Re woofer alternatives, SBA have several 8” woofers that look to have even better specs than those Dayton ones; low Fs, 90dB or better, similar Qts, low distortion and reasonably priced. And some of them are shallow mounting 😀
Nice!
Do you have a link to your friend's build? I wonder how low TPLs are crossed in that config.
BTW, if you ever go to TPL with horn, I highly recommend this notch filter filter 3D printed. File is in the thread. Super easy tweak.
I’m not sure what a high Qms driver is supposed to sound like. I just know that the PRV 5MR450NDY sounds very clear and effortless.
https://www.diyaudio.com/community/threads/sirvalences-tpl-150-sb23nrxs-point-source-horn.353508/
A mechanical notch filter? Cool.
Allegedly high QMS is meant to support a sound that is more lively, open and dynamic. Effortless would fit.
And dynamics of the 5MR450NDY are crazy good. This is especially noticeable when playing with an amp that has serious power behind it even though only playing 6Vrms, the peaks are well resolved and don’t get compressed. I tried a 600wpc amp the other day and the sound was impressively loud, clear, and dynamic.
This speaker has prompted me to ponder on the question of low bass being produced by relatively small drivers. It begs the question, is a 6.5” woofer actually capable of generating say 30hz at anything like a useful SPL ? Well my researches tell me that a driver of that size can produce 30 hz output but that it will be well down in SPL in comparison with the higher frequencies that its producing . So if you want or need to use such drivers then the remedy of course is to use multiple drivers, just as XRK has done. There’s no replacement for displacement, but there is more than one way of getting displacement.
Great idea to use a racetrack driver! Maybe 4 of those would be be perfect. They are taller so cabinet might be too tall with six. Although upper reach on round 8in driver is about 350Hz is not too bad. As the frequency drops, one has to go with lower sensitivity mid ranges as none I know of get 95dB and work well below 300Hz.
That looks very nice. With 4 ohms it would be 3 parallel and 3 series for nominal 6ohms? What do these ceramic drivers cost?
Not cheap. Over £100 ea on this side of the pond, so £1200 for 6 per side. But if you were persuaded that this design is the way to go then that might be a price worth paying as I suspect they would be awesome.
I think the slight decrease in depth for the price is a bit steep given 12 are needed. I would use RS225-8 and that would cost significantly less and I know it’s a superb driver.
I would agree, but in this case, if going with 8" drivers, I'd give the nod to the SBA SB15SFCR39-8 5x8". You still get the 8" extension through the notch, but the easy 5" for depth and compactness. Those 5x8 can be pushed hard and hardly break a sweat, I mean, minimal distortion, even with a heavy hand on the EQ, which they would barely need in this design, I am super impressed how they perform.
And at less than $50 each, they are an amazing price/performance ratio.
Thanks for confirming that these are as good as they look - Its a bit frustrating that the UK retailer I found has put the price up overnight 😒