LOL 🙂 im sure a round port has SOME benefit though...however small. something to do with area to circumference ratio, friction etc.....saying that some additional port losses may be beneficial...
Right a circular pipe has the least surface area for a given length, so for a given area, tuning, material/finish it will be the shortest due to having the least friction.
GM
GM
First of all apologize for the absolutely massive topic bump but I figured it would be better then creating a new topic.
Second, after many months occupied by finishing my grade 11 school year and working throughout the summer, in the last few days I have found the time to finally assemble my ML-voigts. They are now about 80% complete (with only the driver hole to be cut and the interior baffle to be made) and I'm looking for clarification about the driver placement.... Basically I need to know if the driver has to be countersunk. I don't think I have access to the tools nor the woodworking skill to do so..
When I get on my pc later I'll repost the designs I am following (though they are somewhere in this thread posted by planet10).
Thanks,
Russell
Second, after many months occupied by finishing my grade 11 school year and working throughout the summer, in the last few days I have found the time to finally assemble my ML-voigts. They are now about 80% complete (with only the driver hole to be cut and the interior baffle to be made) and I'm looking for clarification about the driver placement.... Basically I need to know if the driver has to be countersunk. I don't think I have access to the tools nor the woodworking skill to do so..
When I get on my pc later I'll repost the designs I am following (though they are somewhere in this thread posted by planet10).
Thanks,
Russell
IIRC this is the one http://creativesound.ca/pdf/ML-Voigt.pdf
The Mark Audio drivers (of which EL70 is one) have a fat circular bezel. If this is left unrebated there will be an increase in the diffration signature, If you can't rebate the driver, you can use various methods to minimize the issue.
Pretty much it these amount to faking a rebate. Find a piece of material the thickness of the bezel (dense wool felt, wood, cork, plastic), cut a hole in it that just fits around the bezel and then place it over the driver and attach to the baffle.
dave
The Mark Audio drivers (of which EL70 is one) have a fat circular bezel. If this is left unrebated there will be an increase in the diffration signature, If you can't rebate the driver, you can use various methods to minimize the issue.
Pretty much it these amount to faking a rebate. Find a piece of material the thickness of the bezel (dense wool felt, wood, cork, plastic), cut a hole in it that just fits around the bezel and then place it over the driver and attach to the baffle.
dave
Dave,
This top-layer - should it be full length of the baffle or partial works too?
-Zia
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Or do as I typically did and make a second full size baffle 'veneer' to both rebate the driver and stiffen it up, 'killing two birds with one stone'. 😉
Note that the rear of the hole ideally needs to be beveled out at >45 deg, but no need for any fancy router work, I just dug it out with a really coarse wood rasp file until I was able to afford an industrial strength Dremel-like hand held grinder/wood rasp bit to make quick work of it.
GM
Note that the rear of the hole ideally needs to be beveled out at >45 deg, but no need for any fancy router work, I just dug it out with a really coarse wood rasp file until I was able to afford an industrial strength Dremel-like hand held grinder/wood rasp bit to make quick work of it.
GM
Full length has advantages as GM points out, but any langth that gives a wider distribution of the length of the centre of the driver to the edge is an improvement over tha all lengths are equal that the edge of the bezel gives.
dave
Alright thanks dave, I think I'll take my chances with getting my dad to use a router to attempt to countersink the driver
Also, I don't fully understand the angled interior bevel. How can you screw the driver into the enclosure after effectively thinning what it's being screwed into
Also, I don't fully understand the angled interior bevel. How can you screw the driver into the enclosure after effectively thinning what it's being screwed into
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The MA baskets are very open at the back so you can get reflections from a vertical wall on the cutout. You can bevel just that part not near the screws. If you built with ply like we do, what is leftover provides enuff meat for the screws.
If you want to go nuts something the heads in the direction of all-out (see picture) works too.
dave
If you want to go nuts something the heads in the direction of all-out (see picture) works too.
dave
ok, driver holes are cut and routed out, i'm going to bevel the inside edges tomorrow.. after that, i only have the interior baffle to make. getting closer!
this is probably the only time i can get away with saying this....
I have a dremel for routing/shaping the rear of a cutout, but i have in the past used a coarse rash and dare i say it? even a Bastard file every now and then...less woodworking and more wood abuse 😀
P10 states about the MA drivers having very open backs, which is true, but in contrast to some Neo drivers which are very open, In my experience, the MA drivers are open but transversely rather than axially, with respect to the cone, so naturally and unfortunately reflections will occur. unless rounded off the inner edges have a profound affect in these cases.
I have a dremel for routing/shaping the rear of a cutout, but i have in the past used a coarse rash and dare i say it? even a Bastard file every now and then...less woodworking and more wood abuse 😀
P10 states about the MA drivers having very open backs, which is true, but in contrast to some Neo drivers which are very open, In my experience, the MA drivers are open but transversely rather than axially, with respect to the cone, so naturally and unfortunately reflections will occur. unless rounded off the inner edges have a profound affect in these cases.
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If you get the back of the cutout at an angle (we do 45 degrees) then waves traveling sideways get reflected towards the back of the box and not right back thru the cone.
dave
dave
Voigt pipe speakers - ADVICE NEEDED!
I am a retired architect with acoustic knowledge; I have no electrical knowledge. I am much more interested in music than in hi-fi per se ;-) . I sold my acoustic double bass and now play a redesigned small EUB "Electric upright bass" - so of course I have to take a separate amp=speaker combo - or do I? The bodyless bass will fit in a tube about 7" x 5" 48" long. If I was make a folded Voigt speaker with those dimensions the total tube length would be about 96" ... What would the bass frequency response be? I am using a tuning that means my lowest frequency is 32hz - is that unattainable with speaker of this size?
So what am I trying to do? Make a hard case for the bass which is ALSO a Voigt pipe enclosure. The bass & a soft case would slot into the wider/lower part of the leg, and the drive unit in the (inaccessible) upper part. SO I would no longer need to carry bass & speaker amp separately....
I am a retired architect with acoustic knowledge; I have no electrical knowledge. I am much more interested in music than in hi-fi per se ;-) . I sold my acoustic double bass and now play a redesigned small EUB "Electric upright bass" - so of course I have to take a separate amp=speaker combo - or do I? The bodyless bass will fit in a tube about 7" x 5" 48" long. If I was make a folded Voigt speaker with those dimensions the total tube length would be about 96" ... What would the bass frequency response be? I am using a tuning that means my lowest frequency is 32hz - is that unattainable with speaker of this size?
So what am I trying to do? Make a hard case for the bass which is ALSO a Voigt pipe enclosure. The bass & a soft case would slot into the wider/lower part of the leg, and the drive unit in the (inaccessible) upper part. SO I would no longer need to carry bass & speaker amp separately....
