My Tang Band W8-1772 Build

[JimOfOakCreek]

I am the process of completing a Full Range speaker project using the Tang Band W8-1772. I haven't installed the port tubes yet but the bass response is already impressive. Using test tones from Bass Mekaniks I am able to get down to 44hz with no port tube! The speaker has a rising top end response which needs to be tamed with a simple BSC circuit. They are quite bright straight out of the box. It's amazing that an 8" full range speaker can have such a strong treble response. Imaging and detail is excellent. Efficeincy is rated at 95db/1w. I highly recommend this driver to any potential DIY enthusiast.

 

[Grainger49]

Jim,

Very nice work!  I have heard a number of speakers using the Tang Band drivers (designed by Jim Griffin) but they were not this sensitive.  The bass was beyond impressive for the driver sizes I heard.

 

[2wo]

Funny, I was just looking at those drivers.

Those look real nice...John

 

[Thoburn]

Nice. I love building speakers. I seem to frequently find myself wondering about my next build.

What plans did you use? Is it a bass reflex or maybe a transmission line? Just for the fun of it, try listening to them without a BSC by taming the raising high frequency by not listening on axis. I am using a Lowther DX4 8 inch driver in a back loaded horn. I have also had them in a mass loaded transmission line design using a BSC that was made with high quality components. I prefer the horn cabinet without any BSC.

 

[mp9]

They look nice, so why did you choose the W8-1772 over a W8-1808 for the type of enclosure you're doing?

 

[JimOfOakCreek]

They look nice, so why did you choose the W8-1772 over a W8-1808 for the type of enclosure you're doing?

The 1772 works well in a smaller box than the 1808 requires. My goal was to build a conservative appearing speaker with a high WAF.

 

[JimOfOakCreek]

What plans did you use? Is it a bass reflex or maybe a transmission line? Just for the fun of it, try listening to them without a BSC by taming the raising high frequency by not listening on axis. I am using a Lowther DX4 8 inch driver in a back loaded horn. I have also had them in a mass loaded transmission line design using a BSC that was made with high quality components. I prefer the horn cabinet without any BSC.

It's a bass reflex design. My design is based on design recommendations from posts by Bob Brines. He recommended a BR 40L box with a 3"X6" port.

 

[JimOfOakCreek]

I prefer the horn cabinet without any BSC.

You've got me thinking. The whole point of FR speakers and SET amps is 'simpler is better' - 'less is better than more'.

I love the dtail I am currently hearing. I am going to try listening off axis with no BSC.

I like your idea. Thanks.

 

[Wanderer]

I have been looking at these Tang Band as well.

Any thought on doing a passive line level BSC between pre and amp ala Sexy speaker? 

 

[JimOfOakCreek]

I have been looking at these Tang Band as well.

Any thought on doing a passive line level BSC between pre and amp ala Sexy speaker? 

Yes, I've been considering that approach as well. That makes a lot of sense in that it keeps the electronic voicing confined to the electronic amplification system. I also like the idea of having the BSC outside the enclosure whether it's between pre and amp or a 'conventional' BSC.

However, at the moment I've become enthusiastic with alternative/simpler approaches to voicing the speakers without circuitry. It fits my newly adopted audio philosophy of less circuitry is better than more.

Out of the box the W8-1772 have a rising top end. This is actually a good thing because it's easy to deal with. It's better to have too strong a high end than no high end. You can deal with a strong high end through various means.

These are very bright speakers on-axis with no BSC. I am amazed that simply listening to my speakers off axis solves the brightness iscue with no circuitry. The detail is amazing without being grating.  I'm going to audition that approach for a few weeks.

 

[howardnair]

jim --very nice -owning 4 pairs of speakers --3 are diy-jericho horn--a electrovoice baronet--both employing the fostex 208 ES -and ribbon tweeters--the 3rd are 4 ft monsters using 15inch and 12 inch EV and coral full range speakers with also a ribbon tweeter--love full range speakers  --no crossover except for the tweeter--i tried with and with out crossover- prefer without-now you have me thinking about doing something with the tangband---somebody tell me what is a BSC--i suspect it is a crossover

 

[JimOfOakCreek]

what is a BSC--i suspect it is a crossover

BSC = Baffle Step Correction. It's a circuit between the amp and the speaker that corrects for the beaming of mid-high frequencies off the speaker baffle. The baffle acts like a reflector which focuses those frequencies forward. Low frequencies are omni-directional and do not get beamed.

The effect increases mid-high frequencies about 3db or more.

A Baffle Step Compensation circuit reducies those frequencies by 3db or more. It is usually incorporated in the crossover circuit with a typical 2 or 3 way speaker.

You can use that same circuit to tame a bright speaker.

A better explaination and a calculator can be found here:http://diyaudioprojects.com/Technical/Baffle-Step-Correction-Circuit-Calculator/

 

[Maxwell_E]

Just curious, what difference does it make when you rotate the speakers in rather than out?

 

[Paul Joppa]

Just curious, what difference does it make when you rotate the speakers in rather than out?

In theory - :^) - it compensates for off-center listening. When you move to one side, the nearer speaker takes precedence due to earlier arrival, but you are more on-axis with the far one so it takes precedence due to being louder in the treble. With luck those effects cancel out. (Without luck, they just confuse your ears!)

 

[JimOfOakCreek]

Just curious, what difference does it make when you rotate the speakers in rather than out?

If you sit in the middle, toeing the speakers inward will beam the treble directly toward your ears.

 

[howardnair]

yes BSC-- i have no love for acronyms--i have plastered for 36 years-but had a stint working part time for usairways as ramp ticket etc--sooo!! tell the pic that there will be a change in the ETD and tell the FA that the gsc needs to talk about the load --tell the captain he won't be leaving for awhile and tell the copilot come out here there is aproblem with some bags-crikey!!--the last couple of speakers i built--the woofer/fullrange was off center as was the tweeter to the side opposite-http://www.diyaudio.com/forums/diyaudio-com-articles/158899-arpeggio-loudspeaker.html
this a interesting article by morgan jones--arpeggio speaker--about baffle diffraction-paul joppa has written  articles also-so far i have not attempted a bsc --run straight to the fullrange and a cap for the tweeter with a attenuator-why --because i read too damn much and it was making me uncomfortably crazy-you know -could I -should I-what if i do what if i dont-well maybe i will-1st -2nd thrd-etc order crossovers right after reading keep it simple stupid-every time i think i weaken the team

 

[Mike B]

I put my W8-1772's in a smaller box, 25 liters, so I could fit them at the wall-ceiling boundary.  I used a 3"diameter x 4" long port side vented into the boundary.  The boundary gain compensates for the higher tune quite nicely.  The close miked peak out of the port was 72 Hz.

Works good.  Helps the bass, but not one note or boomy.

I have the speaks bolted to boards on a circle pattern that are hinged to the wall and allow me to tilt and rotate to my hearts desire.

I use only a modest zobel, the lightest one I found on the web, 3.3 uf in series with 17 ohms.  It just flattens the impedance curve and takes the edge off. 

Works very well.  A lot of driver for the buck. 

 

[Paul Birkeland]

I would do an L-R trap on the Tang for sure, but treat it as a filter for rising response rather than just baffle step.  You could do the RL trap for the rising response, then play with the active BSC if you need a little more response tailoring.
-PB

 

[Mike B]

I added a little BSC to the filter.  Started with .5 mH shunted with 3 ohms.  Sucked the life out of the music.  But I did like the smoothness and thought about one third the effect would be good.

So I built up a new filter, .15 mH 18g inductor with a 1 ohm shunt.  Perfect, I'm done -

Listened to it for 3 hours last night and I like it.  Adds smoothness but does not "suck" -

I am going to glue it to the back of the box.

 

[Grainger49]

Mike,

The audiophile thing to do would be to put it in a separate box, on spikes, filled with sand or better glass beads, sealed with potting wax (or whatever potting is) and connect it with wire made of unobtanium. 

The picture looks good to me.  My builds are often, "Looks bad, sounds good!"  my Eros is the exception.