Funny little W2-1767S....

[Wolf]

I have a pair (Ser# 1,2), and they were discounted nicely at the TS, so here's what I get:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-884

I remind you that they are 2" drivers, 3mm Xmax, and 4 ohm impedance. That means they hit about 81-82dB as a 2.83V spec. They are basically all magnet mass, 'cuz the frames are plastic, the paper cone is covered by an aluminum dustcap, and the half-surround rule only nets you about 13cm^2 of Sd. However- that Bl value is pretty high for a 2" driver. The dustcap sits inside the former for attachment, and a small lip is left around the perimeter that might act as a slight whizzer. It's hard to tell if it will have an affect on FR without measuring it. The spider is vented, but the pole is not. Looks like a periphery venting system. The spider is of the progressive variety, and only has 2 large rolls in it. VC is 'hung well' for a 2" driver, and I can see at least 3mm above the front plate. Former is probably cardboard like most of TB's smaller drivers.

I also have a double of the 3" Titanium PR's to try with these, so we'll see what I come up with....

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=900-W3-1335A

I expect that these may have some 'slam', but not much extension. More of an impact-driver.

More later,
Wolf

[DS-21]

Re: Funny little W2-1767S....

How do they get that Sd with such a large surround?

The Aura Whisper's surround is comparatively less imposing, and its Sd is about the same. (I daresay the Whisper is a much more interesting driver, too, with its 3mm of xmax coming from a large-diameter underhung coil.)

[bobblickle]

Re: Funny little W2-1767S....

Did you do any breaking in at all? I would be tempted with those Ben. I'm looking at that >10% difference in BL.

bb

[superspeeder]

Re: Funny little W2-1767S....

Subscribing

[HareBrained]

Re: Funny little W2-1767S....

I also have a double of the 3" Titanium PR's to try with these, so we'll see what I come up with....

Hmmmm, that sound familiar. Your welcome for the idea. :D I'm interested in how it turns out.

[Æ]

Re: Funny little W2-1767S....

So, you are going to make a reflex system with those 2" drivers and the 3" passives?

The fs of the full range is way up there, you won't be building a "bass" reflex, more like midrange reflex.
Everything below the tuning frequency will be unloaded.

[[email protected]]

Re: Funny little W2-1767S....

I also have a double of the 3" Titanium PR's to try with these, so we'll see what I come up with....

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=900-W3-1335A

Those 3"s make great trophies!

-Rich

[Wolf]

Re: Funny little W2-1767S....

Did you do any breaking in at all? I would be tempted with those Ben. I'm looking at that >10% difference in BL.

bb

Actually, Bob, they are fairly easy moving already. I just flexed the suspension like I always do, and there was really no resistance to doing so.

I have had units spread that far on Bl before, so it didn't really bother me.
Later,
Wolf

[Wolf]

Re: Funny little W2-1767S....

Those 3"s make great trophies!

-Rich

Yeah, Rich? Well- it's better to EARN them than to just make your own. I have a trophy shop close if this doesn't work out.... :rolleyes:

Later,
Wolf

[Wolf]

Re: Funny little W2-1767S....

Hmmmm, that sound familiar. Your welcome for the idea. :D I'm interested in how it turns out.

To be honest, Hare- It modeled better vented than with a PR.

I can get 69Hz out of it...

I had already thought of it before you mentioned it though.

Later,
Wolf

[Wolf]

Re: Funny little W2-1767S....

So, you are going to make a reflex system with those 2" drivers and the 3" passives?

The fs of the full range is way up there, you won't be building a "bass" reflex, more like midrange reflex.
Everything below the tuning frequency will be unloaded.

Not that bad, Alan. You can get 100 Hz with a PR, in a small box.
Wolf

[Wolf]

Box alignments...

Here we go...

Don't even think about sealed....

The PR alignment with a single PR and ~12.5g added, and a small volume.
The thing with using this PR and midbass, is that you cannot get a low enough tuning in a larger box, and a pair of PR's really make the tuning unmanageable, and never low enough. If you bring up the volume and increase the mass to compensate, you get a very shallow rolloff, but it is steep enough to further limit the extension and actually increase the F3.



The Xmax looks really good though!!



Vented box looks a lot better. Granted, you have a narow/deep suckout at 700 Hz and maybe another at 1.4khz, but the EBS alignment really looks like it may yield some punch for a 2" driver. I used a semicircular crosssection of 1.5" PVC for the vent, and am wrapping it around the baffle on 3 sides to provide some edge-diffraction relief. I'll post pictures when I solidify the rest of the plans.



Xmax is reasonable, as it probably handles about 4-5mm before it starts to sound stressed. I've come to expect that from TB drivers, so I hope this holds true. Mind you- this is with 20W applied to hit 90dB, and is more than most will be using this for I suspect.



Also- FWIW- I plan on pairing this with the 13-1761 mini-tweeter to fill in the top octave, and make this a minimalist xover.

Stay tuned!!
Wolf

[Æ]

Re: Funny little W2-1767S....

Not that bad, Alan. You can get 100 Hz with a PR, in a small box.
Wolf

I wonder how that small driver would do in a line kind of like the NEEDLES or a TABAQ. Probably much better than in a reflex enclosure. Of course there is quite a difference in the enclosure sizes.
With a small driver like that, I would relegate it to something like desktop monitors for my computer or use a couple of them in an MTM as midranges only.

[PunkSweeper]

Re: Funny little W2-1767S....

I wonder how that small driver would do in a line kind of like the NEEDLES or a TABAQ. Probably much better than in a reflex enclosure. Of course there is quite a difference in the enclosure sizes.
With a small driver like that, I would relegate it to something like desktop monitors for my computer or use a couple of them in an MTM as midranges only.

That's no fun.

[Æ]

Re: Funny little W2-1767S....

That's no fun.

Why not?

I have a small pair of self amplified JBL (made for COMPAQ) desktop computer speakers, with blown drivers. All I need are some good replacement drivers to repair them. Darn things originally cost me something like $85. Some of those 2" drivers could be made to fit.