LR2 design for the Usher 8945P and 810921 from Jay Kim

[blue934]

240sxguy,
I sent the whole file to your PM. I tried every which way but loose and PE wouldn't let me upload any attachments or pics to this thread. Feel free to post them here if you want. If you succeed, you're a better man than me ;)
David

[steveslagle]

Thanks for posting those dld. I now have JPG screen shots in Photos on my iMac, but don't know how to connect to post them to the forum. They are more clear than the photos I originally sent dld.
The PE board wants a URL and I am lost on what to do to post them. dld did post the info, so maybe no need now.

The ones I sent dld, I got from an archive of Jkim’s site; I think shortly after it was shut down. I think I used the "Wayback Machine” as suggested by someone on another audio site. I wonder if he made different versions.

The one Jkim sent dld look to track LR2 for more octaves vs the one I harvested off the site archive.​ The ones from the site archive have what I think is a simpler crossover.

Steve

[dld]

Hmm... so these are from Steve. They differ from the one I posted earlier. mine were from Jkim via email in in sept. 2011. I'm not knowledgeable enough to say which one is the final or better version. Maybe someone can explain whats going on here between the two.

[Chris Roemer]

Like Bill says,

Take a screen shot (by pressing the "PrtScr" key near the top right of your keyboard), paste that (from your "clipboard") into your photo program (like (MS)"Paint"), and save it as a jpg.

[billfitzmaurice]

Take a screen shot, paste that into your photo program, save it as a jpg.

[steveslagle]

Hi did,

I did just send a word document with the 2nd order schematic and the 2 graphs Jkim included. The full original write up of the 4th order was included as well.
Sorry, I am not tech savvy enough to figure out how to convert my document graphs to images to upload.
The image you posted is not the 2nd order crossover I saved from Jkim's site a few years ago.

Hope you get my email and the document.

Cheers,
Steve

[dld]

I think I found it!

[billfitzmaurice]

I have the info, but the forum won't let me post the schematic or frequency response.

Upload them as images.

[dld]

Steve sent you a pm with my email.
thanks

[steveslagle]

Hello All,

I have the info, but the forum won't let me post the schematic or frequency response.
I may need emails to send this to you.

Cheers,
Steve

[dld]

I would love copy of the documents too. I built these years ago and would like to them together again to see if my current setup compares.

[steveslagle]

Hi 240sxguy,

I tired to paste the LR2 information below, but the schematic and graphs won't paste.
I a word document of the original write-up (LR4) and the LR2 note pasted. I am working this weekend, but could do an message attachment too you on my Monday = your Sunday. (I moved from US to New Zealand, so most of a day ahead.)

Steve Slagle


From J Kim old site:

New Crossover:
I have been working on my LR4 crossover to fix some of the flaws, but I also decided to try a LR2 configuration. The results are interesting. Once the drivers were made to hit the LR2 targets the phase was not tracking well at all with the tweeter polarity reversed (as it should be in a LR2). Switching the tweeter back to positive polarity got the phases closer, but would still have required a very asymmetrical filter to align the phases with any accuracy and they only tracked for a few hundred Hz. So I chose to use a ladder delay network to help align the phases. It is a lot of fiddling, but I think it came out quite well.


(This was the response graphs, but won't paste)


Crossover Info

​
(This was the schematic)


LR2 @ 2200
​

[240sxguy]

I know this is super old, but does someone still have Jay Kim's documents for this build? I built a pair YEARS ago and wanted to revisit them, as they've been shelved for awhile after a move. I printed out the stuff from the geocities site years ago but lost it of course!

[Laurence Platt]

Re: LR2 design for the Usher 8945P and 810921 from Jay Kim

Hi Rory 57
I was wondering about putting them into a cardboard tube! Just happen to have one around from my Ted Jordan days!
The trouble with the pentagons is the difficulty of making the angle correct!
The PE enclosure sure saves a lot of time and frustration.
All the best
Laurence

[rory57]

Re: LR2 design for the Usher 8945P and 810921 from Jay Kim

That looks like a nice piece of work. Ever considered a pentagonal cross section?