Has anybody ported the Tangband W3-871s?

[Jim85IROC]

I've got my tb w3-871s speakers in a .2 cubic foot sealed enclosure, and as you might expect, there's absolutely ZERO bass. I'm planning to build a subwoofer, but right now it looks like I'm going to need to use around a 150hz crossover frequency. I modeled the 871s in WinISD using published specs and get an F3 at 132hz, which sure seems to correlate with what I'm hearing.

Anyway... I modeled the same driver in a .2 cubic foot ported enclosure with a 75hz tuning frequency and get an F3 of 65hz, which would be a HUGE improvement. But... I'm kind of having a hard time believing that the little 3" tb would actually accomplish this feat. I'd probably run the sub crossover around 80 or 100hz, so I don't need the response that low, as long as it's flat to my crossover frequency.

Has anybody used this driver in a ported design?

[DC Dave]

I put two of them in a .2 cu ft ported enclosure with a 1.5" dia by .75" long port and had good results. I think it goes down to around 110 hz. If you want 65hz pick a different driver. This TB driver will not come close. Do a search on google and this forum for the W3-871s and you will find lots of projects and ideas. This driver has been covered to death in the past year or so. Good luck.

[Jim85IROC]

I've seen it covered a lot, but everybody (including myself) just seems to be building John Krutke's sealed boxes.

Since I used 3/4" MDF and I've got a 1 7/8" hole for the terminal cup on the back, maybe I'll make a 1/4" ring to slide into the hole, and voila! 1.5x.75" port.

I have a hard time believing that these things will have useful output down to 65hz even though they modeled that way, but flat down to 100hz would be nice.

[joensd]

Just finished John´s small version TB´s and in another week or so a ML-TQWT with them you can seen them (unfinished) here .
As they are intended for nearfield I might get away without a sub.
And actually for my taste already the small ones are OK.
Only thing is that they´re indeed very directional.
No problem whatsoever sitting in front of the PC.
But already standing up you get the feel the "tweeter" is blown.
Otherwise : Very nice drivers!

Jens

[Jim85IROC]

I use them in a near-field situation and there's absolutely NO way I can handle these without some kind of sub or at least a ported configuration.

Here are some plots in winISD. The yellow is the .2 cubic foot sealed that I have now. The green is the same enclosure tuned to 75hz, and the blue is tuned to 85hz. The t/s specs I used were those measured by creativesound and not tangband's published specs.


I like the response of the blue line myself. The rise in bass will help simulate a baffle step compensation to some extent, and an f3 of 76hz is really as good as I can expect from these little things.

[leadbelly]

But are you looking at power handling as well? You could wind up with shredded paper before you get your desired boom-boom

[Timn8ter]

Hey Jim,
I fooled around with the Elf 1.5 design from CSS. It does get down low enough to integrate with a small sub.

http://www.alegriaaudio.com/css_elf_1.htm

[Jim85IROC]

Originally posted by leadbelly
But are you looking at power handling as well? You could wind up with shredded paper before you get your desired boom-boom

That's something I've been thinking about. Power handling in the sealed box is perfectly adequate. It gets loud enough to make my girlfriend yell at me, and loud enough to force me out of my computer chair.

As long as I high-pass the speakers well enough above the tuning frequency, I don't think power handling will be comprimised by porting the enclosure. That's one reason why the lower tuning frequency may be a better option... the signal will be attenuated that much more at 75hz vs. 85hz.

[coolkhoa]

Jim,

Using ported enclosures with the TBs will yield better integration with a sub since you can cross it over lower, but significant midrange output will be coming out of the port, which isn't good. I believe John K. knows of this problem; hence he builds sealed boxes. One compromise is to mount the port on the front and as close as possible to the driver. It should be made large enough to reduce chuffing noises and ideally be flared.

Of course, you can use a woofer with the TBs in a two-way satellite and combine that with a real subwoofer. The midrange should be cleaner and less distorted since the TB doesn't have to work full-range. Going this route will complicate things, though. Compromises, compromises...

[Jim85IROC]

I had planned on a 1" or 1.5" port diameter. I figure that should be more than enough to prevent port noise for the tiny amount of air that's going to be passing through it. My 8" subwoofer has a 2" cardboard port that's quiet at low excursion.

I hadn't thought about much midrange through the port, but with the shallow depth, I suppose that makes sense.