Exploring high performance ferrite driver options

[Bill Fitzmaurice]

Divide the weight by eight for the load per screw. #12 screws will handle anything.

[Wylandright206]

I just figured since we were talking about the soft parts, I would also talk about the re-coning process a bit more. The eminence kit was purchased from the speaker exchange, it's an aftermarket kit so not quite the same parts, but I have confirmed with others that the first party kits are the same story, disassembled. The eminence kit was 100 dollars shipped to Seattle, the prv was the same, despite being much more of everything and preassembled. The cone on the prv was so thick it was actually difficult to get a utility knife through when removing the old cone. They shipped the recone assembly with a large PVC pipe as a bracing for the voice coil. Very nice. Whatever glue they used smelled like mustard or something it was weird I dunno. It wasn't hard to scrape off the basket without a heat gun. The glue eminence uses REQUIRES a heat gun. This makes re-coning more time consuming and expensive if you don't already own one. It also required using 3 different adhesives in the instructions of the aftermarket kappalite recone kit, which is not included with the first party kit. The prv asks for 2 adhesives, both of which are easily bought at any hardware store. The kappalite surround ships unsealed (but fortunately glued to the cone already) so you have to buy some sort of PVA sealant, not Elmer's but something more flexible. I ordered something from Springfield speaker repair I think it's called, but it's obnoxiously tacky, any dirt that gets in the horn would stick to the surround.

Reconing the prv took a fraction of the time it took to recone the kappalite, cost less, glue was more accessible to me as someone who lives downtown. Overall better experience for the end user. I have included several pictures of the prv before I blew it up so people can see it actually has very high build quality despite the price. The only thing to note is that it is a double layer spider so make sure you get the adhesives between both the spiders as well as between the bottom layer and the frame. The surround ships already sealed and the spider pre-doped so no need for that extra adhesive or whatever. Just shim the coil, glue soft parts to the frame, and epoxy the dust cap on. Much easier direct to customer process and for the layman who's never reconed a driver and is intimidated by it, this makes things much easier. And undoubtedly cost the company more money to assemble the stuff and glue it themselves.

[Bill Fitzmaurice]

Out of curiosity I looked at the 4 ohm version. I models better than the 8 ohm depending on which set of T/S specs you believe. I found three.

[Seth]

Out of curiosity I looked at the 4 ohm version. I models better than the 8 ohm depending on which set of T/S specs you believe. I found three.

The Data sheets seem most reliable. Their website is definitely off. Guessing the other option is third party. Which do you find reliable?

Would you mind posting a pic showing the response of the two in contrast, 4Ω vs. 8Ω?

[Bill Fitzmaurice]

Since there are at least three versions, including two on the PRS site, I can't give credence to any. What caught my attention with one of them was the lower Qts, which when I modeled it as expected smoothed the bump and dip at the bottom of the passband. It's not major, but it's there. The 4 ohm also has its lowermost impedance peak, and along with it excursion peak, a couple of Hz lower. Also not major, but also it's there.

[Wylandright206]

Yes I am discovering exactly what you are talking about about. The inductance and qts are lower on the 4 ohm version. I believe the spec sheet listed on the website was copy and pasted on accident from the 8 ohm version as they are identical, and I believe the downloadable spec sheet more. Might be worth buying a dats and measuring after break in. It seems with the 4 ohm version you can push HPF down to 35hz with a single box 🫨 great I thought I was done with this now I have even more tests to perform. 35hz HPF would be a big deal with this enclosure.

[Wylandright206]

Ooooh ive come to the realization that both of these drivers could take a pretty serious amount of power without filters before unloading in the 24" titan 🫨 if you used these say in your home or something you could limit early and just leave the high pass off. Hornresp says both versions of the driver will take around 375w before unloading without a HPF. I can't imagine using a titan without a HPF at all but it would probably sound fantastic.

[Seth]

...in the 24" titan...

Tuba 24, I presume? Or are you talking about a 24" Titan 48 or 24" Titan 39...

[Wylandright206]

24" wide titan48. I haven't really tied seeing how much I could get out of it before unloading without filter but it seems you can achieve a fairly large part of its output without a high pass filters using either the 4 or 8 ohm version of the PRV 15sw2000.

[Bill Fitzmaurice]

They'll hit xmax at 30Hz with only 35v. I would not run them without high pass.

[Wylandright206]

That's still 300 watts at 4 ohms. That's nearly all of the kappalites power handling. I certainly wouldn't run them completely raw like that but it's interesting to me. You could get creative with the HPF if you were willing to compromise on power handling....