Hello,
I'm observing this forum which is really great (!!!) for quite a time and am building my speakers (see http://mieszkoman.privat.t-online.de).
I would also like to start building a box using the TB W3-871S for my computer room. I am still thinking about the Buschhorn (MK2) or a TQWP (aka TQWT).
Do you guys have any plans for a TWQP enclosure using the TB W3-871s? Could I just take the Solo design (http://www.diyaudio.8m.com/Solo/solo.html) and put a 871s inside instead?
What would you prefer, the Buschhorn or a TQWP ?
Thanks for your help,
Sergiusz from Berlin/Germany
I'm observing this forum which is really great (!!!) for quite a time and am building my speakers (see http://mieszkoman.privat.t-online.de).
I would also like to start building a box using the TB W3-871S for my computer room. I am still thinking about the Buschhorn (MK2) or a TQWP (aka TQWT).
Do you guys have any plans for a TWQP enclosure using the TB W3-871s? Could I just take the Solo design (http://www.diyaudio.8m.com/Solo/solo.html) and put a 871s inside instead?
What would you prefer, the Buschhorn or a TQWP ?
Thanks for your help,
Sergiusz from Berlin/Germany
Hi sergiusz,
I´m soon about to finish a ML-TQWT with the TB speaker.
For a first look at the enclosure click and look here (it´s the tall one on the screen).
If you plan something like the SOLO from your link you certainly have enough space around the PC and might consider something bigger like the Gradient W160AL8 which has got a nice price as well. (the TB is actually quite expensive here in germany
)
A ML-TQWT with the Gradient is my 2nd project on the bench at the moment.
Get back soon.
Regards
Jens
I´m soon about to finish a ML-TQWT with the TB speaker.
For a first look at the enclosure click and look here (it´s the tall one on the screen).
If you plan something like the SOLO from your link you certainly have enough space around the PC and might consider something bigger like the Gradient W160AL8 which has got a nice price as well. (the TB is actually quite expensive here in germany
)A ML-TQWT with the Gradient is my 2nd project on the bench at the moment.
Get back soon.
Regards
Jens
Sorry bout the OT-newbie-question but what´s the point in building a folded pipe with (relatively) high tuning?
Looks like you use a sub with it? so why don´t go sealed for a more linear f/SPL ?
It also has quite a bump at resonance frequency; was that deliberate?
Mine will be :
Line length ===== 15.75"
area at top ===== 18.6 sq in
area at bottom ==18.6 sq in
port tube =======0.492" diameter, 1.18" length
driver position ===7.56" from top of line
port position ==== 14.76" from top of line
Probably not for very high output levels as it´s tuning is quite low (linear down to 70Hz).
Cheers
Jens
The line length I used is to benefit from quarter-wave action inside a tapered pipe. The numbers would be pretty much the same were the pipe not folded. I just happened to have modeled this particular application and assumed that for computer speakers 30" tall speakers would be less desirable. Didn't notice a bump at Fs. I'll look again. For a BR ~16" is correct. I hope I didn't mix this up with my bipole design.
Edit: I ran the numbers again and they look correct other than the tuning frequency comes in at 85 Hz. With an Fs of 110 this is 77% of Fs which is about as far as I'm comfortable going.
Edit: I ran the numbers again and they look correct other than the tuning frequency comes in at 85 Hz. With an Fs of 110 this is 77% of Fs which is about as far as I'm comfortable going.
I´m really sorry for confusing you.
It´s me that is confused.
Diameter is not the same as radius isn´t it?
Now I get your curve; still goes a bit over 90dB at Fres of driver but that might sound good anyway.
Do you use any circuitry (notch, series cap) with them or run a sub?
I made an error with my values BTW:
Diameter is supposed to be 0.984in.
It´s me that is confused.
Diameter is not the same as radius isn´t it?
Now I get your curve; still goes a bit over 90dB at Fres of driver but that might sound good anyway.
Do you use any circuitry (notch, series cap) with them or run a sub?
I made an error with my values BTW:
Diameter is supposed to be 0.984in.
First of all thank you very much for your prompt replies!!!!
I did not expect to have answers that early!!
I found Martin King's pages and will try to simulate a TQWP too.
The reason I chose the TB is because I read good things about it in the forum and would like to build some prototypes using cheap flake board. Now I think I'll try different enclosure types (closed, ported, buschhorn, TQWP) and will let the one live which I like most.
The MathCad sheet from Timn8ter at least looks very neat.
@joensd: I ordered my TB's from spectrumaudio.de. At least I did not find any other german internet shop selling these guys.
I did not expect to have answers that early!!
I found Martin King's pages and will try to simulate a TQWP too.
The reason I chose the TB is because I read good things about it in the forum and would like to build some prototypes using cheap flake board. Now I think I'll try different enclosure types (closed, ported, buschhorn, TQWP) and will let the one live which I like most.
The MathCad sheet from Timn8ter at least looks very neat.
@joensd: I ordered my TB's from spectrumaudio.de. At least I did not find any other german internet shop selling these guys.
I haven't built this exact application, just a model. I've built a few single and dual driver BRs with the 871. Usually they work fine without circuitry other than a low pass on the second driver. Might be interesting to experiment with John Krutke's notch filter though. I have used a sub with them and usually just run them full and use XO on the sub only.
Here´s the response graph of my ML-QWT.
It was simulated with the T/S-parameter given from Tangband.
Tim´s response graph motivated me to play a bit the values again.
For those who are interested I get similar response if I change the port lenght to <=1in.
I´ve already connected one up and it already (without break-in) sounds much better than the little sealed version.
Will "finish" the 2nd tomorrow, play with ports and stuffing and get back.
Chris, I´ll also take a picture tomorrow.
Cheers
Jens
It was simulated with the T/S-parameter given from Tangband.
Tim´s response graph motivated me to play a bit the values again.
For those who are interested I get similar response if I change the port lenght to <=1in.
I´ve already connected one up and it already (without break-in) sounds much better than the little sealed version.
Will "finish" the 2nd tomorrow, play with ports and stuffing and get back.
Chris, I´ll also take a picture tomorrow.
Cheers
Jens
Attachments
What really helped me understand and tackle the matchcad sheets is Bob Brines site and various threads here inthe forums.
And I´m sure I haven´t found all of the good ones.
http://www.diyaudio.com/forums/showthread.php?threadid=24114
http://www.diyaudio.com/forums/showthread.php?threadid=13324
http://www.diyaudio.com/forums/showthread.php?threadid=25388
And I´m sure I haven´t found all of the good ones.
http://www.diyaudio.com/forums/showthread.php?threadid=24114
http://www.diyaudio.com/forums/showthread.php?threadid=13324
http://www.diyaudio.com/forums/showthread.php?threadid=25388
That is (was) with a PC and passive XO?
Still wonder how I´ll tackle that as you usually have one stereo output from the soundcard.
I´d like to use passive XO (like 6dB and to avoid $$$plate amp) but obviously need another set of (buffered) outputs to combine L+R and follow with an inductor.
Maybe I should head for a better soundcard anyway
It´d be nice to have a card with multiple outputs where you cross over at 150Hz and send signals to different outputs.
Probably has to be done with software in real-time.
Cheerio
Jens
I bet it works great. I'm going to bring this up because it's less confusing if we get terms right. You've built a classic TL, not a TQWT. When someone asks about a TQWT, I assume they want to build a tapered line. I agree that your graph looks great and the speaker performance most likely reflects that. Have you considered adding a second driver?
A forum member helped me a lot to get into the matchcad-sheets and actually this is more or less his design (thanks Rudolf!).
He was calling it ML-TQWT too but yes I think it´s a ML-QWT!? as it is not tapered but the woofer/terminus-graphs show quarterwave action.
I´ve seen threads here where even Martin King couldn´t draw a clear line between BR and ML-QWT so I guess it´s very thin.
Any comments welcome as it´s always nice to know what you´ve just build there.
Forgot: Yes I have two pairs of TB W3-871S so I´ve already been thinking about using two per channel reading especially your comments. You´ve must build quite a few variations so what is your favourite. Something more TL-like or the ELF1.5?
Any hint on the 1.5-way crossover the ELF1.5 uses or I´d need?
BTW: Your very nice site was also a reason for me to buy the little wonders which are just too damn expensive here. And in the summer I´ll be in New York.Too late!
He was calling it ML-TQWT too but yes I think it´s a ML-QWT!? as it is not tapered but the woofer/terminus-graphs show quarterwave action.
I´ve seen threads here where even Martin King couldn´t draw a clear line between BR and ML-QWT so I guess it´s very thin.
Any comments welcome as it´s always nice to know what you´ve just build there.
Forgot: Yes I have two pairs of TB W3-871S so I´ve already been thinking about using two per channel reading especially your comments. You´ve must build quite a few variations so what is your favourite. Something more TL-like or the ELF1.5?
Any hint on the 1.5-way crossover the ELF1.5 uses or I´d need?
BTW: Your very nice site was also a reason for me to buy the little wonders which are just too damn expensive here. And in the summer I´ll be in New York.Too late!
The bipole speaker I actually built used the RS 40-1197 and is a TQWT. It performs remarkably well (surprising bass) which leads me to believe the 871 would also, although the LF response would be less. You can roll-off the second driver with a 1.5mH inductor in series with a 1ohm resistor if you want. I run my bipoles full on with no XO. Thanks for the compliments.
I envisioned the top of the line ending 2" above the bottom of the cabinet and placing the port tube under that. This would place the driver on the opposite side for a rear port. I've made some adjustments to smooth out the impedance response. Increase So to 4", SL to 16" and place the driver at 13". Your interior width could then be 4.5". Does that convert to metric well?
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