Bose - 901 Series IV Speaker set

Bose 901 Series IV Direct Reflecting System.

A beautiful fully restored Bose 901 Series IV set with original, revised, and customized equalizer.

This is already the fifth set I have restored in recent times.

Externally, all damages have been updated. One of the images shows that a small piece of new veneer has been inserted.
The speakers are oiled at the factory. I have cleaned the cases and, as needed, repaired them, then treated them with extra-strong parquet oil.
This results in minimal maintenance, better protection of the enclosures against sunlight, and easier maintenance.

All 18 speakers are equipped with new foam rubber edges identical to the original type, specifically those with the double roll edge.
The connection pins of the speakers are also secured in the housing with industrial superglue. The connection pins are pressed into the housings at the factory and are usually loose, which may cause additional noise.
Also internally, the stiff wiring has been replaced with more flexible and thicker wiring.

The associated equalizer has also been thoroughly revised.
All expired electrolytic capacitors have been replaced with equivalent types.
At the rear, the iron RCA connectors have been replaced with gold-plated units.
The equalizer has no power switch from the factory. This means you must always unplug it from the power outlet if you do not have an amplifier with switched power outlets.
I also turn on all my restored equalizers with a small illuminated on and off switch that replaces the neon lamp, allowing you to turn it on and off yourself.


A printed copy of the manual available on Bose's website in English will be provided.
This document explains how to optimally install, connect, and maintain the set.

The original rubber feet are also included, along with new screws.
The manual indicates where you can place it if necessary.

For shipping, the set is packed in new boxes. I have attached a few photos to show that extra care is taken in this process.

The set is offered here with a minimum price of € 500.

Of course, pickup is also an option.

Technical information
Direct Reflecting System
Impedance: 8 Ohms.
Frequency range: 20 Hz/20 KHz.
Maximum power: 270 W.
Walnut wood veneered.
The total weight of the shipment is approximately 38 Kg.