Ultimate Support TSM-138MK Speaker Cabinet Mounting Bracket

Name: Ultimate Support TSM-138MK Speaker Cabinet Mounting Bracket
Brand: Ultimate Support
SKU: TSM-138MK

138 lbs

Securely Mount Speakers Without Built-In Sockets The Ultimate Support TSM-138MK is the perfect solution for mounting speaker cabinets on speaker stands when they lack a built-in socket. This internal metal bracket ensures a secure and stable setup. Specifications: Brand: Ultimate Support Model...

$49.99*

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*Price sourced from Amazon.com. Last updated:Aug 27, 2026.Price and availability are subject to change — details.

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Overview

Securely Mount Speakers Without Built-In Sockets

The Ultimate Support TSM-138MK is the perfect solution for mounting speaker cabinets on speaker stands when they lack a built-in socket. This internal metal bracket ensures a secure and stable setup.

Specifications:

Brand: Ultimate Support
Model: TSM-138MK
Type: Mounting Bracket for Speaker Cabinets
Compatibility: Speaker stands with 1-3/8" (35mm) tube
Fitting Diameter: 4" (102mm) Flange
Weight Capacity: 150 lbs (68.2 kg)
Mounting: Internal metal bracket

Key Features

Secure Mounting: Internal bracket fits flat-bottom speaker cabinets.

Standard Compatibility: Fits 1-3/8" diameter speaker poles.

Compact Design: 4" diameter footprint for tight installs.

Heavy-Duty Fitting: Metal bracket supports up to 138 lbs.

Specifications

Mounting Type

Internal bracket for flat-bottom speaker cabinets

Compatible Pole Diameter

1-3/8"

Footprint Diameter

Material

Metal

Weight Capacity

138 lbs

Frequently Asked Questions

What type of speaker cabinets is the Ultimate Support TSM-138MK designed for?

This mounting bracket is designed for flat-bottom speaker cabinets, providing a secure internal fit.

What size speaker pole does this bracket accommodate?

The TSM-138MK is compatible with standard speaker poles that have a 1-3/8" diameter.

What is the maximum weight capacity of this mounting bracket?

This heavy-duty metal bracket is built to support speaker cabinets weighing up to 138 lbs.

How compact is the design of this speaker mounting bracket?

It features a compact 4" diameter footprint, making it suitable for installations in tight spaces.

Is the installation of this bracket external or internal to the speaker cabinet?

The TSM-138MK is an internal bracket, meaning it fits inside the speaker cabinet for a secure mount.

Strengths & Trade-offs

👍 Pros

Ensures secure mounting for flat-bottom speaker cabinets, providing stability during use.
Offers broad compatibility with standard 1-3/8" diameter speaker poles, making it versatile for many setups.
Features a compact 4" diameter footprint, ideal for installations where space is limited.
Constructed from heavy-duty metal, allowing it to support speakers weighing up to 138 lbs with confidence.
Designed for internal installation, which can offer a clean and integrated look for speaker cabinets.

👎 Cons

Only fits speaker cabinets with a flat bottom, which may limit its compatibility with certain speaker designs.
The bracket is designed for a specific 1-3/8" speaker pole diameter, meaning it will not work with other pole sizes.
Requires internal installation into the speaker cabinet, which may involve some DIY effort or modification.
While it supports up to 138 lbs, users should verify their speaker weight is within this limit to ensure safety.
The 4" diameter footprint, while compact, still requires a minimum amount of internal space within the speaker cabinet.