My TABAQ Build

**BoomieMCT** · **06-13-07, 06:59 PM**

I can't take the credit for the design of these. Another forum tosses around the TABAQ (TAng BAnd Quarterwave) design (mass loaded transmission line) as one that works well with a wide range of 3" and 4" Tang Band extended range drivers. In my case I used them with the new W4-1320 4" bamboo drivers.

They are still breaking in but the sound is remarkably flat with decent bass extension (for a 4" driver). It is a very pleasant and non-fatiguing sound. Vocals are incredibly clear. It does lack some mid-bass punch for hard rocking out - what do you expect from a single 4" driver. I have noticed that they are picky about stuffing - some tuning is required.

I'll post more as they break in. . .

**JCD** · **06-13-07, 09:20 PM**

That looks like some fine woodworking there!

I'm looking forward to your final impressions.

JCD

**BoomieMCT** · **06-16-07, 10:35 AM**

I've been running these for a few days now. I originally used the mathmatically calculated BSC with L=1.0mH and R=8 ohms. The sound was very neutral and even but the was a hollowness to vocals. I ran a FR and, sure enough, the BSC was starting too soon creating a wide dip from about 180 - 280 Hz. I redid the BSC with L=0.7mH and clarity was much much improved.

I like these very much so far. My wife even appreciates the extreme clarity in vocals (she sings in a band). The bass is impressive for a 4" full range. My only complaint remaining is that I would like a tad more high octave reach. This certainly brushes 20kHz but there is a bit of sparkle missing. So far I haven't found any 4" full ranger that can do that so this is no slam on these drivers.

I'll get a FR up when I get my new (and improved) microphone up and running.

**Sonnie** · **06-16-07, 01:09 PM**

Nice job Boom!

**BoomieMCT** · **06-16-07, 01:28 PM**

Got my new Behringer mike up and running (and calibrated). So, here is a FR from these bad boys. My OC703 is still on order so my testing room is still untreated - forgive the peaks and such.

I'm happy to be running this on my PC instead of my wife's Mac as I no longer get weird soundcard artifacts, I can use the new REW AND the graph axis don't loose their labels.

**10-23-07, 08:07 AM**

Hi Boom, I am glad you like my design. I have not tried the 4". I am very pleased with the 3" TB. I know a few DIYers in Sweden are pleased with the 4" as well. I am planning to try the 3.5 " Vifa in the future.

A correction, the resistor should be 3.9 Ohm along with the 1.0 Mh. This might explain your experience with the uneven response ?

**O_ROD** · **10-25-07, 10:00 AM**

Your TABAQS look very well done. Are there any notch filters being used?

I've built a set of Bi-pole TABAQS using 4 TB 871S drivers and they sound absolutely fantastic. My listening room is small (10x10) so I get usable bass down to 26Hz. I found the bi-pole design to open up the TABAQS quite a bit and make them "disappear".

**BoomieMCT** · **10-25-07, 10:08 AM**

Quote:

Bjohannesen wrote:

Hi Boom, I am glad you like my design. I have not tried the 4". I am very pleased with the 3" TB. I know a few DIYers in Sweden are pleased with the 4" as well. I am planning to try the 3.5 " Vifa in the future.

A correction, the resistor should be 3.9 Ohm along with the 1.0 Mh. This might explain your experience with the uneven response ?

Man, I'd love to try that 3.5" Vifa too. People seem to rave about it! I'm also interested in the CSS full range driver. Sadly I have WAY more speakers than places to put them right now.

I tried the TABAQ with a BSC with a 1.0 Mh inductor (what I calculated as appropriate). That was the "textbook" right thing to do. It sounded pretty good, but I preferred it (and got a flatter FR) with the setup as listed. I can't begin to imagine why as the inductor should be based on the width of the baffle and 1.0 Mh is the correct size. I guess I'm "baffled" by this

**10-26-07, 01:58 AM**

Hi both of you.

The BSC I use, is based on the calculations done with Martin J. King´s MathCad models. The driver data is based on factory information, and real life might be different, of course. MJK´s software take into consideration the physical box, driver and opening location and distance to the wall. The BSC is not a dramaticly thing, just a fine tuning resulting is a nicer sound. But once used, you would not do without the filter.

Stuffing and filters is of course tuning options.

http://coolcat.dk/bjoern/TABAQ_TL_for_TB.pdf

Hi from

Bjorn

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