I just found this explanation in Audio Glossary:
"Aperiodic Enclosure - an otherwise sealed enclosure design, but with a vent that is stuffed with damping material, which flattens out the impedance curve of the design. The area of this resistive vent should be about 10 sq. in. per cubic ft. of enclosure volume. This design might take some experimentation with the vent stuffing, testing the impedance curve several times with different amounts of damping material until the flattest impedance curve is found. The aperiodic resistive vent damps the driver in much the same way as fully stuffing a sealed enclosure with damping material (100% fill). In this way, an optimum design may be made up to 20% (or more) smaller due to the extra damping of the resistive vent. Enthusiasts of this design often compare the performance with transmission line enclosures, advocating that the design avoids the "ringing" effects of ported enclosures while alleviating the "pressure effect" of the sealed box. Dynaudio sells a DIY insertable resistive vent called the Variovent"
Does it mean, that I can design an BR enclosure for my AN 12" speakers, and when I finished it, to make some experiments with damping of bass reflex tube?
"Aperiodic Enclosure - an otherwise sealed enclosure design, but with a vent that is stuffed with damping material, which flattens out the impedance curve of the design. The area of this resistive vent should be about 10 sq. in. per cubic ft. of enclosure volume. This design might take some experimentation with the vent stuffing, testing the impedance curve several times with different amounts of damping material until the flattest impedance curve is found. The aperiodic resistive vent damps the driver in much the same way as fully stuffing a sealed enclosure with damping material (100% fill). In this way, an optimum design may be made up to 20% (or more) smaller due to the extra damping of the resistive vent. Enthusiasts of this design often compare the performance with transmission line enclosures, advocating that the design avoids the "ringing" effects of ported enclosures while alleviating the "pressure effect" of the sealed box. Dynaudio sells a DIY insertable resistive vent called the Variovent"
Does it mean, that I can design an BR enclosure for my AN 12" speakers, and when I finished it, to make some experiments with damping of bass reflex tube?
If you can use a BR port as acoustic valve - well, some do that, when the port doesnt work right
BUT, in reality the port area is too small to work properly as acoustic valve(aperiodic)
The BR port fore this driver will actually only be a hole without a tube - which very much resembles a MartinKing MLTL, apart from the calculations
Actually I have done similar a very long time ago - just a hole in the bottom towards the floor, and allthough it had too much bass, I simply couldnt do without it
BUT, in reality the port area is too small to work properly as acoustic valve(aperiodic)
The BR port fore this driver will actually only be a hole without a tube - which very much resembles a MartinKing MLTL, apart from the calculations
Actually I have done similar a very long time ago - just a hole in the bottom towards the floor, and allthough it had too much bass, I simply couldnt do without it
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Thanks for all good advices!
I'm hardly wait to arrive my AN12" from USA...
in meanwhile, I made some arrangements with my friend, who is carpenter, and he will finished the BR enclosures for AN's.
Also, I found some nice 40cm x 150cm panels, to do some preliminary listening sessions with AN s as soon as they arrive...
I will inform You accurately about news& impressions
P.S. I allready have "low power" SET amplifiers from my own resources (2a3 and RE134 SET) in stand-by...
I'm hardly wait to arrive my AN12" from USA...
in meanwhile, I made some arrangements with my friend, who is carpenter, and he will finished the BR enclosures for AN's.
Also, I found some nice 40cm x 150cm panels, to do some preliminary listening sessions with AN s as soon as they arrive...
I will inform You accurately about news& impressions
P.S. I allready have "low power" SET amplifiers from my own resources (2a3 and RE134 SET) in stand-by...
zflazar said:
if - in tests- you need some quick'n'dirty solution for helper tweets,you probably can buy pair of Eminence APT80 locally.......I think that your local supplier can be "PSP" ..........and pair of them is ~40 Euros
hehe - these little critters are in fact good enough for good,not just for tests
edit:
where you found these notworthy REs?
they're good for nothing,and you can freely send them to me for proper disposal..........
Hi folks,
...after a while, it seems that my Nirvana's are finished. Becouse I am not skillfull with words, I should put some picture, to better describe the finish of the boxes...
The inner construction is enforced and additionaly damped. Furnishing is made with natural furnish... BR holes are tuned to cca 40Hz.
Listening impressions: well, in first 150-250 hours on open panels and also, in the new BR boxes there was nothing, what I could characterised, as "pleasent" or "nice".
IMHO, I was very disappointed, and a little bit I felt, that I was a "sucker" who actually buy A Pair Of Something what produces hushy unpleasent sounds, something like "punishment-for-rookie-fullrange-ears"... But I do not give up, every time, when I left home, I switch on the music sistem, to increase the working hour period of AN"s and off course, to frightend the potentional teafs/rats/postmans... And so on, month-or-two...
It seems, there is a rule like: as bigger is the surface of loudspeker membrane, as longer is the burn-in period...?
Finally, and despite the very long burn-in period + necessary "notch filter" network (0.4mH-8.2R-3.2uF) it seems that I have at home a 240l-BR-fullrange loudspeaker with great potential, with very fast, crisp sound, wich is every day even better...!
With my DIY-fanatic friends some weeks ago we made comparation listening-tour with some FOSTEX full range speakers and I can tell You, that AN's sounds just wright! For final judgement, in next days I will compare them with Lowther DX2 in Hedlund horns, and I will inform You.
...after a while, it seems that my Nirvana's are finished. Becouse I am not skillfull with words, I should put some picture, to better describe the finish of the boxes...
The inner construction is enforced and additionaly damped. Furnishing is made with natural furnish... BR holes are tuned to cca 40Hz.
Listening impressions: well, in first 150-250 hours on open panels and also, in the new BR boxes there was nothing, what I could characterised, as "pleasent" or "nice".
IMHO, I was very disappointed, and a little bit I felt, that I was a "sucker" who actually buy A Pair Of Something what produces hushy unpleasent sounds, something like "punishment-for-rookie-fullrange-ears"... But I do not give up, every time, when I left home, I switch on the music sistem, to increase the working hour period of AN"s and off course, to frightend the potentional teafs/rats/postmans... And so on, month-or-two...
It seems, there is a rule like: as bigger is the surface of loudspeker membrane, as longer is the burn-in period...?
Finally, and despite the very long burn-in period + necessary "notch filter" network (0.4mH-8.2R-3.2uF) it seems that I have at home a 240l-BR-fullrange loudspeaker with great potential, with very fast, crisp sound, wich is every day even better...!
With my DIY-fanatic friends some weeks ago we made comparation listening-tour with some FOSTEX full range speakers and I can tell You, that AN's sounds just wright! For final judgement, in next days I will compare them with Lowther DX2 in Hedlund horns, and I will inform You.
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Hi There ZFLAZAR: I noted your question about Aperodic vents and would like to mention a product that is manufactured by Scan Speak and may be available in Europe. Call up Parts Express on Google and enter this part number in the block at the top right of the home page: 296-546. There is an explanation and diagram of the Scan Speak Vent. This device would make it easier to do a good Aperodic enclosure as described on pages 58 & 59 of Van Dickason's book, 7th edition. ...best reagards, Michael
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