B3S + Woofer Passive 2-Way

[sdclc126]

Hi,

Guess the title says it all - I'm curious about a sealed 2-way with either of the Hi Vi B3 speakers, with perhaps an 8" woofer for the bottom end, and the B3 for mids & highs, passive XO. (Or with possibly a small neo tweeter to cover the very top end.) My thinking is to get a decent, budget fullrange 2-way with good bass, without the need to port or use a subwoofer.

I did a search but didn't find anything. I'd like it to be a fairly simple design, although the low sensitivity of and correct filtering needed for the Hi Vis (per Zaph) may make for more XO complexity to get it right.

I'm especially curious about the crossover point - where should it be and what kind of slope, but that of course also depends on the bass driver - I'm thinking of perhaps uding either the MCM 55-2185 - MCM Audio Select 8'' Dual Voice Coil Woofer | 55-2185 (552185) | MCM Audio Select, or the new Dayton DA215-8 - Dayton DA215-8 8" Aluminum Cone Woofer | Parts-Express.com. I'm sure the Dayton is a superior driver but for just handling bass the MCM will probably be adequate.

If anyone has done something like this I'd love to hear about it, or any thoughts or recommendations, positive or negative, are of course welcome. Is this even a design worth pursuing?

 

[mikejennens]

Have you thought about the Pioneer B20FU20? Partnumber=290-045
It runs very nicely with a small tweeter Partnumber=275-025.
There are a variety of ways to enclose it; a search for Pioneer BOFU will provide more info. I built a Half Chang for mine and am impressed with the soud, especially for the price.
Mike

 

[sdclc126]

Thanks mikje - the price is right but this really wasn't the direction I was going - I need the 8" woofer to be a dedicated bass driver that won't need augmentation such as a horn, port etc. The cabinet needs to be a traditional, unobtrusive box, perhaps 0.5 cu. ft.

Also the response plot on the Pioneer looks rather ragged to me!

 

[PeteMcK]

For xover freq, I'd use the baffle step frequency, & if you have well behaved drivers, 1st order would work well. Al cone drivers have a peak that would need to be tamed; I'd stick with poly or paper cones. You'll get the best bass performance for size if you do port... driver choice is critical of course, & the woofer will need a few dB more sensitivity than the B3 if you want some BSC...

 

[picowallspeaker]

driver choice is critical of course, & the woofer will need a few dB more sensitivity than the B3 if you want some BSC...

That it is fairly easy ,'cause I see all the little 2 or 3" are in the 84-86 dB/W/m range .

 

[planet10]

http://www.diyaudio.com/forums/full-range/144099-thread-tysen-variations-fast.html

Tysen is pretty close in concept (except that it uses PLLXO). I'm working on a couple varitions which will (next up an MTM with FF85+CAA EL166 (MA#6 midwoofer))

dave

 

[sdclc126]

For xover freq, I'd use the baffle step frequency, & if you have well behaved drivers, 1st order would work well. Al cone drivers have a peak that would need to be tamed; I'd stick with poly or paper cones. You'll get the best bass performance for size if you do port... driver choice is critical of course, & the woofer will need a few dB more sensitivity than the B3 if you want some BSC...

Hi Pete - thanks. The drivers chosen are for value - high performance vs. price. Yes both drivers have peaks but the Zaph filter for the B3S addresses that, and a 1st order for the bass, at the right frequency, should roll it off well before there are any problems. And yes, ported is still an option, especially since xmax is limited in the woofers I'm considering.

Interesting note - Zaph says the MCM woofer is relatively clean distortion-wise, smooth throughout it's bandwith, and could be crossed LR4 up to 1500 Hz, which means it could be used with a conventional tweeter. So, a more traditional design could be considered here - this would eliminate the B3S sensitivity issue too. Perhaps the Dayton could still be used, as it has more excursion.