Just spent some time going over that link Lusk provided...
I notice a couple of sub woofers in the background, but followed a bit of the logic that was being applied.
Whilst the tweeter is capable of going down to 1.5 kHz he added an C-Quenze 18cm driver to help fill the bottom end of the midrange in a bit more. I think seeing his system gave me a bit more perspective of what the tweeter is capable of, and the lower limits, and even if I worked along a similar line to what he has done there it looks like I really don't need to go any smaller than a 7" - 18cm to close the gap to the tweeter.
I notice a couple of sub woofers in the background, but followed a bit of the logic that was being applied.
Whilst the tweeter is capable of going down to 1.5 kHz he added an C-Quenze 18cm driver to help fill the bottom end of the midrange in a bit more. I think seeing his system gave me a bit more perspective of what the tweeter is capable of, and the lower limits, and even if I worked along a similar line to what he has done there it looks like I really don't need to go any smaller than a 7" - 18cm to close the gap to the tweeter.
I recommend you study this design:
PRELUDE
It neatly sums up the issues you face designing a 3 way with the AT drivers.
I also strongly recommend, for various reasons, if you are set on the AT drivers, you buy the same ones that Troels has used. Not because they are necessarily the best ones, but because:
1. They are proven to work well together
2. You can incorporate some of this design into your speaker (some tweaking needed for different tweeter)
3. If you have problems with integrating the RAAL you have a fall back position (sell the RAAL's, Buy 9900's and build Troels design)
The benefit of the AT drivers is their reasonably flat and well behaved wide-band response that will make it easier to hit target slopes with youre DSP. I get the feeling you won't be modelling the crossover and exporting the transfer function to the DCN28?
I would stop obsessing over driver sensitivity, multiple and large mids. Keep it simple with a WMT design and it has the potential to be an excellent speaker.
PRELUDE
It neatly sums up the issues you face designing a 3 way with the AT drivers.
I also strongly recommend, for various reasons, if you are set on the AT drivers, you buy the same ones that Troels has used. Not because they are necessarily the best ones, but because:
1. They are proven to work well together
2. You can incorporate some of this design into your speaker (some tweaking needed for different tweeter)
3. If you have problems with integrating the RAAL you have a fall back position (sell the RAAL's, Buy 9900's and build Troels design)
The benefit of the AT drivers is their reasonably flat and well behaved wide-band response that will make it easier to hit target slopes with youre DSP. I get the feeling you won't be modelling the crossover and exporting the transfer function to the DCN28?
I would stop obsessing over driver sensitivity, multiple and large mids. Keep it simple with a WMT design and it has the potential to be an excellent speaker.
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thanks dabbler... Lusk posted this link earlier The Building of a Pure Digital System and it seems to be pretty much on the money. He has already had success with the same 140-15D AM tweeter in an active setup, so I was think about mirroring the drivers he used but with my own cabinets.
Hardly original but he put a lot of effort into getting things right so pointless re-inventing the wheel.
Hardly original but he put a lot of effort into getting things right so pointless re-inventing the wheel.
Did a bit of a quick mockup last night in Google Sketchup.
This is an early rendition of what the tweeter cabinet should look like.
Probably round the top and bottom edges, but that is hard to do on a curved surface in Sketchup. Compared to the flatter style they went with.
This is an early rendition of what the tweeter cabinet should look like.
Probably round the top and bottom edges, but that is hard to do on a curved surface in Sketchup. Compared to the flatter style they went with.
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DIY Audio Articles
Plenty of reading here. It does get maths-y occasionally, but there is a lot of involvement of maths in speaker design.
If you don't understand something, either look at the formula and accept that it works, or try to understand exactly what its doing.
Chris
Plenty of reading here. It does get maths-y occasionally, but there is a lot of involvement of maths in speaker design.
If you don't understand something, either look at the formula and accept that it works, or try to understand exactly what its doing.
Chris
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