medium active 3-way

[andy19191]

The Satori 6.5" midbass(MW16P) with acoustic LR4 Xover at 1800Hz to SB29RDNC tweeter is a great combination of well reviewed drivers. Trimming the SB29 faceplace to overlap the Satori reduces the C-to-C and this reduces lobing. A 12" like the SB Acoustics woofer would complete this 3-way.

Consider a clone of the Pass Labs SR-2 with ~3cuft for the SB12 supporting both sealed and ported options.

The cheaper 12" SB woofer is designed for sealed cabinets of ideally more than 4 ft^3 and with the SB 6.5" midwoofer and SB dimple dome tweeter would make a nice large speaker although the 6.5" midwoofer is a bit low on maximum SPL. A ported version in an "ideal" cabinet would be insanely large and in a 3 ft^3 I am not sure how you would tune it(?).

The more expensive 12" SB woofer is designed for a modest sized ported cabinet of a touch over 2 ft^3. This gives a -3dB of around 35 Hz like the sealed speaker above but with a steeper roll-off. It could also be designed to work well in a 3 ft^3. A sealed version in an ideal box is going to have a high 60 Hz or so roll off albeit in a small box. The better motor means this 12" will work nicely well into the midrange and so is likely to be better matched to a "proper" efficient, small displacement, stiff surround 5" midrange rather than a 6.5" midwoofer.

 

[active]

Big is beautiful I will go ahead with a larger project we will likely be out of our condominium as soon as summer 2016. I figure in build time management and it may take up to or close to a year at any rate. Really looking forward to having a larger more dedicated room for my audio.

I want to do them in the separate enclosures as I mentioned and Im pretty firm on that. https://www.madisoundspeakerstore.c...o-sb12.3-sb-acoustics-12-dual-midrange-3-way/

Baffles will be removable and fixed down by hex keys and inserts incase I screw up driver placement I can cut a new ones. Once I have that settled I can duplicate them with solid material that allows me to round out edges.

 

[LineSource]

The SB34NRX75-6 12" driver is well suited as a 3cuft sealed box F3=40Hz woofer, and also with a Linkwitz Transform down to 20-30Hz. This is active's main requirement. A low port tuning around 15Hz will provide modest extended bass in a 3cuft volume, but as andy19191 pointed out the T/S parameters favor a much larger 8cuft box volume for deep ported bass.

A 12" woofer with a lighter cone and Qts around 0.35-0.37 would be better suited for both a good sealed andported alignment.
like: Dayton Audio Series 2 12" 46Hz sealed before boost, 31Hz ported
like: Lambda TD12S with MMs=53g
like: Peerless SLS 830669

I would always select one slightly larger M than two small M in and MTM topology. The other design recommendations in this thread are also for TMW 3-ways.

 

[active]

Im restricted to just 1 pm message. Thanks LS, its all very helpful to me.

 

[LineSource]

AFTER YOUR MOVE --- Compatible 3-way drivers:
T= SB29RDCN-C000-4 Fs=550 Xmax=0.5mm allows LR4 at 1800Hz
M=SATORI MW16P-8 Sd=119cm^2 is closer to 5.5"
W=SB24NRXL75-8 T/S support sealed and ported flexibility in 3cuft box

Attached WinISD of the SB Acoustics SB24NRXL75-8 which has T/S parameters to achieve -3db at 43Hz in a 3cuft sealed box, and -3db at 31Hz in a 3cuft ported box tuned to 31Hz. A lower port tuning extends the down-slanting bass shelf and reduces the -3db frequency. Placing a speaker close to walls provides room bass gain starting around 100Hz-150Hz. It is often possible to adjust the port tuning(bass shelf) to complement the room bass gain and provide a flatter bass SPL curve at the lower port tuning when active equalization is not available.

 

[andy19191]

Attached WinISD of the SB Acoustics SB24NRXL75-8 which has T/S parameters to achieve -3db at 43Hz in a 3cuft sealed box, and -3db at 31Hz in a 3cuft ported box tuned to 31Hz. A lower port tuning extends the down-slanting bass shelf and reduces the -3db frequency. Placing a speaker close to walls provides room bass gain starting around 100Hz-150Hz. It is often possible to adjust the port tuning(bass shelf) to complement the room bass gain and provide a flatter bass SPL curve at the lower port tuning when active equalization is not available.

Those curves are not what one would expect for a 12" woofer with an ideal sealed box volume (Q=0.7) of over 4 ft^3 varying a bit depending on the amount of stuffing. In a smaller box the Q should be greater than 0.7 not less and in a very much smaller than ideal vented box volume with high tuning there should be a large SPL bump as the port output adds to the not yet rolled off much cone output. Have you perhaps used the 12" subwoofer parameters by mistake?