Vintage HiFi Audio Forum

Audio Discussion => DIY => Topic started by: TNRabbit on August 29, 2011, 08:11:08 AM

Title: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 29, 2011, 08:11:08 AM
I have 7 pair of Realistic Minimus 77 speakers I use for surround/center duty (ganged pairs) in various stages of disrepair; I'm putting new woofers & upgraded crossovers in in half of them:

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_22-57-36_414.jpg)

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-00-19_172.jpg)

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-17-11_760.jpg)

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-28-22_16.jpg)

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-36-04_302.jpg)

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-35-55_585.jpg)

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-36-14_840.jpg)
Title: Re: Realistic Minimus 77 Upgrade
Post by: Sir Thrift-a-Lot on August 29, 2011, 09:14:33 AM
I have no 77s but a few 7s (including an orphan wooden 7) and have been interested in some of the mods I've read about.
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 29, 2011, 09:51:00 AM
There's a HUGE thread on AudioKarma that details the specific crossover parts, or you can buy pre-configured kits.  I bought mine from a guy on ebay who's seller ID is "litekeys"

I paid $57 each including shipping for my kits, but I got a discount because I had the guy leave out some crappy acrylic formers he includes so the new woofer (doesn't fit old bolt holes).  I cut the edges out from the old woofers & epoxied them around the new woofer so I could use the old bolts/holes.
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 29, 2011, 09:51:49 AM
Is there no way to edit posts here?

I meant to state the AK thread is for Minimus 7s~
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 29, 2011, 09:53:11 AM
Anywho, the sound wasn't changed so much as the power handling.  The new woofers have 3 times the magnet & are more robust.  I'd guess twice the power handling with no apparent loss in efficiency.
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 29, 2011, 09:58:38 AM
Here's a video example of one I previously modified:

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/th_MOV02950.jpg) (http://s251.photobucket.com/albums/gg286/TNRabbit/Audio/?action=view&current=MOV02950.mp4)

This is what the finished product looks like:

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/DSC02948.jpg)

& this is the crappy acrylic woofer adapter he provides:

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/DSC02941.jpg)

Here's what I used in lieu of the acrylic after I cut them out from the old woofer:

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/DSC02947.jpg)
(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/DSC02944.jpg)

Old woofer:

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/DSC02946.jpg)
(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/DSC02942.jpg)
Title: Re: Realistic Minimus 77 Upgrade
Post by: MacGeek on August 29, 2011, 05:20:23 PM
What's the measurement across the diagonal from mounting hole to mounting hole (center to center)?  It looks like they might fit as replacements in a pair of B&O CX 100s I want to restore.
Title: Re: Realistic Minimus 77 Upgrade
Post by: schwarcw on August 29, 2011, 09:03:27 PM
Gary, are the crossovers shown in the pics the new ones, or the old ones?
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 30, 2011, 08:48:57 AM
Gary, are the crossovers shown in the pics the new ones, or the old ones?

This is the old one, which is retained to run to the tweeter.  The black cap on it is replaced with one of the yellow caps (4.7) that are in the plastic bag.

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-36-14_840.jpg)

This one is the new crossover that is used for the woofer only.  The old crossover didn't have anything for the woofer; it relied on the natural rolloff of the driver.

(http://i251.photobucket.com/albums/gg286/TNRabbit/Audio/2011-08-26_23-35-55_585.jpg)
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 30, 2011, 08:50:06 AM
What's the measurement across the diagonal from mounting hole to mounting hole (center to center)?  It looks like they might fit as replacements in a pair of B&O CX 100s I want to restore.

I don't know; I'll check when I get home & post the result~
Title: Re: Realistic Minimus 77 Upgrade
Post by: schwarcw on August 30, 2011, 09:35:46 PM
Thanks Gary!

I understand now.  I was confused by the various crossover components in the photo.  I was wondering about the big yellow capacitors.

Regards,
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 31, 2011, 04:11:24 AM
Thanks Gary!

I understand now.  I was confused by the various crossover components in the photo.  I was wondering about the big yellow capacitors.

Regards,

Hell, I had the instructions & was confused about the first one I did~
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on August 31, 2011, 03:15:24 PM
What's the measurement across the diagonal from mounting hole to mounting hole (center to center)?  It looks like they might fit as replacements in a pair of B&O CX 100s I want to restore.

 4 3/4" center to center...
Title: Re: Realistic Minimus 77 Upgrade
Post by: MacGeek on August 31, 2011, 06:44:35 PM
Thanks, but Rats!  I need 4 5/16"
Title: Re: Realistic Minimus 77 Upgrade
Post by: TNRabbit on January 31, 2012, 02:15:33 PM
Videos of these little babies in action with Carverfest Tube Amps:
 
http://s251.photobucket.com/albums/gg286/TNRabbit/Audio/CarverFest%20Amp%20Build/?action=view (http://s251.photobucket.com/albums/gg286/TNRabbit/Audio/CarverFest%20Amp%20Build/?action=view)¤t=20120127001803.mp4