a quasi corner placement and so get some help on the extreme bottom end that way. I am not sure yet whether or not I am going to need BSC or not, but I suspect I don't based on preliminary measurements.
They go down pretty far and despite the tuning, or possibly due to the inadvertant "EB" port tuning there is usable output well below 40Hz. This is bass you can feel, and the hyped up bass in some hip hop recordings can be a little scary at times. (I guess they don't mix for Onkens.. LOL) And all that on 7Wrms of 0 fdbk 300B triode power per channel..
The mids and highs are detailed, and seem well balanced. The mid horn and tweeter integrate as one and generally you are not aware that they are separate drivers.
My impression is that the Iconic 165-8G dominates though and the "color" of the system is the color of this driver, and probably because I cross it over at 800Hz. Fortunately this is a great driver out to 1kHz anyway and I can't recommend it enough. I have heard my share of Altec 416 series drivers, not to mention JBL D130, etc. This would probably equal or better any of them. It was expensive, vintage A416 go for roughly the same price, however here you know exactly what you are getting..
The midrange is a JBL 4333 and in cursory bench measurements with a current source it exhibited a peak in output in the 1KHz - 3kHz range and a rising impedance and falling output above this. I doubt that the diaphragms are genie JBL, but am hesitant to purchase new ones from JBL as they are so expensive. ($225 each) They sound good and some judicious x-over design would probably do it.
I have not really investigated the tweeters except to make sure that they function correctly. They aren't useful much above 15kHz which with my ears may be just fine.. or not.. I have access to some Fostex alnico horn drivers like the T900 and will evaluate them sometime in the coming months.
Hey Kevin,
Sounds good! Pun intended.
Seems like the Onken boxes measure nicely. And you're getting good numbers at the listening position, too.
Strange about the port measurements. How far down are they from the speaker cone itself?
So you're playing hip-hop on a 300B SET, eh? You're a real pervert, you know that?
I think most hip-hop is mixed for "one note wonder" car stereos. How do the mixes sound on an audiophile system?
Maybe you should go out and get you a nice Hafler P-series amp for a few 100 watts to run the Onkens. But if you did, we might not ever hear form you again, the EMTs would have to peel you off the back wall of the bat cave.
As far as damping goes, I was just reading some vintage Altec speaker building manuals. They had a simple method to determine "enough" damping.
Keep up the good work Kevin. I may want one of your mic preamp boards, I have a couple of SSM2019 in stock.
Sounds good! Pun intended.
Seems like the Onken boxes measure nicely. And you're getting good numbers at the listening position, too.
Strange about the port measurements. How far down are they from the speaker cone itself?
So you're playing hip-hop on a 300B SET, eh? You're a real pervert, you know that?
I think most hip-hop is mixed for "one note wonder" car stereos. How do the mixes sound on an audiophile system?
Maybe you should go out and get you a nice Hafler P-series amp for a few 100 watts to run the Onkens. But if you did, we might not ever hear form you again, the EMTs would have to peel you off the back wall of the bat cave.
As far as damping goes, I was just reading some vintage Altec speaker building manuals. They had a simple method to determine "enough" damping.
Keep up the good work Kevin. I may want one of your mic preamp boards, I have a couple of SSM2019 in stock.
Greets!
Hmm, Arta's 79/149 euros seems dirt cheap to me for what it does.
WRT the vent's BW, IIRC I addressed this in one of my explanations to Bear, but in a 'nutshell', the vent is a 1/2 WL resonant pipe, ergo it's a consequence of its effective acoustic length. The harmonics are higher than the fundamental due to its small cross sectional area (CSA), so when all of them are summed you wind up with the fundamental being strongest with the proper harmonic decay rate assuming no damping. FYI, MJK's MathCad WSs is the only software I'm aware of that will predict it ~accurately.
This out of phase response comb filters with the driver's output and whatever else is reproducing the same BW. Many folks find this distortion euphonic, but it's a bit much for me so I keep box damping to a minimum and critically damp any long vent(s) using the early pioneer's 'click' test panomaniac posted. You can use Arta's impulse response measurement for greater accuracy.
I believe the vent's comb filtering BW and the acoustically long distance between the woofer/mid WRT to the XO point/slope is what's excessively 'coloring' the system, so while damping the vents and increasing the XO's LF slope and possibly adding a zoebel on the woofer will reduce it, it won't tonally balance it enough.
GM
Hmm, Arta's 79/149 euros seems dirt cheap to me for what it does.
WRT the vent's BW, IIRC I addressed this in one of my explanations to Bear, but in a 'nutshell', the vent is a 1/2 WL resonant pipe, ergo it's a consequence of its effective acoustic length. The harmonics are higher than the fundamental due to its small cross sectional area (CSA), so when all of them are summed you wind up with the fundamental being strongest with the proper harmonic decay rate assuming no damping. FYI, MJK's MathCad WSs is the only software I'm aware of that will predict it ~accurately.
This out of phase response comb filters with the driver's output and whatever else is reproducing the same BW. Many folks find this distortion euphonic, but it's a bit much for me so I keep box damping to a minimum and critically damp any long vent(s) using the early pioneer's 'click' test panomaniac posted. You can use Arta's impulse response measurement for greater accuracy.
I believe the vent's comb filtering BW and the acoustically long distance between the woofer/mid WRT to the XO point/slope is what's excessively 'coloring' the system, so while damping the vents and increasing the XO's LF slope and possibly adding a zoebel on the woofer will reduce it, it won't tonally balance it enough.
GM
Hi Panomaniac,
I'm not sure exactly how far down the port measurements were relative to the direct radiated measurements. I am evaluating Arta right now as a replacement for the very buggy and unstable AudioTester software I currently own. Until I purchase and register Arta I can't save the files, and I didn't learn how to overlay them until after the measurements.. I think we are talking relatively few dB difference though. There is a relatively large peak at 190Hz, and a much smaller one at 30Hz, unfortunately I totally don't remember the actual amplitudes, I would say there was about a 6dB difference between them though.
I expected a lot more attenuation above 200Hz, but apparently everything out to 1kHz has little trouble finding the ports..
I assume to some degree this is internal diffraction/reflection inside the cabinet. I hope to reduce it by adding some additional batting..
I will try the battery click test and see what that yields.
Yeah, I would say most hip hop has a lot of that one note bass going on, but sometimes there is a little more. Clearly a lot of artists are going for the "bonk" factor.. I think they deliberately choose a note that most crummy car subwoofers can reproduce loudly.. 
I'm not sure exactly how far down the port measurements were relative to the direct radiated measurements. I am evaluating Arta right now as a replacement for the very buggy and unstable AudioTester software I currently own. Until I purchase and register Arta I can't save the files, and I didn't learn how to overlay them until after the measurements.. I think we are talking relatively few dB difference though. There is a relatively large peak at 190Hz, and a much smaller one at 30Hz, unfortunately I totally don't remember the actual amplitudes, I would say there was about a 6dB difference between them though.
I expected a lot more attenuation above 200Hz, but apparently everything out to 1kHz has little trouble finding the ports..
I assume to some degree this is internal diffraction/reflection inside the cabinet. I hope to reduce it by adding some additional batting..
I will try the battery click test and see what that yields.
Yeah, I would say most hip hop has a lot of that one note bass going on, but sometimes there is a little more. Clearly a lot of artists are going for the "bonk" factor..
I think they deliberately choose a note that most crummy car subwoofers can reproduce loudly..
Hi GM,
When I used the term color in my description I was actually refering to the performance of the 165-8G which I would characterize as pretty neutral compared to what I have been used to in the past. Because I cross it over at 800Hz its tonal colorations dominate the sonic signature of the system, but considering it imho has rather good behavior in this region I couldn't be happier (for now..LOL) with the result.
Your points on port comb filtering are well taken and relevant. Can you explain how you critically damp the ports in such an implementation? Is it as simple as using a judicious amount of stuffing in the ports themselves? Testing by the afore mentioned battery click technique?
I'm very impressed with Arta and plan to buy it. Getting married in six weeks means I just won't spend the money now.. The manuals incidentally that come with this software are amongst the best I have seen.
When I used the term color in my description I was actually refering to the performance of the 165-8G which I would characterize as pretty neutral compared to what I have been used to in the past. Because I cross it over at 800Hz its tonal colorations dominate the sonic signature of the system, but considering it imho has rather good behavior in this region I couldn't be happier (for now..LOL) with the result.
Your points on port comb filtering are well taken and relevant. Can you explain how you critically damp the ports in such an implementation? Is it as simple as using a judicious amount of stuffing in the ports themselves? Testing by the afore mentioned battery click technique?
I'm very impressed with Arta and plan to buy it. Getting married in six weeks means I just won't spend the money now..
The manuals incidentally that come with this software are amongst the best I have seen.
Greets!
Assuming they're like the old 416/515 series (which they should be according to GP), then they are still somewhat 'colored' compared to more highly damped drivers, so there's still room for 'improvement' since you're not using any of the Altec horns they were voiced with. Horn loaded is where they should 'shine'.
Yes, I used the 'click' test. For an Onken, best IMO to either use a loose fill, or what I did was to put 1" acoustic fiberglass matte on the top and one side due to the parallel walls, then kept adding layers of it on the baffle board until I was satisfied since the cab acts as an end loaded two step pipe. IIRC I wound up with four layers on the 416-8C alignment.
Damping the vents is best for rolling off both its output and its harmonics, like for when they either 'boom' due to being too near a wall or corner or the cab is too small/tuned too high, i.e. make the response more TL-like. Historically it was done by stretching one or more layers of either damping material or grill cloth over the baffle thickness vent opening, but with the longer vents, foam inserts or packing them with drinking straws is preferred.
Good to know about Arta, thanks! Good luck with the marriage too!
GM
Assuming they're like the old 416/515 series (which they should be according to GP), then they are still somewhat 'colored' compared to more highly damped drivers, so there's still room for 'improvement' since you're not using any of the Altec horns they were voiced with. Horn loaded is where they should 'shine'.
Yes, I used the 'click' test. For an Onken, best IMO to either use a loose fill, or what I did was to put 1" acoustic fiberglass matte on the top and one side due to the parallel walls, then kept adding layers of it on the baffle board until I was satisfied since the cab acts as an end loaded two step pipe. IIRC I wound up with four layers on the 416-8C alignment.
Damping the vents is best for rolling off both its output and its harmonics, like for when they either 'boom' due to being too near a wall or corner or the cab is too small/tuned too high, i.e. make the response more TL-like. Historically it was done by stretching one or more layers of either damping material or grill cloth over the baffle thickness vent opening, but with the longer vents, foam inserts or packing them with drinking straws is preferred.
Good to know about Arta, thanks! Good luck with the marriage too!
GM
Hi GM,
I have done this in the past with conventional back ported BR that were placed near side walls with excellent results. I just used rolled up sheets of Dacron to fill the port. Maybe Kevin could do the same, fill in the side ports of his Onken with a thin layer of Dacron first then move up in density to fine tune.
GM, have you tried using other damping materials for Onken or MLTL like Sonic Barrier foam types from PE: Sonic Barrier
BTW, do you have metal or phenolic diaphragm material in your Altec comp drivers? What do you favor?
Thank you.
fred
Looks like we're back to stuffing again. Seems to be all trial and error, no clear rules. The only thing close to precise I've read was the Altec quote.
Kevin, it will be interesting to learn what you find by damping the ports. Save what you can from Arta.
Congrats on the up coming wedding. I've been married for about 6 weeks now. I like it!
Kevin, it will be interesting to learn what you find by damping the ports. Save what you can from Arta.
Congrats on the up coming wedding. I've been married for about 6 weeks now. I like it!
fred76 said:
Greets!
I've done some experimentation with many different foams and felts over the decades, but always went back to either fiberglass acoustic insulation or Miraflex ('itchless fiberglass variant) since they have the best performance Vs cost IMO (works well/dirt cheap - usually free for the taking from a building rehab). Never tried any I had to pay for though (my job allowed me access to generous sized samples), so don't have a clue about what various companies sell or any new formulations since early '94.
My drivers are tagged 808-8A, but I removed the loading caps and originally swapped the Symbiotic diaphragms for the alum. ones to make it an 802D (except 8 ohms) and later upgraded to the ultra light/fragile alum. version from the 802-8G as soon as they became available.
To date I haven't auditioned anything better than the -8G in a 1" exit, and it wasn't enough better to justify swapping out the '802' to get the Tangerine phase plug, though when I queried Jean-Michel Le Cleac'h WRT his comparison of TAD's $$ berylium to Altec's best, he confided it was a close call and probably not worth the $$ unless a person's hearing was up to par.
As always though, YMMV.
GM
Hi GM,
It's always nice to have freebie access to raw materials.
Anyways, thanks for sharing some of your system details. Do you know what's the difference between regular phenolic and the out of production Symbiotik (807 and 808)? I guess the TAD Be $tuff's qualities would be most obvious WRT extended HF and much 'airy' mids due to the much lighter diaph material. But a good 8k to 10k response is already okay with me, as the higher up could be augmented with a helper tweet.
regards,
fred
Greets!
Since you asked principally about the Smybiotik, my opinion is only about it. Frankly, the only folks I've known that didn't find it harsh in a typical horn HIFI app were above average HF hearing impaired from frequenting loud concerts, racing events, overly loud discos, etc. without using hearing protection and my hearing is now bad enough that I seriously doubt I could tell them apart from my alum. diaphragms, much less any difference WRT any perceived harshness.
Phenolics OTOH are much smoother due to their higher damping (especially RCA), but the trade-off is much less HF extension. When you BW limit the Symbiotik to ~mimic the response of the large format phenolics, then they too are smooth enough, but then you need a supertweeter rolled in around 12 kHz/1st order or 7 kHz/2nd whereas the large format unit can be EQ'd, trading efficiency for HF extension.
As always though, YMMV.
GM
Since you asked principally about the Smybiotik, my opinion is only about it. Frankly, the only folks I've known that didn't find it harsh in a typical horn HIFI app were above average HF hearing impaired from frequenting loud concerts, racing events, overly loud discos, etc. without using hearing protection and my hearing is now bad enough that I seriously doubt I could tell them apart from my alum. diaphragms, much less any difference WRT any perceived harshness.
Phenolics OTOH are much smoother due to their higher damping (especially RCA), but the trade-off is much less HF extension. When you BW limit the Symbiotik to ~mimic the response of the large format phenolics, then they too are smooth enough, but then you need a supertweeter rolled in around 12 kHz/1st order or 7 kHz/2nd whereas the large format unit can be EQ'd, trading efficiency for HF extension.
As always though, YMMV.
GM
fred76 said:
Greets, part deux!
FWIW, I loaded borrowed 604Es into the pair of Onken's I built and they pleased most folks that auditioned them (a bit too 'colored' for me and a few others though) except they had to be spaced up quite a bit to get the horn up to ear height, and I've seen pics of a few others as well as other brands on Japanese and European websites over the years.
That said, once I had more info about Onken alignments than just a cab drawing, I concluded that Thuras's original bass reflex patent's test cab layout that inspired the Jensen/'Onken' would be the best overall since it would easily allow a cab proportioned to get the horn up to ear height and be easier to build/fine tune, though maybe lay it out with a bit greater distance between driver/vents:
GM
Attachments
Hi GM,
I was thinking of the same thing WRT phenolics (better damped but early hf roll off). Yeah, a helper tweeter would take care of the roll off. Maybe those drivers using Pascalite (bakelite resin forumulation?) is much closer to basic phenolic. I haven’t heard any of the other diaph types from Altec except the aluminum ones.
I just realized now that I’ve already seen Onken used by coax drivers and commercial stuff at that, specifically on some models of Tannoy's Prestige series. They coin it as ‘distributed port system’. They seem taller and a bit narrower in order to get the HF driver at ear height. I was thinking along the same lines using Beyma 12CX. I’m also wondering what type of XO is most suitable for these with component values at ‘ideal’ cutoff points based on the datasheet. I’ll start a new thread on this I guess. Many thanks.
Regards,
fred
I was thinking of the same thing WRT phenolics (better damped but early hf roll off). Yeah, a helper tweeter would take care of the roll off. Maybe those drivers using Pascalite (bakelite resin forumulation?) is much closer to basic phenolic. I haven’t heard any of the other diaph types from Altec except the aluminum ones.
I just realized now that I’ve already seen Onken used by coax drivers and commercial stuff at that, specifically on some models of Tannoy's Prestige series. They coin it as ‘distributed port system’. They seem taller and a bit narrower in order to get the HF driver at ear height. I was thinking along the same lines using Beyma 12CX. I’m also wondering what type of XO is most suitable for these with component values at ‘ideal’ cutoff points based on the datasheet. I’ll start a new thread on this I guess. Many thanks.
Regards,
fred
would this one go for it ??
hello
me i do have years of l'Audiophil and No 2 with the plans and No 43 with the sandfilled monster onken. Reading a lot of fun
1993 and 94 Paris l'espace Kiron I did get the Onken virus.
Me I do woodwork and build speakers for friends.
I played violin,bass and now piano and guitar.
So a stupid one from a petite blonde with brains LOL
will that do the job?
Vas seems to be ok anyway
McCauley 6174 18'
Freq. Response (-3dB) 15Hz - 800Hz
Recommended Enclosure Volume 6ft³
169.9L
Power Handling (RMS)
Full Range 800W
Max Peak SPL
Full Range 129.031dB
Max Continuous SPL
Full Range 123.031dB
Sensitivity
Full Range 94dB
Theile Small
Free Air Resonance (Fs) 20
4Ù DC Coil Resistance (Re/Dcr) 5.6Ù
Electrical Losses (Qes) 0.38
Mechanical Losses (Qms) 2.9
Total Quality Factor (Qts) 0.34
Equivalent Volume of Air (Vas) 25.9ft³
733.41L
Effective Piston Area (Sd) 199in.²
1283.87cm²
Excursion -- Max BL (Xmax) 0.6in.
15.24mm
Volumn Displacement (Vd) 200in.³
3.28L
Inductance of V.C. (Le) 1.1mH
BL Factor 15.3Tm
Effective Moving Mass 0.222kg
7.83oz.
Nominal Efficiency 0.0066%
Flux Density 13500 gauss
hello
me i do have years of l'Audiophil and No 2 with the plans and No 43 with the sandfilled monster onken. Reading a lot of fun
1993 and 94 Paris l'espace Kiron I did get the Onken virus.
Me I do woodwork and build speakers for friends.
I played violin,bass and now piano and guitar.
So a stupid one from a petite blonde with brains LOL
will that do the job?
Vas seems to be ok anyway
McCauley 6174 18'
Freq. Response (-3dB) 15Hz - 800Hz
Recommended Enclosure Volume 6ft³
169.9L
Power Handling (RMS)
Full Range 800W
Max Peak SPL
Full Range 129.031dB
Max Continuous SPL
Full Range 123.031dB
Sensitivity
Full Range 94dB
Theile Small
Free Air Resonance (Fs) 20
4Ù DC Coil Resistance (Re/Dcr) 5.6Ù
Electrical Losses (Qes) 0.38
Mechanical Losses (Qms) 2.9
Total Quality Factor (Qts) 0.34
Equivalent Volume of Air (Vas) 25.9ft³
733.41L
Effective Piston Area (Sd) 199in.²
1283.87cm²
Excursion -- Max BL (Xmax) 0.6in.
15.24mm
Volumn Displacement (Vd) 200in.³
3.28L
Inductance of V.C. (Le) 1.1mH
BL Factor 15.3Tm
Effective Moving Mass 0.222kg
7.83oz.
Nominal Efficiency 0.0066%
Flux Density 13500 gauss
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