er, I thought life was the big deal...audio is but a nice little diversion 
I can say from first-hand experience that the resistive Onken-style cabinets are very good. I've spent perhaps a total of 2 years listening to a few of Dave's designs.(they are all very good), but the Onken styles are best (methinks). Here's a really simple experiment for any that feel that resistive vents are but a fantasy: If you have a pair of typical Bass Reflex enclosures with suitable drivers in them (commercial or DIY), get em out of storage or wherever you have them and put them into the best system you have access to. Play music that you love (and know well), preferably acoustical but electric blues/jazz, etc is good too (full orchestral pieces can be used too, if not too complex).
Listen at a reasonable level, just don't overdrive the speakers, for at least a couple of songs to re-accustom your ears to the sound. Now get ye a handful of drinking straws and bind a them together with an elastic band. Cut them to the length of the ports or slightly longer. Stuff them into the ports of the loudspeakers. Listen again, without changing anything else (including the volume control). If subjectively the level seems lower, then overall the distortions have been reduced. This suggests a reduction in bass distortion, and more accurate bass. It'll cost ya about 50¢for the whole "experiment. You be the judge.
This is what the Onken style cabinets can do (and aperiodic designs as well). It would be instructive to overlay a frequency sweep below, say, 1K, in a BR, a "stuffed vent BR, and an Onken enclosure, everything else being equal (within reason), and an aperiodic. (I have no testing equipment except what is between my ears). just a couple of thoughts.
I can say from first-hand experience that the resistive Onken-style cabinets are very good. I've spent perhaps a total of 2 years listening to a few of Dave's designs.(they are all very good), but the Onken styles are best (methinks). Here's a really simple experiment for any that feel that resistive vents are but a fantasy: If you have a pair of typical Bass Reflex enclosures with suitable drivers in them (commercial or DIY), get em out of storage or wherever you have them and put them into the best system you have access to. Play music that you love (and know well), preferably acoustical but electric blues/jazz, etc is good too (full orchestral pieces can be used too, if not too complex).
Listen at a reasonable level, just don't overdrive the speakers, for at least a couple of songs to re-accustom your ears to the sound. Now get ye a handful of drinking straws and bind a them together with an elastic band. Cut them to the length of the ports or slightly longer. Stuff them into the ports of the loudspeakers. Listen again, without changing anything else (including the volume control). If subjectively the level seems lower, then overall the distortions have been reduced. This suggests a reduction in bass distortion, and more accurate bass. It'll cost ya about 50¢for the whole "experiment. You be the judge.
This is what the Onken style cabinets can do (and aperiodic designs as well). It would be instructive to overlay a frequency sweep below, say, 1K, in a BR, a "stuffed vent BR, and an Onken enclosure, everything else being equal (within reason), and an aperiodic. (I have no testing equipment except what is between my ears). just a couple of thoughts.
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I wonder what this effect this would have in the Metronome?
Another item I wonder about with the Metronome is what effect padding the base plate (holding the port) with damping material would have....
I am also wondering what the effect would be that instead of having a pipe (round port) of a determined length to have a pipe that has a Karlson slot from 1/4 of the end to the end. The length will need to be increased to where the "center" of the exponential opening area is at the same location as a normal port would finish.
Just musing about possibilities to improve the Metronome.
(build Karlsons in the past and found them very forgiving about different resonance frequencies in the different speakers)
AM
I have always used four small ports, sized to be effective with just the wood thickness as their length. You can use Bass Box Pro to model this, and I assume other programs also. By ear/sight, place a small bit of fluff in one of the four holes and tap the woofer, if it flies out you are just about perfect. I do have a set of stepped drills (both letters and numbers) for this purpose, among many others.
Bud
Bud
Drumroll please.....
The dMar-Ken70's are finally making music.
In brief: they're pretty nice.
Defining characteristics: Heaps more bass than you'd expect, and a nice extended top end. In this cabinet, the CHR-70 is very nearly a "full range" driver.
Oh, and for all that they're low efficiency, they play plenty loud enough - I've been testing with a 15W Class-T amp. I think we sometimes forget that 90dB is actually pretty loud.
The dMar-Ken70's are finally making music.
In brief: they're pretty nice.
Defining characteristics: Heaps more bass than you'd expect, and a nice extended top end. In this cabinet, the CHR-70 is very nearly a "full range" driver.
Oh, and for all that they're low efficiency, they play plenty loud enough - I've been testing with a 15W Class-T amp. I think we sometimes forget that 90dB is actually pretty loud.
Attachments
When you get a chance, send me some big pictures to post.
Is that a MacBook posing with the coffee cup?
Our dMar-Ken7 are playing (A7s are still stock, Chris has them ATM), the dMar-Ken70 await veneer and a set of the CHR Mk2.
If i feel these work out (an so far all the reports indicate they will), i'm thinking of a variation made of Blanda Bowls.
dave
Is that a MacBook posing with the coffee cup?
Our dMar-Ken7 are playing (A7s are still stock, Chris has them ATM), the dMar-Ken70 await veneer and a set of the CHR Mk2.
If i feel these work out (an so far all the reports indicate they will), i'm thinking of a variation made of Blanda Bowls.
dave
For shame, Dave, it's a TEA cup.
The Mac (as well as the speakers, once they're finished) belong to my girlfriend - I can pose my sister's MacBook for the bigger shots if you think my Dell might spoil it
(incidentally, Apple's habit of turning off the integrated sound card to save power is really repulsive - you hit pause and all is silent, then it starts to hum. Then you hit play and it produces an almighty POP! when it switches back on. Not exactly ideal, that.)
I'll charge up the real camera to grab some better shots later - they're still pretty rough, nailgun pockmarks everywhere - and 3 of the 4 chamfers show a brad sliced in half by the circular saw. But that'll mostly clean up once they're filled, sanded and painted.
EDIT: Oh, and do let us know how the dMar-Ken7's compare to the 70's once you have them both playing.
I'm still really impressed by these - the same comments I made back when I was playing them bare still apply. Voices are stunning, imaging is quite remarkable. The only difference is an improvement - they have ample bass, and seeing these little cones swing 4mm whilst playing (quite sucessfully) the infamous TR-808 kick drum sample is hilarious.
Oh, and they can do rock surprisingly well - they never sound strained at lounge room volumes. They're never going to give "the concert experience", but I could live quite happily with these as my only speakers - unfortunately, they're going away, to join the shiny new computer I built, and the DAC that I built, and the amp that I haven't built yet. Why can't I afford to build all these nice things for myself?
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The Mac (as well as the speakers, once they're finished) belong to my girlfriend - I can pose my sister's MacBook for the bigger shots if you think my Dell might spoil it
The Dell would spoil it.
I've never run into that. But then i've not been able to afford an Intel Mac yet, and i almost always use an external DAC (firewire, but i have a USB backup)
You can be sure i will.
Adding a pair of helper woofers goes a lomg ways
Make sure you make a profit on each one...
dave
Yeah! If the speaker is designed for a short-range monitor like that, efficiency is rather moot.
Also, the new "silver cone black dustcap" thing is rather sharp, and the artist in me really wants to design a box that accentuates that feature.
small speakers, big sound, T-amps
I've tried these (dMarKeNs) with several amps. The best thus far has been a SE 6BM8 2 watt Phillip "console" (using the speakers as extension speakers). They are quite beautiful to listen to from 8'+ The sub does add some 'staging abilities (not that the dMarKeNs are deficient in any way in this regard)
None need make excuses for these speakers, they truly are "almost full range". They play deeper than my Castle Durham 900 loudspeakers (similar efficiency). I've tried a 10" Kef powered subwoofer with the X-over set to 30Hz, and output barely perceivable while inches away from the sub box itself. These little speakers will play plenty loud enough to drive most people from a moderately sized room (not any of Dave's rooms as he has 15'-20' ceilings at his place).
In order of preference for amplifiers tried that I have on hand:
The Nuforce Icon is the natural choice, even though Nuforce suggests not to use the Icon as an integrated in a home audio system. I think this combination is the "cheapskate's choice". I will be writing up further comments for June's Affordable$$Audio, I think (but I better get writing;p ).
I still have not tried them with the DNA 0.5, as I finally discovered the problem with it and have fixed it. I needed to replace all 4 fuses--- only replacing the one that was burnt resulted in terrible sound.
Since completing the dMarKeNs I have tried the CHR-70eNs in a small baffle that is designed to replace the Jordan JX92s OB portion of the Spirit of Orion loudspeakers. Comparing the Jordans vs. the "eNs" is a no-brainer. The "eNs" are much smoother. They lack a tiny bit of sparkle compared to the Jordans, but I suspect that the Jordans add sparkle. I still have not finished the cabinets (they are built, just have no finish on them), but will do so now that the drivers are in the little baffles.
I've tried these (dMarKeNs) with several amps. The best thus far has been a SE 6BM8 2 watt Phillip "console" (using the speakers as extension speakers). They are quite beautiful to listen to from 8'+ The sub does add some 'staging abilities (not that the dMarKeNs are deficient in any way in this regard)
None need make excuses for these speakers, they truly are "almost full range". They play deeper than my Castle Durham 900 loudspeakers (similar efficiency). I've tried a 10" Kef powered subwoofer with the X-over set to 30Hz, and output barely perceivable while inches away from the sub box itself. These little speakers will play plenty loud enough to drive most people from a moderately sized room (not any of Dave's rooms as he has 15'-20' ceilings at his place).
In order of preference for amplifiers tried that I have on hand:
- Phillips 6BM8 console, circa 1961
- Nuforce Icon digital amp (not a T-amp)
- Teac Reference 100 mini system, used as an amplifier only
- Nakamichi SR-2 Stasis receiver (thanks to Nelson Pass for designing and licensing the topography that allowed these to be made)
The Nuforce Icon is the natural choice, even though Nuforce suggests not to use the Icon as an integrated in a home audio system. I think this combination is the "cheapskate's choice". I will be writing up further comments for June's Affordable$$Audio, I think (but I better get writing;p ).
I still have not tried them with the DNA 0.5, as I finally discovered the problem with it and have fixed it. I needed to replace all 4 fuses--- only replacing the one that was burnt resulted in terrible sound.
Since completing the dMarKeNs I have tried the CHR-70eNs in a small baffle that is designed to replace the Jordan JX92s OB portion of the Spirit of Orion loudspeakers. Comparing the Jordans vs. the "eNs" is a no-brainer. The "eNs" are much smoother. They lack a tiny bit of sparkle compared to the Jordans, but I suspect that the Jordans add sparkle. I still have not finished the cabinets (they are built, just have no finish on them), but will do so now that the drivers are in the little baffles.
Attachments
It will be interesting to hear how the Alpair12eN works out... they (currently) have the same retail as the JX92 (and to my ear) start out ahead.
I think that Stew's point is that you can buy 2 pair of CHR70eN for the price of a stock set of Jordans (with change left over) -- gives you an idea how well the CHRs respond to EnABL (no other treatment, other than matching) on these
dave
yes, by what i recall they were intended to cross somewhere infront of the listener, so have a rise to maintaing hf balanced, or something like this in some interview to venerable Ted Jordan.
Dave, did you got a chance to listen to enabled alpair10 and compare them to enabled chr70?
Nanook, what frequency do you cross them OB? once crossed what spl do you think they will handle, is there a way to calculate it?
Yes. The A10 responds in all the same ways as the CHR. I think they need a bit more work to sweeten the top end, but with the A10 Mk2 almost here, i'll have to start over again. I also loaned them out (in Mar-Ken10) an they don't seem to be coming back. I think Jeff hopes i forgot he has them
Just got a 2nd set of A7, that is where i'll be starting with the new gen of Alpairs. 2 dozen CHR Mk2 should be here shortly too.
And i have a special project in the works for the A12.
dave
my comments regarding versatility of the CHR70eN drivers.
The point is not to pick on the Jordans. Personally I like the Jordans, and I like their slight top end rise. Obviously the Jordans should be treated as well... but... my audio partner (Mike) has the Spirits, and the complete speakers are his.
He had enough faith in me and my "design" abilities to take a chance and buy all the required supplies to make them. The investment was: plate amps (2); the subs (2); the Jordans; and all the wood, binding posts etc. None of the items were cheap, including the Baltic Birch plywood used for the compete enclosures (I still don't have pictures of the complete speakers). I supplied templates/guides for the side "cheeks" (modelled after Linkwitz's Orion loudspeakers and basic dimensions for the subs). Together we wired the amps up, and built the speakers and amp enclosure. The decision to eNABL them is entirely his. However getting together to make refinements and changes is difficult because his business is very weather dependant. He is generally "on call" 24 hours a day for 10 months+ per year. Even listening to each other's systems can be difficult, if not impossible.
Concerning affordability, the intent was to show that you can have (what I feel) is superior performance (the CHR70eNs) at a much lower cost (than the Jordan JX92s drivers). As far as versatility, I have found the CHR70s to work very well in a small OB, and the Onken style cabinet design of Dave's. This opens up this hobby to many more folks based on amplifier power, type, and costs. The CHRs are 90dB efficient vs the Jordans at 88dB, so the need for more powerful amplifiers are not required. Good quality watts cost $$$, as illustrated by Nelson Pass' "First Watt" concepts and amplifiers. Rather spend $$$s on a few GOOD watts than lots of them. (I have spent essentially all of my adult life promoting this idea to as many people as would listen. Unfortunately it usually falls upon deaf ears. The few that I have convinced to listen to a low power system, usually become life-long converts and embrace it whole heartedly)
Perhaps Dave can comment on the measured sensitivities of these two drivers, or a comparison of the impedance curves should be considered, but with at least 2dB difference, the CHRs can be driven quite nicely by a smaller class D, class T, or tube amp. The Jordans seem to realy like solid state amplification (or perhaps the increased dampening factor) usually associated with them.
Folks (and not intended as an affront to Bud, who I respect and enjoy...
particular the one chance I have had to share "face time" with him), but I have tried to stay on task and on topic for this thread. Bud's contributions cannot be understated regarding the "EnABL" process (his invention, free for personal use), the "ground pool electrons (again his use and implementation), and of course the transformer work that he has carried on with many years.
The point is not to pick on the Jordans. Personally I like the Jordans, and I like their slight top end rise. Obviously the Jordans should be treated as well... but... my audio partner (Mike) has the Spirits, and the complete speakers are his.
He had enough faith in me and my "design" abilities to take a chance and buy all the required supplies to make them. The investment was: plate amps (2); the subs (2); the Jordans; and all the wood, binding posts etc. None of the items were cheap, including the Baltic Birch plywood used for the compete enclosures (I still don't have pictures of the complete speakers). I supplied templates/guides for the side "cheeks" (modelled after Linkwitz's Orion loudspeakers and basic dimensions for the subs). Together we wired the amps up, and built the speakers and amp enclosure. The decision to eNABL them is entirely his. However getting together to make refinements and changes is difficult because his business is very weather dependant. He is generally "on call" 24 hours a day for 10 months+ per year. Even listening to each other's systems can be difficult, if not impossible.
Concerning affordability, the intent was to show that you can have (what I feel) is superior performance (the CHR70eNs) at a much lower cost (than the Jordan JX92s drivers). As far as versatility, I have found the CHR70s to work very well in a small OB, and the Onken style cabinet design of Dave's. This opens up this hobby to many more folks based on amplifier power, type, and costs. The CHRs are 90dB efficient vs the Jordans at 88dB, so the need for more powerful amplifiers are not required. Good quality watts cost $$$, as illustrated by Nelson Pass' "First Watt" concepts and amplifiers. Rather spend $$$s on a few GOOD watts than lots of them. (I have spent essentially all of my adult life promoting this idea to as many people as would listen. Unfortunately it usually falls upon deaf ears. The few that I have convinced to listen to a low power system, usually become life-long converts and embrace it whole heartedly)
Perhaps Dave can comment on the measured sensitivities of these two drivers, or a comparison of the impedance curves should be considered, but with at least 2dB difference, the CHRs can be driven quite nicely by a smaller class D, class T, or tube amp. The Jordans seem to realy like solid state amplification (or perhaps the increased dampening factor) usually associated with them.
Folks (and not intended as an affront to Bud, who I respect and enjoy...
particular the one chance I have had to share "face time" with him), but I have tried to stay on task and on topic for this thread. Bud's contributions cannot be understated regarding the "EnABL" process (his invention, free for personal use), the "ground pool electrons (again his use and implementation), and of course the transformer work that he has carried on with many years.
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