# High Efficiency Experiment



## Savjac (Apr 17, 2008)

After reading through the entries in this forum, I am somewhat embarrassed to post this single driver experiment, but it sounds so very very good. I will now take the nasty cabinet and transform them into something that can be displayed in public. 

This build started as an idea by a friend that got me excited enough to go for it. The speakers in question are a pair of Tang Band W8-1772's which are 8" midrange drivers with a bit of the old whizzer cone and shiny bullet plug. The Tang Band's are not exactly cheap but the cast frame, multiple-element neodymium magnet system, paper cone, and cloth half-roll surround made me go for it. Love the magnet structure, it just oozes quality. 
These guys are not mean to go particularly loud or low as the Xmas is only 3mm but I was told the sound may stop my heart it is so good.

So, the raw drivers showed up and look like this when removed from the box









Now to solder the internal wiring to the driver before making the cabinet and crossover.










Set up the table, vacuum and got ready to cut










Now the external panels are cut to width, 










Cutting panels to length










Cut and ready to assemble after a bit of sanding.










Time to make and secure the filter (Zoebel) to help the top end a bit.










Once again Parts Express comes through.










Cut the perf board to fit in the connection cup and voila, we have a Zoebel










End of Part One


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## robbo266317 (Sep 22, 2008)

I look forward to seeing the finished project and your evaluation of it.


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## Savjac (Apr 17, 2008)

Part Two

Start the cabinet

Back side of the motor board. Hole routed out using a 3hp dewalt plunge, jasper jig and a round over bit for the back side.










Front side of motor board with countersink for the woofer basket



















Getting somewhat square on top of router table










Put connection cup and Zoebel in place, center brace, GR Research No Rez and well you know before sealing up. Also added 3" x 4" port on back near top of cabinet










Put on motor board and get ready to mount driver










Driver in place, burning in with a small Topping amp and an iPod










Drivers fully secured, cabinet closed up and breaking in on workbench in the garage. Believe it or not that little class T amp rocks....well kind of.










After filling the garage/work space with tunes they get moved into the main room for some listening. I did not make the stands yet, as I wanted to make sure they sounded good, so bar stools work well. 










And NO NO NO the cabinet does not sag in the middle, it has a rounded semi circular front that gives the appearance of a sag. It is straight as a laser.

Sooo I tried them with small amps, medium amps, large amp and tube amp, wanna know how they sound ???


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## fusseli (May 1, 2007)

Those look like nice drivers! And your cabinets look great. Are you using EQ for baffle compensation or did you design a circuit for it?


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## Savjac (Apr 17, 2008)

No compensation at this time. In viewing other plans using this driver, the only change I see being used is to add a 3/4" oval board to the front of the cabinet which will help offset any possible diffraction issues. I will make one of those boards and attach to this cab to see if I can hear any differences. Then....a much bigger cabinet for reasons that may know already but will be explained shortly in discussing the sound.


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## B- one (Jan 13, 2013)

Wow you have been busy cant wait to see the finish. I wish I had the time Nd skill to build stuff. I was go an mention that your gear looks packed tight in there does anything run hot? At first I was thinking the bottom was bowing good to know its not.


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## Savjac (Apr 17, 2008)

B- one said:


> Wow you have been busy cant wait to see the finish. I wish I had the time Nd skill to build stuff. I was go an mention that your gear looks packed tight in there does anything run hot? At first I was thinking the bottom was bowing good to know its not.


I was worried about heat but nope, I have had no problems. Actually the AVR on top gets kind of hot, but the back of the rack is open and away from the wall, so air flows well enough. Never been a shut down or any issue. 
Things will be thinning out now, much of the equipment was redundant and of little use. There is no real market for some of it, so, I guess good will.


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## Wardsweb (Apr 2, 2010)

Very nicely done. Then again, having the right tools makes it a whole lot easier.


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## Nuwisha (Apr 21, 2013)

[QUOTE=" And NO NO NO the cabinet does not sag in the middle, it has a rounded semi circular front that gives the appearance of a sag. It is straight as a laser"[/QUOTE]

I laughed when I read this as that was exactly my first thought. That is a very cool looking driver.


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## Savjac (Apr 17, 2008)

Thank You all for the kind words, but imo that cabinet, while solid, must be either painted or veneered. They kind of look like skinny trolls now. 

And YES, the right tools for a guy like me make all the difference in the world.

I have to put the drivers in a large cabinet as the bottom end in the present boxes is not very satisfying.


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## Savjac (Apr 17, 2008)

And once they were broken in and the sound evened out it was time to celebrate, on the porch of course.


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## Savjac (Apr 17, 2008)

Ok been working on the review and it should be done shortly, these drivers take some serious time to loosen up and let down their guard. I think I have finally gotten a good measure of these guys and I am quite impressed.

I also learned a very important lesson with these Tang Band W8-1772 8" Neodymium magnet speakers. The magnets are placed in a circle around the voice coil area and these magnets are stronger than the hulk as they kept pulling my tools and soldering gun into them while I was trying to fix the wires coming from the Zoebel. Quite disconcerting indeed :gulp:


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## xrk971 (Jan 5, 2014)

Jack,
What tweeter are you using and is it aimed at the rear for ambience? Very nice build, I really like the 1772 driver but a bit pricey for me at the moment. Do you find any issues with 'beaming' since it is an 8 in full range? I use 3.5 in full range drivers and much bigger than that, beaming is sometimes an issue.
Regards,
X


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## Savjac (Apr 17, 2008)

X

I dont use a tweeter in this particular speaker as the Tang Band is very wide range and it is my understanding that with the whizzer cone it helps act as a faux tweeter if you will. No, i really do not have a beaming issue but I have noticed that it can occur if the speakers are not towed correctly. Too much toe in however, will cause high frequencies to go away and the speakers sound a good bit duller. 

I cant call this a full range speaker as it has roll offs in the bottom end as well as top end so without a woofer to cover say below 60hz or do, this speaker will not do as well. I am using to very tight servo type controlled subs, one in each channel and have set the contour points where the tang band and the external woofer do not collide and it works ok. 

This speaker will change shortly and be put in a larger enclosure to help bring the bottom end down closer to 40hz.


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## xrk971 (Jan 5, 2014)

Got it. The Zoebel was mounted to the terminal cup which I mistook for a tweeter. This driver in MLTL hits 40 Hz as I recall. What are you using for the servo subs?


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## Savjac (Apr 17, 2008)

Velodyne. They work well with no bloat or slop that I can really hear. I am not particularly fond of subs with too much chestiness or subs that lack control of the woofer, just my opinion of course.


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