Hello fellow diyaudio peeps-
Some of you might recall my copper speaker at Burning Amp. It is one of a pair that I put together for my camp at Burning Man. The speaker cabinets were not assembled by me; I just 'dressed them up' with copper and brass; and added the tripod stands. Cabinets are made on 3/4" MDF.
While on the playa, the drivers blew out. They were fairly cheap University 8" full range units from the 60's (model 308's).
I would like to find a suitable replacement driver; possibly a full range unit that can handle al least 60 watts. I intend to add some form of tweeter assembly above or mid/tweet in the center. It needs to be fairly durable as it will be exposed to the hot desert elements for a week.
I calculated the internal cabinet volume, appx 1.25 cubic feet. There is a port (3in dia. X 3in long) but this can be closed or changed if need be. Driver size can be anything up to ~9".
I realize this is not going to go down too low; I would be lucky to get to 100hz!
I am not much of a speaker designer and there seems to be a wide choice of 8" units.
This is how they appeared on the playa, below. If anyone can help, I would be grateful!
Cheers- Kent
Some of you might recall my copper speaker at Burning Amp. It is one of a pair that I put together for my camp at Burning Man. The speaker cabinets were not assembled by me; I just 'dressed them up' with copper and brass; and added the tripod stands. Cabinets are made on 3/4" MDF.
While on the playa, the drivers blew out. They were fairly cheap University 8" full range units from the 60's (model 308's).
I would like to find a suitable replacement driver; possibly a full range unit that can handle al least 60 watts. I intend to add some form of tweeter assembly above or mid/tweet in the center. It needs to be fairly durable as it will be exposed to the hot desert elements for a week.
I calculated the internal cabinet volume, appx 1.25 cubic feet. There is a port (3in dia. X 3in long) but this can be closed or changed if need be. Driver size can be anything up to ~9".
I realize this is not going to go down too low; I would be lucky to get to 100hz!
I am not much of a speaker designer and there seems to be a wide choice of 8" units.
This is how they appeared on the playa, below. If anyone can help, I would be grateful!
Cheers- Kent
Attachments
Sounds like a job for the pioneer BOFU to me.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-045
Lots of other options too. I believe you could seal off the port, maybe do a little tweaking or possibly just add tweeter and have something that sounds pretty good. These drivers have a pretty awesome reputation considering their price.
Good luck
Robert
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-045
Lots of other options too. I believe you could seal off the port, maybe do a little tweaking or possibly just add tweeter and have something that sounds pretty good. These drivers have a pretty awesome reputation considering their price.
Good luck
Robert
Hmmm .......
8" units that are genuine bass / midranges are increasingly rare.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=296-175
Looks relatively easy to work with according to PE sample
measurements, i.e. no large or narrowband peaks / dips.
http://www.parts-express.com/pdf/296-175g.pdf
It will get you down to at least 40Hz but genuine freefield as
in your picture is an entirely different matter to use in a normal
sized room.
My experience of Audax drivers is they are very robust and take
abuse. An 8" fullrange by default must have a delicate voice coil.
Its ideal for your box size and IMO a 2" diameter 5" long port.
Thats ~ 33Hz tuning though you can go up to ~ 40Hz.
Lining your port with 1/2" foam is workable, ~ 37Hz.
The tweeter one has to suggest :
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-409
Just because of the packaging.
It needs a proper crossover at > 3kHz, simple will not work
well nor will trying to cross lower, 5th harmonic distortion
has a peak at 1.5Khz you neeed to avoid.
I suggest you read up on Baffle step compensation and
diffraction effects of cabinets if you want a good crossover.
You may be able to get away with a single large inductor
on the bass driver, this will be a lot larger than than a
"textbook" cross over value, due to response tailoring.
http://www.parts-express.com/projectshowcase/indexn.cfm?project=Sc51
Is worth perusing as an example of how not to go about
crossing over two drivers, off the shelf does not work.
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/DesigningXO.htm
As a minimum experiment with various series inductors to get
the driver ~ flat and bring in the tweeter at 3KHz, using an
L-pad to set its level. Tweeter c/o 2nd or 3rd order electrical.
/sreten.
8" units that are genuine bass / midranges are increasingly rare.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=296-175
Looks relatively easy to work with according to PE sample
measurements, i.e. no large or narrowband peaks / dips.
http://www.parts-express.com/pdf/296-175g.pdf
It will get you down to at least 40Hz but genuine freefield as
in your picture is an entirely different matter to use in a normal
sized room.
My experience of Audax drivers is they are very robust and take
abuse. An 8" fullrange by default must have a delicate voice coil.
Its ideal for your box size and IMO a 2" diameter 5" long port.
Thats ~ 33Hz tuning though you can go up to ~ 40Hz.
Lining your port with 1/2" foam is workable, ~ 37Hz.
The tweeter one has to suggest :
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-409
Just because of the packaging.
It needs a proper crossover at > 3kHz, simple will not work
well nor will trying to cross lower, 5th harmonic distortion
has a peak at 1.5Khz you neeed to avoid.
I suggest you read up on Baffle step compensation and
diffraction effects of cabinets if you want a good crossover.
You may be able to get away with a single large inductor
on the bass driver, this will be a lot larger than than a
"textbook" cross over value, due to response tailoring.
http://www.parts-express.com/projectshowcase/indexn.cfm?project=Sc51
Is worth perusing as an example of how not to go about
crossing over two drivers, off the shelf does not work.
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/DesigningXO.htm
As a minimum experiment with various series inductors to get
the driver ~ flat and bring in the tweeter at 3KHz, using an
L-pad to set its level. Tweeter c/o 2nd or 3rd order electrical.
/sreten.
Hi
My guess is that sheer SPL and "survival" is more important than bass to this application? If so, then a BSC design is out.
Assuming that then, a 8" pro driver that rolls off quickly to match the tweeters sensitivity would be ideal. But after mulling that over, you might probably want a 1" compression tweeter with a new DIY biggish copper horn?
My guess is that sheer SPL and "survival" is more important than bass to this application? If so, then a BSC design is out.
Assuming that then, a 8" pro driver that rolls off quickly to match the tweeters sensitivity would be ideal. But after mulling that over, you might probably want a 1" compression tweeter with a new DIY biggish copper horn?
Those are some great looking "Steampunk" speakers!
I did a pair of copper faced speakers, once. Tall and narrow, the theme was Tiki. My wife did the copper bas-relief with the tweeter in the tiki's mouth, woofer in it's belly. (see my avatar for an idea of her work)
Wish I had taken photos.......
Good look with your project - I hope you find drivers as sturdy as those cool boxes.
I did a pair of copper faced speakers, once. Tall and narrow, the theme was Tiki. My wife did the copper bas-relief with the tweeter in the tiki's mouth, woofer in it's belly. (see my avatar for an idea of her work)
Wish I had taken photos.......
Good look with your project - I hope you find drivers as sturdy as those cool boxes.
Hi Chaps-
Thanks for great ideas & driver selections. Very helpful!
Yes, I can pad the interior. There is some carpet glued to some of the inside panels already. I would like to keep away from paper cones and foam surrounds due to the sun and elements. I like that teardrop tweeter- seen it before. Yes, 'survival' is more important than bass for this project.
Cosmetics- one idea was to use a translucent cone-
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-055
I had an idea to 'light' the interior, this would look cool. Hey, it's Burning Man, fun night-time lighting is big part of the event! But coupling it with the teardrop shape tweeter will leave a big suckout in the 2-3k range...
Hmm....a diy horn? Now you got me thinking! It might get kind of long- I need to do some modeling to figure out sizes.
Yes, the term steampunk has been used before describing these. I prefer the term 'Jules Verne-esque'.
Thanks for great ideas & driver selections. Very helpful!
Yes, I can pad the interior. There is some carpet glued to some of the inside panels already. I would like to keep away from paper cones and foam surrounds due to the sun and elements. I like that teardrop tweeter- seen it before. Yes, 'survival' is more important than bass for this project.
Cosmetics- one idea was to use a translucent cone-
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-055
I had an idea to 'light' the interior, this would look cool. Hey, it's Burning Man, fun night-time lighting is big part of the event! But coupling it with the teardrop shape tweeter will leave a big suckout in the 2-3k range...
Hmm....a diy horn? Now you got me thinking!
It might get kind of long- I need to do some modeling to figure out sizes.Yes, the term steampunk has been used before describing these. I prefer the term 'Jules Verne-esque'.
Hi
I like it...lighting behind the cone or even with a DIY transluscent grammaphone horn.
Try using bright LED's with a self powered VU circuit.
see post 6 http://www.diyaudio.com/forums/showthread.php?s=&threadid=79249&highlight=
I like it...lighting behind the cone or even with a DIY transluscent grammaphone horn.
Try using bright LED's with a self powered VU circuit.
see post 6 http://www.diyaudio.com/forums/showthread.php?s=&threadid=79249&highlight=
Attachments
kstlfido said:Hi Chaps-
Cosmetics- one idea was to use a translucent cone-
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-055
I had an idea to 'light' the interior, this would look cool.
Hey, it's Burning Man, fun night-time lighting is big part of the event! But coupling it with the teardrop shape tweeter
will leave a big suckout in the 2-3k range...
Hi,
You have a frequency response for this driver ?
It has a foam surround ....
It will work in your box with an EBS vented alignment.
A 3/8" lining of your port is about right.
But with no frequency response you are stumbling in the dark.
/sreten.
Have you thought about a pro CoAxial ? The B&C 8cx21 springs immediately to mind. The frame is the correct shape for your "boxes" as well.
They are awesome drivers, i have four of them in use as monitors.
And, the biggest plus of all is they're quite cheap from Parts Express.
They don't go really low though.
I just re read your first post, these drivers will easily withstand the desert, we live in one of the nastiest environments in Oz and mine live outside for barbies. Plus in your cab they'll get down to 65Hz.
mine are in a 7.5 litre box with a 57 mm dia port at 80mm long, they get down to 68Hz
They are awesome drivers, i have four of them in use as monitors.
And, the biggest plus of all is they're quite cheap from Parts Express.
They don't go really low though.
I just re read your first post, these drivers will easily withstand the desert, we live in one of the nastiest environments in Oz and mine live outside for barbies. Plus in your cab they'll get down to 65Hz.
mine are in a 7.5 litre box with a 57 mm dia port at 80mm long, they get down to 68Hz
Found these-
http://www.madisound.com/catalog/product_info.php?cPath=45_238&products_id=1615
Seas 7" coaxial. Clear cone. Not 8" but close enough!
Any experience out there with these?
-Kent
http://www.madisound.com/catalog/product_info.php?cPath=45_238&products_id=1615
Seas 7" coaxial. Clear cone. Not 8" but close enough!
Any experience out there with these?
-Kent
Hi Kent!
I've used the 6.5 inch predecessors of those Seas coax in my Sputniks (when they were $65), but with the voice coil gap unprotected from dust like they are and at over $150 each I wouldn't recommend them in the desert.
What if you used three Hi-Vi B3N or next size up in a triangle (with a centered tweeter or another B3N)? They're only about $10 each, decent 'full-range,' slightly copper colored, and in a triangular layout they might complement the hexagonal baffle.
I've used the 6.5 inch predecessors of those Seas coax in my Sputniks (when they were $65), but with the voice coil gap unprotected from dust like they are and at over $150 each I wouldn't recommend them in the desert.
What if you used three Hi-Vi B3N or next size up in a triangle (with a centered tweeter or another B3N)? They're only about $10 each, decent 'full-range,' slightly copper colored, and in a triangular layout they might complement the hexagonal baffle.
B&C's for coppercabs
Hi Kent,
I didn't realise they were that dear, last time i looked they were on special at 99.00
I have two pairs in boxes, shipping is quite dear but the Aussie Peso is now worth F*** all.
If you are interested you can have them for my trade price (it is a lot less than PE charge)
Surface to USandA is $72.00 Oz (Pacific Pesos) that's per driver, they are very heavy.
Cheers,
Peter.
Hi Kent,
I didn't realise they were that dear, last time i looked they were on special at 99.00
I have two pairs in boxes, shipping is quite dear but the Aussie Peso is now worth F*** all.
If you are interested you can have them for my trade price (it is a lot less than PE charge)
Surface to USandA is $72.00 Oz (Pacific Pesos) that's per driver, they are very heavy.
Cheers,
Peter.
another idea
How about the Tannoy 6.5inch cast frame CoAxials ? I have at least 6 of them left, possibly more. I keep finding stuff in boxes.
These have the open Tulip waveguide/horn, you would need to buy the fine dustcap from Tannoy or any reconer.
These would work as good or better than the B&C's (more bass) but without the ultimate loudness or "punch".
My personal choice is for the B&C's.
But the Tannoys have the X/O's supplied (a small bonus)
These are the drivers used in the PBM control room and desk monitors.
How about the Tannoy 6.5inch cast frame CoAxials ? I have at least 6 of them left, possibly more. I keep finding stuff in boxes.
These have the open Tulip waveguide/horn, you would need to buy the fine dustcap from Tannoy or any reconer.
These would work as good or better than the B&C's (more bass) but without the ultimate loudness or "punch".
My personal choice is for the B&C's.
But the Tannoys have the X/O's supplied (a small bonus)
These are the drivers used in the PBM control room and desk monitors.
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