Are you talking about this design in cardboard?
I just bought an HP 24in commercial inkjet plotter (my old eyes cannot follow schematics on 8.5x11 anymore) and it came in a huge triple ply cardboard box the size of a coffin. I should save the cardboard for nifty cardboard speakers.
I just bought an HP 24in commercial inkjet plotter (my old eyes cannot follow schematics on 8.5x11 anymore) and it came in a huge triple ply cardboard box the size of a coffin. I should save the cardboard for nifty cardboard speakers.
I imagine that would be a really good bit of cardboard to work with! We had to pick up a couple of desks for our kids, and they came in double-walled cardboard, so no lamination was required this time
I did treat the cardboard like wood, though. Rather than using hot glue I used the Gorilla expanding foam glue, with some clamps and weights to hold things in place while the glue cured, and so the whole build took a couple of days. You could substitute clamps with painter's tape, though, which I did a number of times
The 15 inch boxes with the 3FE22 speakers were still the nicest build, though. Even with my dull blade I was able to complete the pair in an evening.
I did treat the cardboard like wood, though. Rather than using hot glue I used the Gorilla expanding foam glue, with some clamps and weights to hold things in place while the glue cured, and so the whole build took a couple of days. You could substitute clamps with painter's tape, though, which I did a number of times
The 15 inch boxes with the 3FE22 speakers were still the nicest build, though. Even with my dull blade I was able to complete the pair in an evening.
I had another idea - making a 2-way where I used the GRS PT-6825 and a Visaton R10S. Here's a mock-up in foam core:
It's the same 15" pizza box design as before, but with a 2x1x7.325" port to tune the box to 70Hz. I accidentally put the port at the wrong end of the transmission line, so I need to fix that, but it still sounds pretty good even without the crossovers.
The planar driver is in a separate chamber to the woofer, so the transmission line only affects the Visaton. I added it to cover the missing response between the planar driver and a subwoofer.
After this, I realised that it would probably be possible to use a 4" subwoofer, as they reach quite high in some cases, so they would mate with this planar driver quite well, and a separate sub wouldn't be required. Granted, the volume of the box would require it to be twice as deep (and the transmission line length be doubled in length, but that's not too much extra work.
I'll fix the port, make a second one, and get the crossover components and see how they sound The planar driver's so even in its output.
It's the same 15" pizza box design as before, but with a 2x1x7.325" port to tune the box to 70Hz. I accidentally put the port at the wrong end of the transmission line, so I need to fix that, but it still sounds pretty good even without the crossovers.
The planar driver is in a separate chamber to the woofer, so the transmission line only affects the Visaton. I added it to cover the missing response between the planar driver and a subwoofer.
After this, I realised that it would probably be possible to use a 4" subwoofer, as they reach quite high in some cases, so they would mate with this planar driver quite well, and a separate sub wouldn't be required. Granted, the volume of the box would require it to be twice as deep (and the transmission line length be doubled in length, but that's not too much extra work.
I'll fix the port, make a second one, and get the crossover components and see how they sound
The planar driver's so even in its output.
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Cool!
One thing to keep in mind when integrating a sub with high reach to a full range of tweeter is the distance between the drivers. Try to keep the CTC distance smaller than 1/3rd the lowest wavelength so that the sources sound like they are from same point. For example, if choosing a 250Hz crossover frequency, that’s about 9.6in CTC distance from mid to woofer. Which is why remote subs work well below 80Hz. The distance is much larger.
One thing to keep in mind when integrating a sub with high reach to a full range of tweeter is the distance between the drivers. Try to keep the CTC distance smaller than 1/3rd the lowest wavelength so that the sources sound like they are from same point. For example, if choosing a 250Hz crossover frequency, that’s about 9.6in CTC distance from mid to woofer. Which is why remote subs work well below 80Hz. The distance is much larger.
Yes, that definitely makes sense. I wonder if it's different with a woofer crossing to a planar driver, but I can't hear the separate drivers in that enclosure so far
My own personal goal would be to have a small subwoofer driver replace the Visaton driver, and have that cross over at around that 250-300Hz point, where the planar naturally starts to kick in, so it would more serve as a sub and midbass than attempt to push it beyond its sweet spot.
My own personal goal would be to have a small subwoofer driver replace the Visaton driver, and have that cross over at around that 250-300Hz point, where the planar naturally starts to kick in, so it would more serve as a sub and midbass than attempt to push it beyond its sweet spot.
Have you considered experimenting with an acoustic lens mounted over the face of the driver such as the JBL2308? just a thought.
Hello X. Cn you tell me what criteria do you consider when choosing what frequency to tune your horn lengths to when designing a dual horn backloadd design? Thanks.
Hello Dave has anyone built this design to your knowledge yet ? Would this be good for very small drivers like 2 inch ones?
Select the deepest fundamental note. That sets the longest 1/4 wave length path. Make the shorter horn 2/3rds the length of the longest. You want to avoid even ratio. This will help fill out the gaps and not reinforce the main nodes.
Thank you Dave. So what are the current "to die for 3 inch FR drivers these days? Is it possible to run a three inch in a Cornucopya from 80 Hz. up and achieve 95 db (or close)? Thanks for your comments.
Ok I will take a look at this driver out on paper and check the cost as well. So what size Cornucopya would this require? Thank you for the information.
I had been wondering about orientation but these day one is so often afraid to ask. My first guess given wall placement would have been to shoot the longest horn toward the next closest boundary which in my st up would be toward the floor. Did yo play with different set up and if so what did you find. Would be most interested in your comments. Thanks Cal.
