FlorianO said:
When Chris & i did the 1st rev of the A126 with the smaller CC we had a midrange problem too -- our description was a bit different (a closed in, hands cupped kind of colouration on vocals), but with the inaccuarcy of using words to descibe what something sounds like, we could be talking about the same thing. Ron took what we had said and went back and deiscovered analytically what we were trying to describe, leading to the largwe CC and the supraBaffle to compensate for the change in low-pass the larger CC brought about.
Deflex eats volume, so that should go, a little damping with increase the apparent volume a little bit (why Ed needs to add some to the Horn). A temporary spacer could be added to the front to explicitly experiment with larger CC vol, and then have extra volume built into the supra-baffle.
Also worthwhile cutting out a cardboard supraBaffle just to see how that affects things.
dave
resonance problems
My 126A did have a resonance problem which was solved by glueing 1/4 inch hardi- backer to the exterior sides of the box. I did not use great plywood and that must be the reason. I clamped wood and other things at various times on the sides which made a differance, but the 1/4" board made a dramatic differance, maybe just because it was clue applied.
As far as inlarging the CC, I cut the baffle board area out where the speaker was mounted so that the opening is square and flush with the interior sides. I added a SB that was two layers on one and three layers on the other. The carving out of SB interior to flow into the box interior gives a bit more volume. I did not measure the volume, but the three layer baffle seems to sound more full spectrum.
Bob
My 126A did have a resonance problem which was solved by glueing 1/4 inch hardi- backer to the exterior sides of the box. I did not use great plywood and that must be the reason. I clamped wood and other things at various times on the sides which made a differance, but the 1/4" board made a dramatic differance, maybe just because it was clue applied.
As far as inlarging the CC, I cut the baffle board area out where the speaker was mounted so that the opening is square and flush with the interior sides. I added a SB that was two layers on one and three layers on the other. The carving out of SB interior to flow into the box interior gives a bit more volume. I did not measure the volume, but the three layer baffle seems to sound more full spectrum.
Bob
Bob,
I was thinking the same way: Enlarging the driver cut-out in the front baffle all the way to the the sides (practically means cutting the top 155mm square of the front baffle) and mounting the SB on top. The reason was to avoid creating a 54 mm (2.1'') round "tube" out of the 3xT circular cut-outs for the driver (1xT in front baffle, 2xT for the SB). But that will not allow removing the SB afterwards if I in the end I will still prefer it without the full monty 😎
All that if I will mount the SB that way, that is. Haven't gave too much though to alternative ways of mounting the SB -- like building it _around_ the front baffle and sides or smth.
gnat_leader,
I assumed that when you said "resonances" you did meant just that. Colorations and closed-in sounds are a different matter. I for one just took Dave and Chris extensive experiences and advice and dimensioned mine accordingly.
For me a very telling experiment was to mount the driver on a mini OB and give it a listen (during driver break in). _That_ made me appreciate how good A126 truely is
.
I was thinking the same way: Enlarging the driver cut-out in the front baffle all the way to the the sides (practically means cutting the top 155mm square of the front baffle) and mounting the SB on top. The reason was to avoid creating a 54 mm (2.1'') round "tube" out of the 3xT circular cut-outs for the driver (1xT in front baffle, 2xT for the SB). But that will not allow removing the SB afterwards if I in the end I will still prefer it without the full monty 😎
All that if I will mount the SB that way, that is. Haven't gave too much though to alternative ways of mounting the SB -- like building it _around_ the front baffle and sides or smth.
gnat_leader,
I assumed that when you said "resonances" you did meant just that. Colorations and closed-in sounds are a different matter. I for one just took Dave and Chris extensive experiences and advice and dimensioned mine accordingly.
For me a very telling experiment was to mount the driver on a mini OB and give it a listen (during driver break in). _That_ made me appreciate how good A126 truely is
.cc correction
Florian
Seems to me , your correction of the volume of the CC was the best. It kept the design and allowed the increase in size. My 126A does have a sort of boxy sound to them[a sort of echo chamber] I would have liked to compare the before and after[without the SB and with the SB], but having cut out the baffle area, I could not. My 166A does not yet have a SB and it does not have that sound, but there is a bit more of a story with them. I am using a 166es-r and I diminished the size of the CC by lining the side walls with rug material. there is a point where the sound begins to lose that auditoriom quality and get more appropriate.I can easily change it and have tried more and less amounts. This can be done because the CC volume requirements for the 166es-r is less as I understand. So, I did one of those"I wonder what would happen if I did this? and it seems to have worked just fine. I should pull the rug liners just to see if there is any comparison of the two sets of speakers.
Bob
Florian
Seems to me , your correction of the volume of the CC was the best. It kept the design and allowed the increase in size. My 126A does have a sort of boxy sound to them[a sort of echo chamber] I would have liked to compare the before and after[without the SB and with the SB], but having cut out the baffle area, I could not. My 166A does not yet have a SB and it does not have that sound, but there is a bit more of a story with them. I am using a 166es-r and I diminished the size of the CC by lining the side walls with rug material. there is a point where the sound begins to lose that auditoriom quality and get more appropriate.I can easily change it and have tried more and less amounts. This can be done because the CC volume requirements for the 166es-r is less as I understand. So, I did one of those"I wonder what would happen if I did this? and it seems to have worked just fine. I should pull the rug liners just to see if there is any comparison of the two sets of speakers.
Bob
Bob,
Thanks for the kind words. Again, that CC mod was a matter of following Dave, Chris and Ron's advice (and some luck, I guess 🙂)
Today I've installed an SB (carboard, temporary) and I have to say I was not _that_ impressed after a half-serious listen. Comparative listening with or without is a bit difficult -- will try to do it by bending the SB and then unbending that carboard. On a second thought maybe I should be a bit more selective and find material with more energy around the 260 Hz and look for differences there (since they should be rather subtle)
gnat_leader
While listening for the SB today I noticed a really annoying boom on mid bass, especially on male voices. Worryingly similar to your report on Chris Isaak material.
After a closer analyisis (well, that means running the material through a RTA 😉) it turned out that it was around 100Hz. After some thought I remember noticing that on some classical material that I know has a peak there too, so it was not a coincidence.
Still, upon checking the room modes for my dedicated listening room (rectangular, no openings) it I do have some room modes concentrated there (80Hz, 107Hz,134 Hz longitudinal, 89Hz and 134 Hz lateral and 84 Hz height). As such it would be a fair explanation to blame that on the room.
Anyway, I still have to listen to it "properly" in another room to rule out cabinet/horn resonances completely (my uber-cheapo DVD player + digital amp in my livingroom doesn't really qualify
)
Hope this helps,
Florian
P.S. As I mentioned above in this very thread -- and confirmed more then plenty today -- placing the horn firmly in the corner bloated the bass to the point of rendering it unlistenable. But that is only due to my concrete walls and is definitvely not speaker related (by moving it inside the room I can tune the bass quite a bit).
Thanks for the kind words. Again, that CC mod was a matter of following Dave, Chris and Ron's advice (and some luck, I guess 🙂)
Today I've installed an SB (carboard, temporary) and I have to say I was not _that_ impressed after a half-serious listen. Comparative listening with or without is a bit difficult -- will try to do it by bending the SB and then unbending that carboard. On a second thought maybe I should be a bit more selective and find material with more energy around the 260 Hz and look for differences there (since they should be rather subtle)
gnat_leader
While listening for the SB today I noticed a really annoying boom on mid bass, especially on male voices. Worryingly similar to your report on Chris Isaak material.
After a closer analyisis (well, that means running the material through a RTA 😉) it turned out that it was around 100Hz. After some thought I remember noticing that on some classical material that I know has a peak there too, so it was not a coincidence.
Still, upon checking the room modes for my dedicated listening room (rectangular, no openings) it I do have some room modes concentrated there (80Hz, 107Hz,134 Hz longitudinal, 89Hz and 134 Hz lateral and 84 Hz height). As such it would be a fair explanation to blame that on the room.
Anyway, I still have to listen to it "properly" in another room to rule out cabinet/horn resonances completely (my uber-cheapo DVD player + digital amp in my livingroom doesn't really qualify
)Hope this helps,
Florian
P.S. As I mentioned above in this very thread -- and confirmed more then plenty today -- placing the horn firmly in the corner bloated the bass to the point of rendering it unlistenable. But that is only due to my concrete walls and is definitvely not speaker related (by moving it inside the room I can tune the bass quite a bit).
Dave,
thanks much for your reply. I do believe we are talking about the same problem/issue. Question: if we add a spacer or supra-baffle of the specified thickness , what diameter should we increase the existing driver hole to? ie, to let the back-wave from the driver "breath"? Right now we have it just large enough to fit the driver and scalloped at 45 degrees on the rear of the baffle.
thanks much for your reply. I do believe we are talking about the same problem/issue. Question: if we add a spacer or supra-baffle of the specified thickness , what diameter should we increase the existing driver hole to? ie, to let the back-wave from the driver "breath"? Right now we have it just large enough to fit the driver and scalloped at 45 degrees on the rear of the baffle.
Make the hole as big as you can get away with. A rechangolar cutout (with 45s) is probably better then round.
dave
dave
gnat_leader said:
When using drivers with the limited clearance from large magnets such at least the entire FEnn6 series of Fostex, I'd agree that it's very important to allow some "breathing" room on the rear side of the baffles, and particularly so with double layers as a separate supra-baffle will create.
One solution is to flush mount the driver on the standard width enclosure panel, and bevel the driver opening on the front side of the supra baffle. Depending on the thickness of material for the SB, you can end up with a shallow waveguide, such as seen below.
These were sized for a friction fit, to allow the quick demonstration of "with and without". (hint - they seldom play for long without them)
Aluminum angle brackets and closed cell weather strip tape could make for a fairly simple, and well sealed installation - just don't use the baffle as a carrying handle.
An externally hosted image should be here but it was not working when we last tested it.
If the panel to which the driver is presently mounted is not removable, it won't be particularly troublesome to enlarge the hole, but it obviously be a nightmare to chamfer the rear side. In that case, I'd be inclined to cut a square opening, almost flush to the perimeter of the 4 sides of the CC.
For those concerned about the extra volume that such spacing of the driver's mounting plane will create, this'll make it much easier to add solid blocking to the rear or side walls of the CC.
Chris,
Thanks for the feedback, but I'm not sure you've been following what we've been talking about. One of the reasons for adding the supra-baffle is to increase the CC volume provided by moving the driver forward the thickness of the baffle. If your version of baffle is added then how would we increase the CC volume?
Thanks for the feedback, but I'm not sure you've been following what we've been talking about. One of the reasons for adding the supra-baffle is to increase the CC volume provided by moving the driver forward the thickness of the baffle. If your version of baffle is added then how would we increase the CC volume?
gnat_leader said:
Sorry, it wasn't clear from the above posting that the CC in this pair had already been enlarged after our first audition. In addition to a cosmetic modification to the outside shape, there was some major surgery involved in routing off the sides, and moving the rear wall back several inches. ( somewhere Dave has pictures)
You'll note in the posted picture additional plywood "cheeks" that enclose the revised CC, as well as layer of 1" MDF on the outside of horn mouth, for resonance damping.
So what IS the ideal CC size then? Is it 2.2 liters as mentioned in the first post of this thread? ...
"As posted by Dave in the above thread the way to reach the recommended 2.2 liters is to extend the CC by moving backwards the top part of the CC: "
And if so, how can I calculate the dimentions? Man, if I would have known how incomplete the plans pulled off the Frugel-horn site were, I'm not sure I would have started this project. Sorry to bicht, I know it's allot of work and you guys are not getting paid for this....
"As posted by Dave in the above thread the way to reach the recommended 2.2 liters is to extend the CC by moving backwards the top part of the CC: "
And if so, how can I calculate the dimentions? Man, if I would have known how incomplete the plans pulled off the Frugel-horn site were, I'm not sure I would have started this project. Sorry to bicht, I know it's allot of work and you guys are not getting paid for this....
gnat_leader said:
There is a comment to that affect "Note: these are plan documents assembled from various bits & pieces that were gathered from various places on the web. I will be working with Ron to get prettier, more consistent (& up-to-date in some cases) drawings"
dave
Another satisfied customer?
Dave let me crank up my home CAD and see if i cant get some DWGs to replace the old ones. If the old revs are incorrect they shouldnt be posted.
Problem is i am involved with at least 5 projects at work and another 5 involving audio and auto and GEO greenhouses. So if i post a horn design with a large transparent dome cover with controlled air flow and ground insulation and articulated steering then i have my projects crossed.
Added to all this is a general poor health and being a semi temporary resident at the local hospital and the sum total of load ,all i can do is try.
ron
(Forums are an easy place to gripe)
Dave let me crank up my home CAD and see if i cant get some DWGs to replace the old ones. If the old revs are incorrect they shouldnt be posted.
Problem is i am involved with at least 5 projects at work and another 5 involving audio and auto and GEO greenhouses. So if i post a horn design with a large transparent dome cover with controlled air flow and ground insulation and articulated steering then i have my projects crossed.
Added to all this is a general poor health and being a semi temporary resident at the local hospital and the sum total of load ,all i can do is try.
ron
(Forums are an easy place to gripe)
Ron,
Don't worry about it man. I think I got it figured out. I'm thankful to you for your designs... and based on my initial listening session, I'm salivating at what this will sound like if I can get the CC right and lose that "hand clasped reverberation" problem.
cheers, -Brad-
Don't worry about it man. I think I got it figured out. I'm thankful to you for your designs... and based on my initial listening session, I'm salivating at what this will sound like if I can get the CC right and lose that "hand clasped reverberation" problem.
cheers, -Brad-
Sounds good. I am sorry if i did not see this in the original plans ,but all i can offer is the fact that the math worked out. I am not truly an audiophile, but more of a number cruncher and general problem solver, it took Dave and Chris to bring my errors to light.
ron
ron
It looks like we need to add .51 liters (31 cubic inches) to the CC.
If we cut out a square 6"x6"x.75" piece of front baffle and add another on top, we get close (27 cubic inches). If we can cut a rectangle 6"w x 7"L (down) without moving into the horn throat area we will get 31 cubic inches.
If we cut out a square 6"x6"x.75" piece of front baffle and add another on top, we get close (27 cubic inches). If we can cut a rectangle 6"w x 7"L (down) without moving into the horn throat area we will get 31 cubic inches.
gnat_leader,
I calculated the CC volume by computing the CC cross-section area (as in the PDF) using old fashion planar geometry. To get the CC volume just multiply it with the baffle width. Nothing complicated.
As posted by someone else on a related thread (see my first post) another quick-and-dirty way to measure the CC volume is to put a plastic bag in the CC and check how much water you can pour in it.
Sorry if being too direct but I think you should have been a bit more careful in at least reading the PDF -- if not parsing the posts and reports from previous builders. IMHO this is one of the builds with quite a few reports.
Besides, Ron is already very busy in devising the plans for the Altec VOTT clone (without articulated steering) 😀
Ron,
Take good care of you man. Health comes before anything else. Best wishes.
Florian
I calculated the CC volume by computing the CC cross-section area (as in the PDF) using old fashion planar geometry. To get the CC volume just multiply it with the baffle width. Nothing complicated.
As posted by someone else on a related thread (see my first post) another quick-and-dirty way to measure the CC volume is to put a plastic bag in the CC and check how much water you can pour in it.
Sorry if being too direct but I think you should have been a bit more careful in at least reading the PDF -- if not parsing the posts and reports from previous builders. IMHO this is one of the builds with quite a few reports.
Besides, Ron is already very busy in devising the plans for the Altec VOTT clone (without articulated steering) 😀
Ron,
Take good care of you man. Health comes before anything else. Best wishes.
Florian
I did read the PDF along with two friends who helped with cutting the wood. We found numerous shortcomings, especially with the drawings of the side firing version we are building. As for going through the posts.... I barely have time to build these things... let alone reading through hundreds of postings trying to dig out the truth. It's frustrating, but I understand... these plans are free, and people have donated their time to create both the design and the drawings. Btw, personally I'd rather pay some small fee.. say $25 for the plans and know they will be spot-on. It's worth it to me not to waist the time. So Dave/Ron... perhaps there's potential here. You guys could make a few bucks and get duely compensated for your efforts! ;-)
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