Designing Tang Band 881si Enclosures

[xrk971]

Guangui,
This looks like a Weems horn design - they can be very good but this is the smallest I have seen it - did you use a calculator online to design dimensions? It should sound nice. I think damping here will be polyfill stuffing in the triangle closed end and felt if you have it in the top area to line surfaces directly behind driver and top wall and 4 inches or so of top of back wall to reduce reflected sound. Use polyfill stuffing to taste after the driver little by little probably no more than 2 inches past the driver towards open end as it will really attenuate bass from such a small driver. I don't think you need anything in the main chamber before the terminus.

[guangui]

Originally Posted by xrk971

Guangui,
This looks like a Weems horn design - they can be very good but this is the smallest I have seen it - did you use a calculator online to design dimensions? It should sound nice. I think damping here will be polyfill stuffing in the triangle closed end and felt if you have it in the top area to line surfaces directly behind driver and top wall and 4 inches or so of top of back wall to reduce reflected sound. Use polyfill stuffing to taste after the driver little by little probably no more than 2 inches past the driver towards open end as it will really attenuate bass from such a small driver. I don't think you need anything in the main chamber before the terminus.

Yes, I used a calculator (MH). The curiosity was simply too much. I've always seen them at a larger scale. There is always a first time, and an interesting project. The calc. gives me the port dimensions based on a cylinder (round), so I replicated the area in a rectangular port. I will start working on it. We'll see how they turn out, and will compare the sound to the uFonken. It will have to be an "ear" comparison, as I have not purchased the mic and software to do so. Any recommendations, as far as analytical software goes? Don't want the latest bells & whistles, just a simple one that works.

[xrk971]

The sound will be very different than a uFonken. I would imagine much more bass efficiency and extension. The measurement stuff is easy, buy a Panasonic wm61a capsule from Digikey for $2 ea, get several, wire them to a 3.5 mm jack and cable from an old cheap pair of headphones (follow guides online do search for wm61a and measurement) plug into your mic jack and you have a flat mic from 20 to 20 khz. Download the holmimpulse software. There is a thread on it and how to use, it even has a calibration curve for this mic.

[Bob Brines]

As I think was mentioned before what you have drawn is a "Weem's Pipe", which is a variation of the "Voigt" pipe. My personal experience with both is that the driver is on the wrong side of the "Weem's Pipe". If you do the modeling, you will see that the driver needs to be farther down, toward to vent. That puts the vent on the back of the cabinet, which may or may not be a good idea depending on room placement.

Bob

[xrk971]

Originally Posted by Bob Brines

As I think was mentioned before what you have drawn is a "Weem's Pipe", which is a variation of the "Voigt" pipe. My personal experience with both is that the driver is on the wrong side of the "Weem's Pipe". If you do the modeling, you will see that the driver needs to be farther down, toward to vent. That puts the vent on the back of the cabinet, which may or may not be a good idea depending on room placement.

Bob

I think you are right Bob, if you place the driver on the other side and add a horn expansion to the terminus you end up with something like this :



FH3-inspired Foam Core Mini Build

I love the sound from mine. The W3-881si can probably work here too.

[guangui]

Great info from all! Will check on the port, I prefer front as they will be very close to a wall. Though the wall might help with bass response.

[xrk971]

That's one of the advantages of rear-firing ports or horns, the wall boundary enhances the bass even more. If you flip the port to the back and have room for a horn, the bass enhancement is even better. I think you can use the design I have in the above thread for the Tang Band, the drivers are close enough in size, but it wouldn't hurt to order some TC9FD's on the next order from PE or Madisound
, it is only $2 more than W3-881wsi
.

[gychang]

Originally Posted by guangui

It's the same subject, so I hope is not a thread hijack...Anyways, all my DIY projects have been copied from proven designs (ie. uFonken), OB, and BR enclosures. In order to learn other type of enclosures, I started reading on TWQT, and did a simple design, which I will make of Foam Core to try it. The W3-881SI is the driver for this design.

good idea, post your impressions...

[guangui]

Originally Posted by xrk971

That's one of the advantages of rear-firing ports or horns, the wall boundary enhances the bass even more. If you flip the port to the back and have room for a horn, the bass enhancement is even better. I think you can use the design I have in the above thread for the Tang Band, the drivers are close enough in size, but it wouldn't hurt to order some TC9FD's on the next order from PE or Madisound
, it is only $2 more than W3-881wsi
.

Thanks for the tip on the VIFA...I see them all the time, but the specs have never convinced me, maybe I'm looking them the wrong way. Anyways, in March I will be placing an order with Madisound for FF85WK's, so will add a pair of the VIFA to try.

[guangui]

Originally Posted by xrk971

I think you are right Bob, if you place the driver on the other side and add a horn expansion to the terminus you end up with something like this :



FH3-inspired Foam Core Mini Build

I love the sound from mine. The W3-881si can probably work here too.

Nice! Besides sounding good, like you mentioned, they also look great! For my intended purposes it won't work, but basically because a lack of space on the desk. Though you have given me an idea...What if a horn was designed for either the front port, or driver? This will be a fun project.