Fostex and Tang Band

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Hi guys,

Here's the latest project of mine that's been in the pipeline for a bit.

My previous set-up (see signature) was reasonably good, but I wanted more dynamic range: the Fostex drivers were giving up at higher volumes.

Drivers used here are Tang Band W6-1139SG and Fostex FE126eN with phase plugs.

So, what's needed is a higher crossover point. With the tapped horn subwoofers I have, that's not possible. What I need is a smallish desktop system (with university on the horizon, big floorstanders wouldn't be feasible) with plenty of oomph.

I set about designing some cabinets that'd allow a higher crossover point between the woofer and Fostex drivers, while balancing bass response vs compactness.

After playing around on winISD for a bit, I decided on ~9.5L for the woofers tuned ~42Hz was about as small as it'd go and keep decent extension etc (there's a ~1dB rise before rolloff). The Fostex driver has an internal sealed enclosure of about 2L. This gives a rolloff of ~200Hz, which will be the first crossover point I try on my Behringer active crossover gismo.

Now, I'm not going to lie: I don't have the patience for any "proper" woodwork. I appreciate those that do, as I've seen some stunning creations on here.

So, I contacted the local cabinet builder (Toppsy), showed him my designs, talked a little about veneer and he came back with these....

I'm going to add some eye candy then go to bed - I haven't put the drivers in yet for fear of rushing and screwing up.

Chris

PS - big thank-you again to Colin for getting these looking like they do. I'm just hoping they'll sound good enough to match.
 

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Hi Chris,
Why did you pick the TB driver? I'd be worried about the not-too-similar-but-nevertheless-worrisome measurements of the W6-1721 (Zaph|Audio). Have you found distortion info on those drivers?

The main reasons were these:

I already have them, and they'll do reasonable bass in small boxes.

You have to remember that I'm a student with fairly limited money, so if I have a pair of woofers that fit the bill, I'm likely to use those instead of shelving them.
As always, the proof is in the pudding: if I find there is too much distortion, I can look into trying other drivers.


Boris, yes, the port will be on top. Due to the L-shaped woofer enclosure, this was the only option as I've gone for a 2" port (to minimise chuffing: I've read that 1.5" diameter ain't quite enough), meaning it has to be >10" long to get the right tuning.

Chris
 
Bit of a teaser shot - I have actually got the speakers up and running (with chocky block at the port exit to connect the drivers), but haven't taken any more photos yet.

More tonight, but I'm liking what I'm hearing so far.

Chris
 

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Hey guys, here's some more photos for you.

I'm really liking the sound these make.

I'm just finding myself drifting off into the music - surely a good sign.
They can put out plenty of bass when required - I'm still amazed that a speaker this small will hit 40Hz clean. There's still some output at 30Hz, but the woofer has unloaded by then.

When I first fired these up, the first thing that hit me was the sheer amount of bass coming out.
After enjoying a vibro-massage via the sofa, I set about making them sound a little more neutral. A handful of stuffing in each port seems to have done the trick. It must be the port output interacting with the room (boundry gain near the wall) that meant there was too much low end, but this seems to have been tamed now.

This is the first time I've heard 4" FR drivers come close to rocking out. The little Tripath amplifier is probably the limiting factor now (10w/ch clean into 8ohm), but there's now far more dynamic range than before - I'm very impressed.


The 'scope trace is the output of each amplifier - lets see who can guess which is for which driver.

Chris
 

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Bit of an old thread and I hate to revive the dead but...

It's funny that I just came across this because I am in practically the same situation right now. I am going from my main home system to something small I can take to college, on a pretty tight budget. It's amusing to find something so similar coming out of such a like situation

As it stands my plan is a Fostex FE126en, with a pair of Tang Band W69-1042J 6"x9" Subwoofer 264-837 and a pair of Bohlender Graebener Neo3W Planar Tweeter w/Back Cup 264-730 (I already have the tweets) in a sort of quasi-FAST system. XO points at 300Hz and 6000Hz, passive 6db/oct at the top end (cheap components) and active XO and eq on the bottom provided by a minidsp. Fully sealed, aiming for an F3 of 50Hz with EQ & room gain, f10 around 30 Hz. Eventually I would add a small sub.

Theoretically the two of those fostex drivers could hit 116 dB on peaks in their passband, that is so much more than I am used to from similar sized full rangers its crazy.

You still happy with these?
 
For what they are, yes I am.

With the controls set to "party", the bass amp (clips at 50v peak) clips before the smaller amp for the Fostex drivers. The sound as a whole stays clean, even with the red lights (clipping indicator) flickering occasionally.

Mine stop at 40Hz, which is plenty enough for most music. Of course, extension clean down to 20Hz would be nice, but my cabinets are 15L per side, so really low stuff is off the menu.

For use at university (or college), I'd strongly consider using one of those bass drivers per side, porting the cabinet, and using the other two in a subwoofer to even out room nodes - my room is pretty terrible for peaks/dips - there's a big standing wave ~200Hz and then the amount of bass you get is very position dependent.

I also think the Fostex drivers won't keep up with a pair of those bass drivers per side, but its your call - either way, the extra headroom in the bass will always be used up - teenagers at a party listen for the THD rise, and set the volume accordingly.

Chris
 
Well I will only have 2 of the bass drivers, not 4, but I think I want to go sealed. I want to get the maximum quality sound, even at the expense of quantity, because I will have to live with it under normal use for quite a while. And I can always just add a sub...

I think this plan would result in something pretty versatile, good enough sounding that I will be happy with it, small enough that it will fit, and loud enough that it could be used to fill up a dorm room without stress.

But yes I agree extra low end headroom is always useful. I like dubstep (sub 40Hz!) and electronic music (as well as pretty much everything else, including classical) so it's good to have options. It's easier to turn a capable system down than an incapable system up...
 
Great project, I might have chosen a similar chassis set. Its obvious that the small Tang bands will not show off with massive bass but sure considering their size they have potential. I mostly favor closed cabinet constructions for bass becauese ot the much better transient response.

Good stuff though!
 
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