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Discussion Starter #1
just that...

oh and is it the same as open baffle?
 
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Just about any dynamic cone driver can be use to produce dipole mid to mid bass frequencies. Low distortion and a smallish rear structure/open basket are desirable. If you are refering strictly to bass/low bass frequencies, then xmax becomes very important. A dipole must move lots of air. Also important is the aerodynamic noise created by the driver at high excursion levels.
An "Open Baffle" speaker is a dipole. However, a "Dipole" can be a closed baffle (box), so a dipole doesn't have to be an open baffle, just a speaker system whose rear radiated output is of opposite (180deg) phase from the front radiated output.

A "box" dipole (JohnK's CRAW sub)



An "Open Baffle" speaker (mine :) )



Cheers,

AJ
 

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wow I really like your open baffle speakers! thats the coolest design i've seen in a while. sound as good as they look?

-Jeff
 

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Discussion Starter #6
smallish orion design... horn loaded but same tweet? xls?

very nice
 

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Discussion Starter #8
what 8 would work for dipole use for the sub frequencies that could holds its own but reduce size?
 
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sound as good as they look?
I'd like to think so Jeff, but I would never,never want to tout my own design too much (too much of that sort of foolishness on internet forums) :) .

smallish orion design... horn loaded but same tweet? xls?
Yes, my (crude) interpretation of Siegfried Linkwitz's masterpiece. Waveguide (low gain horn) loaded XT19 and XLS12's.

what 8 would work for dipole use for the sub frequencies that could holds its own but reduce size?
It would be next to impossible to use a single 8" driver for dipole "sub" use.
(Dipole)SPL is a function of Xmax x Sd. An 8" driver, even with huge Xmax, simple won't have the surface area to move the volume of air required for dipole "sub" use, even if your "D" (acoustic short circuit path) was rather large - which is what you are trying to avoid in the first place ;) .
Now you could use a line array of 8's if you wanted to. That would work. Here's some $9 Madisound Audax Car 6.5er's (sub-bass) and a 8" KEF UniQ.



For something more "cube" compact, multiple 8's in a W-frame might work:
http://www.linkwitzlab.com/woofer.htm
I have plans for just such a design with some TB 8's that I yanked from some Logitech Z subs. Way down the road however :( .
BTW the Linkwitz website is what I consider to be the Holy Grail of loudspeaker design. If you are serious about DIY (even Car only) you owe it to yourself to peruse this vast site, loaded with great info about all aspects of speaker design, not just dipoles.


Cheers,

AJ
 

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Wow AJ... fantastic looking work...
What are my chaces of getting an audition ;)
 

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hey I live in tampa too! I wanna listen... :D

i've been to that site before; I remembering my jaw dropping when I saw the orions... So damn sexy...

here in a little I'm planning on building an interesting speaker of totally different design - you ever listen to a back loaded horn? just got to finish the install in my car first... although maybe I should listen to examples of different types before building a set ;)

-Jeff
 

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geoffire said:
here in a little I'm planning on building an interesting speaker of totally different design - you ever listen to a back loaded horn?f
BLH's can be quite good, as long as you brace the living hell out of them and don't expect any real bass. A friend of mine who's an ace cabinet builder uses a pair of Hedlund horns with 8" Fostexes and supertweets in them for his main system right now, and I got to spend some time with them a couple weeks ago. (The model of Fostex escapes me, but they're the ones that people often modify by using a Craftsman socket for a phase plug.) According to him they weren't terribly good until he added more bracing, and he had already (as shown in this old pic of his listening room) made them with double-thick (1.5") walls and a spine brace. Also, he quickly determined that despite their size they need bass support, in the form of two (I think) Dayton Quatro 10's mounted as pedestals behind the horn, firing backwards. I wasn't terribly prepared to like them, but I did. They threw a huge image, had stellar bass/mid focus, mids that might not quite rival a big Tannoy dual but were better than most of the stuff in the typical hi-fi salon, and were only let down by some roughness in the treble.
 

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Wow if i visit FL im definitly comming to ur house..really nice work man
 

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OMG DS-21 i know those are your friends...but wow...That whole setup looks awesome. Are all of those TL's outside of the 2 mains....And are the two mains Horns?

I'd really like to figure out how to build some like that....but my fab skills arn't that great.

BTW i want a clock like that....thats looks freaking awesome and really origional.
 

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AJinFLA said:
An "Open Baffle" speaker (mine :) )

Sweet man. I've been drooling over the Orion design since I discovered them not too long ago. I wish I could afford them, though I would modify the design some (ribbon tweeters and the 12" XXLS instead of the 10"'s). Are you running them active or passive? Man oh man I wish I had the money to run active in the home audio environment, but my wife wants a house and a baby (in that order) so that kills any of my high end home audio dreams for a long time. Hah oh well maybe one day..

Ryan
 
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Raul/Jeff,

I'll be taking a weekend off within the next couple weeks (yes I work 7 days a week :( ). I'll try to arrange it so you can both come over for an audition.
I'd certainly like to hear Raul's set up in his car and Jeff, I've been interested in those TB 2"s for a while now.
Whenever I decide on which weekend, I'll try to give you as much heads up as possible.

Cheers,

AJ
 

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sweet :D Yeah, I work a crazy schedule too 11:30pm-8am 4 on, 2 off (rotating) with school from 11am-2pm... sleep fits somewhere in there...

Last night I stuck the 2"s to my dash (literally, not boxed, just double sided tape) as I needed something to go with the 7"ers in the door. I hooked them up to the factory amp running full range... Dispite those handicaps I think they sound really good! highs are a little directional, so I may add a tweeter, and maybe a touch tinny, but good detail and imaging! There's no audible distortion running full range and the 7"ers fill in the lack of bass nicely, and to me sounds pretty seamless with the 7"s crossed around 1k (3rd order I think). Tonight i'll route them through my crossover and work on making pods, I just ran out of time last night. Overall I was impressed with the sound of my locost setup :) When its complete I'll post some pics...
 

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demon2091tb said:
OMG DS-21 i know those are your friends...but wow...That whole setup looks awesome. Are all of those TL's outside of the 2 mains....And are the two mains Horns?
The two speakers in the middle are Hedlund horns, the speakers on the outside are Voigt Pipes, similar to the Cain & Cain Abby.

I'd really like to figure out how to build some like that....but my fab skills arn't that great. He also built the amp, a single-ended tube deal, and the preamp, a Bottlehead model of some sort. (He's changed those components since then.) However, if you think those are wild, here is something truly amazing. Lowthers in the horns, Klipsch LcScala-clone horns for the midbass. Unfortunately I didn't get to hear them - the smooth horn is out of commission right now, being used to make a fiberglass mold - but there's a dude on one of the fora who has reported positive results with Tannoy duals at the mouth of big front-loaded horns, and I can't help but notice how perfect a Tannoy 2046 would fit at the mouth of Les's horns....
 
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