The idea came from xrk971’s 10F/RS225 FAST thread.
I was looking at woofers I could get around here since the Daytons are not available locally, and shipping here is prohibitive.
A distributor with good pricing recently showed up for SBAcoustics, and it got me excited that I may find a suitable woofer, as I already had the Visaton B80 laying around.
Going through the SBA website is no joke! There are so many products, it’s easy to get confused.
I was going nuts trying to find a match to the RS225, then I stumbled onto their new 5x8” race track woofer.
It looked ok to try and I shared the idea on the 10F thread.
That’s when BYRTT pointed out that c-to-c using the 5x8 woofers and a small full range driver would be very interesting, and how about a MTM, or in this case WFW?
The data that BYRTT shared pushed me in that direction easily. Having played with XSim and the manufacturer’s curves, I thought it had great potential.
So, I contacted the distributor, and 2 days later, all 6 drivers showed at my door, COD for only $6 shipping cost! That’s service!
BTW, as a plug, this is the distributor in Taiwan, should anyone be interested. They are very nice, and they speak, or write, Chinese as well as English.
thlaudio web site pages
So, this will be a thread on how it will turn out in the end.
I have an idea, but I may change a few things along the way according to measurements, I’m not inflexible.
Shall we start?
So, as we already know, the woofers will be the 5”X 8” SB15SFCR39-8. Two of them per enclosures.
The enclosures will be sealed.
Inside, sandwiched between the 5x8s will be a 2½" SB65WBAC25-4. It will have a sealed space inside the enclosures. This driver has been reviewed as having a great dispersion and great high end reach… close to a tweeter.
These are BYRTT’s measurements of this driver, in FR and dispersion… pretty good!
MTM, or in they case WFW, improves the vertical polars, as more data shared by BYRTT showed here
After I build them an enclosure, I’ll first try a simple 1st order XO, but will probably settled on a more elaborate one later on…
I’m sure I forgot something, but this is the beginning, so, I’ll keep adding up.
I was looking at woofers I could get around here since the Daytons are not available locally, and shipping here is prohibitive.
A distributor with good pricing recently showed up for SBAcoustics, and it got me excited that I may find a suitable woofer, as I already had the Visaton B80 laying around.
Going through the SBA website is no joke! There are so many products, it’s easy to get confused.
I was going nuts trying to find a match to the RS225, then I stumbled onto their new 5x8” race track woofer.
It looked ok to try and I shared the idea on the 10F thread.
That’s when BYRTT pointed out that c-to-c using the 5x8 woofers and a small full range driver would be very interesting, and how about a MTM, or in this case WFW?
The data that BYRTT shared pushed me in that direction easily. Having played with XSim and the manufacturer’s curves, I thought it had great potential.
So, I contacted the distributor, and 2 days later, all 6 drivers showed at my door, COD for only $6 shipping cost! That’s service!
BTW, as a plug, this is the distributor in Taiwan, should anyone be interested. They are very nice, and they speak, or write, Chinese as well as English.
thlaudio web site pages
So, this will be a thread on how it will turn out in the end.
I have an idea, but I may change a few things along the way according to measurements, I’m not inflexible.
Shall we start?
So, as we already know, the woofers will be the 5”X 8” SB15SFCR39-8. Two of them per enclosures.
The enclosures will be sealed.
Inside, sandwiched between the 5x8s will be a 2½" SB65WBAC25-4. It will have a sealed space inside the enclosures. This driver has been reviewed as having a great dispersion and great high end reach… close to a tweeter.
These are BYRTT’s measurements of this driver, in FR and dispersion… pretty good!
MTM, or in they case WFW, improves the vertical polars, as more data shared by BYRTT showed here
After I build them an enclosure, I’ll first try a simple 1st order XO, but will probably settled on a more elaborate one later on…
I’m sure I forgot something, but this is the beginning, so, I’ll keep adding up.
This looks really promising! Nice description of the project at hand - I am very interested in seeing how this turns out. Might have to make a pair for myself if it looks good.
Thanks for starting thread.
Thanks for starting thread.
The racetrack woofer would be a nice way of getting lots of LF output from a slim enclosure. Interested to see how this turns out.
Chris
Chris
I presumed he was planning to use the oval drivers across the baffle to get the centres as close as possible?
Yes, indeed.
As presented with BYRTT's data, the very close spacing, c-to-c, with the oval driver set horizontally has really nice polars.
And yes again, it will be "fun" to do the cutouts for them!
As presented with BYRTT's data, the very close spacing, c-to-c, with the oval driver set horizontally has really nice polars.
And yes again, it will be "fun" to do the cutouts for them!
No great shakes 😀 take your time with a electric jigsaw, it's all I've ever used for speaker cut outs, don't know why people get so worked up about making holes 😉And yes again, it will be "fun" to do the cutouts for them!
Perceval, if you have a hole saw that will match the diameter of the half-circle ends of the woofer you can cut out each end then make straight cuts with the jig saw to complete the cutout.
Craig, I'm pretty sure I don't have a hole cutter that big, except the one for foam!
But, I'll keep it in mind.
Only had time to put the drivers through DATS, and that's right out of the box. I will have to let them play a bit then measure again.
The good news is that impedance matches completely with online specs, but T/S are a little off... not that much, and might get closer to online specs after break in.
So far, so good!
But, I'll keep it in mind.
Only had time to put the drivers through DATS, and that's right out of the box. I will have to let them play a bit then measure again.
The good news is that impedance matches completely with online specs, but T/S are a little off... not that much, and might get closer to online specs after break in.
So far, so good!
Attachments
Alright, finally moving on this...
It was a windy, rainy and cool day here, so I decided to make a box.
Went optimal with 60 litres. I was expecting big, but this might be a little too much.
I think I can go down to 40 litres, and only lose 3Hz at f-10.
Didn't have time to get the parts for the more complicated XO, so I rigged this with 4.8mH and 3 Ohms on the woofer, and 52uF on the tweet.
Also, I know I could put the woofers closer to the tweet but this is XPS foam and I was afraid it would weaken the baffle too much. When I'll do them in wood, they will be closer.
Just played a bit of music, I need to let the drivers break in a bit... but that SB65 is very nice! Loads of details. And the woofers are nice and tight in this sealed enclosure.
This looks like it might not need much tweaking but I'll still play with the box shape, and probably make a second one at 40 litres to compare.
Measurements will come soon.
It was a windy, rainy and cool day here, so I decided to make a box.
Went optimal with 60 litres. I was expecting big, but this might be a little too much.
I think I can go down to 40 litres, and only lose 3Hz at f-10.
Didn't have time to get the parts for the more complicated XO, so I rigged this with 4.8mH and 3 Ohms on the woofer, and 52uF on the tweet.
Also, I know I could put the woofers closer to the tweet but this is XPS foam and I was afraid it would weaken the baffle too much. When I'll do them in wood, they will be closer.
Just played a bit of music, I need to let the drivers break in a bit... but that SB65 is very nice! Loads of details. And the woofers are nice and tight in this sealed enclosure.
This looks like it might not need much tweaking but I'll still play with the box shape, and probably make a second one at 40 litres to compare.
Measurements will come soon.
Attachments
Looking good so far 🙂 My only criticism would be your acronym.... Shouldn't it more accurately be WWW WAW? 😉
I know, but this section of the forum is called Full Range... so unless you get DIYAudio to change it to Wideband... then WFW it will stay. 😉
Nice work Perceval. That box is big! Yes, if you can cut volume in half that would be much better. Looks like the simple 1st order XO is working?
This has me wanting to try my own WAW build for my first project (in addition to the others that I'm pondering)... Seeing stuff like this makes it tough. I dunno which of my ideas to finally pull the trigger on!
The oval woofers are definitely cool. Love the close CTC ability. Has that old school look to em without being unobtanium.
The oval woofers are definitely cool. Love the close CTC ability. Has that old school look to em without being unobtanium.
I was listening to them this morning, and I just couldn't wait to get initial findings!
So, after only 8 hours break in, here's what it looks like.
X, yes, this is the simple 1st order XO with a 52uF cap and a 4.8mH inductor with 3 Ohms attenuation.
In order, first we have the horizontal measurements at 0, 15, 30 and 45 degrees.
Then, it's the vertical measurements at 0, 15, 30 and 45 degrees.
Group delay from a sealed box, so that's good enough.
4th is the distortion. I was not expecting much... remember this is a XPS foam glued together in half a day, it's got some bracing but I think I can forget anything under 200Hz. 1st and 2nd harmonics are 30 to 45dBs lower, and then a drop at the 3rd.
Finally, the impulse and Step. We can see the SB65 (inverted) arriving much ahead of the woofers. Surprisingly, there's quite a lot of small wobbles from the SB65 all the way to 1ms.
Next step is to make a smaller box and move the SB65 back. I'm not sure how I will do that, as the frame is very thin, and there's not much space between it and roll. Mounting it behind the baffle might prove to be a challenge. I might try with the woofers angled in on the baffle, a little like the Usher CP-777.
So, after only 8 hours break in, here's what it looks like.
X, yes, this is the simple 1st order XO with a 52uF cap and a 4.8mH inductor with 3 Ohms attenuation.
In order, first we have the horizontal measurements at 0, 15, 30 and 45 degrees.
Then, it's the vertical measurements at 0, 15, 30 and 45 degrees.
Group delay from a sealed box, so that's good enough.
4th is the distortion. I was not expecting much... remember this is a XPS foam glued together in half a day, it's got some bracing but I think I can forget anything under 200Hz. 1st and 2nd harmonics are 30 to 45dBs lower, and then a drop at the 3rd.
Finally, the impulse and Step. We can see the SB65 (inverted) arriving much ahead of the woofers. Surprisingly, there's quite a lot of small wobbles from the SB65 all the way to 1ms.
Next step is to make a smaller box and move the SB65 back. I'm not sure how I will do that, as the frame is very thin, and there's not much space between it and roll. Mounting it behind the baffle might prove to be a challenge. I might try with the woofers angled in on the baffle, a little like the Usher CP-777.
Attachments
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I will go active for designing the thing.
It would be perfect for a miniDSP 2x4 HD, or their SHD units.
But in the end, I'd like this to be a passive system. Hook up and go.
It would be perfect for a miniDSP 2x4 HD, or their SHD units.
But in the end, I'd like this to be a passive system. Hook up and go.
Looks very encouraging with the simple XO you have right now. Maybe a waveguide for the SB65 to get a -3in setback? That will increase CTC distance but I think the overall effect is still going to be fine. Passive is the way to go of you have well behaved drivers for a 1st order transient perfect.