Cabinet for Tang Band W3-871S

[GM]

>How about an 871 cabinet with a sloping front baffle? Not for phase alignment (obviously) but for reducing standing waves...

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Again, it has to be at least 1:6 and the sides tapered a like amount to be worth the effort in a large cab, and a small one can be easily damped. There is some advantage to the pyramid shape WRT averaging the baffle step diffraction loss though.

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>The question is should I place the driver near the top of the slope or the bottom?

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You want the driver positioned somewhere around the mean, so as the taper increases, the driver position shifts downward.

GM

 

[coolkhoa]

so the inner ones would be full range, and the outer ones lows?

I think others would agree when I say that the outer ones (angled slightly outward) should be operating full-range and the inner bass. However, don't space out the drivers too much, or else your midrange response directly on-axis won't be good. BTW this arrangement is to reduce lobing in the all-important midrange; the experts can certainly give you a more detailed explanation.

Good luck to you and your brother.

 

[coolkhoa]

GM,

Sincere thanks for your advice. Based on it, I probably won't attempt an enclosure to reduce standing waves for the 871. It just isn't worth the effort.

 

[coolkhoa]

A general cabinet construction question for small speakers:

Do you think it's better to have all 45-degree miter joints or have the front/back butted to the sides (or fit within the sides)? Fitting the front within the sides is a common method, but sometimes the driver has to overhang the front panel.

Please discuss.

 

[Chris8sirhC]

for making a sloping internal volume while maintaining a rectangular outside, wouldnt it be pretty easy to make 5 sides of the box (not including the front baffle) then use something like concrete or some other material that changes from a liquid to a solid. First the starting box would have to be bigger than the desired finished volume. You would just tilt the box at whatever angle you want the internal volume to be angled (sloped) at, and pour in the correct amount of material, when it dries you can untilt the box and you have a nice sloped interior. You can then repeat for the 4 other sides, then glue the front baffle on.

 

[454Casull]

for making a sloping internal volume while maintaining a rectangular outside, wouldnt it be pretty easy to make 5 sides of the box (not including the front baffle) then use something like concrete or some other material that changes from a liquid to a solid. First the starting box would have to be bigger than the desired finished volume. You would just tilt the box at whatever angle you want the internal volume to be angled (sloped) at, and pour in the correct amount of material, when it dries you can untilt the box and you have a nice sloped interior. You can then repeat for the 4 other sides, then glue the front baffle on.

Yep, don't see why that wouldn't work. You could stab bracing into the concrete mix while it dries, so you only have to fasten one side.

 

[officeboy]

A general cabinet construction question for small speakers:

Do you think it's better to have all 45-degree miter joints or have the front/back butted to the sides (or fit within the sides)? Fitting the front within the sides is a common method, but sometimes the driver has to overhang the front panel.

Please discuss.

In my experience it is infinity easier to butt all your edges, I've yet to get my best mitered joint to line up as well as even a mediocre butted joint. Of course sometimes design issues don’t let you butt your edges. Well then your stuck. So buy some corner clamps.

 

[RAW]

Or with out clamps.
Get a piece of 1/2 X 1/2 x say 4 feet long stock.
Lay your MDF down were you are going to butt joint your pieces.
Make the inside of the boards were your 3/4" thickness is.
cut a few scraps of the small 1/2" stock.
And pre drill the holes in the stock.
Place the stock on the line and glue and screw in place.
^This will give you a stop for the sides to hit.
And if you do this correctly you can just do a little sanding and your edges will be great.

 

[critofur]

...I understand that the 871 doesn't have a very good Xmax, and too small a box can lead to it reaching the excursion limit.

Huh? Smaller box will limit (reduce) the excursion.

Why don't you try WinISD: a small simple free program and it will help you figure out what size of box to use, very nice for that and much easier to use than most other speaker software, and FREE! The "Pro" version doesn't have some of the features that I like in the non-Pro one implemented yet.

 

[infinia]

Critofur
You realise you are responding to posts that are over 2 yrs old?

 

[jb74]

I was happy that critofur revisited this thread - which brought my attention to it - must have missed it earlier.

An impressive amount of valuable information to be found
here -

I hear music from W3-871's at least a part of every day - constructed a year or so ago from John Krutke's taller box design. (Well, close anyway)

These Tangband's are used in partnership with stereo subs - Peerless 831709

All powered with 4 units of LM1875, LR 24db Xo, Linkwitz
transform for the subs, all DIY (Thanks DIYaudio)

jb74

 

[gychang]

I was happy that critofur revisited this thread - which brought my attention to it - must have missed it earlier.

An impressive amount of valuable information to be found
here -

I hear music from W3-871's at least a part of every day - constructed a year or so ago from John Krutke's taller box design. (Well, close anyway)

jb74

is there a website with exact dimensions?, have 871s laying around in the garage...

gychang