Replacing the Vifa D26

[tombond]

Now that this fine little tweeter looks to become unobtainium, what are our choices for a small neo tweeter. Seas looks to have some that may be close and Zaph likes the Vifa DQ25.

So, I'm looking for tweeter candidates that could rival the performance and size characteristics of the D26 and cross around 2.5K give or take. I would exclude anything that requires a crossover point above 3K.

[Pete Schumacher ®]

Now that this fine little tweeter looks to become unobtainium, what are our choices for a small neo tweeter. Seas looks to have some that may be close and Zaph likes the Vifa DQ25.

So, I'm looking for tweeter candidates that could rival the performance and size characteristics of the D26 and cross around 2.5K give or take. I would exclude anything that requires a crossover point above 3K.

The little SEAS unit can do that quite well. Also, Dayton ND28 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=275-040) is a viable alternate.

http://www.parts-express.com/images/item_large/275-040_L.jpg

[jkim]

Not many inexpensive neo tweeters if you ask for 2.0 k to 2.5 kHz LR4. But You and Pete pretty much summed up the list. The Seas neo (three variants), Vifa DQ25 and BC25, and the Dayton ND28 will definitely be able to handle the 2.0 kHz xover point in an LR4 2-way design. I'd rate the Seas higher due to their higher quality internal construction and better QC consistency.

-jAy

[JRT]

Now that this fine little tweeter looks to become unobtainium, what are our choices for a small neo tweeter. Seas looks to have some that may be close and Zaph likes the Vifa DQ25.

So, I'm looking for tweeter candidates that could rival the performance and size characteristics of the D26 and cross around 2.5K give or take. I would exclude anything that requires a crossover point above 3K.

One alternative would be to throw a little more money into the design budget and use the ScanSpeak D3004/602010 (http://www.tymphany.com/files/products/pdf/D3004_602010.pdf).

John Krutke tested one recently. (http://www.zaphaudio.com/tweetermishmash/)






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[Paul Ebert]

I might be willing to sell a pair of D26s I have stored away in the basement. They are unused and are Danish made (bought just before the move to China). If you're interested send me a PM.

Paul

[jkim]

One alternative would be to throw a little more money into the design budget and use the ScanSpeak D3004/602010 (http://www.tymphany.com/files/products/pdf/D3004_602010.pdf).

John Krutke tested one recently. (http://www.zaphaudio.com/tweetermishmash/)

"A little more" money? Are you kidding? :)

[JRT]

Are you kidding? :)


No. Not this time. To me it looks like a good performing tweeter with a small space claim that can be crossed low while exhibiting low nonlinear distortion, smooth response, good near axis response, etc.

I'm not aware of any less expensive tweeter that doesn't come with a major performance or geometry tradeoff. And I am not aware of any similar sized soft dome tweeter that offers significant performance improvement regardless of cost. To me it seems like it provides a good balance of performance and value at ~$200 each.

I don't yet have an application for it, but very probably will...





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[Wolf]

Tang Band 25-1719S and 25-1166SJ (2.5kHz for these)
Morel MDT12/22/39/40/44 and the new CAT derivative
Dayton ND28
The 3 Seas tweeters, beware the 3 ohm impedance
SS Illuminator & D2904/6000-01
Vifa BC/DQ and XT25SC50
HiVi TN25 (steep-order)

I did an exhaustive search when I revamped the Audinums into the Xenums, and the above is about it. I've heard the DQ25, and it sounds really nice!

[Pete Schumacher ®]

No. Not this time. To me it looks like a good performing tweeter with a small space claim that can be crossed low while exhibiting low nonlinear distortion, smooth response, good near axis response, etc.

I'm not aware of any less expensive tweeter that doesn't come with a major performance or geometry tradeoff. And I am not aware of any similar sized soft dome tweeter that offers significant performance improvement regardless of cost. To me it seems like it provides a good balance of performance and value at ~$200 each.

I don't yet have an application for it, but very probably will...





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The SEAS unit is arguably the equal of the Scan from 2KHz on up. Above 2K, the Scan has less 3rd harmonic, but much more 4th harmonic than the SEAS. Both are very smooth above 2KHz. Really hard to justify the Scan if you intend to cross above 2KHz.

[dlneubec]

Hey Tom,

I believe you told me you were thinking about doing a shallow waveguide mount for the tweeter. If you decide to do that, it may open up some other options. Many tweeters have an easily removable face-plate and without the faceplate have a much smaller footprint. The body size becomes the limiting factor. In that case, you could consider some of the more conventional, popular, tweeters by checking their body sizes and whether the face plate is removable.

[tombond]

Hey Tom,

I believe you told me you were thinking about doing a shallow waveguide mount for the tweeter. If you decide to do that, it may open up some other options. Many tweeters have an easily removable face-plate and without the faceplate have a much smaller footprint. The body size becomes the limiting factor. In that case, you could consider some of the more conventional, popular, tweeters by checking their body sizes and whether the face plate is removable.

Yes, I do intend to mount the tweeter from the rear using a waveguide. If I remember from your measurements, there wasn't much difference between the roundover and a chamfer, I would prefer to use a 45 degree chamfer.

I had thought of removing the faceplate from a regular tweeter, so any with a small body size would probably work. The DQ25 looks pretty good off axis, I think that will be an important consideration for this application.

[dlneubec]

I did a study of various shallow waveguides with the Peerless HDS for my BaSSlines project. I felt the roundover was indeed significantly better than the chamfer, at least for that tweeter.

With a rear mounted midrange, the on axis was very close to the same with either a roundover or chamfer. However, there was some peaking in the off axis with the chamfer that was not present with the roundover, so in that case, I felt the roundover was better also.

At cabinet edges, I'm not certain there is an avantage either way. In many modeling programs, the chamfers seem to perform a little better at cabinet edges, for the same size (i.e 3/4" chamfer and 3/4" roundover).

[mike1234]

Not intending to hijack but I have a half dozen D26's I bought a few months ago I "may" decide to sell. They're all NIB... well new anyway... they didn't come individually boxed.;)

[tombond]

Not intending to hijack but I have a half dozen D26's I bought a few months ago I "may" decide to sell. They're all NIB... well new anyway... they didn't come individually boxed.;)


Thanks for the offer Mike, I think I'm just going to explore other options, if I blow one or drop it on the floor, replacements would be unlikey. I think the best option is to stick with something that has some availability.

[tombond]

I did a study of various shallow waveguides with the Peerless HDS for my BaSSlines project. I felt the roundover was indeed significantly better than the chamfer, at least for that tweeter.

With a rear mounted midrange, the on axis was very close to the same with either a roundover or chamfer. However, there was some peaking in the off axis with the chamfer that was not present with the roundover, so in that case, I felt the roundover was better also.

At cabinet edges, I'm not certain there is an avantage either way. In many modeling programs, the chamfers seem to perform a little better at cabinet edges, for the same size (i.e 3/4" chamfer and 3/4" roundover).


Thanks for the clarification Dan, I guess I'll be doing roundovers.

[mike1234]

Thanks for the offer Mike, I think I'm just going to explore other options, if I blow one or drop it on the floor, replacements would be unlikey. I think the best option is to stick with something that has some availability.

Very true. This is why I always buy extras.

[tombond]

Looking at the two Seas tweeters, 27TFFNC/G & 27TFFNC/CG. The latter (/CG) appears to have better response off axis, looking at the manufacturers FR. Zaph's measurement of the two are sufficiently different from each other, but he states they are the same tweeter with a different faceplate. Could the faceplate account for the difference in measurements? I would think they were probably surface mounted for testing.

http://www.madisound.com/catalog/product_info.php?products_id=1466
http://www.madisound.com/catalog/product_info.php?products_id=8177

The Vifa DQ25 also has good off axis response. Looking at Zaph's distortion data, its better on the low end, but the Seas is better above 2K. I suppose I could order one of each, the Vifa is pretty inexpensive.

[jkim]

Could the faceplate account for the difference in measurements? I would think they were probably surface mounted for testing.

The faceplate could. As far as I know, Zaph always flush mounts a tweeter for testing (Zaph mentioned before) unless it is designed to be surface mounted. The /G version is to be surface mounted, isn't it?

I'm very interested in the /G and TAFNC/D versions, BTW. The little hump around 10 kHz and up can be a good thing. A little emphasis in this range only gives an airy feel, not necessarily fatiguing.

-jAy