Just bought a pair of SB26ADC to try this out. Playing on a set of Seas DXT right now, which require a rather narrow baffle to play good.
Does the 4" waveguide make it possible to place it closer to the midrange than the 5".... I mean does the shape change or does is becomre higher, creating a bigger CTC?
Also... was there not a round waveguide at some point for the 26ADC?
Does the 4" waveguide make it possible to place it closer to the midrange than the 5".... I mean does the shape change or does is becomre higher, creating a bigger CTC?
Also... was there not a round waveguide at some point for the 26ADC?
I can't access them at the moment but in general each size is just scaled up. But sometimes I used a slightly different aspect ratio (for elliptical mouths) at the extremes. The best way to know is to download the file and open it in software that can show measurements, and see if it works for your requirements.
I did a round waveguide but I didn't care for response. As you moved off-axis the responses became curved. I prefer ones that stay flat, sloping down of course, but flat. I had modeled this in ATH/ABEC and saw this behavior, so it was nice to have that confirmed.
I did a round waveguide but I didn't care for response. As you moved off-axis the responses became curved. I prefer ones that stay flat, sloping down of course, but flat. I had modeled this in ATH/ABEC and saw this behavior, so it was nice to have that confirmed.
This has been brought up a few times before in this thread, but it would be very interesting to compare an optimized waveguide with DXT performance.
Would digitalthor be willling to measure and post?
Would digitalthor be willling to measure and post?
Thank you. I was just being lazy.... thinking about how to make the cut-out for the oblate shape 😀 But now I just have to make that happen... because the drivers are coming next week 🙂
Sure! I will do my best to make some feedback on this, as soon as I get the drivers and waveguide in my hands 🙂
Digitalthor: Oblate shape is a pain to cut. Have tried more than once to do this freehand and with hard wood, almost impossible to not make a small mistake.
The best way to do it is maybe via a template: Tutorial: How to flush-mount irregular shaped speakers : diyaudio
Not so fast to make.
another way is to add a layer similar to the the depth of WG on top of the baffle. Then cut it freehand with a jigsaw.
Foamboard is maybe the softest yet very "dead" material to work with. "Jem & Fix" has this: Kapa Line hobbyplade 10 mm, 1000 x 700 mm
Edit: They even have a 5 mm black version.
Easy to cut with a stanley.
Or else quick and dirty is of course cardboard and you are ready to measure in no time 😀
Though this is crap for longterm use (the glue in the tape sticks to the surface), it is plenty fine for fixing the board. I use it often for fixing wood, that is difficult to fixate with clamps while routing:
Dobbeltklaebende taeppetape | Billigst i jem & fix
The best way to do it is maybe via a template: Tutorial: How to flush-mount irregular shaped speakers : diyaudio
Not so fast to make.
another way is to add a layer similar to the the depth of WG on top of the baffle. Then cut it freehand with a jigsaw.
Foamboard is maybe the softest yet very "dead" material to work with. "Jem & Fix" has this: Kapa Line hobbyplade 10 mm, 1000 x 700 mm
Edit: They even have a 5 mm black version.
Easy to cut with a stanley.
Or else quick and dirty is of course cardboard and you are ready to measure in no time 😀
Though this is crap for longterm use (the glue in the tape sticks to the surface), it is plenty fine for fixing the board. I use it often for fixing wood, that is difficult to fixate with clamps while routing:
Dobbeltklaebende taeppetape | Billigst i jem & fix
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Just another taste of just how good these waveguides are.
2 way, 15L bass reflex 15W8530K00+SB26ADC in 5" WG. LR4 2500 xo, quickly slapped into a test cabinet.
I'm using DSP to correct the on axis smoothness, but the normalization gives a good indication of the DI match between WG and 5" Mid-bass. The tweeter did still require 0.06ms delay to get perfect phase match between drivers on axis.
2 way, 15L bass reflex 15W8530K00+SB26ADC in 5" WG. LR4 2500 xo, quickly slapped into a test cabinet.
I'm using DSP to correct the on axis smoothness, but the normalization gives a good indication of the DI match between WG and 5" Mid-bass. The tweeter did still require 0.06ms delay to get perfect phase match between drivers on axis.
Sweet project, mainframe99! Any reason for the 2.5khz xo? You could smooth that directivity even more if you dropped it some.
I started working on a 3D-printed template for routing the baffle. It does force me to make the mounting flange even narrower at 3/8", which I'm hoping leaves enough material for the screws. The idea would be to use thin double-sided tape to tape the template to the baffle. I also include alignment grooves that you would align with marks on the baffle so the waveguide is oriented correctly. You would use a 5/16" template guide bushing to route the mounting flange rebate, and 1" bushing for the hole.
I started working on a 3D-printed template for routing the baffle. It does force me to make the mounting flange even narrower at 3/8", which I'm hoping leaves enough material for the screws. The idea would be to use thin double-sided tape to tape the template to the baffle. I also include alignment grooves that you would align with marks on the baffle so the waveguide is oriented correctly. You would use a 5/16" template guide bushing to route the mounting flange rebate, and 1" bushing for the hole.
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Hi Brandon,
I did exactly this kind of template when I built one project with your 6.5" waveguide (T25B) and noticed that the template wrapped a little in time (even when stocked properly on flat surface). Anyway it's still usable
I did exactly this kind of template when I built one project with your 6.5" waveguide (T25B) and noticed that the template wrapped a little in time (even when stocked properly on flat surface). Anyway it's still usable
Hi, just reporting in to say that I’ve put together my first prototype box using one of these waveguides! The off-axis seems to be well behaved, though I have some work to do to generate reliable measurements. Early crossover work in the Minidsp has gone fairly well.
It seems that the on-axis response of the RST28a in the 8” waveguide *does* have that >10khz cut and I’m still deciding how I feel about it. I think the final word on that will probably be how it sounds after I’ve developed the passive crossover. For home theater use (my intended purpose) it definitely isn’t a deal breaker, but it’s something I’m paying attention to.
Thanks again for sharing the files, it’s a great resource!
It seems that the on-axis response of the RST28a in the 8” waveguide *does* have that >10khz cut and I’m still deciding how I feel about it. I think the final word on that will probably be how it sounds after I’ve developed the passive crossover. For home theater use (my intended purpose) it definitely isn’t a deal breaker, but it’s something I’m paying attention to.
Thanks again for sharing the files, it’s a great resource!
@fluid I wonder if that is just indicative or real geometry. I imagine for 3D modelling the mounting is the main issue for a designer... not the curve of the waveguide. It's not uncommon in industry to obscure such a thing. Interesting pickup though.
Little teaser of some waveguides I'll be measuring this week:
I'll also be verifying the T25A works on the waveguides I did for the T25B. And the newest generation of Scanspeak waveguides where I hope to continue the improvement I made last time for the soft domes, which can be a real problem on waveguides.
I'll also be verifying the T25A works on the waveguides I did for the T25B. And the newest generation of Scanspeak waveguides where I hope to continue the improvement I made last time for the soft domes, which can be a real problem on waveguides.
I don't have a driver to compare to give give a definitive answer. Why model all these features in this level of detail or even post them at all if obscuring was their intention.
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If that's the 9900, the dome is glued to the waveguide and not the magnet, I just opened one the other day to see if it could possible mate up to augerpros waveguide. It is not. And I snapped the VC lead in wires. Oh well
My images are of the D2608, I am interested in looking at tweeters where a waveguide can be fit to the existing driver without having to take it apart and risk what happened to you.
The Elsinore waveguide mounts over the D2608 and Dutch and Dutch do it without any obvious issue in the response
The Elsinore waveguide mounts over the D2608 and Dutch and Dutch do it without any obvious issue in the response
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Hi Brandon,
Is the second one on your picture a Bliesma T34B ?
Curious to see the results of your findings then !
Thanks again for your invaluable work