Neither horn loading nor mass break up is visible in their fr although they claim exponential with fc=500 hz. There is also no description about smoothing applied. The driver seems to have only a 3 slit pp. One might trim this curve with a very narrow vertical horn. Anyway it would be wise to wait and see how this driver performs in a well known horn.
I'm really enjoying the hell out of this thread, one of my all time favorites. Much appreciation to all who've laid down lifetimes worth of very detailed knowledge, amazing for a novice like me (at 60)!
I'm not through the entire thread yet so forgive me if this has been covered somewhere, but I wanted to mention the build I'm working on, which falls right in with this thread:
I'm planning to use Faital Pro 15PR400 woofers in a 140ish Liter box, tuned to 42Hz. I know the 416s are everyone's darling, but I don't trust buying old ones, and GPA has priced themselves out of reach for me unfortunately.
I'm still not sure about CDs, but after seeing some of the feedback on the SBA Rosso 65CDN-T, it's my current choice, followed by the Beyma CP755Nd. The compression drivers will be attached to Martin's AH425 horns, which he's building as we speak!
I'm looking for any feedback those of you with more experience might have, on my driver choices especially. FWIW, I'll probably use passive crossovers, although I'm seriously considering going active, although the whole point of this build was to have a pair of speakers to pair with my little Alan Eaton 45 SET, so it's more likely I'll end up going passive, possibly with autoformers on the CD rather than an L-pad.
Any feedback is appreciated, thanks!
Bryan
I'm not through the entire thread yet so forgive me if this has been covered somewhere, but I wanted to mention the build I'm working on, which falls right in with this thread:
I'm planning to use Faital Pro 15PR400 woofers in a 140ish Liter box, tuned to 42Hz. I know the 416s are everyone's darling, but I don't trust buying old ones, and GPA has priced themselves out of reach for me unfortunately.
I'm still not sure about CDs, but after seeing some of the feedback on the SBA Rosso 65CDN-T, it's my current choice, followed by the Beyma CP755Nd. The compression drivers will be attached to Martin's AH425 horns, which he's building as we speak!
I'm looking for any feedback those of you with more experience might have, on my driver choices especially. FWIW, I'll probably use passive crossovers, although I'm seriously considering going active, although the whole point of this build was to have a pair of speakers to pair with my little Alan Eaton 45 SET, so it's more likely I'll end up going passive, possibly with autoformers on the CD rather than an L-pad.
Any feedback is appreciated, thanks!
Bryan
Hi Lynn,
Thank you for this thread and your nutshell hifi site before it. Together they have influenced more than a couple of the speaker projects I've worked on going back to the end of the 90's. It's good to see you are still working on this "Beyond the Ariel" project". At one point in this thread, I think you were leaning toward the AH426 with a ribbon super (or semi-super) tweeter. Have you shifted towards a 2 way with the horn handling everything from ~600-800Hz on up? Was this because of the extended topend performance of the drivers like the SB CDN-65?
Dan
@Lynn Olson
I agree with Marco.
Some clarification of the quoted text would be useful here.
I'm guessing that you didn't want to end up recommending a modified A290 radial ( that would only be available from a singular source >> inadvertently creating a captured market for that source ).
I got burned on the A290 purchase. I thought I was getting a discount, which is standard practice for those of us in the trade, but a US importer found out that I was going publish test results and threatened legal action.
Yes, I know that makes no sense. At all. But frankly, I didn't want to deal with this person ever again, so the A290's are getting sold. If I had directly imported the A290's from the country of origin (Athos Audio) I doubt there would have been a problem.
Yes, I know that makes no sense. At all. But frankly, I didn't want to deal with this person ever again, so the A290's are getting sold. If I had directly imported the A290's from the country of origin (Athos Audio) I doubt there would have been a problem.
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I really hope you guys end up using a Joseph Crowe horn. As you've probably noticed, Troy measures and publishes thorough measurements on every horn and horn driver combination he's making and sharing with DIY. His horns and other designs are always professionally modelled in true 3D CAD on commercial CAD software, Solidworks. And, I think Troy would be happy to simulate your horn configuration in real space and take whatever measurements you like. Troy is also now publishing the Gedlee gm measurement for all new horn and driver measurements. These measurements are very useful on their own, but what's really powerful, IMHOP, is that now we are approaching a deep database of many drivers and some horns all published online by Troy. So, we can follow along, compare, and then dip into this database. If others follow his measurement script, this database could really grow.
I am collaborating with Joseph Crowe right now. He's done a great job measuring the Altec/GPA 416, and he is advising me on his favorite compression drivers.
The ideal horn is still up in the air. I own four AH425 Azurahorns, the same horns that Gary Dahl is using, but Joseph Crowe also working on some interesting new designs.
The ideal horn is still up in the air. I own four AH425 Azurahorns, the same horns that Gary Dahl is using, but Joseph Crowe also working on some interesting new designs.
Who said 416s ( and 414s for that matter ) are everyone's darlings? They have no use below 60 and above 300 hz . Actually pretty useless drivers altogether. New GPA may have more life to them I dunno. How I loved idea of Altec reading the countless posts and looking at pictures ,especially the Shindo green ( though even he recognized original drivers are crap and modified them) Work with 515, 803A , Biflex . Ditch all Altec speakers designs. It's garbage. Plain and simple. Well ,maybe Laguna in Heathkit version with Peerless crossover. Whatever Altec farted out for home use is utter ,complete garbage.
Joseph Crowe's 416 measurements
Joseph Crowe's ES450 Horn
As mentioned in the 416 report, a crossover in 500 to 800 Hz region looks quite feasible.
Joseph Crowe's ES450 Horn
As mentioned in the 416 report, a crossover in 500 to 800 Hz region looks quite feasible.
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Not exactly modern... but the Beyma 15MI100, still in production after more than two decades (IIRC), would be my best bet.
Which drivers have you tested so far????
I've never seen much IMD info on woofers but I wonder how much difference there is between a 15" from each pro manufacture with a similar specs;
Qts/Qes <0.3
Mms <89g