I showed several examples of this earlier, please read the thread. It is dictated by depth of chamber and that is same as quarter wave frequency. Also chamber volume but that requires simulation in program like Akabak or HornResp etc. changing velocity would require simulation. Or you could build a small mock up for one pair of woofers and measure it.
Compared to a 15in woofer on a circa 20in wide baffle, I think the 8x 6.5in has 25% more surface area on the membrane and the effective baffle width is about 1.5x more. So I suspect it won’t go as deep or have as much sensitivity or slam. More importantly, a 20in wide baffle won’t be acceptable for sheer size in a domestic setting. But I can’t be sure as I have not personally listened to some thing like this. AE are supposed to be nice drivers for OB.
Ok, thanks. Upper end is not so important for me. Looking for a mid bass that is fast and can kick ;j Something between 70 and 250-300 Hz maybe.
Will use it with this:
Never liked the original Bastanis 18” Ripol.
There might be a way to use a smaller slot, to allow higher frequency extension, with a larger woofer:
Red = the slot side profile eg 6" x 6", front to the right
Blue = driver SD eg 7" for a 8" woofer
With this a 8" woofer can be applied to slot of 6" instead of the usual 8" + 1" = 9"
The front slot reduces the output area of a woofer loading the woofer. If the cut-out area above is more then the slot area/2 (for two woofers per slot) it will not additionally load the woofer. The magnets will both need to be out of the slot like the Pass deign. The lateral dimension is the woofer dust cover depth x2 plus slot. So in the x axis, the cone depth x2 + slot width </= slot depth
Red = the slot side profile eg 6" x 6", front to the right
Blue = driver SD eg 7" for a 8" woofer
With this a 8" woofer can be applied to slot of 6" instead of the usual 8" + 1" = 9"
The front slot reduces the output area of a woofer loading the woofer. If the cut-out area above is more then the slot area/2 (for two woofers per slot) it will not additionally load the woofer. The magnets will both need to be out of the slot like the Pass deign. The lateral dimension is the woofer dust cover depth x2 plus slot. So in the x axis, the cone depth x2 + slot width </= slot depth
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Exactly. For those wanting to use big woofers in a SLOB withn a cut down slot size, the x-axis woofer dustcover to dustcover separation will quickly become the slot dimension limiter.
Theres a fix for that. Just divide the slot in the centreline along the z-axis. The divider will be equally loaded so could be relatively thin and still be low resonance. Then the x-axis is only half and no longer a limiter.
I am not sure what the orientation of the divider is? It needs to reduce the front to back dimension (back to slot mouth distance). If that is there, it blocks air flow from the back half out to the front. One could put very porous reticulated foam in the chamber to reduce the resonance cutoff.
I just built up the XO for the second channel with PRV 5MR450NDY driver. I was lucky I had enough parts in my XO development kit to make a second one. Listening in stereo now. Gorgeous sound. Vocals are super and astonishingly clear. The midrange is the star in this speaker and it helps to use the best one you can find.
I just built up the XO for the second channel with PRV 5MR450NDY driver. I was lucky I had enough parts in my XO development kit to make a second one. Listening in stereo now. Gorgeous sound. Vocals are super and astonishingly clear. The midrange is the star in this speaker and it helps to use the best one you can find.
I just soldered up a P2P crossover board for one channel. I think it’s pretty much locked in now. This will let me move the speaker to another room to test it out in a different environment. (Sorry about the redacted values) It may be my imagination, but the soldered joints XO seems to sound better. More clear and a bit louder vs temporary Wago clip connectors. Mundorf EVO aluminum in oil cap for the tweeter. A huge MKP film cap for the mid and combo electrolytic and large MKP box cap for the woofer.
The stereo pair with the PRVs and the new soldered permanent crossovers sounds glorious. These are some of the best sounding speakers I have ever heard. It’s way up there. 
There is so much music that just sounds natural and right. The articulation of the bass notes is amazing. I don’t think it can get better on another speaker.
There is so much music that just sounds natural and right. The articulation of the bass notes is amazing. I don’t think it can get better on another speaker.
-Just a thought you may want to look at - https://www.parts-express.com/GRS-PT5010-8-10-Planar-Mid-Tweeter-8-Ohm-272-130
-- GRS PT5010-8 10" Planar Mid/Tweeter 8 Ohm
- It is more money but it's around 94db , and ALL reports say it is one of the BEST midrange drivers people have ever heard!!- I'll try and find the thread where they were talking about it being the best they have used in their diy speakers .
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-- Also GR Research is using the Neo 10's made by a different company but very comparable to the GRS driver in their Top of the Line Speaker a Line Array it's around $30,000 , they are still working on the other company getting the final version of their driver completed. . . . . but the GRS driver is pretty close to it.