TABAQ TL for Tang Band

I am starting this thread not to mix up things like I did on http://www.diyaudio.com/forums/showthread.php?s=&postid=1036908#post1036908

:D

Take a look at the thread above, which has a link to my Quarter Wave design TABAQ for the nice 3" TB drivers.

I would appreciate commments and suggestions as I am not the right person to claim "it is a nice speaker".

I am impressed, however, how much you can get out of these small drivers.

I have tested my TABAQ with TB W3-926S and W3-315SC. Both are doing well.

I am a great fan of Martin J. King´s models, and I have simulated TABAQ with TB 4" driver. On paper it looks very promising, but I have not tried it in real life.

I have enclosed the simulations.


Hi from
Bjorn
 

Attachments

  • tabaq with tang band 4.pdf
    42.8 KB · Views: 12,612
Looks pretty good to me. The TB drivers have enough excursion to keep distortion in the LF regions low, and there's a nice, gradual roll-off too, so no boom. Will need to be placed against a rear wall or into a corner though, or have a BSC circuit as the baffle-step point will be too high to cancel out with room gain. I like. Great little cabinet for those who don't fancy an MLTL or horn. Nice job Bjorn.
 
Bjohannesen said:
I am starting this thread not to mix up things like I did on http://www.diyaudio.com/forums/showthread.php?s=&postid=1036908#post1036908

:D

Take a look at the thread above, which has a link to my Quarter Wave design TABAQ for the nice 3" TB drivers.

I would appreciate commments and suggestions as I am not the right person to claim "it is a nice speaker".

I am impressed, however, how much you can get out of these small drivers.

I have tested my TABAQ with TB W3-926S and W3-315SC. Both are doing well.

I am a great fan of Martin J. King´s models, and I have simulated TABAQ with TB 4" driver. On paper it looks very promising, but I have not tried it in real life.

I have enclosed the simulations.


Hi from
Bjorn


I would have never seen this if you hadn't started
the new thread so it's much appreciated.

I will try anything to get my W871's in something
that sounds decent. With all the talk about the small
Tangbands, I've never been happy with the builds
I've done for them. I did a TL in PVC to 41 inches,
small open baffle, and a 16 in tall "whiskey carton"
design ala' John Krutke. No happiness after all of
these. Small open baffle actually sounded best
at extreme nearfield.

Your design looks like it has real possibilities. Also
the presentation for new builders in the pdf is very
well-done.
 

Svein_B

Member
2005-10-24 7:34 pm
Nice work Bjorn!

I notice that your simulations are "ruler flat" down to around 55Hz. I am not (yet) very familiar with the MJK simulations, so I am not sure if it assumes free space, or if it takes into account floor reflections and rear wall room gain.

If the sims are free space, I wonder if they might offer a little too much lower bass "boom", especially in a smaller room. Would it be possible to dimension for a slight drop in gain for the lower octave, possible with a little lower tuning?

I am just curious regarding sims vs. reality. Do you have any (subjective) listening experiences to share with us ?


Svein.
 
Hi Scootmoose


As you can see in the article (link in the other thread), I am using BSC. 3.9 Ohm in parallell with a 0.1 mH coil.

The bass is not boomy at allwith the 3" drivers, not even in i a corner. For fun I tried the TABAQ with Hi-Vi B3S - and then, the bass got too "impressive".

I have not tested the 4" driver, but I expect this to perform nicely as well.


The stuffing density is 3 times higher than I use in my other quarter wave contructions (subs - but that is another story).

Bjorn
 
Hi Solve,

if you look at the plots, the 4" has a more gentle roll off and goes deeper. This is simulations only, however.

But I would expect the 4" to do better than the 3" if you compared them in real life. The 4" has a lower Qtc etc.

I focused on the 3" because they are cute, cost "nothing" and are doing so well. This is the experience in other contructions as well.

Bjorn
 

Attachments

  • tb 3 and 4.pdf
    30 KB · Views: 3,523
Hi Bjorn,

First of all a big thanks for your plans. I have started to make a pair of these speakers today - all cut and started glueing. One question I now have is that the driver position seems low compared to ear level. Can these be put on stands, or is the response modelled with the floor gain included and hence something would be lost.

I have a second question for whoever can answer it - where is the best source from the UK to buy the resistor and inductor for the notch filter. Also what types are recommended - i.e. air core inductor vs ferrite etc and type and rating of the resistor. Any advice on this would be greatly appreciated.

Cheers
 
Bjohannesen said:
I am starting this thread not to mix up things like I did on http://www.diyaudio.com/forums/showthread.php?s=&postid=1036908#post1036908

:D

I am impressed, however, how much you can get out of these small drivers.

I have tested my TABAQ with TB W3-926S and W3-315SC. Both are doing well.

I have enclosed the simulations.


Hi from
Bjorn


Thans Bjorn, good work, your file is most complete and understandable for this newbie,

thanks,

gychang
 

Svein_B

Member
2005-10-24 7:34 pm
Filters for the W3-871S

Here is a little survey of [notch]-filters for the W3-871s, with the addition of a few personal opinions and analysis.

Bjohannesen is suggesting a traditional BSC filter for the TABAQ. This will attenuate everything above about 1.3 KHz by a few dB.

Due to the falling off-axis HF response of full rangers, it may be desirable to avoid damping the higher frequencies. Most designs with the W3-871s are therefore recommending a notch-filter. This notch serves two purposes; it will reduces a small bump in the speaker's natural response in the 1.5-3 KHz area, and the baffle step hump is in the same vicinity.

Cyburgs Needle : 0.56mH, 6.8uF, 6.8ohm (fo=2.6KHz)

The Lancetta: 0.56mH, 6.8uF, 6.8ohm, the same as the Needle. The article in Hobby HiFi 6/2004 also show measurements for the very slight variations when changing values; L 0.39-0.82, C 4.7-10, and R 4.7-10.

ZaphAudio also had an article on their web site some time ago with measurements of filters for different boxes with W3-871s.
Very narrow low-diffraction box: 8.2uF, 0.7mh 6.8ohm (Fo=2.1 KHZ).
5.75" wide box: 3.3uF, 0.7mH, 6.8ohm (Fo=3.3KHz)

Regarding component choices:
Inductors: Most designers recommend good quality air-core inductors with thick AWG16 wire or copper-foil. A more modest coil with 0.8mm wire (AWG20) will have R=0.8ohm. This has the effect of slight rise of Qts from 0.59 to 0.65. I would be satisfied with this since the smaller size is much cheaper and easier to fit in the cabinet without obstructing the air-flow.

Caps: Exotic "boutique" caps may be the best, but kind of ruins the budget approach of using a cheap driver in the first place. I use cheap polyester-foil capacitors, and avoid Solen/SCR polyprop since I feel they add a hard glassy sound - just what the filter was intended to reduce.

MOX resistors seem to be in fashion these days. If you can not find them, use simple wire-wound.

Personally I use the Needle/Lancetta filter with budget parts, and very happy with that. :)

SveinB
 
Thanks for the full and detailed reply Svein_B. So from what you say it sounds like a notch filter would be best, rather that just the BSC that has been proposed. I guess the other advantage of using the notch filter from Cyburgs needle would be that I can test the filter with this enclosure also. I'm going to spend some time searching for hopefully suitable inductors, capacitors and resistors tonight.

Gychang - I'll post again with listening impressions once I have the filters and cabinets finished!!
 
I am now considering having an external notch filter that can be tranferred between cabinets and based on the values for the needle. Should I buy the components from a known audio shop e.g. IPL or Wilmslow Audio from the UK (or another audio shop).

I am tempted by the idea that Svein_B suggested that since this is supposed to be a budget project using notch filter components that cost more than the driver and cabinets combined sounds like overkill - could someone recommend cheaper alternatives - e.g. are there caps / resistors / inductors from e.g. Maplin or RS or Rapid electronics that would do the job. Specifically the polyester foil caps that Svein_B suggested.

Thanks again for any help.
 
About the notch filter: It is calculated by the use of MJK software and is designed for the actual TABAQ cabinet.

The filter is taking care of the otherwise lift in SPL from about 700 Hz.

Other cabinets might need other values for a filter.

I know the driver is not in the perfect position when placed on the floor. The software from MJK simulate distance from back wall, not the hight above the floor.

I have not done much testing with the speaker placed higher.

Bjorn
 

Solve

Member
2006-05-03 10:43 am
I have pre built my TABAQ, still one wall not glued yet, just clamped.I put in a pair of w3-871 while il wait for my w4-1320.
I took what i had to make an BSC filter.
0,8 mh+6,8ohm.
What frequens is that?
How it sounds?
I must say it sounds very good!!
Very good bas and well balanced sound.
Easy to build.
My wife like them! :bigeyes:
I cant compare with needle or any other TL beacause this my first build.
In a few dayes i get my w4...
Just wonder if its going to get boomy?
Maybe build them in 16mm MDF?
 

Solve

Member
2006-05-03 10:43 am
I dont know if as usual when you build something and WANT it to sound good and the brain slowly accept it as good means that it is good.
But this must be the DIY kit for the Tangband W3-871!
Easy to build!
Sounds very good!!
But, still not clear with 12mm MDF board.
Could feel some "booms" sometimes.
Why 12mm?
If i goe to 16mm not worth it?
Tell me!

Im an musician and have worked as sound enginer so i have critical ears.
I hope... :)


For you jazzlovers-check Esbjorn Svensson latest.