Tang Band 2 way design

tweeter33

Member
2016-03-12 3:42 pm
Quite new to speaker building so trying to tread carefully ... attached Tang Band 2 way bass reflex design( SUG2-10 - 6.5" 2 Way Cabinet Suggestion - TB SPEAKER CO., LTD.) that was on their website - using a one inch tweeter and 6 inch woofer; the frequency response of the speaker looked great, however without a listening test it is hard to ascertain how it will really sound in practice because the 2 bass reflex ports are front facing and are below and to the left and right of the tweeter ... which is somewhat unusual ( at least to me ) ... my question is how would the low frequency sounds coming out from the ports interact with the high frequency sounds from the tweeter ...or it would not be an issue.

Like to hear your comments ...
 

tweeter33

Member
2016-03-12 3:42 pm
thanks for your input ...and looking at the youtube video link ( seeing sound ! ) included in picowallspeaker's reply brought up an issue that I have been trying to resolve - how to widen the narrow beam of high frequencies so that one is not confined to a small sweet spot to enjoy the best sound.

Some speaker manufacturers have addressed this problem by using sound reflectors ... Bang & Olfsen calls their high frequency sound reflectors acoustic lens, some other manufacturers have opted for horns and others omni-speaker designs also use some sort of reflector to disperse the sound ... do you know of any retail outlets where diyers can purchase these types of reflectors ?
 
Hi, that what you call a "sound reflector" is properly a waveguide.
The same used in the little Genelec speaker in the video.
Plus, rounded edges of the box help minimize diffraction ( at borders ).
It helps ( the WG) also to widen dispersion when increasing frequency, thus allowing for constant directivity ( index).
Many tweeters incorporate a WG, which enhances sensitivity, and allows to cross the tweeter lower -it's a sort of a horn that loads the membrane, yes !
The membrane has to be stiffer than normal ( silk -treated) because of the major pressure in the nearby.
I use to build WGs with broken speakers, using primer & sanding on a dead cone :eek:
 

eriksquires

Member
2013-05-10 4:11 pm
The worst case scenario is that the low end tweeter polar response gets wonky.

The problem with the ports isn't the bass coming out it's the lack of baffle. At the low end of the tweeter response the waves will be hemispherical and the baffle boundary limits the dissipation of the energy to be into half-space. Take that away with random cut-outs and you could end up with some very interesting effects. :)

Of course, without a way to model it or build it this is just conjecture. Nothing beats empirical observations to put random theories to rest.


Best,


Erik

Quite new to speaker building so trying to tread carefully ... attached Tang Band 2 way bass reflex design( SUG2-10 - 6.5" 2 Way Cabinet Suggestion - TB SPEAKER CO., LTD.) that was on their website - using a one inch tweeter and 6 inch woofer; the frequency response of the speaker looked great, however without a listening test it is hard to ascertain how it will really sound in practice because the 2 bass reflex ports are front facing and are below and to the left and right of the tweeter ... which is somewhat unusual ( at least to me ) ... my question is how would the low frequency sounds coming out from the ports interact with the high frequency sounds from the tweeter ...or it would not be an issue.

Like to hear your comments ...
 
included in picowallspeaker's reply brought up an issue that I have been trying to resolve - how to widen the narrow beam of high frequencies so that one is not confined to a small sweet spot to enjoy the best sound.

Some speaker manufacturers have addressed this problem by using sound reflectors ... Bang & Olfsen calls their high frequency sound reflectors acoustic lens, some other manufacturers have opted for horns and others omni-speaker designs also use some sort of reflector to disperse the sound ... do you know of any retail outlets where diyers can purchase these types of reflectors ?

There is a study for that:
http://www.diva-portal.org/smash/get/diva2:356308/FULLTEXT01.pdf

basically you need to think an up or down firing mid/treble with a reflector (cone or ball) to spread it evenly like a point source.

Then put the bass woofer vertically - never put these horizontally as you need to 'aim' the sound to parts of the room that don't resonate.

Do 300Hz to 20kHz+ in the one reflected driver - 3" or 4". You then get the critical voice on the one driver.

Then from 300Hz down pick a suitable sub. Job done.

Also use cylinders as your pressure vessels like divers do, if you use a box with flat sides the sides flap in and out adding colouration to the sound.