I call the project: Clabby (Clone Abby)
What do you think about these simulations?
http://www.diyaudio.com/forums/showthread.php?postid=509765#post509765
I want a good compromise between cloning the look and cloning the sound. I am also planning to use solid wood to do the TL.
What do you think about these simulations?
http://www.diyaudio.com/forums/showthread.php?postid=509765#post509765
I want a good compromise between cloning the look and cloning the sound. I am also planning to use solid wood to do the TL.
Mr. Cain,
My complements to you on your loudspeakers. As you say they are not expensive. In fact considering the artistry, the time, and the quality materials put into them they represent a true bargain. I too am a life long woodworker and I appreciate what you have achieved.
That being said, this is after all, a DIY forum. You need to expect that the people here will generally choose to build rather than buy if possible. But I suspect that your comment was tongue in cheek.
Since you are here as a member I would like to ask you a couple of questions about your Abbey loudspeaker. You have included a turned. round plate behind the driver as a design element. Seigfried Linkwitz has some very interesting half space frequency response curves that he recorded using circular and square open baffle backing plates. These are on his web site and show significant comb filtering effects for the circular plates. I was wondering why you chose to use the circular plate as opposed to none at all. The port you use seems a bit small for the Fostex driver used and I was also wondering what the design rational was for the oval shape as opposed to square. Comments?
Regards,
GL
My complements to you on your loudspeakers. As you say they are not expensive. In fact considering the artistry, the time, and the quality materials put into them they represent a true bargain. I too am a life long woodworker and I appreciate what you have achieved.
That being said, this is after all, a DIY forum. You need to expect that the people here will generally choose to build rather than buy if possible. But I suspect that your comment was tongue in cheek.
Since you are here as a member I would like to ask you a couple of questions about your Abbey loudspeaker. You have included a turned. round plate behind the driver as a design element. Seigfried Linkwitz has some very interesting half space frequency response curves that he recorded using circular and square open baffle backing plates. These are on his web site and show significant comb filtering effects for the circular plates. I was wondering why you chose to use the circular plate as opposed to none at all. The port you use seems a bit small for the Fostex driver used and I was also wondering what the design rational was for the oval shape as opposed to square. Comments?
Regards,
GL
Terry has made his choices, some of which contradict
conventional wisdom. From the little I know about how
he proceeds, his product contains a great deal of trial
and error and his decisions are based on listening more
than anything else. The result is an excellent product
which I'm happy to say I bought and use.
conventional wisdom. From the little I know about how
he proceeds, his product contains a great deal of trial
and error and his decisions are based on listening more
than anything else. The result is an excellent product
which I'm happy to say I bought and use.
Off Topic
FrankDIY,
A strange connection just closed in my mind...
You aren't by any chance moonlighting as a wine steward for a guy named Marcel, are you?
http://www.marcelgagne.com/
Cody
FrankDIY,
A strange connection just closed in my mind...
You aren't by any chance moonlighting as a wine steward for a guy named Marcel, are you?
http://www.marcelgagne.com/
Cody
Re: Off Topic
I agree Mr Cain. The price asked for these speakers is very low. Unfortunatelly they are not available in Montreal and like most people here, we enjoy DIY and we love designing new projects or cloning great ideas. I did the same thing with many projects from Pass Labs. See that project a rewards for your unique and great quality product. Nobody on this forum is cloning bad product. I think this is a good sign
Seeing the pass few comments, I am very proud to see I have generated interest from two famous people
This pair of speaker will be presented in a contest that I am organizing in Montreal. Any comments on my design will be always appreciated.
No connection with that guy
Thanks for your comments!
TC said:
I agree Mr Cain. The price asked for these speakers is very low. Unfortunatelly they are not available in Montreal and like most people here, we enjoy DIY and we love designing new projects or cloning great ideas. I did the same thing with many projects from Pass Labs. See that project a rewards for your unique and great quality product. Nobody on this forum is cloning bad product. I think this is a good sign
Seeing the pass few comments, I am very proud to see I have generated interest from two famous people
This pair of speaker will be presented in a contest that I am organizing in Montreal. Any comments on my design will be always appreciated.
reverber said:
No connection with that guy
Thanks for your comments!
Thanks for the compliments gl. Yeah, I was attempting a veiled "funny".
The circular baffle projects the speaker out and away from the main baffle. With all the edges rounded with a long gradually decreasing radii, diffraction effects have been minimised. While I am sure some artifacts could be measured bouncing off the baffle I doubt it adds anything annoying that you could hear. It has been speculated that the baffle I make contributes to the large soundstage my spkr seems able to produce, again by elevating the driver off of the main cabinet a bit. Moreover I was interested in further reducing cabinet energy from reaching the driver by adding the (circular) mass. "Comb filtering" effects would be something that 2 drivers do, or two radiation points.. The diffraction effects of a single driver _can_ be seens as comb filtering though i see it as a stretch, implying first order cancellations. Not having read SL's paper you mention I am only guessing. The added mass and fluid surface adds benefits to the rest of the spectrum, if a slight cancellation/reinforcement results from a circular baffle it must be very slight.
Now if the circular baffle had sharp edges and was flush with the driver for it's circumference that could be easier to measure a step.
The port area was arrived at by building many a pipe. The design subscribes to alot of different theories about Voigts. I rely primariliy on actual physical modeling and measurements to arrive at these designs after the initial design work is complete. Choking off the pipe reduces ripple and pipe effect. The oval shape creates a wider sloping, fluid velocity value, lowering it's own self noise. May not even be audible vs a circular port.
TC
The circular baffle projects the speaker out and away from the main baffle. With all the edges rounded with a long gradually decreasing radii, diffraction effects have been minimised. While I am sure some artifacts could be measured bouncing off the baffle I doubt it adds anything annoying that you could hear. It has been speculated that the baffle I make contributes to the large soundstage my spkr seems able to produce, again by elevating the driver off of the main cabinet a bit. Moreover I was interested in further reducing cabinet energy from reaching the driver by adding the (circular) mass. "Comb filtering" effects would be something that 2 drivers do, or two radiation points.. The diffraction effects of a single driver _can_ be seens as comb filtering though i see it as a stretch, implying first order cancellations. Not having read SL's paper you mention I am only guessing. The added mass and fluid surface adds benefits to the rest of the spectrum, if a slight cancellation/reinforcement results from a circular baffle it must be very slight.
Now if the circular baffle had sharp edges and was flush with the driver for it's circumference that could be easier to measure a step.
The port area was arrived at by building many a pipe. The design subscribes to alot of different theories about Voigts. I rely primariliy on actual physical modeling and measurements to arrive at these designs after the initial design work is complete. Choking off the pipe reduces ripple and pipe effect. The oval shape creates a wider sloping, fluid velocity value, lowering it's own self noise. May not even be audible vs a circular port.
TC
Right.
Thanks again. and good on ya.
TC
Here's a link to a nice clone http://cls.audiogon.com/cgi-bin/cls.pl?spkrfull&1105182133
Mr. Cain,
Thank you for your gracious and detailed reply. I appreciate you sharing your design experiences with us. I also appreciate you taking the time to answer my questions. I am experimenting with FR stuff at the moment and those particular questions about the Abbey have been in the back of my mind for a while.
Regards,
Graeme
Thank you for your gracious and detailed reply. I appreciate you sharing your design experiences with us. I also appreciate you taking the time to answer my questions. I am experimenting with FR stuff at the moment and those particular questions about the Abbey have been in the back of my mind for a while.
Regards,
Graeme
Nelson Pass said:That's a little better than I get at 1 M with the speakers away
from walls. Where did you measure? - nevermind, I see from
the picture.
In my own anechoic room
(basement)This is nice to see that my modest measurement equipment can produce good results.
chris ma said:
This is just priliminary measurements to see the FR of the speaker. Nearfield measurement is useful to minimize room effect on the measurement when you don't have an adequate room. I was also doing this to see the influence of the break-in period on these Fostex.
When the enclosuse will be finished, I will be able to make measurement at the listening position.
Here is some news about this project.
This week I have built two prototypes. The first one (big one) is my own design based on the MathCad sheets.
The second one is very close to the real Abby. Unfortunatelly I do not have access to a real pair of loudspeaker so the dimensions are based on published data and picture approximation. I have no clue about the damping so I used this ratio: 2/3 of the box at 0.5 lbs/ft3.
The sound is surprisingly similar for both boxes. One problem I noticed is that the sweet spot of my design is pretty high due to the angle of the baffle.
The picture of both boxes:
The measurements (green=the small box, pink=the big box):
This week I have built two prototypes. The first one (big one) is my own design based on the MathCad sheets.
The second one is very close to the real Abby. Unfortunatelly I do not have access to a real pair of loudspeaker so the dimensions are based on published data and picture approximation. I have no clue about the damping so I used this ratio: 2/3 of the box at 0.5 lbs/ft3.
The sound is surprisingly similar for both boxes. One problem I noticed is that the sweet spot of my design is pretty high due to the angle of the baffle.
The picture of both boxes:
An externally hosted image should be here but it was not working when we last tested it.
The measurements (green=the small box, pink=the big box):
An externally hosted image should be here but it was not working when we last tested it.
MDF
Having some experience listening to real Abby's, as well as a few DIY fullrangers, (horns/ TQWP) I would suggest that MDF is not the most suitable material for the enclosure, and most definitely for the round baffle.
If I'm not mistaken, Terry uses raw "standard" particle board for the back panel and perhaps ( with veneer) for the sides as well. The front flat panel and round baffle are edge laminated solid hardwood. I'm not sure whether he uses different species, or just a talented finisher.
If I ever get a chance to visit his factory, I'll know for sure, but only after signing that non-disclosure agreement.
And don't overlook the 200 or so hours of mandatory break-in on the Fostex drivers. After about 4 months, my FE108E Sigmas are finally opening up and developing some reasonable bottom end extension and weight in the Buschhorn enclosure.
Anyways, if you're encouraged by you initial results, you owe the design the opportunity to shine with at least Baltic Birch plywood. As for the round baffle, you could always get creative with a spoke-shave.
Having some experience listening to real Abby's, as well as a few DIY fullrangers, (horns/ TQWP) I would suggest that MDF is not the most suitable material for the enclosure, and most definitely for the round baffle.
If I'm not mistaken, Terry uses raw "standard" particle board for the back panel and perhaps ( with veneer) for the sides as well. The front flat panel and round baffle are edge laminated solid hardwood. I'm not sure whether he uses different species, or just a talented finisher.
If I ever get a chance to visit his factory, I'll know for sure, but only after signing that non-disclosure agreement.
And don't overlook the 200 or so hours of mandatory break-in on the Fostex drivers. After about 4 months, my FE108E Sigmas are finally opening up and developing some reasonable bottom end extension and weight in the Buschhorn enclosure.
Anyways, if you're encouraged by you initial results, you owe the design the opportunity to shine with at least Baltic Birch plywood. As for the round baffle, you could always get creative with a spoke-shave.
Banned
Joined 2002
Dave's not here man
As of noon, we've got about 6" of fresh snow here in Langford at the bottom of "the mountain" . I'd suspect that not even Dave is crazy enough to venture out with the threat of 4 or 5 more by day's end.
I'm barely gonna make it home with my light duty "all season" tires.
OTOH, maybe that's why we can't reach him! That's not a snow bank, that's Dave!
For myself, no - the last few times the expresso machine was broke down, and I'm still recovering from my last overdose of the professor, and I still have to finish that EL84 amp for Dave. (no smoke to let out, but still some "Lou")
Cheers
As of noon, we've got about 6" of fresh snow here in Langford at the bottom of "the mountain" . I'd suspect that not even Dave is crazy enough to venture out with the threat of 4 or 5 more by day's end.
I'm barely gonna make it home with my light duty "all season" tires.
OTOH, maybe that's why we can't reach him! That's not a snow bank, that's Dave!
For myself, no - the last few times the expresso machine was broke down, and I'm still recovering from my last overdose of the professor, and I still have to finish that EL84 amp for Dave. (no smoke to let out, but still some "Lou")
Cheers
Banned
Joined 2002
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