ESB Audio 9.1T-28 Ring — 9000 Series 9.1T-28 CNC Mounting Ring (pair) | HF Audio Labs

An Optional CNC Housing That Extends Mounting Options and Adds an Acoustic Benefit

The ESB 9.1T-28 Ring is a CNC gun-metal anodized aluminum housing designed for the 9.1T-28 tweeter. It serves two functions: it extends the tweeter's mounting compatibility to openings up to 95mm, and it adds a rear acoustic chamber behind the tweeter dome that ESB reports improves low-frequency extension.

Design

The ring housing is CNC-machined from aluminum — consistent with the manufacturing approach of the 9000 Series. A silver finishing ring fixed by magnets provides a clean visual finish and allows easy removal. The rear chamber modifies the air loading behind the dome, which affects the tweeter's performance at the lower end of its operating range. For installations where the 9.1T-28 will be crossed over at a lower frequency, this acoustic benefit may be relevant to the system design.

System Application

The 9.1T-28 Ring is an optional accessory for 9.1T-28 installations. It is most useful when the installation location requires a larger mounting footprint than the tweeter's native profile provides, or when the rear acoustic chamber benefit is relevant to how the tweeter will be crossed over in the active system.

HF Audio Perspective

Tweeter placement quality determines a significant portion of what the 9.1T-28 can contribute to the front stage. The ring housing exists to expand the range of locations where correct tweeter placement is possible — and to provide an acoustic benefit when the installation allows for it. For 9.1T-28 installations where the standard housing does not provide the best mounting option, the ring is the correct accessory.