Double Reflex Alignment
Sorry to bother you guys but I can't find the info I'm after... In order to save some space I'd like not to eat up the internal volume of one of my two chambers with the ''linking'' port so heres the question ; can I link the two chambers with the port entierly placed in the 2/3(bigger one) part of my enclosure.
Goodnight
Goss
Sorry to bother you guys but I can't find the info I'm after... In order to save some space I'd like not to eat up the internal volume of one of my two chambers with the ''linking'' port so heres the question ; can I link the two chambers with the port entierly placed in the 2/3(bigger one) part of my enclosure.
Goodnight
Goss
😕 Sorry, but I've always meant, that both chambers in such an alignment should probably be of same volume?
A german brand uses such an alignment with their fullrange- speakers, and we had a lot of duscussions about how to figure out the secrets of such an alignment...
A german brand uses such an alignment with their fullrange- speakers, and we had a lot of duscussions about how to figure out the secrets of such an alignment...
.....that both chambers in such an alignment should probably be of same volume?
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News to me, at least WRT Weems concept. Here's an informative site: http://planeta.terra.com.br/educacao/claudionegro/english/
GM
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News to me, at least WRT Weems concept. Here's an informative site: http://planeta.terra.com.br/educacao/claudionegro/english/
GM
hi
well i can go into lengths as to why you can have a whole lot of combinations for dual chamber bass reflex - the classic is to tune one chamber at around 70 hz while the other at 35 hz bothe the chambers wikk have different internal volumes - instead of going further
please go over Audio Amateur - Loudspeker Designs Speacial - Issue there are whole lot of dual chamber reflex s and the priciple is explaind there
i am a transducer design engineer - and know the relation ship why t/s parameters are there beleave me there are whole loy of approaches - other thatn the conventional - all you have to do is keep the mechanical load on the drive unit - suitable to the drive unit ypu are building it for
how you do it ts parameters is a guidance
suranjan
transducer design engineer
well i can go into lengths as to why you can have a whole lot of combinations for dual chamber bass reflex - the classic is to tune one chamber at around 70 hz while the other at 35 hz bothe the chambers wikk have different internal volumes - instead of going further
please go over Audio Amateur - Loudspeker Designs Speacial - Issue there are whole lot of dual chamber reflex s and the priciple is explaind there
i am a transducer design engineer - and know the relation ship why t/s parameters are there beleave me there are whole loy of approaches - other thatn the conventional - all you have to do is keep the mechanical load on the drive unit - suitable to the drive unit ypu are building it for
how you do it ts parameters is a guidance
suranjan
transducer design engineer
The conventional way of building one, as invented by Augspurger and modified by Weems to fit Thiele-Small parameters, is shown in the following link.
Pay attention to posts 35,36, 37 and 38.
http://www.diyaudio.com/forums/showthread.php?postid=93570#post93570
Pay attention to posts 35,36, 37 and 38.
http://www.diyaudio.com/forums/showthread.php?postid=93570#post93570
>well i can go into lengths as to why you can have a whole lot of combinations for dual chamber bass reflex - the classic is to tune one chamber at around 70 hz while the other at 35 hz bothe the chambers wikk have different internal volumes
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Agreed, there can be many combinations, though most aren't worth the effort IMO. Frankly, I don't much care for the 'one note' sound of the popular 2:1 ratio design.
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>......as invented by Augspurger......
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Actually, Karlson's early '50s K-15 is the earliest use of a DBR chamber I've seen so far.
GM
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Agreed, there can be many combinations, though most aren't worth the effort IMO. Frankly, I don't much care for the 'one note' sound of the popular 2:1 ratio design.
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>......as invented by Augspurger......
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Actually, Karlson's early '50s K-15 is the earliest use of a DBR chamber I've seen so far.
GM
GM said:
When I said Augspurger invented the box, I meant the box with those specific chamber ratios and tunings.
Weems credits Augpurger with the development of the box with the ratio of chamber volumes and tuning method he uses. Weems just related the whole thing to Thiele-Small numbers, which came later. This seems to be the most popular setup that Claudio and others use.
Perhaps Karlson's enclosure has a different tuning, or maybe unspecified chamber ratios and tunings?
Karlson's original design used a 1.0:0.707 chamber ratio with identical CSA vents. I haven't reverse engineered his later ones yet, but it seems reasonable to me that Augspurger just adapted Karlson's invention (if indeed it's truly his idea) to offset the lack of mass loading by a long tapered vent. I don't consider adapting an existing design to suit your needs as an invention, but I don't know how the patent office views it.
GM
GM
Augspurger got his patent. Weems gave the patent number in an article he published in an electronics magazine, which I lost. Happily, I did remember to keep the Xeroxes of the section of The Loudspeaker Design Cookbook which gives the same information on how to build them. Unfortunately, the Loudspeaker Design Cookbook does not contain the patent number to Augspurger's version of the unit.
Nevertheless, it useful to know that Karlsen invented the box first, with Augspurger patenting an improvement in it. Up to know, I thought Augspurger came up with the whole concept.
Nevertheless, it useful to know that Karlsen invented the box first, with Augspurger patenting an improvement in it. Up to know, I thought Augspurger came up with the whole concept.
What about 'double tuned bass reflex'? I'm looking for a good reading about those multiple BR chambers but there is a lot of junk among the info.
Guss, what do you need to know? You have already received the necessary info on how to build one type of popular double tuned reflex.
I've never built one, but I have done extensive reading on them. Tell you what. Give me the Thilele-Small parameters of the woofer you are planning to use and I will design one for you step-by-step according to Weems' instructions.
The woofer you select should be usable for just a normal bass reflex box as well.
Okay?
I've never built one, but I have done extensive reading on them. Tell you what. Give me the Thilele-Small parameters of the woofer you are planning to use and I will design one for you step-by-step according to Weems' instructions.
The woofer you select should be usable for just a normal bass reflex box as well.
Okay?
Guss,
I thought that my HP explains in a simple way Weems' DCR: what do you think is "junk" in my explanation?
Regards
Claudio
I thought that my HP explains in a simple way Weems' DCR: what do you think is "junk" in my explanation?
Regards
Claudio
kelticwizard said:
I can design it and yes the woofer I plan to use is suitable for BR. I know enough about the popular DCR, true, but I realized that there is another way to go, the one listed as DBR Fostex' on your page Claudio. From the drawings I guess the chambers are two perfect 1/2 of the total volume and the port is the same. Twas all I really wanted to know...
Weems :
2:1 woofr and the port
1:2 port
3 ports, same lengths , is computed as a dual ported box
Now correct me if I'm wrong
DBR fostex ?? :
1:1 woofer
1:1 port
2 ports , same lengths , might be computed as a single ported box?
>Nevertheless, it useful to know that Karlsen invented the box first, with Augspurger patenting an improvement in it. Up to know, I thought Augspurger came up with the whole concept.
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Yeah, as the inventor Tom Danley has lamented, the ancients keep stealing all his 'inventions'. 😉
Anyway, I got to looking at the math I did late last night since I do it so poorly and found I'd totally screwed it up. 🙁 The K -15 is actually a quadra reflex chambered design, or DBR + BP depending on how you choose to view it and the DBR ratio is almost exactly 1.0:0.5 (2:1), so once the driver's Vb is subtracted out it should be ~spot on.
Just speculating, but it looks like Augspurger did like B*** and so many others have done in that once the original patents expired, applied for it as their own. Oh well, you can only manipulate a soundwave in so many ways and the more I've studied old patents, the more it appears that the audio pioneers pretty much tried them all.
GM
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Yeah, as the inventor Tom Danley has lamented, the ancients keep stealing all his 'inventions'. 😉
Anyway, I got to looking at the math I did late last night since I do it so poorly and found I'd totally screwed it up. 🙁 The K -15 is actually a quadra reflex chambered design, or DBR + BP depending on how you choose to view it and the DBR ratio is almost exactly 1.0:0.5 (2:1), so once the driver's Vb is subtracted out it should be ~spot on.
Just speculating, but it looks like Augspurger did like B*** and so many others have done in that once the original patents expired, applied for it as their own. Oh well, you can only manipulate a soundwave in so many ways and the more I've studied old patents, the more it appears that the audio pioneers pretty much tried them all.
GM
Guss:
The Fostex style DBX can be modelled on the Adire freeware version of LspCAD, provided Adire has a woofer available with a Qts equal to or less than the woofer you plan to use.
The Adire version of LspCAD allows you to add a resistor in series to the woofer. This raises the Qts-Weems gives instructions on how to do it, I can help you with that. Then just come up with a box you like the graph of, and divide the box volumes by the same proportions of the Vas of the Adire woofer divided by the Vas of the driver you are using. If the driver you are using has half the Vas of the Adire driver, then the box volumes you need for your woofer are half the volumes that LspCAD says is required for the Adire woofer.
Am I making myself clear? 🙂
I have modelled a few boxes on the Adire freeware, and I should report that the Fostex style DBR has a notch in the response, frequently very significant. The freeware models the size of the notch.
The Fostex style DBX can be modelled on the Adire freeware version of LspCAD, provided Adire has a woofer available with a Qts equal to or less than the woofer you plan to use.
The Adire version of LspCAD allows you to add a resistor in series to the woofer. This raises the Qts-Weems gives instructions on how to do it, I can help you with that. Then just come up with a box you like the graph of, and divide the box volumes by the same proportions of the Vas of the Adire woofer divided by the Vas of the driver you are using. If the driver you are using has half the Vas of the Adire driver, then the box volumes you need for your woofer are half the volumes that LspCAD says is required for the Adire woofer.
Am I making myself clear? 🙂
I have modelled a few boxes on the Adire freeware, and I should report that the Fostex style DBR has a notch in the response, frequently very significant. The freeware models the size of the notch.
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