Long time lurker here poking thru hundreds of posts and still looking to connect some dots, any help would be appreciated.
I run a simple 6V6 driven SET ~2W) tied a sub 90dB efficiency speak (ported) that sounds very articulate and pleasing, but now looking to build high impedance matching speaker for a small computer room. Those speakers will go back to being driven by a PP amp that seems to be better matched at higher volumes in the room that it is in.
The new situation would be somewhat of a close coupled listening (not a perfect room at all) and would need to target a smaller sized cabinet. I realize most of the legacy drivers impedance curves did match well for high impedance amps, but now wondering if any of the recent gen drivers fill this bill? Much of the work on the earlier drivers/cab's seem to be obsolete and the newer drivers dont seem to be developed much with the older speaker designs, at least not in depth.
The min- Onken or FHL or would be nice if possible and MA drivers?
Thank you in advance!
I run a simple 6V6 driven SET ~2W) tied a sub 90dB efficiency speak (ported) that sounds very articulate and pleasing, but now looking to build high impedance matching speaker for a small computer room. Those speakers will go back to being driven by a PP amp that seems to be better matched at higher volumes in the room that it is in.
The new situation would be somewhat of a close coupled listening (not a perfect room at all) and would need to target a smaller sized cabinet. I realize most of the legacy drivers impedance curves did match well for high impedance amps, but now wondering if any of the recent gen drivers fill this bill? Much of the work on the earlier drivers/cab's seem to be obsolete and the newer drivers dont seem to be developed much with the older speaker designs, at least not in depth.
The min- Onken or FHL or would be nice if possible and MA drivers?
Thank you in advance!
There are many miniOnkens for MA drivers. And they were a prime target for the frugel-Horns.
Note that MA is more a less a direct evolution of Ted Jordan’s work that he started in the 50s. Modern modeling and manufacturing give modern manufactures an advntage — if they wish to explout it.
What kind of budget? How big?
dave
Note that MA is more a less a direct evolution of Ted Jordan’s work that he started in the 50s. Modern modeling and manufacturing give modern manufactures an advntage — if they wish to explout it.
What kind of budget? How big?
dave
Hi Dave - thanks for the quick reply and contributions throughout these many years to any and all inquiries, I am grateful and honestly amazed.
My budget is fortunately not a big concern, complexity is very welcome and size maybe the most constraining. The room, a home office, is a narrow rectangular affair that once was a porch when the home was first built in the 20's, converted thereafter with lots of windows half tall windows and wonderful views. It is something on the order of 10' x 20'. I envision lower volume listening although that flea amp comfortably filled a 20 x 40' living room. I suppose with great success, this project could even go back into the living room??
One further question, assuming baltic is no longer reasonably available, are folks just moving to cabinet grade veneer ply for boxes. I noted in many cases that MDF was much less preferred, but no clear alternatives.
My budget is fortunately not a big concern, complexity is very welcome and size maybe the most constraining. The room, a home office, is a narrow rectangular affair that once was a porch when the home was first built in the 20's, converted thereafter with lots of windows half tall windows and wonderful views. It is something on the order of 10' x 20'. I envision lower volume listening although that flea amp comfortably filled a 20 x 40' living room. I suppose with great success, this project could even go back into the living room??
One further question, assuming baltic is no longer reasonably available, are folks just moving to cabinet grade veneer ply for boxes. I noted in many cases that MDF was much less preferred, but no clear alternatives.
There are a wide range of 9 litre miniOnkens which may be well suited to your task. A range of Mark Audio, and more.
Trapezoid (with A7p)
Rectangular:
There are also Classic GOlde Ratio boxes
dave
Trapezoid (with A7p)
Rectangular:
There are also Classic GOlde Ratio boxes
dave
Mark Audio drivers are indeed what i also would recommend. I use an own design bookshelf in a similar room. I now use it with a transistor ab class amp, but i did run it with various amps in the past (also high output inpendance) and those drivers work with both. 2W is little altough so only fit for close listening. But if you want high volume from 2w, you will need huge horns anyway, no small cabinet will do that, with any driver.
Planet10's designs are good (and certainly an option), but for the record, this is my design that is double as large (17.9L) but tuned lower (44Hz): https://www.dropbox.com/s/e619di32n...0M-Slot-Ported-Official-CAD-drawings.pdf?dl=0
Planet10's designs are good (and certainly an option), but for the record, this is my design that is double as large (17.9L) but tuned lower (44Hz): https://www.dropbox.com/s/e619di32n...0M-Slot-Ported-Official-CAD-drawings.pdf?dl=0
Attachments
Thank you for the attachments. The Trapezoid design seems intuitive as 3rd dimension horn?
The A7P drive (while obsolete) looks to be a remarkable FR driver, the betters the recent vintages? Annndd Madisound only has 1 unit left to order ;( so I guess we move on. Is the Pluvia 7PHD the closest equivalent?
One question on the dwgs, can you please clarify what the highlighted line represents? It is shown in both dwgs of this design family and I cannot figure it out.
I guess the fun part is building and tuning multiple boxes....the smaller sizes dont consume too much material.
The A7P drive (while obsolete) looks to be a remarkable FR driver, the betters the recent vintages? Annndd Madisound only has 1 unit left to order ;( so I guess we move on. Is the Pluvia 7PHD the closest equivalent?
One question on the dwgs, can you please clarify what the highlighted line represents? It is shown in both dwgs of this design family and I cannot figure it out.
There are a wide range of 9 litre miniOnkens which may be well suited to your task. A range of Mark Audio, and more.
Trapezoid (with A7p)
Rectangular:
There are also Classic GOlde Ratio boxes
dave
I guess the fun part is building and tuning multiple boxes....the smaller sizes dont consume too much material.
Interesting design, thank you for sharing.
Which driver did you use that worked well with this notch filter? And is this really a notch filter....I am not familiar with it?
The P7 PHD Paper cones are on sale right now so would be good to grab if this is what you tuned to.
Not a horn, a reflex with highR vents pushing the box towards aperiodic.
The little bit you hi-lighted is the vent spacer reaching all the way to the back of the box.
One of MA’s misses. It takes a lot of break-in but the people that have it like it a lot. It does not have teh same lovely voicing of the A6p/A10p. P7PHD is NOT the same. Like the CHN70 it is voiced for the Japanese, and while they have their adherents, generally not what those in the west tend to prefer.
I still have at least 1 pr.
dave
I build it with the Alpair 10.3, simulations say that the Alpair 10P would also work. The other Mark Audio drivers not.
The notch filter is to tame the driver resonance in the treble. I like it more like that, altough it's not mandatory to sound good. It's an classic passive notch filter, nothing special except that it's tuned to the driver's response that i measured in a sealed cabinet i build before (and had measurements of). The difference of cabinet does not matter, as that won't influence that notch filter.
Excellent, makes sense now on the spacer. Is the spacing itself a tuning element (recommend to tune) and or should this in the end be fully glued and seal in place during the build?
As for the extra pair.....are you will to part with them? And if not, what other driver options should be tried now that the end is near for the A7P?
I keep the width of the vents the same. That gives a maximum vent exit of the height of the loudspeaker. That is too high for almost all drivers so its exit are needs to be decreased. The vent spacers fill the unwanted space (FF125wk & A6p in millSize box are perfect without a spacer).
But what drew me to the Onken vent structure was the naturally braced multiple iBeam wall which is very stiff. on its own. So the vent spacers can be considered braces as well.
If you find a miniOnken to have to have bass adjusted it can be damped down by introducing open cel foam as additional aperiodic damping into the vents. This is useful sometimes when adding woofer support, and we found it necessary in our first miniOnken for the FR125 when used with an SE amp with high Rout.
I would love to see the A7p go to good homes, and pricing will be aggressive.
dave
But what drew me to the Onken vent structure was the naturally braced multiple iBeam wall which is very stiff. on its own. So the vent spacers can be considered braces as well.
If you find a miniOnken to have to have bass adjusted it can be damped down by introducing open cel foam as additional aperiodic damping into the vents. This is useful sometimes when adding woofer support, and we found it necessary in our first miniOnken for the FR125 when used with an SE amp with high Rout.
I would love to see the A7p go to good homes, and pricing will be aggressive.
dave
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Yes this trapezoid structure must be extremely stiff in all directions.
I am planning 2 ply bonded wood cross grained to get to full thickness and added stiffness. I have some self milled Dutch Elm that has never found a home that will be glued to some maple for the inside facing surface. The vent pieces likely maple as well...
I would love the AP7's, let me know if this is an option and then shipping...I am in California US.
I am planning 2 ply bonded wood cross grained to get to full thickness and added stiffness. I have some self milled Dutch Elm that has never found a home that will be glued to some maple for the inside facing surface. The vent pieces likely maple as well...
I would love the AP7's, let me know if this is an option and then shipping...I am in California US.
Great - PM on the way.
BTW - I just did a 2D layout....are the vents intended to be ~6mm opening (vent spacer thickness)? This is sort of eyeballed since the length of the flat sides do not seem to be as big as your layout. If I try to match your layout to have "bigger" flat sections, the vents obviously get narrower. The yellow highlighted are is the opening thickness now shown just under 6mm.
And then what should the vent opening heights be, looking from the front? The top and bottom vents look to be about 1/2 the 2 middle vent heights?
BTW - I just did a 2D layout....are the vents intended to be ~6mm opening (vent spacer thickness)? This is sort of eyeballed since the length of the flat sides do not seem to be as big as your layout. If I try to match your layout to have "bigger" flat sections, the vents obviously get narrower. The yellow highlighted are is the opening thickness now shown just under 6mm.
And then what should the vent opening heights be, looking from the front? The top and bottom vents look to be about 1/2 the 2 middle vent heights?
I don’t think i have used 6mm on any vents. 7mm on the µSize, 9mm on larger size bookselves (like the one for A7p), 12, 15mm in the moster miniOnkens and some of the CGRs and milliSize.
Those drawings are readily available with full dimensioning (i’ll toss in the planset with the drivers i have left ($25 bonus).
Your other dimensions suggest that you have scaled the box down not quite to half.
dave
Those drawings are readily available with full dimensioning (i’ll toss in the planset with the drivers i have left ($25 bonus).
Your other dimensions suggest that you have scaled the box down not quite to half.
dave