I kind of know what xrk is thinking but history project and experience did show us wide baffe are best for bass woofer With the new complexity I doubt the new idea is good
XRK, based off the Voice Coil measurements (below), it looks like the PTT6.5 is 6dB down at 45° at a frequency of around 2250Hz. If a waveguide was used on the Raal to both boost the low frequency SPL on axis as well as delay the Raal relative to the woofer, could a Harsch crossover still be implemented at a 2.25kHz crossover frequency? Also, how would you feel about crossing the 70-20XR that low?
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The Harsch XO requires that the tweeter be delayed by 2xTau where Tau is the characteristic period (in seconds) of one cycle of sound at the XO frequency. The difference between 2500Hz and 3500Hz is 200 microseconds. Multiply this by the speed of sound (342 m/s) and the extra delay needed for a 2500Hz XO is an extra 2.7in deep setback relative to where it was for the 3500Hz crossover. So if your new 25000Hz waveguide is 2.7in deeper than the one I used (which I got lucky with how everything lined up, then it can work.
I think I RAAL 70-20xr should be ok at 2500Hz. Specs say it can be crossed 4th order at 1800Hz. Only a single cap is needed as the inductors are already built into the signal transformer inside.
I think I RAAL 70-20xr should be ok at 2500Hz. Specs say it can be crossed 4th order at 1800Hz. Only a single cap is needed as the inductors are already built into the signal transformer inside.
It’s was 2.1” (at 3500Hz) plus the additional 2.7” you quote to XO at 2500Hz is a total of 4.8” Z offset. Not sure a OS waveguide will give me that offset for a 90° waveguide that holds pattern to 2500Hz but I’ll cross that bridge when I get to it.
Hi X,
I had not really thought about a waveguide, since I was planning on a budget speaker. Probably don't want to spend a lot of money on drivers that are not high value. If the TL requires a waveguide, then I will look for a different application. Kind of why I asked about a monitor TL, probably with a folded line, smaller and more useful to me.
If these are not possible, then I know of a few floor stander plans that would suit my purpose, not TL though.
Thanks for your thoughts and comments.
MM
I had not really thought about a waveguide, since I was planning on a budget speaker. Probably don't want to spend a lot of money on drivers that are not high value. If the TL requires a waveguide, then I will look for a different application. Kind of why I asked about a monitor TL, probably with a folded line, smaller and more useful to me.
If these are not possible, then I know of a few floor stander plans that would suit my purpose, not TL though.
Thanks for your thoughts and comments.
MM
No DSP in my house yet, maybe in the future when I get building this set of speakers and other speakers. I really don't know that much about DSP, so will have to research how it works and what a person needs.
I can still use a passive crossover, just will have to redesign the crossover, correct?
I can still use a passive crossover, just will have to redesign the crossover, correct?
Thanks for the info on DSP. This will definitely be on the back burner until approval by the better half. The speaker design course I have yet to complete has a module on passive / active crossover design, so hopefully i can learn and design what I need.
Any ways, this is future work, it is good to know that the TL enclosure should work. Since the plans are digital, I assume they will be available at any time.?
Any ways, this is future work, it is good to know that the TL enclosure should work. Since the plans are digital, I assume they will be available at any time.?
I have listened to a few horn implementations. The property that has been most consistent is an addition of "body" to the presentation...on practically any driver. Having the opp to play that raal 2k/2.5k would add another dimension to that speaker. Most of us would most likely just do the raal as is. I would still wish that maybe put a much higher cap on the raal, and try this thing at 2.5That is too much trouble to get a waveguide installed on the 70-20XR.
I also don't see a reason to use a waveguide on the 70-20XR with your current PTT6.5 setup:
- your XO point is at 3.5Khz, you don't need the extra output of the waveguide
- the 70-20XR should be used above 3Kz, below is too much distortion
- the great accidental XO will be not so great anymore
Yes those magnets are very strong, I've discovered that when a screw and my screwdriver was pulled to it, lucky there is that mesh.
🧙♂️
Bringing this thread back from the dead. Did you ever get around to building these, or did it remain a concept? I'm looking into making a bookshelf version of this so I'm curious how it turned out.
Also, as someone who heard it up close, is there much difference in the timbre of the raal and something like a metal dome tweeter, or is that all subjective?
Bringing this thread back from the dead. Did you ever get around to building these, or did it remain a concept? I'm looking into making a bookshelf version of this so I'm curious how it turned out.
Also, as someone who heard it up close, is there much difference in the timbre of the raal and something like a metal dome tweeter, or is that all subjective?
I sold my PTT6.5 woofers and waveguide dome tweeter in TL to a friend - never got a replacement, just seems too expensive. I have the RAALs still ( on loan from friend who hasn’t had a need for them back. )
In the meantime, I found a great alternative woofer - custom OEM Wiggins XBL technology. 10mm xmax, linear BL motor. Custom OEM ribbon. My own crossover. It became the LSA Statement 100
Having listened to both woofers, I can say the Wiggins is almost as good and at a fraction of the cost. I just can’t justify spending $400+ on a 6.5in woofer anymore.
In the meantime, I found a great alternative woofer - custom OEM Wiggins XBL technology. 10mm xmax, linear BL motor. Custom OEM ribbon. My own crossover. It became the LSA Statement 100
Having listened to both woofers, I can say the Wiggins is almost as good and at a fraction of the cost. I just can’t justify spending $400+ on a 6.5in woofer anymore.
Those look really nice! The finish on them looks really good too.
I've been working on kind of a "ultimate bookshelf" design and wanted to use a pair of purifis with corresponding PRs and a RAAL tweeter. Been taking a crack at analog design to make an active system. Was thinking about adding a pair of aluminum dome tweeters in tandem with the RAAL to even out the sound, but if the RAALs perform exactly the same then I'll probably just stick to one tweeter.
I've been working on kind of a "ultimate bookshelf" design and wanted to use a pair of purifis with corresponding PRs and a RAAL tweeter. Been taking a crack at analog design to make an active system. Was thinking about adding a pair of aluminum dome tweeters in tandem with the RAAL to even out the sound, but if the RAALs perform exactly the same then I'll probably just stick to one tweeter.