RobWells said:
I have worked in the boat building industry and we use alot of bog (body filler for cars) to bond wooden cores to fibregass hulls. Bog is basically pollyester resin (the same stuff we use for the fibreglass) that is thickened with a powder called arocell or q-cell.
Even though bog dosen't work to well on cars (metal) it works very well on wood, fibreglass ect. good enough to glue supper youghts together
We mix our own but the stuff you get from the hadwear store is basically the same (automotive bog and builders bog)
Also you can make your own bendy MDF by cutting lots of slots in it with a bench saw or cercaler saw
Rob, I was considering this. My wife is a sculptor and she worked a lot with polyester and epoxy resins. You need very good ventilation, you certainly don’t want to use it at home. And polyester needs several months before the styrene smell fades away if not hardened at higher temperature (app. 40 deg C). Epoxy is a better option, but can be harmful to the skin when working with it. Besides these concerns, wood always contains an amount of moisture. Her main concern is what such large amounts of wood will do on the long term? Will the bond last when you lock the wood hermetically?
I am considering just using white wood glue and applying a layer of Arimide/Kevlar fabric between the layers of MDF to reinforce the MDF structure. It will then have a lot higher strength I think and also high internal damping.
Cheers
Btw beautiful horns Peter, that must have been a hell of work
Petervv,
Could you maby explain the sound differences of the horns above you made below a few years back and the horns your using now with separate JBL.
""At the moment I'm using FE103Sigma's in a 200Hz Oris103 fronthorns, these are prototypes from Bert Doppenberg. I'm using sand-damping on the plastic horn. On top is a modified Audax PR120i, below is a JBL K120 in a 50Hz horn."""
Im mainly concerned with the behavior of the delayed bass of the longer horn and how it integrates with the music. The JBL is much more powerfull down low i presume? (at low listening volumes).
The back chamber shape must have alot of influence as well.
Thanks for any info..
Coolin
Could you maby explain the sound differences of the horns above you made below a few years back and the horns your using now with separate JBL.
""At the moment I'm using FE103Sigma's in a 200Hz Oris103 fronthorns, these are prototypes from Bert Doppenberg. I'm using sand-damping on the plastic horn. On top is a modified Audax PR120i, below is a JBL K120 in a 50Hz horn."""
Im mainly concerned with the behavior of the delayed bass of the longer horn and how it integrates with the music. The JBL is much more powerfull down low i presume? (at low listening volumes).
The back chamber shape must have alot of influence as well.
Thanks for any info..
Coolin
Hi Coolin,
>Could you maby explain the sound differences of the horns >above you made below a few years back and the horns your >using now with separate JBL.
Distorsion is very much reduced by taking the low frequencies away from the 103. By using the fronthorn, the efficiency goes up, which also reduces distorsion.
Sound is as big as the system is physically.
Because of the depth of the horn (ca 55cm), treble falls away above 10kHz, that's why I use the seperate tweeter.
Disadvantage of the deep fronthorn is also a very small sweet spot.
All in all, sound is very vey much better than a single driver, but the system is much more big and complex, and the sweet spot is small.
>Im mainly concerned with the behavior of the delayed bass of >the longer horn and how it integrates with the music.
Delay is essential, I use a DCX2496
>The JBL is much more powerfull down low i presume? (at low >listening volumes).
The K120 is a vintage guitar speaker with a low mass cone and an alnico magnet. Sound character is the same on low and high volume levels.
>The back chamber shape must have alot of influence as well.
I suppose you mean the sphere I used on my backloaded design? I suppose the shape does make a difference, the sphere was also almost solid, absolutely silent.
regards, Peter
>Could you maby explain the sound differences of the horns >above you made below a few years back and the horns your >using now with separate JBL.
Distorsion is very much reduced by taking the low frequencies away from the 103. By using the fronthorn, the efficiency goes up, which also reduces distorsion.
Sound is as big as the system is physically.
Because of the depth of the horn (ca 55cm), treble falls away above 10kHz, that's why I use the seperate tweeter.
Disadvantage of the deep fronthorn is also a very small sweet spot.
All in all, sound is very vey much better than a single driver, but the system is much more big and complex, and the sweet spot is small.
>Im mainly concerned with the behavior of the delayed bass of >the longer horn and how it integrates with the music.
Delay is essential, I use a DCX2496
>The JBL is much more powerfull down low i presume? (at low >listening volumes).
The K120 is a vintage guitar speaker with a low mass cone and an alnico magnet. Sound character is the same on low and high volume levels.
>The back chamber shape must have alot of influence as well.
I suppose you mean the sphere I used on my backloaded design? I suppose the shape does make a difference, the sphere was also almost solid, absolutely silent.
regards, Peter
Old Layer Subwoofer
Hi, i'm a new guy here... just want to comment that i've had built a layered subwoofer back in 2001 using 1" mdf. I tried to cut manually first with a template using a jigsaw, but didn't work very well. I had brought to work and the guys in the shop cut it with CNC. Take a look at the pictures....
Hi, i'm a new guy here... just want to comment that i've had built a layered subwoofer back in 2001 using 1" mdf. I tried to cut manually first with a template using a jigsaw, but didn't work very well. I had brought to work and the guys in the shop cut it with CNC. Take a look at the pictures....
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Hasehiro Revisited
This thread has been dead for a long time, but the question was never answered. Has anyone actually heard or seen a frequency response for Hasehiro's hybrid ??? speakers?
Considering their small size, the hope would be that they would be at least as good as a simple bass reflex design. But they have a small compression chamber, short path, and small mouth. So what are they? I am curious enough to try to reverse engineer the box using a template, router, and pattern bit.
This thread has been dead for a long time, but the question was never answered. Has anyone actually heard or seen a frequency response for Hasehiro's hybrid ??? speakers?
Considering their small size, the hope would be that they would be at least as good as a simple bass reflex design. But they have a small compression chamber, short path, and small mouth. So what are they? I am curious enough to try to reverse engineer the box using a template, router, and pattern bit.
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