Pioneer 8" build, the Chang variant

gychang · 13th August 2007, 01:16 AM

Dave and Scott have been a tremendous inspiration for a novice like me to build these fantastic projects.

My constant pestering around here have actually resulted in the Chang spawn. Specifically designed with the Pioneer B20FU20-51FW, and of course with my name on it, I had to build it...

Lots of work to do yet, will be putting finishing touch on the brace, put on edge veneering, finishing with poyurethane without stain, and also will be reinforcing the driver frame with the epoxy.

I finally figured out how to upload pics from photobucket. Can I get by using the heavy carpet on the top/bottom of the main cabinet?, I have polyfil but is in the pillow and not layered, and find it ackward to use on the top...

Any help on the sound damping will be appreciated.

gychang

gychang · 13th August 2007, 01:24 AM

one more.

latest as of sunday PM.

gychang

Godzilla · 13th August 2007, 01:45 AM

That looks SOOOO GREAT! And its not even that tall at around 63 inches. I may have to build it too! But let me ask a question: can i build it half height with only the opening at the bottom? I am not sure how these double horns work but wonder if building only half of the design would result in a well designed speaker... or does it have to have both horns top and bottom to sound best?

What will you be using for a tweetah? I always liked the cheap piezo with the B20 but i'm sure there are many other different flavors that will work well.

Godzilla

gychang · 13th August 2007, 02:14 AM

Quote:

Originally posted by Godzilla
That looks SOOOO GREAT! .. or does it have to have both horns top and bottom to sound best?

What will you be using for a tweetah? I always liked the cheap piezo with the B20 but i'm sure there are many other different flavors that will work well.

Godzilla

Godzilla: I am anticipating a great sound from the classic 8" Pioneer. Scott have designed double horn and not sure what effect it will have just with one horn.

I have been told by a reliable source, a tweeter from partsexpress

http://www.partsexpress.com/pe/pshow...TOKEN=83033797

will work well with 4uf capacitor on + side of the tweeter, that will result in crossing at 5KHz. when used with the Pioneer. No other crossover needed.

Is this correct?, I plan to try it later if I need more sparkle...

gychang

OzMikeH · 13th August 2007, 02:51 AM

Quote:

Originally posted by gychang

Any help on the sound damping will be appreciated.

gychang

staple gun helps stick the polyfill in place. set it gentle so they only go halfway in.

gychang · 13th August 2007, 03:09 AM

Quote:

Originally posted by OzMikeH

staple gun helps stick the polyfill in place. set it gentle so they only go halfway in.

thanks, will try it.

gychang

OzMikeH · 13th August 2007, 05:07 AM

I just noticed your back panel is 276 wide. Any particular reason you went this way instead of 240mm?

Are your sides 310 wide?

Scottmoose · 13th August 2007, 08:45 AM

I would assume he used a full width back-panel with the side panels attached to the front face. Going to a width of 310mm with internal 276 would of course result in a completely different cabinet design. Lovely work BTW Greg.

Jeff, yes, there's no reason why a version of this couldn't be done with a single flared vent rather than the doubled ones. The back-chamber would remain constant, it'd just need the vent retuning / sizing to work. I'll look into it when I get chance if you like. Greg is building to the v1.0 design. The v1.1 plans have a concave front designed for them by Ron, which loads the driver front & rear & provides an optimal wavefront -see attached render by Marce, (Marc, who only lives about 50 miles from where I'm based), who's planning on building a pair soon.

OzMikeH · 13th August 2007, 09:39 AM

I was talking about the sides being 310, I should have said deep not wide.

I'm building a pair too, I'll start in about 2 weeks. The curved front put the WAF through the roof so they beat the Bruce.
I'll make it with chopped corners - no voids. I will need a leg or something at the back to stand it up which will be a good place to conceal the wiring and connector. I might even lean them back a bit. I want to join the top, diagonals, back and bottom all with 22.5 degree cuts so the wood matches up nicely at the 45 degree intersections.

I need to figure out how to make the horn flare for the backmounted tweeter. It's looking like an unpleasant couple of days with the rasp and sandpaper at this stage.

I hope Greg doesn't mind me freeloading in his thread, this is his build after all.

It will be interesting to see where the Chang fits in the Frugal family tree. Calhoun's mutant half-brother the heart of a Pioneer and super powers from the gamma rays leaking out from under Ron's hat, able to leap tall wallets in a single bound... Man, I need more sleep.

Scottmoose · 13th August 2007, 11:44 AM

The Spawn range is going to come in for a bit of reorganising over the next month or so. These boxes are the direction the BVRs are now going in, though the legacy types will probably continue for those who like the aesthetics. I'll work on it when I get time. I need to get the dimensions over to Dave & Ron later today actually for the smaller two boxes.

13th August 2007, 01:16 AM	#1
gychang diyAudio Member Join Date: Feb 2005 Location: Phoenix, Arizona	8" Pioneer, build, the Chang variant Dave and Scott have been a tremendous inspiration for a novice like me to build these fantastic projects. My constant pestering around here have actually resulted in the Chang spawn. Specifically designed with the Pioneer B20FU20-51FW, and of course with my name on it, I had to build it... Lots of work to do yet, will be putting finishing touch on the brace, put on edge veneering, finishing with poyurethane without stain, and also will be reinforcing the driver frame with the epoxy. I finally figured out how to upload pics from photobucket. Can I get by using the heavy carpet on the top/bottom of the main cabinet?, I have polyfil but is in the pillow and not layered, and find it ackward to use on the top... Any help on the sound damping will be appreciated. gychang

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13th August 2007, 01:24 AM	#2
gychang diyAudio Member Join Date: Feb 2005 Location: Phoenix, Arizona	one more. latest as of sunday PM. gychang

13th August 2007, 01:45 AM	#3
Godzilla diyAudio Member Join Date: Nov 2005 Location: New York	That looks SOOOO GREAT! And its not even that tall at around 63 inches. I may have to build it too! But let me ask a question: can i build it half height with only the opening at the bottom? I am not sure how these double horns work but wonder if building only half of the design would result in a well designed speaker... or does it have to have both horns top and bottom to sound best? What will you be using for a tweetah? I always liked the cheap piezo with the B20 but i'm sure there are many other different flavors that will work well. Godzilla

13th August 2007, 05:07 AM	#7
OzMikeH diyAudio Member Join Date: Mar 2007	I just noticed your back panel is 276 wide. Any particular reason you went this way instead of 240mm? Are your sides 310 wide?

13th August 2007, 09:39 AM	#9
OzMikeH diyAudio Member Join Date: Mar 2007	I was talking about the sides being 310, I should have said deep not wide. I'm building a pair too, I'll start in about 2 weeks. The curved front put the WAF through the roof so they beat the Bruce. I'll make it with chopped corners - no voids. I will need a leg or something at the back to stand it up which will be a good place to conceal the wiring and connector. I might even lean them back a bit. I want to join the top, diagonals, back and bottom all with 22.5 degree cuts so the wood matches up nicely at the 45 degree intersections. I need to figure out how to make the horn flare for the backmounted tweeter. It's looking like an unpleasant couple of days with the rasp and sandpaper at this stage. I hope Greg doesn't mind me freeloading in his thread, this is his build after all. It will be interesting to see where the Chang fits in the Frugal family tree. Calhoun's mutant half-brother the heart of a Pioneer and super powers from the gamma rays leaking out from under Ron's hat, able to leap tall wallets in a single bound... Man, I need more sleep.

13th August 2007, 11:44 AM	#10
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	The Spawn range is going to come in for a bit of reorganising over the next month or so. These boxes are the direction the BVRs are now going in, though the legacy types will probably continue for those who like the aesthetics. I'll work on it when I get time. I need to get the dimensions over to Dave & Ron later today actually for the smaller two boxes.