Small active 3-way floor stander with a punch

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Hello nipper, Thanks for the input! Glad to hear more good things about SB!

It is time! I will start building on saturday! :D

I have one small question (more will probably follow xD). How do you guys seal the holes for internal wiring?

I use silicon based RTV (room temperature vulcanizing) "caulk" to seal seams and wire holes. There are variants that call themselves "adhesive/caulk"; some silicon based, others not. I give it 48 hours to cure even though the instructions say 24 hours.

I have been impressed with SB so far; I have some Satori 6 inch mids that really put many other higher priced drivers to shame! I have a few of there very basic drivers as well; same story though, much better than some other brands in their price range and above. My SB sub-woofer project isn't finished yet but I find it amazing that a "9 inch" driver in a small, closed box can put out very deep bass. Of course, the Hypex plate amplifier has numerous EQ, gain, X/O, etc. adjustments and plenty of power to "push" the SB that low. 16Hz is hard to come by; I am getting this in the small room. I have several recordings of pipe organ, 16 Hz comes from the 32 feet pipes!

Cheers and good luck!
 
And then just drill a overzised hole for the wires to allow room for "glue"?

I actually just recieved my MW19P's and started testing with them. They sure have a amazing build quality and also seem promising when it comes to sound! I still haven't had time to pay that much but currently this is my reponse at listening position with a MW19P in 22L.
 

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My subs will also be "pushed" into the lower frequencies with the DSP built into the Fusion Amps. I hope that my dual 10" will also be able to deliver some decent SPL in the sub 30Hz range! So far simulations says that 2 of my subs will reach 100 dB at 30 Hz. So with a total of 4 subs i should be in for a good low F3 point with room gain i hope :)
 
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And then just drill a overzised hole for the wires to allow room for "glue"?

I actually just recieved my MW19P's and started testing with them. They sure have a amazing build quality and also seem promising when it comes to sound! I still haven't had time to pay that much but currently this is my reponse at listening position with a MW19P in 22L.

Yep; over-size the hole then apply caulk/adhesive/glue (whatever) to both sides if possible. Make sure to get plenty into the wire hole. You might need to use tape to temporarily hold the wires from moving until cured (remove the tape after cure).

Looks good, I'm sure you will be very happy with the end results. Does your DSP have a filter for infra-sonic? My Hypex has a 12 Hz, 24 dB/Oct. highpass filter. This is especially important if you are playing vinyl because I've read that the warp frequencies are around 4 Hz. The sub-woofers could be going way past X-max if the record is warped bad enough!
 
Okay so i have been looking on subwoofer drivers again. Considering your advice on back to back woofers and I think I will be going with the SB driver: "SW26DBAC76-3-DV"

Also the cabinet design will change again.. I will just make it as one combined unit, this will allow me to move the Amp down to the bottom of the speaker, simpler design and more volume for the Sub's.

Thank you for sharing your excellent cabinet CAD work. I am surprised you gave up the flexibility of 2-cabinets, especially with a heavy duty side subwoofer like the SW26DBAC76-3-DV. The 300W SB model SW26DBAC76-3-DV with 2 * 2.4ohm voice coils should dim the lights!

My computer desk speakers use the MW19P-4 midwoofer and the SB29RDC-4 dome tweeter with a 1650Hz crossover. I used a 0.75cuft Parts Express cabinet, which leaves about 0.6cuft usable volume, and included a rear port which is easy to seal. I really enjoy low volume close up listening to the MW19P...

Listen to vocals.... your brain will notice... "that's how voices should sound"
 
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Nipper#
Thanks for the tips! :)

My DSP have free filtering possibilities from 10 to 25k Hz. So it should be possible to do pretty much anything :)
I never listen to vinyls (I don’t have a player – yet, at least :p), But will implement something like your filter I think.

LineSource#
I love to look at other people’s designs and drawings, so I kinda have to share :p
I realized that I can use the cabinet volume better this way – smaller speaker. It will also make the cabinet construction simpler.
Do you think I might regret the subs?
I actually talked to SB and they recommended that I used the 8-Ohm version instead. It will yield a slightly better performer and will use my amps as good as possible compared to the DV version.

Glad to hear you like the woofer. My first impressions are also good!

Can’t wait to have the new cabinets and actually mount the woofer properly and hear the Sub’s!!
 
Actually I think 2 of those 26DBAC76-8 subs sealed in about 20L will do even better than you think they will. Attached is what Unibox shows for max SPL without exceeding xmax.

You're looking at more like 105dB at 30Hz and about 110dB at 40Hz.
 

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So I thought you should see the final design as-is before I start building. We will see if it will remain this way until the build is finished :p

The driver alignment pr. speaker will be:
Tweeter: 1 pcs. ScanSpeak Illuminator R3004/662000
Midwoofer: 1 pcs. SB-Acoustics MW19P-04
Subwoofers: 2 pcs SB-Acoustics SW26DBAC76-8 in Back to Back configuration as side firing woofers.

Crossovers will probably be:
Harsch XO at 1700 Hz
Harsch XO at 80-150 Hz
Linkwitz Transform to extend bassresponse as deep as makes sense – ideally 15-30Hz

The tweeter will have its own small chamber to avoid leakage from midwoofer.
The midwoofer will be in a aperiodic/ported (undecided) enclosure of 13,2L (with bracing subtracted).
The subwoofers will share a sealed cabinet of 19,3L (with bracings subtracted).

Each speaker will be driven by a FA253 plate amp.

This is what it all will (hopefully) look like in the end:

o19tLKu.png
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And on the inside:
pSdKJgc.png



MabitEA.png
 
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My DSP has up to 19Ms time delay (I think both + and minus).
The slanted baffle is mostly for style. I like the look and I think it feels less intrusive in the room. Furthermore, the speakers are only 80 cm tall so in order for the drivers to be pointed at ear height in listening position i need some tilt.
 
Some construction images

I started out by cutting a template for the basic shape of the skeleton. Glued a 1:1 drawing on a precut piece of 21mm ply.
WzKfGXK.jpg


Then from this template i routed all the pieces of this shape.
C1OJtnz.jpg


Then i glued on new 1:1 drawings on the pieces and started drilling.
oiUetfD.jpg




And cutting.
Zs4fVAf.jpg


The fronts and back where cut on a table saw and then templates where glued on for routing alignment traces.
1dSMoDf.jpg






Stay tuned!
 
I have to say this is the first time I have seen the glued-on 1:1 drawing approach, but the detail-oriented side of me loves it. Great project and I will be very interested to hear your results, especially with two 10s in such a small cabinet. What are the approximate exterior dimensions you settled on?
 
Hello Wright#
If you are sure your printer prints 1:1 (at least very close - i think my drawings are in scale 1,005 which is way more accurate than my jigsaw skillz xD) then i really like this approach. I have all center points for drilling and lines for cutting. If you use the proper glue the paper can be pealed right off when done. :)
Allthough this approax has its limitations in aligning the paper properly of course..

I am also VERY excited to hear them!
These subs may not be the most musical subs in the world (i never heard them before, but my guess). But in this cabinet size they should have a Q of 0,702 without any fill. And i am sure they are really good for movies! And i am sure they are some of the very best flat subs :)

I have attached some pictures with outside dimensions. They are really small!
 

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