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-   -   Genesis Physics II rebuild and update... (http://www.diyaudio.com/forums/multi-way/199689-genesis-physics-ii-rebuild-update.html)

chops 2nd November 2011 02:46 AM

Genesis Physics II rebuild and update...
 
I had another thread going about crossover upgrades on these speakers, but now since I have finished with the upgrade, I figured I'd start a new thread dedicated to the Genesis II's and the process.

To make a long story short, I decided to preserve the original crossovers and terminal plates and go with all new components. New aluminum terminal plates and polished nickle binding posts replace the old. These were surface mounted on the rear instead of inside like the originals.

The original crossovers were glued to the back of the terminal plates and incorporated an attenuation switch for the tweeter which I kept bypassed. One speaker's crossover used a single 10uF poly cap and a large 2 ohm resistor. The other one used two 5uF electrolytic caps and a small 2 ohm resistor. Both used the same 22awg 0.47mH inductor.

The new, upgraded crossovers are made up of three capacitors to make up the 10uF needed. Known as "Cascade Bypass", I used a Dayton 1% Precision Audio 6.8uF cap, a Jantzen Z-Standard 2.2uF cap, a Jantzen Z-Superior 1.0uF cap, and a Jantzen 18awg 0.47mH inductor. I replaced all the internal 20awg wiring with quality OFC 16awg speaker wire. For mounting the crossover, I used Duct Seal. This stuff is excellent and I've used it a million times for such things as this. It not only isolates the components from vibration, but allows them to stick like glue to the enclosure's internal surface. Obviously, a horizontal flat spot is used. In this case, the bottom panel.


I've only had the system playing for about an hour at low volume, but from what I hear already, the bass is stronger, punchier and tighter and seems to have a little more detail. This is apparently from the larger cable alone since the woofer runs fullrange. Then again, the quality binding posts probably have something to do with it as well since those old spring terminals had seen better days.

Lower midrange appears to be just a tad more up front now. This might be due to the new arrangement of the fiberglass damping inside. When reinstalling the fiberglass, I created a nice direct "tunnel" of airflow straight to the PR. Upper midrange is highly detailed and neutral. The transition to the treble is completely seamless where that wonderful inverted dome tweeter takes over at a lofty 1.8kHz.

I believe I have read somewhere that those Jantzen caps I'm using take a while to properly break in. I have to say, even with an hour of running, they have opened up the upper midrange and treble noticeably. They're not brighter per say, but I can detect more detail in the music as well as a little more "air". The tweeters are still sweet and smooth which they are known for, but do seem to be a little bit more extended.


Now on to some pics...

Here they are in stock form.
http://charlest.zenfolio.com/img/s11...07830914-5.jpg

Yes, someone used a bunch of Gorilla Glue on this one and it was a PITA to remove.
http://charlest.zenfolio.com/img/s11...94747006-5.jpg

http://charlest.zenfolio.com/img/s11...21307608-5.jpg

And that great tweeter that still gets plenty of praise today.
http://charlest.zenfolio.com/img/s11...71997112-4.jpg

chops 2nd November 2011 02:50 AM

Now opening up one of them to do the upgrades.

http://charlest.zenfolio.com/img/s11...11844049-4.jpg

All the drivers are within a day of each other , either 9-12-79 or 9-13-79.
http://charlest.zenfolio.com/img/s11...55285346-4.jpg

All pulled and sitting on top of my NHT 2.9.
http://charlest.zenfolio.com/img/s11...95218089-4.jpg

All of that itchy fiberglass, and all up against the drivers.
http://charlest.zenfolio.com/img/s11...74883497-4.jpg

One of the stock crossovers. This is the one with the poly cap.
http://charlest.zenfolio.com/img/s11...89276213-4.jpg

chops 2nd November 2011 02:53 AM

The new terminal panel and polished nickle binding posts installed.
http://charlest.zenfolio.com/img/s11...97907257-4.jpg

http://charlest.zenfolio.com/img/s11...58373935-4.jpg

The new crossover components.
http://charlest.zenfolio.com/img/s1/...19956763-4.jpg

All soldered up and ready to go in.
http://charlest.zenfolio.com/img/s11...23292510-4.jpg

When the "woofer" is away, the cats will play...
http://charlest.zenfolio.com/img/s11...02322983-4.jpg

chops 2nd November 2011 02:58 AM

Making the connections.
http://charlest.zenfolio.com/img/s11...79771678-4.jpg

Where the new crossovers will reside.
http://charlest.zenfolio.com/img/s11...34987678-4.jpg

The crossover in its new place with duct seal holding it securely.
http://charlest.zenfolio.com/img/s11...31737761-4.jpg

Ready for the fiberglass to go back in.
http://charlest.zenfolio.com/img/s11...44080982-4.jpg

Fiberglass in with stock cloth netting to keep the fiberglass away from the drivers.
http://charlest.zenfolio.com/img/s11...17859856-4.jpg

chops 2nd November 2011 03:00 AM

The drivers back in and buttoned up.
http://charlest.zenfolio.com/img/s11...36353754-4.jpg

Wired to the tube amp.
http://charlest.zenfolio.com/img/s11...42435129-4.jpg

Up and running and sounding great doing so.
http://charlest.zenfolio.com/img/s11...30592209-4.jpg

chops 6th November 2011 04:41 PM

Just as a quick update...

I have had the system running the entire weekend since Friday evening to run in the new caps along with a different amp. I pulled out the Baldwin tube amp to make room for a new amp I have coming. In the meantime, I'm using Dayton's version of the little Sonic T-amp. It doesn't sound too bad, but the top end seems a bit lacking and the bass is a bit softer. This is not due to the speaker mods because I had the tube amp playing for the first couple of hours Friday evening before switching it out.

Hopefully by the end of the week, my new amp will be here, the single ended, pure Class A, Monarchy Audio SM-70 Pro. :cool:

chops 8th November 2011 04:05 PM

Listening to a song right now by Ray Charles and Norah Jones (Here We Go Again). There's a xylophone that's heard in the far right. It's so far right and genuine sounding, it scared me the first couple of times I heard it!

It sounded so real and lifelike that I got up and went into the kitchen looking for it, thinking that maybe my girlfriend left her iPhone in there and someone was texting her or something.

I never heard that before so I played that track again! I caught myself look over at the kitchen again one time. LOL! While listening closer this time around, I also noticed the B3 Hammond twirling and whizzing away to the near but yet still far left, directly along side my head. Ray and Norah clearly standing about two feet in front of the speakers and about at normal standing height.

All of this with the cheap Dayton DTA-1 T-amp. Man, I can't wait to get the Monarchy Audio amp in the chain.

Not that anyone on here gives a hoot... :(

MCPete 10th November 2011 01:08 AM

Quote:

Originally Posted by chops (Post 2766860)
I I replaced all the internal 20awg wiring with quality OFC 16awg speaker wire.

OFC = oxygen free copper, I assume. Is this legitimate? What are supposed to be the benefits of this type of wire? How do you produce OFC?

Now and then, I hear about OFC and am just curious what it is all about.

Some time ago I spoke to a former employee of the Genesis company. He currently supplies replacement drivers for I guess at least some of the Genesis
line. See Human Speakers

Regards,
Pete

chops 10th November 2011 02:08 AM

Quote:

Originally Posted by MCPete (Post 2776059)
OFC = oxygen free copper, I assume. Is this legitimate? What are supposed to be the benefits of this type of wire? How do you produce OFC?

Now and then, I hear about OFC and am just curious what it is all about.

Some time ago I spoke to a former employee of the Genesis company. He currently supplies replacement drivers for I guess at least some of the Genesis
line. See Human Speakers

Regards,
Pete

No oxidation on the copper I guess, hence lower resistance maybe? I never really looked into it actually.

I'm well aware of the "Human" site and all the drivers and components Huw offers. However, I decided to go the route I did because I didn't care for the new/replacement speaker terminal panels, binding posts and crossovers that he supplies. I'm also a little upset that after two emails to him, I never received a response which I find odd as everyone else says that he responds rather quickly.

As good as these speakers sounded in their stock state, I wanted to make sure I put the best components possible that I could afford, or at least willing to put into them. I'm already hearing a vast improvement over the original, more ways that one.

speaker dave 10th November 2011 10:04 AM

Nice rebuild thread and good clear pictures. Nice to have a good pair of Genesis speakers ready for another 20 years.

Has anyone seen the cat lately?

David S.


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