Here I am trying to restore a pair of a famous Rank Arena HT525.

The specifications has been copied from hifi-wiki.com.

• Manufacturer: Rank Arena
• Model: HT-525
• Type: Loudspeaker
• Years of manufacture: 1972 - 1974
• Manufactured in: Horsens, Denmark
• Color: Wood, optionally in walnut, white, teak, rosewood
• Dimensions: 280 x 430 x 240 mm (WxHxD)
• Weight: 8,1 kg
• Original price approx.: 258 DM / piece

Technical Data

• Type: 3-way, 3 speakers, closed
• Chassis:
  • Bass: Cone
  • Midrange: cone
  • Tweeter: cone

Technical data DIN power handling capacity 60 watts

• Music power handling capacity 100 watts
• Impedance 4 ohm
• Frequency response: 30 Hz - 20 kHz
• Crossover: 500 Hz, 3'000 Hz
• Impedance: 4 Ohm

Like many old loudspeakers the crossover use electrolytic capacitors which are very old so we may find large differences in value compared to the original.

Schematic of the original filter

Schematic of the new filter

Follows the new frequency response at 1m with MLS

Frequency response at 30cm near to the woofer axe only to check the crossover point.

This is the total impedance, min 3.6ohm at 1.5KHz.

PHOTOS AND DETAILS

The old crossover

The new crossover on testing phase