Explore our collection of phase plugs, each tailored for distinct listening improvements.
A phase plug is a fixed, shaped component at the centre of a loudspeaker drive unit that controls how sound waves leave the cone, reducing internal reflections and phase cancellation for a smoother, more coherent high-frequency response. Lowther was a pioneer of the phase plug in full-range drivers and makes three interchangeable designs - the Standard Dome, the Phase Equaliser ("Pepper Pot") and the Sound Diffuser ("Door Knob") - so the top-end character can be tailored to your system.
Explore our collection of phase plugs, each tailored for distinct listening improvements. While every drive unit comes with a selected phase plug as standard, we recognise the desire for personalisation in audio setups. Our range of phase plugs, available both in individual pairs and as a complete set, allows for customisation to suit your unique listening preference.
The Dome is the core of Lowther's sound excellence. It's expertly crafted to manage sound waves from the heart of the speaker driver, enhancing sound dispersion and reducing internal reflections. This phase plug ensures a smoother high-frequency response, crucial for clear and refined audio output.
Lovingly referred to as "the Pepper Pot", this is our innovative approach to superior sound quality. Our Phase Equaliser not only enhances traditional phase plug capabilities but also acts as an effective diffuser. It's engineered to guide sound waves optimally, significantly improving high-frequency and mid-range responses. The result? A sound that's cleaner, clearer, and impeccably balanced.
We call it "the Door Knob" and its very familiar shape works well in our larger drive units. The Sound Diffuser provides a more even and natural sound experience. It's designed to minimise resonances and ensure a harmonious listening experience.
Tailor your Lowther experience with precision-engineered phase plugs
£60* per pair*
£110* per pair*
£240* per pair*
£350* for all 3 Pairs*
Frequently asked
A phase plug is a fixed, shaped component mounted at the centre of a loudspeaker drive unit, in front of the voice coil and pole piece. It fills the space in the middle of the cone and controls the path the sound waves take as they leave the driver. By equalising the distance sound travels from different parts of the diaphragm, a phase plug reduces internal reflections and phase cancellations, giving a smoother, more coherent high-frequency response. Lowther was one of the pioneers of the phase plug in full-range drive units.
Yes. In a full-range driver a phase plug improves high-frequency dispersion and smooths the top end by preventing the path-length differences that cause phase cancellation at the centre of the cone. The audible result is cleaner treble, better clarity and a more even response. Because the effect depends on the shape, Lowther offers three interchangeable phase plugs, the Standard Dome, the Phase Equaliser (the "Pepper Pot") and the Sound Diffuser (the "Door Knob"), so you can tune the presentation to your taste and driver.
Lowther makes three phase plugs. The Standard Dome is the core design fitted as standard and gives a smooth, refined high-frequency response. The Phase Equaliser ("Pepper Pot") also acts as a diffuser for improved high- and mid-range response. The Sound Diffuser ("Door Knob") suits the larger drive units and gives an even, natural presentation. All are available individually per pair or as a complete set.
Yes. Lowther phase plugs are interchangeable across the full-range drive units, so you can fit a replacement or an alternative phase plug to a PM4A (and other Lowther models). Each drive unit ships with a selected phase plug as standard, and you can order the Standard Dome, Phase Equaliser or Sound Diffuser separately as a pair, or the complete set, to replace or experiment with the top-end character.
The Standard Dome is the default and best all-round choice. Choose the Phase Equaliser ("Pepper Pot") if you want additional diffusion and an airier high/mid response, or the Sound Diffuser ("Door Knob") for larger drive units where a very even, natural balance is preferred. Many owners buy the complete set to compare all three in their own system.
Ein Phase Plug ist ein feststehendes, geformtes Bauteil in der Mitte eines Lautsprecherchassis, direkt vor der Schwingspule und dem Polkern. Er steuert die Laufwege der Schallwellen, reduziert innere Reflexionen und Phasenauslöschungen und sorgt so für einen glatteren, kohärenteren Hochtonverlauf. Lowther gehörte zu den Pionieren des Phase Plugs bei Breitband-Chassis und bietet drei austauschbare Varianten an: Standard Dome, Phase Equaliser („Pepper Pot“) und Sound Diffuser („Door Knob“).
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