Woofer for Near-Field 3-Way?

[HareBrained]

I have been using a Vifa PL11WH and Morel MDT40 that I cobbled together as my computer speakers. I like how they sound but have nothing the in bottom octaves. I'm guessing F3~85Hz. I'd like to add a woofer and convert to a small 3-way. My set-up would allow ~0.35cf (10L) total airspace for the speaker (exterior of ~8.5"x6.5"x18"). Figuring 1.5L sealed for the PL11 and 0.5L for a port, what sub-$50 driver would you recommend for the remaining ~8L?

I did find the Peerless 830946 SLS 6.5" that will do F3~40Hz but I have no experience with it. It's Re is quite low, as is the sensitivity. Opinions?

If you can make a case for a sealed driver, I'd be willing to consider it.

TIA,
John

[fjhuerta]

A NF 3 way? Isn't that some sort of contradiction?

[HareBrained]

A NF 3 way? Isn't that some sort of contradiction?

Yeah, somewhat. I could get a woofer for a 2-way and save the PL11's for a future project. But it's gonna have to be beatin' into me.

The HiVi M5n can do 50Hz in 8L. Is this a good option?

[Operandi]

Why not just cross them to a subwoofer?

[HareBrained]

Why not just cross them to a subwoofer?

I had considered that. My budget is somewhat limited and to do the drivers justice, I need to redo the xovers ("cobbled" was literal). A Dayton SD215 + SA70 would be inexpensive, but since I'm redoing the xover, adding a woofer would be cheaper. Plus, I get to play some more.

Just ran the Dayton DC160S-8 thru Unibox and it'll hit 46Hz in 8L. Of the 3, the Peerless has the lowest box Q. If I set an upper F3 limit of <50Hz. The Peerless could actually go into a smaller volume, 6L, and still be reasonable, 47Hz. Thoughts?

[Curt C]

A NF 3 way? Isn't that some sort of contradiction?

My initial thought as well, but actually not as counterintuitive as it sounds. If the woofer is crossed fairly low, the actual phase error due to driver offset on the baffle will be small, and near field integration of the woofer shouldn't be an issue.

A small box and low f3 suggests a driver with low sensitivity. Consequently, bi-amping might be worth consideration. The TB W5-1138A will provide an f3 near 40 Hz in 8 liters, and puts out prodigious amounts of SPL with modest power requirements.

C

[HareBrained]

My initial thought as well, but actually not as counterintuitive as it sounds. If the woofer is crossed fairly low, the actual phase error due to driver offset on the baffle will be small, and near field integration of the woofer shouldn't be an issue.

A small box and low f3 suggests a driver with low sensitivity. Consequently, bi-amping might be worth consideration. The TB W5-1138A will provide an f3 near 40 Hz in 8 liters, and puts out prodigious amounts of SPL with modest power requirements.

C

How low is "fairly"? :B I was thinking 400-500Hz but I'm open to going to 250Hz. Any lower and I might need a larger subenclosure for the PL11. If it matters, the minimum C2C for the PL11 (R=62.5mm) to the SLS (R=82mm) would be 145mm (wavelength for 2380Hz).

If I can't work it without bi-amping, I'm just going with a new, cheap TM. I bought the PL11's on sale for another purpose. And the MDT was from another design that I disassembled because I didn't want to pay to ship the boxes. Zaph's ZMV5 has an F3~50Hz. I've already got it modeled and could adjust it for my situation. Or maybe a M5N with the MDT40. I'm not convinced the 3way is not possible yet.

The TB W5 is another solution (and cheaper) but it's -3db@1W compared to the SLS. The FR graph on the Peerless, W5 and TB W6 Neo are very similar. The SLS is only good to ~700Hz where it begins a 10+db dive.

[benchtester]

Curt,

Is there much difference between the W5-1138A and the W5-1138SM?

Is the F3 of 40 Hz. based on experience or the Tang Band graphs?

I have a pair and thought they would make a good tiny three way, but I moved on to other projects. Maybe they deserve a chance...