CSS LD25X?

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I have a set of their Ld22C here and have been playing with them. Quite nice tweeters with some fairly unique characteristics that make it a really good value at its pricepoint.

The LD25X may be a very nice tweeter as well, but at the $100-165 pricepoint, there is a lot of stiff competition. I personally would like to see a lot more data before considering buying them, especially with exceptional tweeters like the Peerless DA25TX coming in close to 1/2 the cost. If I were trying to promote this tweeter, I'd be sending samples to audioxpress and posting comprehensive specifications, measurements, and maybe usage notes.

I am a big CSS fan, and have patronized them frequently, but I think preordering items like this is a bad idea in general; plenty of good options out there and I feel no rush to get a hold of the newest driver. Others may have different appetites for novelty or higher risk tolerance than I do, so YMMV.
 
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I found these measurements of the original by Jeff Bagby: Box

I messaged them (CSS) and they said that it is essentially the same tweeter but a distortion reducing shorting ring has been added to lower the higher order harmonics even further. They said the specs will be almost identical to the previous version. If they really have improved upon the measurements shown, I would think it would be a very nice tweeter.
 
I agree, it *should* be a very nice tweeter based on the tech used and their claims for it, as well as their reputation.

At the same time, there's a LOT of very nice tweeters at or below it's pricepoint now. And the devil is in the details; many a small manufacturer (or not so small, witness Dayton's RS28 QC issues) has been let down by the OEM buildhouse's implementation of their high-tech designs.. not least CSS themselves.

Personally, not being able to afford multiple tweeters at this pricepoint, I'd be inclined to wait until there were testing that could be compared directly to other premium tweeters under the same measurements conditions. Perhaps more importantly, until it was clear that the QC issues with the previous model were resolved.
 
I agree, it *should* be a very nice tweeter based on the tech used and their claims for it, as well as their reputation.

At the same time, there's a LOT of very nice tweeters at or below it's pricepoint now. And the devil is in the details; many a small manufacturer (or not so small, witness Dayton's RS28 QC issues) has been let down by the OEM buildhouse's implementation of their high-tech designs.. not least CSS themselves.

Personally, not being able to afford multiple tweeters at this pricepoint, I'd be inclined to wait until there were testing that could be compared directly to other premium tweeters under the same measurements conditions. Perhaps more importantly, until it was clear that the QC issues with the previous model were resolved.



Are you talking about the new RS28 or the old ones? I never heard any issues wit QC on the old ones but I haven’t heard really anything good or bad on the new ones.
 
Are you talking about the new RS28 or the old ones? I never heard any issues wit QC on the old ones but I haven’t heard really anything good or bad on the new ones.

New RS28F I believe, there seem to have been some batches with responses that were quite off spec. There's a thread on PE right now talking about ways to improve/fix the b-stock versions.
 
In reference to the old RS28, made by Usher, and being the A version since the F didn't come until much later, The RS28A was originally with Ferrofluid for the first 100 pieces, and then Usher removed it from the following batch without telling PE that they did so. As it turned out, FF actually increased the HD levels in the their tweeters and they just decided to eliminate it from their products. PE caught wind of it much later, and then offered FF as a individual packetized product for those that still wanted it with the proper amount in each packet for a single tweeter. This was around 2007 or so.

As to the new ones, the RST28F-4 was the only one affected by a change in manufacturing processes. The RST28A-4 was unaffected, so PE was swapping textile faces onto aluminum faced motors to keep up with orders (or send out good units for bad RTV issues) momentarily until they could get the next batch in house. This became known around March of this year. This is why the F were out of stock for a bit.

I'm the person who started the thread on the B-Stock tweeters, as I was an MWAF entrant, and was informed by a staff member while there that they were B-Stock in our free product gift-bags, and supposedly were matched before given out. Being they were free, I had nothing to lose if I could not improve their responses. I had some experience with doing this kind of modification on a pair of Airborne tweeters I had about 7 years ago, and it proved beneficial, so I gave it a shot.

Does it make them a better tweeter than initially received? Yes.
Does it improve on the HD characteristics of both the out of spec and spec units? Yes, and mildly yes.
Is the HD performance resulting from the mod then world-class or SOTA? No. There is still some second order HD spiking around 5k or so, followed by another higher frequency second order HD spike. These spikes are notably -35dB to -40dB in range from the fundamental. It's not bad performance, especially for a $35 tweeter, but it is not suppressed enough to stomp the older RS28A from Usher in terms of distortion. The T has lower HD from 1-5K as a result of my testing, but the ancestor has lower HD from 5k and up. The unmodified B-Stock had high 3rd order HD, and that was unacceptable.

There is more info over there should you want to find out more.
Later,
Wolf
 
Thanks for providing the details and context Wolf.

I wasn't that familiar, and thus didn't do a very good job of being precise about what was affected or the extent of the issues. I also didn't intend to single Dayton (or indeed CSS) out for this, but to point out how these things can happen with any new driver or change of build house.
 
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