[ebag4]

Danny,
I picked up 4 of these from you last week.  I am wanting to build a pair of speakers for a small office in a nearfield (read as desktop) setting.  I have a couple of cabinet ideas I am considering but I was wondering if you gleaned enough information to make a recommendation as to what type of small speaker may work best with these drivers.

Thanks,
Ed

[Danny Richie]

I am all out of these BTW.

I am making my kids some computer speakers out of them.

Each one needs .055 cubic feet of air space and a port that is 1/2" by 1/2".

[jn316]

Also, as Danny mentioned to me on the phone the other day, that port size is just a 1/2" hole drilled through the 1/2" material you build the box out of, if you decide to use that material thickness. Piece of cake!

[ebag4]

I am all out of these BTW.

I am making my kids some computer speakers out of them.

Each one needs .055 cubic feet of air space and a port that is 1/2" by 1/2".

Danny,
If I wanted to use two of these drivers in a single enclosure and do the cap trick across the lower driver's terminals, what would this do to the port?  I am assuming I would simply double the size of the enclosure.

Thanks,
Ed

[Danny Richie]

Danny,
If I wanted to use two of these drivers in a single enclosure and do the cap trick across the lower driver's terminals, what would this do to the port?  I am assuming I would simply double the size of the enclosure.

Thanks,
Ed

That is exactly what I am doing.

Double the air space and the ports.

[roymail]

PM sent to Ed

[Oscillate]

"...and a port that is 1/2" by 1/2""

So basically drilling a 1/2" hole through the enclosure (or two holes if two
drivers are used) is all that is required to properly port these?

[ebag4]

That is exactly what I am doing.

Double the air space and the ports.

Thanks Danny!

PM sent to Ed

Hi Roy, PM replied.

Best.
Ed

[Peter J]

Danny,
If I wanted to use two of these drivers in a single enclosure and do the cap trick across the lower driver's terminals, what would this do to the port?  I am assuming I would simply double the size of the enclosure.

Thanks,
Ed

Can you elaborate on the cap trick?

[ebag4]

Can you elaborate on the cap trick?

See Danny's post here:
http://www.audiocircle.com/index.php?topic=83025.msg802021#msg802021

Best,
Ed

[Danny Richie]

Yep, that's the cap trick.

The LS-C uses this cap trick too. 

[Mr. Oczka]

This project sounds like an inexpensive chance for me to attempt to build some small speaker boxes!  My dream is to build a nice set of Danny's speakers, but my carpentry skills at this point are pretty limited.  This size box will give me an opportunity to practice using wood veneer. 

Well, it's late, I can't sleep and my feeble brain is having difficulty with the box dimensions.  Danny says that the ideal size for this full range speaker is .055 cubic feet.  I'm coming up with 5 inches high by 4.8 inches  wide by 3.6 inches deep.  That seems really small even for this 3 inch driver.  Is my math correct?  What dimensions will you use?

Doubling up the drivers also interests me.  It will give me an opportunity to experiment with different size caps to hear the difference in sound clarity.  What size box would you build for 2 drivers?  I'm one to believe that two is always better than one.

Any guidance would be appreciated. 
Thanks,

Tom

[Æ]

This project sounds like an inexpensive chance for me to attempt to build some small speaker boxes!  My dream is to build a nice set of Danny's speakers, but my carpentry skills at this point are pretty limited.  This size box will give me an opportunity to practice using wood veneer. 

Well, it's late, I can't sleep and my feeble brain is having difficulty with the box dimensions.  Danny says that the ideal size for this full range speaker is .055 cubic feet.  I'm coming up with 5 inches high by 4.8 inches  wide by 3.6 inches deep.  That seems really small even for this 3 inch driver.  Is my math correct?  What dimensions will you use?

Doubling up the drivers also interests me.  It will give me an opportunity to experiment with different size caps to hear the difference in sound clarity.  What size box would you build for 2 drivers?  I'm one to believe that two is always better than one.

Any guidance would be appreciated. 
Thanks,

Tom

According to the manufacturers specs, the Vas for that driver is only 1.68 liters or 0.059 cu.ft.

[Danny Richie]

The specs on the ones that I have may be a little different than the newer ones. Mine are an earlier version with twice the X-Max of the later ones.

[Æ]

The specs on the ones that I have may be a little different than the newer ones. Mine are an earlier version with twice the X-Max of the later ones.

I actually have some of the first generation W3-319 on hand, not really sure how much Xmax they have. I have a few different specs sheets. A print out from 2002 shows 0.5mm Xmax, but at another website it was listed at 1.0mm Xmax. Currently it is listed at 0.25 Xmax.

[Danny Richie]

I actually have some of the first generation W3-319 on hand, not really sure how much Xmax they have. I have a few different specs sheets. A print out from 2002 shows 0.5mm Xmax, but at another website it was listed at 1.0mm Xmax. Currently it is listed at 0.25 Xmax.

The version I had was the 1mm version.

[ebag4]

Danny,
What type of cap are you using for the lower drivers?  From what I can find film caps are getting physically large and expensive at this size.  Are you getting smaller values and paralleling them to get the desired value?

Edit:
Didn't see many at this value looking though the usual suspects, there are a few at Parts Express but I am not familiar with the brands.  I did find a Jantzen unit, it is nearly 2"x2.5", it can be found here:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=027-952&utm_source=googleps

Has anyone used a Jantzen cap, if so what did you think?  What are the brands you use at this value.



Thanks,
Ed

[Danny Richie]

I did quite a bit of testing with these drivers.

I did by-pass the lower woofer with a cap in the 47uF range for best results. But it still needed a baffle step compensation filter to flatten out the response. This made the sensitivity drop below 83db and the impedance high at an average of about 12 to 14 ohms.

Since my kids were using these as computer speakers, and driving them with a little T-amp that doesn't mind a 4 ohm load, I tried something else. I made it a 1.5 way design and paralleled the lower woofer and put a 1.5mH inductor in line with it. This flattened the impedance out and made it pretty smooth 4 ohm load and brought the sensitivity up to 92db.

They sound really good until you play anything wit a lot of bass, then they sound a little thin. But overall they sound great.

[ebag4]

I did quite a bit of testing with these drivers.

I did by-pass the lower woofer with a cap in the 47uF range for best results. But it still needed a baffle step compensation filter to flatten out the response. This made the sensitivity drop below 83db and the impedance high at an average of about 12 to 14 ohms.

Since my kids were using these as computer speakers, and driving them with a little T-amp that doesn't mind a 4 ohm load, I tried something else. I made it a 1.5 way design and paralleled the lower woofer and put a 1.5mH inductor in line with it. This flattened the impedance out and made it pretty smooth 4 ohm load and brought the sensitivity up to 92db.

They sound really good until you play anything wit a lot of bass, then they sound a little thin. But overall they sound great.

Danny, thanks for this, much appreciated.  I have a pair of 1 mh coils in my junk box, how critical is this value, will these work?

Is this the correct wiring:





Best,
Ed                     

[Danny Richie]

Yep, that will do it and the 1 mH will get you close.