Lou's Home Page The Shticks Measurements
Compact, inexpensive, shielded, floor standing tower
  • 1/2 " Baltic Birch
  • 22 Liter Net   
  • 1 7/8"D X 4 3/4" Port    
  • F3 about 35Hz      
  • 2.3 Liter sealed mid chamber

With the B3S (or B3N) this is a very good speaker by any standard. For the price, the size, the full range bass, I'd be hard pressed to come up with anything else this capable.

Nov 3, 2008 Xavier Does a Set

For his sister's wedding. In these, the drivers & baffle are recessed 1/2" and a full length grill will be attached with velcro. We just extended the side panels to 7.75 inches. We also used the B3N. After working with the B3S & B3N, I don't see any sonic differences (at least in the range I'm using). I think the B3N is better built, and easier to mount in the box. Tolerances are tight for both drivers.

This pair also used the W5-1138SM version of the Tangband woofer. Again no major differences in the design.

For the mid padding we chose two 8 ohm resistors wired in parallel. (4 ohm nominal) This seemed just right for placement at 1-2 feet from the wall.

We did final voicing on a NAD stereo receiver and found the midrange to be exquisite but the top end a bit dull. We finally settled on a 10 Ohm padding resistor. This setting also seemed best with an entry level Yamaha HT receiver.

I recommend doing final voicing yourself in your environment. Tastes differ, component tolerances are pretty loose, and crossover parts even have some issues. There's only so much QC on a $5 tweeter.

The inside of the main box was stuffed using tubes/rolls of dacron batting instead of lining with mattress topper. I couldn't hear anything I objected to. (The originals are long gone so I can't do any A/B comparos)

The wood here is quarter cut Anigre with medium figure. Just a whisper of brown dye in 1 lb cut of shellac for a sealer. Four coats of Fuhr 380 water based acrylic. Finish is straight off the gun. This has a lovely ribbon flame that you see hinted at in the photo.

Black portions were painted with Krylon then clear coated with Fuhr. The base is 1" stock with a 60 degree chamfer. There is a 1" spacer between the plinth & box.

Feb 27, 2008 Final Design

Final boxes are done. I lined the woofer sections with foam mattress topper. The sealed mid chamber also got a lining of foam and additional dacron "fluff". A couple of coats of black Duratex and they are ready to rock.

We've been listening to these in the garage for a couple of days while we worked on other projects. Now that the TangBands have broken in, these little boxes really thump! Even at ear bleeding levels, there's no sign of distress from those woofers. Bass is clean, tight, and extends well into the 30's.

Presentation is clean, with exceptional imaging depth. There's a bit of a vertical sweet spot, but the image holds up well off axis. They stay very clean until you push them into the 98+db range where they get just a bit edgy. Even Xavier (an Accuton guy) was impressed.

Jan 21, 2008 Project Updated with B3S Mids

Since the A3S was a buyout, and I had the B3S in stock, I thought I would throw a pair in the box, and remeasure. I fired up a CD just to see how different the sound would be. I knew immediately, no measures would be needed. Other than reducing the midrange padding to 4.0 ohms, the B3S was a drop in for this crossover. Actually the B3S took the whole design up a notch. Upper bass is punchier, there seems to be more bottom end as well. The mids seem smoother and more detailed. The balance across the audible spectrum is just "spot on". The A3 is a very capable driver, the B3 just seems better. (BTW I am not suggesting these drivers are interchangeable in any other design.) As designed, the tweeter may be a wee bit hot on axis. Off axis it's quite smooth.

I can't say I'm overly impressed with HiVi quality control, 2 of 6 had surrounds detached from the frame. I was able to repair them with PE "Speaker Repair Glue" 340-076.

So which should you build? If you have the A3SII buyouts, and want to build with them, I don't think you will be unhappy with them at all. Considering the costs, this will still be a primo system. If you are looking for that next 5%, then the B3S is the driver of choice. The bass is better(probably from lower sensitivity on the B3), the mids are cleaner.
If you haven't bought drivers yet, I'd go B3S or B3N.

Suggested Mid Padding Resistor
Driver Dead Room Live Room
A3S 4.3 4.7
B3 4.0 4.3
Dec 31,2007 - Prototype Box & Crossover with A3SII

This project began as another "buyout special"using the HiVi A3SII, and the sale on the Tangband W5-1138SG. The current version of the TB is the W5-1138SM - a version that may or may not work the same but it should be close. Several folks liked the idea of my Periscope project, but wanted something a bit more compact. I chose the Dayton ND16FA for the tweeter to keep the MTM spacing as close as possible. I moved the woofers down on the baffle to get as much floor assistance as I could. The safe way would be to run a WMTMW configuration, but I wanted to get the tweeter well up off the floor.

The box is 1/2 " baltic birch with braces between the woofers and beneath the lower MTM driver. The mids are in their own sealed chamber. The mid chamber is 2.5" deep and 10.5" high, and the width of the box (about 2.3 liters).

I tried to keep the crossover fairly simple with a reasonable part count. For modelling I wound up using the a spliced nearfield/farfield measurement for the woofers and reducing the sensitivity to farfield levels. Final tweaking has been done by ear and SWAG modelling. (Those double woofers present some interesting measurement challenges). The TB's actually measured remarkably flat out almost 1000 hz. The HiVi's run out of gas about 350 Hz. [Measurements Here]

As with any 3 way, keeping the impedance up is always a challenge. I'd have to call this a 4 ohm design, (6 ohm if I were commercial) But it should be safe for decent solid state gear. The crossovers are at 350 & 4500. The series notch on the woofers enabled some necessary shaping in mid cross area. The mid circuit is basically 2nd order electrical. (All the resistors are real and have been adjusted for DCR of 20ga coils where appropriate).

As of this writing, I have only one prototype box finished with a cobbled up crossover. To get any significant bass volume, I wound up padding down the mids & tweeter considerably. Overall, the prototype is very "precise". Nice airy presentation, a bit of emphasis on the upper mids, but not really harsh. The HiVi's are a little bit edgier than some mids I've heard, but very listenable and articulate. If you like the B3S, you'll like these too. Very good off axis dispersion. The hand off from the mids to the woofers is basically smooth at 6 feet or more, but there is a little bit of muddiness at closer ranges (different arrival times from the woofers.)

I ran some signals from WinISD to break in the Tangbands. The cones were well controlled at 40 hz, flapping wildly at 30 Hz. Exactly what was predicted. In listening, the low bass is present, and well produced, not overwhelming. (But certainly better than one would expect from any 5" driver) I think near wall placement, and a fully prepared, damped, cabinet will bring up the bottom. For music only, I think this is truly a full range speaker. You will need a few watts to get that potential. Probably 81-83 dB sensitivity as I have designed it.