Tang Band W5-1138SMF Bass heavy floor standing speaker

PA5cAL1

Member
2013-01-10 6:30 pm
After heaving built a few pairs of more audiophile like speakers it's time for me to built something with a bit more oomph. A want to built a pair of compact floor standing speakers with built in subwoofers. For the subs i will be using the TangBand W5-1138SMF. I like the neodymium version a bit more but those are hard to find in Europe and are very expensive. For the mids and highs i will be using a full range driver to keep things simple. At the moment i think i will be using the Tang Band W3-926SDF but i haven't completely decided on that one.

For the enclosure i want to built something i'm addicted to for quite a wile now, a transmission line. After a bit of modeling in Hornresp i came up with a pretty good looking response. Yes, it could be a bit flatter but it's not too bad. I can always change it later on.

After spending a bit of time in Sketchup i came up with a pretty awesome looking enclosure to my taste. I did have some clearance issues with that big ferrite magnet. A double stacked baffle was used to solve those issues. I also had to find a way to incorporate the fullrange driver into the enclosure. In the end i came up with a small closed box of around 1liter. I would have liked it to be a bit bigger but there wasn't much I could do about it without making the box look ridiculous.

Because of the small closed box i might have to cross the drivers a bit higher than i originally anticipated. I could possibly use a bit of the natural roll off from the full range driver though. This speaker won't be very efficient but I don't really mind that, my amps has way more than enough guts to power a pair of these.

The only thing i'm not to sure of is the crossover because i haven't crossed drivers this low before (around 150 - 200Hz). I certainly do need an l-pad for the full range driver but do I also need a baffle step compensation cicuit? For the rest i would like to keep things simple, just a two-way 2nd order crossover. Any suggestions would be helpfull.
 

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Hmmmm...

IMHO, you need to either drop the TL enclosure, or the small full-ranger.

You're gonna have trouble integrating the two while ensuring the FR driver doesn't run into power handling issues. Active crossovers would help, but I'd guesstimate your BSC circuit needs to come in around 500Hz. You could get that high by stuffing the transmission line to attenuate the mush that comes out the back, but you'll also lose bass.

You could get a 4" plus tweeter to sit in a larger cavity (extend it vertically), which would mean you can cross down to 100Hz or so and get a reasonable amount of power handling. You could then keep the transmission line if that's what you're after.


If it were mine, I'd go for a ported cabinet. You'll get similar bass performance with a much smaller cabinet. You could even use the money saved on materials to get more woofers (they are, after all, very inefficient).
The relatively narrow operating bandwidth of the port means the midrange response of the woofers is pretty much that shown by the datasheet, which will open up a lot more crossover options.

Others will have had different experiences, so don't take this reply as gospel: I've done a similar project, but using the W6-1139s, and went ported so I could cross high, and do BSC and crossing over in one go.

Chris

PS - now I have a pair of those Behringer 8" + tweeter monitors, and haven't looked back. I'm currently using the passive ones, but I'd expect the active ones to be even better.
 

PA5cAL1

Member
2013-01-10 6:30 pm
I was already thinking the same thing. I was running into some problems when i was designing the crossover. Dropping the TL enclosure does spoil the whole idea tho. I came up with the idea of using a full range driver because of simplicity and costs. A 3-way crossover will increase costs and make things more complicated. A vented box might be the solution but the efficiency is really setting me off. Only 81db 1w/1m compared to about 85 from the t-line. That will certainly drop though when the line is stuffed adequately.

With around 25 watts rms of input power and a crossover frequency of 200Hz, the driver displacement is just under 2mm. Increasing the box volume doesn't change much at all.

Thanks for your advise,
 
You're gonna need more power. Budget in a used solid state amp of the >100w/ch variety. These mini-subs can push out some volume, but need a rocket up them to do so. Need more output? Add another woofer per side, put them in series (or parallel, if the amp's 2-ohm stable) and you've got twice the displacement capability.

You'd also be able to go for active crossovers. At the 100s of Hz frequencies, active crossovers really pay off.

Chris

PS - there's nothing to stop you getting a smallish coaxial (the drivers from the KEF satellites are rather good) and treating it as a full-range speaker ;)
 
Hi Pascal,

I know this little bass speaker well (have used both versions), and it works great in a BR enclosure, tuned a bit below 40Hz.

The neo version has no advantage over the ferrite version other than weight. You are going to build a heavy piece of furniture anyways, and in that case a heavier magnet is only advantageous. The Mms of this thing is about 36 gr., from memory, and that creates quite some reaction forces if you swing it around at 40 Hz. A big slug of matter behind the voice coil is only good.

I don't see how switching to a BR would ruin your idea; you could still use the same form factor.

The only thing is that it is not very practical to do this with a passive filter/ you would want to cross over really low, like 100 to 200 Hz, and it is much cheaper and better to do this active, with a MiniDSP or so to start with.

Edit: looking back again at your drawing, this quarter wave style enclosure will severely limit power handling, and you will only know you went too far after having destroyed the driver mechanically.
 
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PA5cAL1

Member
2013-01-10 6:30 pm
Thanks for the advise. It will be a vented box than. That will save lots of problems i had with my crossover and will increase power handling. I should have forgotten that transmission line design immediately. I have seen someone built something similar before using the same driver and he ended up blowing up his subwoofer.

The box will be 12 - 14 liters tuned to 35 - 36Hz. The only problem is the extremely large port. About 59cm long. Tuning it higher is a bad idea, the response will than become very peaky. Efficiency is 82db 1w/1m. It has an F3 of 31Hz so in my room there is really no need for an extra subwoofer. Crossover frequency will be at 500Hz which is entirely possible according to the specsheet. I would like to keep that design, i think it looks good. The only thing i want to change is the depth of the enclosure. The height will also help with accommodating that huge port. I will also increase the volume for the fullrange driver a bit.

Powering these beasts also won't be a problem, my amp can supply op to 120 watt rms each channel at a 4ohm load. It's not 2ohm stable tho so adding a second 5.25'' driver certainly won't happen. And also don't forget the increase of costs. All help is really appreciated. I'm sort of on the right track now, at least I hope so.
 
You could wire the drivers in series. Model the 120w into the current favourite, and see how excursion looks.
Then try doubling the drivers and cabinet volume, and go with 60w. See how excursion looks again.
IMO, you'll appreciate the extra oomph of the increased drivers. It'll also make porting a bit easier, as a larger cabinet means a shorter port for the same volume.

Vacuphile, have you managed to mechanically destroy this type of driver?

My W6-1139s have stood a 250w/ch driven into clipping for a while, and sounded surprisingly clean doing it.
 
Chris, no, but I only drive them hard in an enclosure that limits excursion where it counts.

In open air burn in, I found two things: 1) @ fairly low voltage @ low frequencies, the driver already approaches the sort of excursions that warn you not to push it any further. and 2) @ higher frequencies, let's say 200 Hz, power handling fast becomes an issue for thermal reasons.

I don't know what you used as xover frequency, but probably it was quite a bit lower than 500Kz.

Pascal, I think crossing over as high as 500 Hz will lead to disappointment; since at that point you are almost 5 octaves into the 10 audible ones that we have. Much of the music takes place here. The TB driver will do it, but it won't do it nicely. Distortion above 100 Hz gets rather ugly. Any decent FR will do much better in this respect. In addition, the FR will also have a much lighter cone, and for that reason will inject much less vibration into the enclosure.

Edit: your pipe length appears to be very long. What size diameter do you intend to use? 2" would be sufficient. But still, it might be long enough to have a pipe resonance below 500 Hz.
 
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PA5cAL1

Member
2013-01-10 6:30 pm
In the end i did find a way to cross that subwoofer at 200Hz, it's a two-way 2nd order Linkwitz-Riley crossover, the sub is crossed at 200Hz and the Fr at 250Hz. The response is actually not that bad. Lots of very high value parts though but not entirely impossible to obtain.
 
Chris, no, but I only drive them hard in an enclosure that limits excursion where it counts.

In open air burn in, I found two things: 1) @ fairly low voltage @ low frequencies, the driver already approaches the sort of excursions that warn you not to push it any further. and 2) @ higher frequencies, let's say 200 Hz, power handling fast becomes an issue for thermal reasons.

I don't know what you used as xover frequency, but probably it was quite a bit lower than 500Kz.

The suspension system seems very very good at limiting excursion to safe amounts - even with fairly stupid power inputs, those woofers don't bottom out.

My crossover certainly sounded like 500Hz, and that was what was indicated by my active crossover.


I haven't seen any distortion measurements for these drivers, though - could you provide a link?

Cheers
Chris
 

PA5cAL1

Member
2013-01-10 6:30 pm
I have just finished designing the bass reflex enclosure for the 5.25'' TangBand driver. It doesn't look too bad. I don't like having a bend in the port but porting the enclosure on bottom would cause lots of issues as well. I have done some comparisons between the t-line and the bass reflex and the t-line actually didn't look half bad. Driver displacement was on both enclosures pretty much identical below 40Hz. I might just built one t-line for the sake of it. It will cost less than 10 euro's for one enclosure. Most of it will be made out of MDF, I would like to make that baffle out of some real wood tho. I will probably get told it's a bad idea but I can always try. I'm not going to push these speakers a lot either. It's just for some day to day listening on volume levels around 80db without using an external subwoofer.
 

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PA5cAL1

Member
2013-01-10 6:30 pm
I have done some more work on the crossover today, i have changed the crossover for the fullrange driver to a first order crossover. Crossover frequencies remain the same. Now i only have one cross coil in the circuit which should keep distortion low. This also means i can spent a bit more money on a higher quality crossover coil for the subwoofer, that will increase efficiency by a fair bit. Now i'm just hoping the driver won't mind being crossed over at 200Hz.
 

PA5cAL1

Member
2013-01-10 6:30 pm
Any update on how this project is going?

Yes, I have a been building them and I´m certainly not dissapointed. They sound quite different from what I´m used to. I´m really satisfied with them. The low end on these speakers is absolutely insane. Not overpowering by any means but quite surprising for their size. I might make a separate build threat for these speakers. I have also completely reworked the crossover because the old design just wasn´t going to work. In the end I was able to cross the sub at 120Hz 12db 2nd order low pass and the fullrange driver at 150Hz 6db first oder high pass.
 

PA5cAL1

Member
2013-01-10 6:30 pm
What did you end up with for the full range? I am considering the same type project (FAST) using the same TB woofer. I was also considering the new Fountek FR58EX for the FR but not sure it will handle the power that low.

Fountek FR58EX 2" Neodymium Full Range Driver 296-725

I used the Tang Band W3-926SDF Tang Band W3-926SDF 3" Full Range Speaker 264-912

That fountek driver looks nice and you could possibly do a crossover point at around 150Hz. It won´t have the same power handling tho as the tangband driver. I might also suggest stepping up to the 6.5" version of the little 5.25'' subwoofer Tang Band W6-1139SIF 6-1/2" Paper Cone Subwoofer Speaker 264-919

If that's too big for you, you can always just use the same driver as I did but don't expect it to deliver wonders around 30Hz.
 
I would Like to keep it small. I would not expect an unreasonable request of a speaker of this type. My model for that driver says about 6 to 7 L and tuned to about 40-45 hz. That alignment seems to offer a decent compromise of power handling and bass extension for a small speaker. I think the trick to this design is to pick the FR carefully to keep the cross point as low as possible but still have decent high extension. Not too much to ask of a full range...lol.

Thanks for your input. I will continue to follow this thread. Very interesting build.
 

PA5cAL1

Member
2013-01-10 6:30 pm
I would Like to keep it small. I would not expect an unreasonable request of a speaker of this type. My model for that driver says about 6 to 7 L and tuned to about 40-45 hz. That alignment seems to offer a decent compromise of power handling and bass extension for a small speaker. I think the trick to this design is to pick the FR carefully to keep the cross point as low as possible but still have decent high extension. Not too much to ask of a full range...lol.

Thanks for your input. I will continue to follow this thread. Very interesting build.

Just like you said, the hardest part will be getting the crossover right. Using a simple first order crossover for the fullrange driver is in my opinion the best way to do it because you won't need any crossover coils in path of the fullrange driver which will reduce distortion and lower the costs.