FT28D - Loudspeaker FOSTEX - Free user manual and instructions

Product Type	Loudspeaker driver (tweeter)
Brand	Fostex
Model	FT28D
Driver Type	1-inch soft dome tweeter
Impedance	8 ohms
Frequency Range	2.5 kHz - 20 kHz
Sensitivity	90 dB (1W/1m)
Power Handling	50 W RMS
Magnet Type	Ferrite magnet
Dimensions	Approx. 104 mm diameter x 48 mm depth
Mounting Cutout	Approx. 94 mm diameter
Weight	Approx. 0.6 kg
Connector Type	Screw terminals
Cooling	Ferrofluid cooled voice coil
Installation	Recessed mounting
Compatibility	Hi-fi loudspeaker systems
Country of Origin	Japan
Maintenance	Clean with a dry, soft cloth
Safety	Avoid touching the diaphragm
Repairability	Replaceable diaphragm assembly
General Information	High-quality reproduction of high frequencies

Frequently Asked Questions - FT28D FOSTEX

What is the impedance of the Fostex FT28D?

The Fostex FT28D has a nominal impedance of 8 ohms, making it compatible with most home audio amplifiers and crossover networks.

How do I connect the FT28D to my amplifier?

Connect the tweeter to the amplifier through a crossover network to ensure only high frequencies reach the driver. The terminals are standard screw-type connectors; maintain correct polarity for proper phase.

What crossover frequency is recommended for the FT28D?

A crossover frequency of 2.5 kHz or higher is recommended to protect the tweeter from excessive low-frequency excursion and ensure clean sound reproduction.

How do I clean the FT28D?

Use a soft, dry cloth to gently wipe the outer surfaces. Do not use any liquids or solvents, and avoid touching the diaphragm or dome.

Can I use the FT28D in a car audio system?

Yes, the FT28D can be used in car audio if properly mounted on a surface and connected via a compatible crossover. However, ensure it is protected from moisture and dust.

How do I replace the diaphragm of the FT28D?

The diaphragm is replaceable: carefully unscrew the front cover, remove the damaged diaphragm, and install a genuine replacement diaphragm from Fostex. Reassemble and test polarity.

What type of speaker system is this tweeter designed for?

The FT28D is designed for 2-way or 3-way hi-fi speakers and can be used as a high-frequency driver in bookshelf or floorstanding speakers.

How can I avoid damaging the tweeter?

Avoid feeding it low frequencies or excessive power without a crossover, and never touch the dome. Use the tweeter within its rated power handling to prevent overheating.

Is the FT28D suitable for a 2-way or 3-way speaker?

Yes, it works in both configurations. In a 2-way system, pair it with a woofer; in a 3-way system, combine it with a midrange and a woofer for extended response.

What power can the FT28D handle?

The FT28D can handle up to 50 watts RMS nominal with appropriate crossover. For short peaks, it can withstand higher transient signals but avoid sustained clipping.

USER MANUAL FT28D FOSTEX

♦Dome Tweeter
♦8 ohm impedance
◆1kHz to 50kHz frequency response
◆90dB sensitivity at 1W/1m (3.3ft)
◆0.528kg (1.164 lb) net weight

Specifications

Impedance : 8 ohm

Reproduction Frequency Response: 1kHz - 50kHz

S.P.L. : 90dB/W (m)

Music Power : 40W

Recommended Cross-over Frequency: more than 2kHz

Magnet Weight : 228.3g (0.503 lb)

Net Weight : 528g (1.164 lb)

Frequency Response / Impedance

Configuration Example

Dimensions & Mounting Information