Recent content by frperdurabo

To me, that EQ is the biggest advantage. You're getting the biggest boost from the waveguide down low, which allows you to back off power, and therefore reduce distortion, which gets high - sometimes sky-high - as you approach Fs. But hey, To-MAY-to, To-MAH-to.... :-)

Why the leeriness on controlled directivity? I mean, you're using horns, and even the non-CD type do reasonable pattern control - heck, that was the reason for the old multi-cell jobs.

Thanks for posting those photos. I've lost 80lbs this year, and it's reassuring to see I'm now skinnier than I was 20 years ago. (For those playing at home, I'm the one crouching behind the sofa. The event was written up as Boston Bash on Enjoy The Music - where I briefly advertised and...

I've recently come into some money, some of which will be spent on an insane pair of DIY speakers. Also, Crowley Acoustics, my ill-fated attempt to market high-efficiency speakers, deserves, potentially, a cool new prototype I can truck around to various peoples' houses. (MRHardy was the...

I've used REW to measure the M King Alpha 15 Fostex FE103 project. It was enlightening, to say the least. Measure harmonic distortion. I found VERY high levels from the Alpha 15 (which makes sense - high QTs means it's profoundly underdamped). Curious if you replicate those results. At the...

Your restoration looks great! The local Unitarian church has a set of these. Full range, very smooth. Not as detailed as modern speakers, but very, very musical. Quantity, as a famous Russian general observed, has a quality all its own.

These are big, efficient, easy to drive speakers. Start with this: https://www.amazon.com/Nobsound-TPA3116-Channel-Digital-Amplifier/dp/B00WTOAC1M/ref=sr_1_1_sspa?ie=UTF8&qid=1543946394&sr=8-1-spons&keywords=3116+amplifier&psc=1 You'll be surprised, and maybe not even upgrade. I use one on my...

Also, those are the Urei version, and aren't they supposed to have blue foam on the horn lips? They probably sound OK w/o it, but you can use as negotiating leverage. Also, some of the Urei versions didn't use Altec components, because Altec had QA issues in the 70s.

My one exposure was SERIOUSLY underwhelming, as in I'm still wondering if the horn sections were actually not working and I only heard the woofers. Obviously these things are legendary, so if you get a reasonably full-range sound (minus deep bass, obviously) and the price is right, I'd go for...

On rereading the original eBay ad, I conclude the seller mistook the 4 screw wholes in the front gasket for damage. Wow. Other drivers are fine. I'll have to reserve judgement until the correct woofer is installed, but looks like the crossovers have aged at different rates. The tweeter and...

Plot twist: the 2nd speaker just arrived and ... the surround is fine. Intact, flexible. I don't see any issues. Damn, when was the last time an eBay description was wrong in the buyer's favor. The dust cap is pushed in. Maybe I'll get out the vacuum cleaner lately. First order of...

The woofer in the 2nd speaker is NOT the correct woofer for a 4311. It's to be moved on, using the proceeds to get a correct "matching" woofer. Sorry about rambling. Shoulda skipped the whole "OMIGOD, I just found I LOVE vintage JBL after all" stuff. I'm on disability because I'm...

Having watched the Speakerwords video on Youtube I'm pretty sure I can do the refoam. Will update this thread, as the other speaker with the 122A is being delivered 2morrow.

No, but I have surcharges hanging around from when I drove like that, which keep me from being behind the wheel, sadly.

Got the platter off. Motor turns w/o it. As the video predicted, EVERYTHING has turned to varnish. Sending Diane From The Basement (who owns it) out for gear oil and denatured alcohol, because I am NOT riding my bicycle* to the Home Depot in Paterson.... *I don't drive.