LEAK Sandwich 150 Standmount Speakers

The LEAK Sandwich 150 is a two-way bass-reflex loudspeaker inspired by the original LEAK Sandwich speaker introduced in 1961.

It combines a 170mm aluminium and foam-core Sandwich mid/bass driver with a 30mm coated textile-dome tweeter, housed within a substantial real wood veneered cabinet.

The speakers are supplied as a matched, handed pair and require a separate stereo amplifier, speaker cable and suitable stands.

The LEAK Sandwich Driver

The Sandwich 150 takes its name from the construction of its 170mm mid/bass cone.

A lightweight structural foam core is bonded between stiff aluminium outer skins. This creates a cone intended to combine low moving mass with considerably greater rigidity than many conventional single-material diaphragms.

Greater stiffness helps the cone move more consistently in response to the amplifier signal, reducing uncontrolled flexing that could otherwise colour vocals, instruments and bass notes.

The modern driver applies the principle behind LEAK’s original Sandwich loudspeaker using current materials, manufacturing methods and motor-system design.

170mm Mid/Bass Driver

The relatively large 170mm driver gives the Sandwich 150 more cone area and cabinet presence than many compact standmount speakers.

It reproduces both the bass and midrange, covering voices and instruments before handing over to the tweeter at 2.4kHz.

LEAK specifies a frequency response reaching 44Hz within ±3dB and bass extension down to 38Hz at -6dB, giving the speaker useful low-frequency weight without requiring a floorstanding enclosure.

30mm Coated Textile-Dome Tweeter

High frequencies are reproduced by a 30mm coated textile-dome tweeter.

Its larger-than-average dome is designed to provide strong power handling and useful overlap with the mid/bass driver.

A damped rear chamber absorbs energy produced behind the dome, isolating the tweeter from pressure within the main cabinet and lowering its resonant frequency below the crossover region.

This helps the two drivers integrate smoothly without requiring an excessively sharp or aggressive high-frequency balance.

Listening-Developed Crossover

The crossover divides the musical signal between the mid/bass driver and tweeter at 2.4kHz.

LEAK developed the network through measurement, simulation and extensive listening, with particular attention given to the transition between the two drive units.

The aim is to create a coherent presentation in which voices and instruments remain consistent as their harmonics pass from one driver to the other.

Layered Cabinet Construction

The cabinet creates a second interpretation of the Sandwich principle by combining MDF and composite board in a layered structure.

Internal bracing strengthens the enclosure and helps reduce unwanted panel vibration.

A front-to-rear brace is secured by the visible countersunk fixing on the back of the cabinet, retaining a distinctive feature associated with the original LEAK design.

Each speaker weighs 12.3kg, reflecting the substantial enclosure behind its traditional appearance.

Matched and Handed Pair

Sandwich 150 speakers are supplied as a matched pair with a handed driver arrangement.

The left and right speakers should be placed in their corresponding positions rather than treated as interchangeable cabinets.

This mirrored presentation allows the driver arrangement to operate symmetrically and supports a more precisely organised stereo soundstage.

Bass-Reflex Loading

The Sandwich 150 uses a vented bass-reflex enclosure to reinforce the lower-frequency output of its 170mm driver.

Room boundaries will affect the amount and balance of bass, so the final position should be established by listening rather than placing the speakers as close to the wall as possible.

Moving the speakers nearer the rear wall will usually increase bass weight, while bringing them further into the room may improve definition and stereo depth.

Speaker Stands and Positioning

Although sometimes described as a bookshelf speaker, the Sandwich 150 is a substantial 12.3kg design that will normally perform best on rigid floor stands.

Suitable stands should position the tweeters close to seated ear height and provide a top plate large enough to support the 250mm-wide cabinet securely.

Begin with the speakers clear of the rear and side walls, positioned an equal distance from the main listening seat. Adjust their position gradually using familiar recordings.

Browse our speaker stands and brackets or speak to Audio T about an appropriate match.

Toe-In and Stereo Imaging

Begin with the speakers facing forwards or angled gently towards the main listening position.

Additional toe-in may improve central image focus, while reducing the angle can create a wider and more open soundstage.

Both speakers should use the same angle and remain level and stable on their stands.

Amplifier Matching

LEAK recommends amplifiers rated between 25W and 150W per channel.

The Sandwich 150 has a sensitivity of 86.5dB, a nominal impedance of 6O and a minimum impedance of 4O.

It will therefore benefit from an amplifier with stable power delivery and good control, particularly when used in a larger room or at higher listening levels.

The LEAK Stereo 130 provides a visually matching option for modest to medium-sized rooms, while more powerful amplification may be appropriate where greater volume and dynamic headroom are required.

Single-Wire Speaker Connections

Each speaker uses one pair of terminals for a conventional single-wire connection.

Maintain correct polarity by connecting positive to positive and negative to negative at the amplifier and both speakers.

Switch the amplifier off before connecting or changing speaker cables and make sure no loose wire strands can bridge the terminals.

Walnut Real Wood Veneer

The Sandwich 150 is finished in Walnut real wood veneer with aluminium trim and a traditional fabric grille.

Natural variations in colour and grain should be expected between individual pieces of real wood veneer.

The supplied grille has been selected to complement the classic LEAK design while remaining acoustically transparent.

Clean the cabinets with a soft, dry cloth and avoid abrasive cleaners, solvents and conventional furniture polish.

Sandwich 150 or Sandwich 250?

The LEAK Sandwich 250 is a considerably larger three-way speaker using a 280mm bass driver, separate 108mm midrange unit and the same 30mm textile-dome tweeter.

The Sandwich 250 offers greater scale, sensitivity and bass extension, while the Sandwich 150 is easier to accommodate and better suited to more modest rooms.

Key Features

• Two-way passive standmount speakers
• Supplied as a matched and handed pair
• 170mm aluminium and foam-core Sandwich driver
• 30mm coated textile-dome tweeter
• Damped tweeter rear chamber
• 2.4kHz crossover frequency
• Layered MDF and composite-board cabinet
• Internal cabinet bracing
• Traditional front-to-rear brace and rear fixing
• Bass-reflex enclosure
• 44Hz–26kHz frequency response
• 38Hz bass extension at -6dB
• 86.5dB sensitivity
• 6O nominal impedance
• 4O minimum impedance
• 25W–150W recommended amplifier power
• 106dB specified peak sound pressure level
• Walnut real wood veneer
• Traditional fabric grilles
• Rubber feet included

Technical Specifications

Frequently Asked Questions