Home » Audio » Speaker » Newest acquisition 2 - 8" full range from Roland
Newest acquisition 2 - 8" full range from Roland [message #20379] Sun, 12 September 2004 12:57 Go to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)

I've been looking for some 8" to build a Voigy pipes
for some time: started out leaning toward Goldwood, then
Pioneer. There was a tip that these 8 inchers were being
sold in pairs on Ebay for $10. EventuallY I got the base
bid in and am waiting on shipment.


But the speaks come with no information. The seller
recommends a nearfield or studio monitor config. I'll
have to see how they sound when they get here.


Anyway, just for discussion, here's the link I have.



Re: Newest acquisition 2 - 8" full range from Roland [message #20380 is a reply to message #20379] Mon, 13 September 2004 06:34 Go to previous messageGo to next message
akhilesh is currently offline  akhilesh
Messages: 1275
Registered: May 2009
Illuminati (3rd Degree)
I saw these too. Do tell us how they sound!
-akhilesh

Re: Newest acquisition 2 - 8" full range from Roland [message #20384 is a reply to message #20379] Mon, 13 September 2004 14:53 Go to previous messageGo to next message
Ralph is currently offline  Ralph
Messages: 75
Registered: May 2009
Viscount
I hope those are good speakers for you. Let us know when they arrive. It looks like the person selling them had them in ported boxes. How tall do you plan to make your Voigt pipe, i.e. what frequency will they be tuned to?

Re: Newest acquisition 2 - 8" full range from Roland [message #20385 is a reply to message #20384] Mon, 13 September 2004 15:32 Go to previous messageGo to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)
The taller the better for an 8"driver, I imagine.

Below is the image of one that is 72" overall.


I have another (harder to grab) that's 74" so both are
pretty close. The problem with one of these is that
the driver used has been discontinued.


I also have considered the ide aof mounting the driver on the
slant side and using an angled piece at the port terminus... or
a curved piece which is bent and snapped into place.


Driver mounting should be at 40" for the 74" design,
but if mounted on the slant side, other factors may apply.


A recent _audioXpress_ has a series on why the front
pf speaks should be slanted, so I wanted to apply the concept
to the Voigt and do both techniques at once. I don't know
if this is a good idea but they seemed to go together.


Re: Newest acquisition 2 - 8" full range from Roland [message #20386 is a reply to message #20379] Mon, 13 September 2004 19:39 Go to previous messageGo to next message
roncla is currently offline  roncla
Messages: 125
Registered: May 2009
Master
The pointy type pipes went out a long time ago. Its much better to make the throat (top section) at least equal to the Sd of the driver.The mouth (bottom section) should be around 4 x Sd.This will hold down ripple in given sections of the FR curve.Without T/S parameters its more or less of a crapshoot,unless you have methods to establish them.
ron

Re: Newest acquisition 2 - 8" full range from Roland [message #20387 is a reply to message #20386] Mon, 13 September 2004 21:34 Go to previous messageGo to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)

Maybe it's a phase I have to go through. :-)


From reading I seem to recall that this design is pretty
forgiving and is good with inexpensive drivers. That was my reason
for concentrating on the unusual design. If, indeed, you made the
top less pointy, I'd say it'd be an MLTL.


I am putting a pair of those (MLTL) together-- much smaller
format design -- based on some numbers from GM at Full Range
Driver Forum. These use the FE127e from Fostex. And I can
make them out of 70 cent shelving from the Farm and Fleet.


Before anything, I want to put my line array together
as least a test build.


Thanks for the help. I am not at the stage of doing
from-scratch designs with CAD and spreadsheets. I'm learning
my tools yet. It is pretty slow going.



Re: Newest acquisition 2 - 8" full range from Roland [message #20388 is a reply to message #20386] Mon, 13 September 2004 22:14 Go to previous messageGo to next message
Don is currently offline  Don
Messages: 9
Registered: May 2009
Esquire
Are you saying that a truncated TQWP is better than one that tapers to a point? Why would having the point at the top add ripples to the response curve? Seems like the position of the driver in the pipe would keep that from mattering much. I would expect the end to end taper expansion, overall length and position of the driver to matter more than the area of the tip of the small end.
Curious,
Don

Re: Newest acquisition 2 - 8" full range from Roland [message #20392 is a reply to message #20388] Tue, 14 September 2004 13:40 Go to previous messageGo to next message
lon is currently offline  lon
Messages: 760
Registered: May 2009
Illuminati (2nd Degree)

While this discussion is going, if I made the bottom
square to the base and just moved the taper up past the
vent opening, how would that change things?


There would be a curved piece snapped into place
at the rear to the height of the vent opening. Something like a
piece of rubber floor tile. (?)


(No speak delivery yet today)




Re: Newest acquisition 2 - 8" full range from Roland [message #20393 is a reply to message #20388] Tue, 14 September 2004 16:09 Go to previous messageGo to next message
roncla is currently offline  roncla
Messages: 125
Registered: May 2009
Master
If the throat of a horn ,which is little more than a flared TL, has zero area (So=0)then you will get excessive ripple in the FR curve no matter what the length.
Bob's sim shows what happens.Look to the left of the page and click on Voight pipes and read what the results were.
ron

http://www.geocities.com/rbrines1

Re: Newest acquisition 2 - 8" full range from Roland [message #20394 is a reply to message #20393] Tue, 14 September 2004 16:34 Go to previous messageGo to previous message
Don is currently offline  Don
Messages: 9
Registered: May 2009
Esquire
The thing is the throat *isn't* zero area, as none really can be. The pipe is loaded in the middle.
Regards,
Don

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