TABAQ TL for Tang Band

[skirmitt]

Originally Posted by Bjohannesen

Hi skirmit, my original TABAQ is now playing
I will see if i can make a vidoe one of these days.

Ooh, I'm very curious to see/hear the movie :-) A lot of other people too I guess.

[Scottmoose]

Originally Posted by krakatoa

Thank you Scottmoose, but I think there may be other advantages - related to driver placement, one firing up for example,

Well, you asked about array effects, not drivers mounted on dissimilar baffles, and I'm not a mind reader. An forward-firing with upward firing unit will produce a semi-omnidirectional polar response, with a dense comb-filter effect.

lower distortion for same SPL, more headroom for excursion for same SPL ... but that doesn't tell me how it sounds... I'll find out when I get there.

Well, it tells you you will nominally have less distortion and greater dynamic range available compared to a single unit. That's about all that can be realistically said.

[toobhed]

Hi Bjohannesen,

I'm in the early stages of construction on your TABAQ w/ 4" TB bamboo and I have a question on the stuffing. Your diagrams states "Opening and the last 25cm of the line is not stuffed".

Is the opening considered to be the full length of the 9.7cm filter compartment such that, from the top of back of the box, 25cm + 9.7cm = 34.7cm unstuffed?

Or does the 25cm include the compartment such that, from the top of the back of the box, only 25cm unstuffed?

Thank you for the great idea and drawing...I've never attempted a folded transmission line before!

Regards,
Mario

[Bjohannesen]

Hi Mario, i could also have put it in this way: Only the upper 2/3 of the line is stuffed. The last one third and the opening is not stuffed. This is not critical, a few centimeres would not make much different. Also note that this is simulation.

You might find the bass a little too tight, but this depends on the placement of the speakers and your personal taste.

I tried to remove about one third of the stuffing (still upper 2/3 but more loose). This resulted on a little bit more and lively bass, but i went back to the original stuffing. I preffer a clean bass wihout "boom effects". With music I do not use my sub with the 4" TABAQ.

Have fun !
Regards
Bjorn

[toobhed]

Thanks Bjorn,
Mario

[toobhed]

....getting there slowly but surely. Using 3/4" BB for baffle and 1/2" for the rest of the cabinets...will finish the cabs before 2 wks vacation on Sunday and will veneer them when I return....thanks for the plans Bjorn,
Mario

[Havoc08]

Originally Posted by bAD kLOPFER

On the desk I would try to move the port to the rear panel instead of the top/bottom. You simply extend the top to the rear panel outer surface (1,3 cm + wall thickness rear panel) and shorten the rear panel (1,3 cm + wall thickness top). I have done this with the "Ten Öre" (see picture). With 10 cm distance to the wall behind my desk it was okay.

You are doing exactly what I thought of. But, I thought you had to put in angled inserts in the corners to maintain the correct cross section throughout the line?

[Havoc08]

BTW... should give a review now that I actually built these.
I made them as per Bjohannesens PDF file from his website and used the "plenty bass" BSC with the 881 TBs from the PE buyout.

So what do I think about the sound? I need to sweep the FR as it sounds as if there is a small attenuation in the upper bass area, but besides from that and a small shouty peak I have yet to determine, they are very linear.
They are really impressive for what they are. The zaphs with B3N sound better when cut off correctly, but the bottom end from these as stand alone is amazing! They image quite well although with very narrow sweet spot as expected. Tilting them on axis makes a large difference so test it out (it also affects the high end FR as you know).
The 881s are the utmost low cost option (but the engineer that decided to use non-drying sticky glue for the membrane should get punched or forced to pick out saw dust with tweezers like I did) and for what they are they rock with my 2024 test t-amp. However, they run out of steam fast so I would look for a driver with more Xmax than the .5mm the 881s sport. As one can imagine, very busy music is not their favourite and loud rock music will clearly strain the little membrane when trying to reproduce it all. The sound becomes harsh but muddy and imaging worsens. It is to be expected though as the laws of physics still apply. Coupling the 881 to the 2024 amp is a good match as excursion runs out right before clipping escalates. A little headroom on the driver would be nice though as bottoming out sounds awful. Sensitivity is avg on the 881s (85dB roughly per memory, have measured specs at home), but enough to fill a normal sized living room with loud, clean music. Room loading is of course not good and playing into ~125 cubic meters was optimistic. In smaller rooms like offices etc. it works great.

I will be looking into folding the line and using different 4" TBs.

P.s. Thanks for making this project available Bjørn

[pjblakey]

I put together a folded Tabag, slightly modified to place the port at the bottom front. maintained the required length and cross sectional area. The cabinets, except for the MDF baffle are made from a an old oak tree I felled a few years ago(3/4" thick). The 3" bamboo TBs sound really good.(my better half prefers them to my Apogees). Easy to adjust the stuffing with the removeable baffles, which has a profound effect on the quality of the bass.
Has anyone tried CHP-70 in the Tabaq? I picked up a pair this week (thanks MikeJen!!!!) and thought I might experiment a little.
Bjorn - thank you for a providing the design - top notch - great imaging.

[toobhed]

sounds like a good idea....do you have any pics? As soon as I locate the right veneer, I'll post pics of my completed folder T-line TABAQ,
Mario