Fisher XP7 upgrade

Fisher XP7 upgrade


Designer:
Mort

Project Category:
Loudspeakers/Cabinets

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
Over $1,000

Project Description:
Take a pair of 1965 Fisher XP7s and modernize them but keep their vintage look.

Design Goals:
Create a good three way design that will fit the vintage speaker box.

Driver Selection:
I decided to go with all Dayton audio drivers. I like the look of the drivers and was able to make them work in my existing cabinets with some modification to the front baffle.
DSA315-8 Woofer PN # 295-534
RST28A-4 Tweeter PN # 275-131
RS52AN-8 Midrange PN # 285-020

Enclosure Design:
The original Fisher XP7 is a sealed enclosure with sub enclosures behind the midrange drivers. I decided to keep them sealed, and removed the original sub enclosures, the new midranges are a sealed back design, and I wanted to take advantage of as much cabinet volume as possible.

Enclosure Assembly:
I had to carefully remove the original grills as they were nailed on. I Plugged the original holes in the baffle that I was not going to use with with new MDF and wood glue. I modified the original tweeter hole the same way and cut the new hole using a palm router and some custom templates. I had to plug, and re cut the Terminal cup hole on the back of the enclosure as well. I made the original Grills removable with the small 3/8 neodymium magnet kit that Parts express sells. I then refinished the exterior and used Exohyde coating for the baffle and back of the cabinet. The cabinet is stuffed with poly-fill.

Crossover Design:
I used Xover pro to design the crossover. I went with a 750 Hz and 2500 Hz crossover points. I used second order filters on the low pass and high pass filters and a first order solen split on the band pass filter. I went ahead and incorporated the impedance EQs on all the filters. I wired the speakers so they can be bi-wired with separate amps between the woofers and the high frequency drivers. I built a separate filter board for each driver.

Conclusion:
This is the first time I have done this and I couldn’t be happier with the results. The speakers sound very clear and articulate. The bass needs a little boost with the tone controls but sounds great. I have played them for friends and family, and everyone was very surprised at how well they turned out.

About the Designer:
I have been an Aircraft structures mechanic for 25 years and an audiophile all my life.

Project Parts List:

https://www.parts-express.com/Dayton-Audio-DSA315-8-12-Designer-Series-Aluminum-Cone-Woofer-295-534
https://www.parts-express.com/Dayton-Audio-RST28A-4-1-1-8-Reference-Series-Aluminum-Dome-Tweeter-4-Ohm-275-131
https://www.parts-express.com/Dayton-Audio-RS52AN-8-2-Reference-Aluminum-Dome-Midrange-285-020

3 Comments

Add yours
  1. 2
    Ray

    Our Dad sat in front of these while Mort played them, our dad is 80 and loves his music. Absolutely fantastic sound. Close your eyes and your on stage.

  2. 3
    Don Warrick

    I own a set of XP-7s that I bought new when I came home from Viet Nam in 68. Guess I will always be old school. I have a Kenwood KR-7600, Pioneer Cassette, Dual 1212 Turntable and Sony Reel to Reel. Opened up my Fishers recently and couldn’t believe how clean and dust free they were after all these years. Was thinking about recapping the crossovers but my son begged me to leave them completely as they are as he figures they will be his one day. Really loved what you did. Hope to hear more on your project. Don Warrick

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