micro subwoofer a-la velodyne microvee

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well on thing i was missing: when i did the sim of the 6.5 tangband i took the PR specs from the partsexpress site.

when i did the others today, i took the PR specs from the loudspeakerfreaks page i had open.

on partsexpress the Vas is listed as 39.7 litres
on loudspeakerfreaks the Vas is listed as 1.4 litres!

i wondered why the PR's were barely changing the response of the box...
 
nope, im not after more spl.. its just gotta be as small as poss and help out with a pair of booshelf speakers (mission 780 se's on their third rebuild, running on a circa 30wpc gainclone amp)

im happy if it hits noticeable levels at the lower registers (25 hz or so) , which, surprisingly, this design seems to.

i was planning two but i suspect one will be sufficient.
 
questions regarding box size and stuffing:

i know that the volume needs to be 20 litres, however, does winisd consider the volume of the drivers intruding into the space? or do i need to increase the volume to compensate? also, stuffing reduces the cabinet size necessary, so how do i decide how big to make the box?

with 3 PRs and a driver intruding into the box, there is quite a lot of internal space eaten up..
 
I thnik you will be able to get some output down low with the tangbamds. That is what they are good at. I wouldnt drop the idea of having two though. The tangbands are in my experience not good with handling power and getting loud. A 6.5" is going to be struggling filling a room at 30Hz. But used at lower levels the deep bass will be impressive.
 
Ok so, reading a bit more abd educating myself, it seems the group delay of my design may be an issue. Its 11ms at 50 hz, and rises exponentially, 18ms at 40 hz, 38ms at 30 hz, and a whopping 60 ms at 25 hz. It peaks at 70 ms at 22 hz but i dont care about down so low.

Is this a really bad result? Will it sound awful? Can it be compensated for with a minidsp?
 
It kinda is. Some parameters will look absolutely horrible. You want to play with it, and also experience what´s wrong for your ear, and what´s not. I remember one of my bass boxes (12TBX100 tuned at 60Hz), it has absolutely horrible GD at 60Hz, and it sounded tight and generally sounded strong and beautiful!
 
ok so im very frustrated. ive been in touch with a local supplier of TangBand.

he stated that they do not stock the w6-2100 driver

https://www.parts-express.com/tang-band-w6-2100-6-1-2-rbm-flat-panel-subwoofer-4-ohm--264-954

because it has a design flaw.. the holes in the chassis behind the cone are too small, and cause performace issues. im not sure what he meant in practice.. youd imagine that such a fundamental flaw would have been caught early in the design process. he also said that is why parts-express are offering it at a massive discount...
 
ive literally been running sims on every 6.5 and 8 inch sub driver i can find and NONE of them can get quite such a nice response as that one. closest ive got is a response that is 4 db down at 30hz, and cannot play as loud overall.. according to sims cone would only bottom out at about 120w , but the driver in question is rated for 55rms..
 
he also said that is why parts-express are offering it at a massive discount...

$130 is not a discount, if you ask me. That is their regular price!

The 5" is on closeout, but it performs well as used by more than one builder and in projects I've personally heard myself. I find nothing to complain about in terms of performance there.

Later,
Wolf
 
Ok so ive been going round in circles, so im starting a challenge (if anyone is interested of course) using a maximum of 20 litres, match or exceed the frequency response and spl of my design, and critically, using a driver thats available in europe that doesnt cost a fortune. Ive looked at dozens, and the only contenders are the dayton ultimax 8", which with two imported eminence high excursion PR's manages to best my design in every way.. However its all imported components and costs upwards of 400 euros just for the driver and PR's including shipping (not even considering the criminal import duties that italy slap on everything from the US)
 
Ive found one supplier of the tang band in europe, but only sold in a bundle with a TB passive radiator, for almost 200 euros, and that bundle doesnt come close to my simmed design. As mentioned i want the smallest box and low registers at not very high spls. Check my sim to see my result.
 
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