Hello all, my first post and my first cab build in need of some adivce.
The cab has been cnc cut from baltic birch ply to the djk plan cut list found on the web via this site. Drivers will be kappa pro lf 2 as dictated with the cab.
Pic shows mock up now I have sanded the cuts.
I intend to use evostick pva and 4mm x40 screws, should I add baton braces anywhere - I was planning on using them in most areas internally. [image][image][/image][/image]
I have added a centre support to tne cab - not on the plans - will this have a negative effect?
Looking at the cab I think it need 4 handles in the top part of the cab, is there concensus on making the handles out of the side kf the cab with some layered ply on the inside to make handles seen on most high end cabs, or should I just go with prefab screw in recessed handles?
Should I buy or make a recess plate for the power connectors? I assume to use NL4s.
I intend to finish in warnex paint.
Any help appreciated
Rich, UK
The cab has been cnc cut from baltic birch ply to the djk plan cut list found on the web via this site. Drivers will be kappa pro lf 2 as dictated with the cab.
Pic shows mock up now I have sanded the cuts.
I intend to use evostick pva and 4mm x40 screws, should I add baton braces anywhere - I was planning on using them in most areas internally. [image][image][/image][/image]
I have added a centre support to tne cab - not on the plans - will this have a negative effect?
Looking at the cab I think it need 4 handles in the top part of the cab, is there concensus on making the handles out of the side kf the cab with some layered ply on the inside to make handles seen on most high end cabs, or should I just go with prefab screw in recessed handles?
Should I buy or make a recess plate for the power connectors? I assume to use NL4s.
I intend to finish in warnex paint.
Any help appreciated
Rich, UK
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Rich,
1) Unless the battens and bracing reduce the internal volume too much, you can't have too many.
2)Prefab are easier, making your own pocket handles can be better in that they can be made to pick up in any orientation. As far as handle placement, lifting from the bottom or center of a cabinet is a lot easier than lifting from the top.
3) Yes, they tend to get sheared off in transit if not recessed. A plywood board or pre-punched metal sheet can be used behind, or a pocket can be routed in the existing ply.
Art
The center brace runs down the length of the port, across the back, and up to the front.
I don't need handles, the cabinet will always ride on a two-wheeled cart.
I use Penn-Elcom dual D input cups.
Nice logo work!
My latest PPSL, a 27hz quad-12 owned by Norman Bates!
I don't need handles, the cabinet will always ride on a two-wheeled cart.
I use Penn-Elcom dual D input cups.
Nice logo work!
My latest PPSL, a 27hz quad-12 owned by Norman Bates!
The center brace runs down the length of the port, across the back, and up to the front.
I don't need handles, the cabinet will always ride on a two-wheeled cart.
I use Penn-Elcom dual D input cups.
Nice logo work!
My latest PPSL, a 27hz quad-12 owned by Norman Bates!
what 12 you used in this box??
Thanks for the replies.
djk, I was reading in the large PPSL thread about reducing plenum slot volume to extend the mid range response. This might be useful to me as I could narrow the slot allowing placement of my handle - which I really need. Also as I am using RCF C3110 it might give me a better crossover to their response? What do you think?
Also what x-over point for this cab/slope(I intend to use a DCX2496)
Does it matter how I mount the drivers, I was going to have both with motors facing up.
I will power them with a Macro tech 2401 - do you think that's big enough?
Best regards
Rich, UK
djk, I was reading in the large PPSL thread about reducing plenum slot volume to extend the mid range response. This might be useful to me as I could narrow the slot allowing placement of my handle - which I really need. Also as I am using RCF C3110 it might give me a better crossover to their response? What do you think?
Also what x-over point for this cab/slope(I intend to use a DCX2496)
Does it matter how I mount the drivers, I was going to have both with motors facing up.
I will power them with a Macro tech 2401 - do you think that's big enough?
Best regards
Rich, UK
High JDK,
What is the usable high frequency rolloff and is that box ported?
I'm looking to design a PPSL to go as high as possible to include the "punchy" midbass. Also to mount the design close to the wall\floor junction to take advantage of room boundries and follow in Allisons footsteps.
Thanks!!!
What is the usable high frequency rolloff and is that box ported?
I'm looking to design a PPSL to go as high as possible to include the "punchy" midbass. Also to mount the design close to the wall\floor junction to take advantage of room boundries and follow in Allisons footsteps.
Thanks!!!
"I was reading in the large PPSL thread about reducing plenum slot volume to extend the mid range response"
The main limitation is the depth of the slot, not the width.
"What is the usable high frequency rolloff and is that box ported?"
It's got a slot port at the bottom, about 16" deep.
I have yet to measure the HF response, it should make it to at least 200hz, I'm hoping 300hz. I want to mate it with a Unity/Synergy style HF.
The main limitation is the depth of the slot, not the width.
"What is the usable high frequency rolloff and is that box ported?"
It's got a slot port at the bottom, about 16" deep.
I have yet to measure the HF response, it should make it to at least 200hz, I'm hoping 300hz. I want to mate it with a Unity/Synergy style HF.
what happens to performance and response if the plenum is lightly filled with polyfil? are 6th order assisted alignments the best way overall?
Very nice clean look!
That looks very tidy and professional!
This design makes me wonder whether it'd play nicely with 4x 3015lf.
I keep building different boxes for them (BR, 3 different TH, T36) and they all have their quirks.
But PPSLis one design I'm embarrassed not yet to have tried.
Do you feel there are benefits to putting 4 drivers in a single box, aside from sheer convenience?
Regards, Ben
That looks very tidy and professional!
This design makes me wonder whether it'd play nicely with 4x 3015lf.
I keep building different boxes for them (BR, 3 different TH, T36) and they all have their quirks.
But PPSLis one design I'm embarrassed not yet to have tried.
Do you feel there are benefits to putting 4 drivers in a single box, aside from sheer convenience?
Regards, Ben
Placing four drivers in a single plenum insures the output will be within 1/4 wavelength to a higher frequency than two dual boxes, which improves upper output in comparison to two more widely spaced units.
The four drivers facing different directions looks cool too.
The port works out better with the bigger box too.
The port works out better with the bigger box too.
Another bonus?
Is the frontal area of the speaker cabinet (can we call it a baffle if the drivers aren't mounted in it?) around the mouth/exit large enough to achieve the boundary effect of the designs such as the
BC 415 | Danley Sound Labs, Inc.
?
Regards, Ben
Is the frontal area of the speaker cabinet (can we call it a baffle if the drivers aren't mounted in it?) around the mouth/exit large enough to achieve the boundary effect of the designs such as the
BC 415 | Danley Sound Labs, Inc.
?
Regards, Ben
That can be modeled in AkAbak.
On my double 15 PPSL stacks it seems to add a couple of dB, but I haven't tried to measure it.
There is some gain from compression in the slot when you have multiple cabinets stacked for more baffle area. One builder measures about 2.75dB gain with a stacked pair (above the normal 3dB gain from stacking). It takes a lot of area to hold this gain up to the lowest frequencies.
On my double 15 PPSL stacks it seems to add a couple of dB, but I haven't tried to measure it.
There is some gain from compression in the slot when you have multiple cabinets stacked for more baffle area. One builder measures about 2.75dB gain with a stacked pair (above the normal 3dB gain from stacking). It takes a lot of area to hold this gain up to the lowest frequencies.
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Ben,
The BC 415 has a 60" x 60" inch frontal area, a PPSL usually has the same or less frontal area as a normal BR. If you make "wings" for any type of cabinet the boundary will increase forward directivity, but the BC cabinets also incorporate the boundary as part of the horn expansion.
Simply doubling frontal area gives a quite measurable SPL increase, around 3 dB as you can see in tests here:
http://www.diyaudio.com/forums/subwoofers/184986-horn-extender-wave-guide-th.html
Art
Cab is now built, needs sockets and painting. Currently building a second top cab.
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