Help & Answers
Everything you might want to know about Lowther loudspeakers, our drive units and amplifiers, building your own, and how to get in touch. Can't find your answer? Email us at hello@lowtherloudspeakers.com.
Lowther Masterpieces are our handcrafted folded-horn loudspeakers, built to order in the veneers and style that suit your home.
Horn loaded designs use carefully shaped enclosures to control how sound leaves the driver, giving higher efficiency, scale, and realism from a single full-range unit.
They are for listeners who value natural, lifelike reproduction and are willing to invest in carefully placed, handmade loudspeakers rather than mass-market systems.
Yes. Our "Build your Lowther" plans and drive units are designed for home builders who want to create their own horn loaded loudspeakers using our designs.
Lowther drive units are true full-range drivers, a design patented in the 1930s by co-founder Paul Voigt. One drive unit covers the whole frequency range using two paper cones with a mechanical crossover formed by the paper fibre itself, so no electrical crossover, separate woofer or tweeter is needed when the unit is housed in a suitable horn-loaded cabinet. The sound comes from a single hand-wound voice coil in a 1 mm gap, which is why Lowther imaging and detail are so distinctive.
Lowther products carry a 10-year warranty covering malfunctions, including both parts and labour, with the exception of Concert collection drive units, which carry a 2-year warranty. It does not cover wear and tear (such as foam surrounds, which have a natural lifespan), misuse, improper connections, transit damage from poor packaging, professional use, or lack of maintenance. Your purchase invoice is your proof of warranty, so keep it safe.
Yes, Lowther's listening room is on the 2nd floor, 1 Foundry Street, Northampton NN1 1PN, and visitors are welcome by appointment, including weekends. You can listen to music of your choice on a range of sources (turntable, CD, streaming) through Lowther valve and hybrid amplification. Please note the room is reached by a few flights of stairs and the building has no lift. Email hello@lowtherloudspeakers.com to arrange a visit.
Alnico ('A' Series) is the original Lowther magnet, its stiff magnetic field reveals the harmonic texture of voices and instruments, favoured for classical and vocal music, and it can be re-energised during renovation. Ceramic ('C' Series) is the most affordable and has a softer, more forgiving presentation that suits older or imperfect recordings. Neodymium (DX and EX ranges) is the lightest and fastest, with lightning transient response and a bold character that suits rock and jazz. Which is "best" depends on your music, amplifier, cabinet and room.
As a guide from Lowther's specification notes: the Almira and Edilia are designed for modest rooms that larger cabinets would dominate, with a more linear response for closer listening. The Acousta 117 suits rooms of about 25 square metres and up and is easy to position. The Fidelio needs about 20 square metres minimum plus space behind it, and care with positioning in square rooms. The TP2 and Audiovector are for larger rooms, roughly 25 to 30 square metres upwards; the TP2 is designed to sit close into corners. A pair of most models is on demonstration in Northampton, and an audition in person is always the best guide.
Lowther supplies two kinds of measurements. Free-air Thiele-Small parameters and SPL and impulse graphs are attached to each drive unit's product page; these are laboratory tests used to judge cabinet suitability. Room response graphs are measured in Lowther's 5 x 4 m demonstration room with REW software, with each pair positioned identically and a calibrated microphone at the listening position; they give a visual comparison of how each cabinet behaves in a real room, often shown as two views of the same data plus a spectrogram. Every new pair also ships with left and right impedance graphs. The graphs help you shortlist and compare, but they are not a substitute for an audition.
Standard veneers are Light Oak and American Walnut. Premium and bespoke matched veneer sets, such as Rosewood, Olive, Australian Gum Walnut, Zebrano and Ebony, are available as a custom order quoted separately, and Lowther is happy to source a veneer or colour of your choice if it can be obtained.
Lowther is a British manufacturer of high-end, handcrafted full-range loudspeaker drive units, horn-loaded and full-range loudspeakers, valve amplifiers (such as the PX4) and related accessories. Founded in 1934, Lowther designs and builds full-range, crossover-free drivers and the cabinets that horn-load them, and also supplies plans and drive units to DIY home builders. Everything is made to order in Britain.
Lowther traces its loudspeaker heritage to the pioneering acoustic engineer Paul Voigt, who developed the Domestic Corner Horn in 1934 and met O.P. Lowther of the Lowther Manufacturing Company Ltd that same year. Voigt's full-range, horn-loaded designs became the foundation of the Lowther sound. The company later flourished under Donald Chave, who championed and developed the Lowther full-range drive units through the mid-20th century.
Donald Chave was the driving force behind Lowther for much of the 20th century, developing and promoting Lowther's full-range drive units and horn loudspeakers after the pioneering work of Paul Voigt. The "Donald Chave era" is central to Lowther's identity as a full-range, horn-loading loudspeaker company.
The brand operates as Lowther Loudspeakers and has historic links to the Lowther Manufacturing Company Ltd founded by O.P. Lowther. For the exact current registered company name and number, please contact Lowther directly at hello@lowtherloudspeakers.com.
Today Lowther makes full-range drive units (the Concert, Sinfonia, Philharmonic and Grand Opera collections, including Alnico, ceramic, neodymium and field-coil variants), complete handcrafted loudspeakers, the PX4 valve amplifier, phase plugs, cables and accessories. Lowther also publishes cabinet plans and supplies drive units for DIY builders, and offers refurbishment and upgrade services for older units.
A Lowther DIY project centres on a matched pair of Lowther full-range drive units together with the official Lowther cabinet plans for the design you choose. The plans give the full cut sheet, internal geometry and assembly guidance; you source the cabinet material (we recommend high-grade MDF or Baltic birch plywood) and build the enclosure yourself. Recommended drive units for each cabinet can be added directly to your cart once you are signed in.
Yes. Lowther provides official cabinet plans for classic designs including the Acousta 90, Acousta 115/116, Acousta 124, Bicor 200, Accolade 2, Accolade 4 and the Academy. Create a free account on the Build Your Own Lowther page and you can download the PDF plans at no cost, along with recommended drive units for each cabinet.
Each plan lists a recommended and a standard drive unit. As a guide: the Acousta 90 and Bicor 200 suit a single pair of DX3 Concert (or EX3 Concert sealed) units; the Acousta 115/116 pairs well with the PM6A Sinfonia; the Acousta 124 and Academy use four PM7A Sinfonia or DX3/EX3 Concert units. Full-range Lowther drivers are single-driver, crossover-free designs, so the cabinet is matched to the driver rather than the other way around. If you are unsure, our team will help you choose the right units for your amplifier.
Builds range from Beginner (Acousta 90) through Intermediate (Acousta 115/116, 124, Bicor 200, Accolade 2 and 4) to Advanced (Academy). You will need standard woodworking tools, a table saw or track saw for accurate angled cuts, clamps, wood glue for airtight joints, and finishing equipment for veneering or painting. Sealing the cabinet correctly is the single most important step for good sound.
Choose a cabinet design that matches your chosen Lowther drive unit, download the official plans, cut the panels accurately (paying attention to the angled joints), assemble with airtight glued joints, seal the enclosure, then mount the drive unit and finish the cabinet with veneer or a pigmented lacquer. Because Lowther drivers are full-range, there is no crossover to build, the enclosure does the acoustic work.
The Academy is an advanced Lowther cabinet design first released in the 1990s. It uses two drive units, with the second mounted in the upper section so sound radiates upward and outward for an unusually large sense of scale. Because of its labyrinth and size it is rated an advanced build, and plans are available to download.
Ja. Lowther stellt offizielle Gehäusepläne für klassische Designs wie Acousta 90, Acousta 115/116, Acousta 124, Bicor 200, Accolade 2, Accolade 4 und die Academy bereit. Erstellen Sie auf der Seite „Build Your Own Lowther“ ein kostenloses Konto, dann können Sie die PDF-Pläne kostenlos herunterladen, zusammen mit den empfohlenen Chassis (Drive Units) für jedes Gehäuse. Für die Acousta gab es historisch mehrere Gehäusevarianten; die aktuellen Pläne decken die empfohlenen Ausführungen ab.
Jeder Plan nennt ein empfohlenes und ein Standard-Chassis. Als Orientierung: Acousta 90 und Bicor 200 nutzen ein Paar DX3 Concert (oder EX3 Concert geschlossen); die Acousta 115/116 harmoniert mit dem PM6A Sinfonia; Acousta 124 und Academy verwenden vier PM7A Sinfonia oder DX3/EX3 Concert. Lowther-Chassis sind Breitbänder ohne Frequenzweiche, daher wird das Gehäuse auf das Chassis abgestimmt. Unser Team hilft Ihnen gern bei der Auswahl passend zu Ihrem Verstärker.
An open baffle needs the diaphragm exposed in free air with nothing behind it. The DX range works well, and builders most often choose the Alnico PM2A or PM5A, whose diaphragms move slightly more; the PM6A and PM7A should also work, while the PM4A is probably too large and powerful. The EX range is unsuitable, its rear compression chamber is precisely what an open baffle must not have.
EX drive units carry a built-in compression chamber that acts as a tuned rear baffle, stopping most of the mid-range entering the bass horn. They are designed for home-built or third-party horn cabinets that have no rear baffle of their own, the unit fires directly into the horn. Lowther factory cabinets already include a rear baffle, so they use standard units. Note: pre-1980 Acousta designs need a spacer for the EX module's extra depth, and EX units do not fit the Acousta 115.
Lowther factory cabinets use no stuffing or cladding, properly built, they do not require damping. The same applies to a self-build if the joints are completely airtight, though adding damping does no harm; it is a personal choice. Lowther's plans specify MDF.
Aim for a total cabinet impedance that suits your amplifier, usually 8 or 15 ohms. Two 8 ohm units in series give 16 ohms; in parallel, 4 ohms. Two 15 ohm units in parallel give 7.5 ohms, effectively 8, which is why 15 ohm drivers are the usual choice for two-driver cabinets. Never present an amplifier's 15 ohm output with an 8 ohm load.
No, the pre-machined Acousta kit has been discontinued. The official cabinet plans remain free to download with an account on the Build a Lowther page, and the original assembly instructions are still available to help anyone building from plans or completing an old kit. If you would rather not build, Lowther still makes finished Acousta cabinets to order.
Keep the cabinet true: square, straight and airtight. Glue small groups of interior components working from the inside out, and dry-assemble the whole cabinet around each glued group to check squareness before the glue sets, because a tiny interior error will throw out the finished cabinet. Use an expanding polyurethane gel adhesive for the interior trenches to guarantee airtight joints and quality PVA elsewhere. Avoid screws in the outside panels, never force parts, and fill cosmetic gaps with decorator's caulk rather than silicone. Fit and wire the drive units before finally fixing the back.
They share the same core front-facing folded horn design and similar dimensions. The 115 dates from 1962 and was Jimi Hendrix's speaker of choice; the 116 adds small build improvements; the 117 is the current factory version with Baltic birch plywood throughout, thicker 18 mm outer panels, modern adhesives and finishes, removable cloth grilles and upgraded binding posts. Plans for the 115/116 are downloadable for self-builders, and the 117 is available built to order. Recommended drive units are the PM6A, PM7A or DX3; all units fit except the PM2A and PM4A, whose magnets are too deep.
No. The Almira and Edilia are handmade numbered limited pairs, and no drawings or advanced specifications are released because the whole design is considered optimum as built, including its laminated internal curves. For self-builders, Lowther offers free plans for the Acousta 90, Acousta 115/116, Acousta 124, Bicor 200, Accolade 2 and 4, and the Academy.
The Lowther PX4 is a handcrafted British Class-A valve (tube) amplifier built around the classic PX4 output triode. It delivers 10 W + 10 W into 6 Ω, uses automatic cathode bias, and can be run as either push-pull or single-ended. It is designed as a high-end partner for Lowther full-range and horn-loaded loudspeakers.
The Lowther PX4 can operate in both modes. Single-ended (SET) operation is prized for its purity and the directness of a single amplifying device, and it pairs naturally with high-efficiency Lowther drivers. Push-pull operation cancels even-order distortion and delivers more usable power and tighter bass control. By offering both, the PX4 lets the listener choose between the intimate directness of single-ended and the greater grip and headroom of push-pull, rather than being locked into one topology.
The PX4 produces 10 W + 10 W into 6 Ω. Because Lowther loudspeakers are high-efficiency (typically around 96–99 dB), this modest but pure valve output is more than enough to drive them to realistic levels. Its frequency response is 10 Hz – 45 kHz (-3 dB) with a 93 dB signal-to-noise ratio.
The PX4 is designed and handcrafted by Lowther, a British manufacturer with over 90 years of audio heritage. It is a high-end, made-to-order valve amplifier, using four PX4 output valves with 6SN7, 6J5 and 5U4G/5AR4 support valves, automatic cathode bias, and user-adjustable feedback from 0 dB to 10 dB.
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“).
Lowther can refurbish and upgrade its full-range drive units and loudspeakers. Typical work includes re-coning and re-gapping drive units, replacing or upgrading diaphragms and voice coils, refreshing magnets and metalwork, and upgrading older units to a current specification (for example moving from an older Concert unit to a Sinfonia or Philharmonic diaphragm). Cabinets can also be assessed and restored.
Yes. Because Lowther drive units are hand-built, they can be serviced by the people who make them. Re-coning (fitting a new diaphragm) and re-gapping (resetting the voice coil in the magnetic gap) are standard refurbishment operations that can return a decades-old driver to full performance, and often allow an upgrade to a newer diaphragm at the same time.
Yes, this is normal and expected. Lowther full-range drivers have a genuine break-in (settling-in) period during which the diaphragm suspension relaxes and the frequency response smooths out. This is more rapid with the Sinfonia and Philharmonic diaphragms, while Concert diaphragms typically take a few weeks of playing to stabilise, and many owners report continued subtle improvement well beyond 1,000 hours. It is a characteristic of the design, not a fault.
Turnaround depends on the work required and current workshop demand, and because every unit is assessed and hand-serviced it is quoted per job. Submit the refurbishment or upgrade enquiry form on this page with your drive unit type, serial number and year of purchase, and the Lowther team will confirm the scope, cost and expected timescale.
Use the refurbishment or upgrade request form on this page, or email hello@lowtherloudspeakers.com with your drive unit model, serial number and the year you purchased them. The team will advise what can be done and provide a quotation.
Renovation is a complete refurbishment: the unit is stripped down and only the magnet (and possibly the frame) is kept. Everything else is replaced new, including cones with Lowther's improved coating, the modern cones are much paler than the historic Lowther yellow, though the traditional colour can be requested when ordering. Alnico magnets are re-energised if needed, and every unit is rebuilt, tested and oscillated before return. Fixing holes are unchanged, so renovated units fit your existing cabinets unless they are recessed.
Foams have a limited life: a minimum of around 10 years in a humid climate and far longer in temperate conditions, some have lasted 30 years. Store unused units somewhere warm. Lowther has tested alternative materials, but all proved detrimental to the Lowther sound, so the foam composition has instead been refined to extend its life. Foam sets can be supplied for a local service engineer to fit, though re-foaming demands precision, the voice coil gap is only 1 mm.
Fitting the diaphragm to the magnet is easy (four screws), but centring it correctly requires experience and an oscillator, even a speck of dust in the 1 mm gap affects performance, and damage caused during fitting invalidates the warranty. Never touch the paper cone, as this can distort the voice coil. If your drivers are very old, quote your serial number first: the diaphragm design was improved some years ago and old-style diaphragms are no longer available, so Lowther will check compatibility with your steelwork.
Yes, but the renovation should include the modern frame. Pre-1970 square frames were built to the old BSI standard; modern cones sit slightly deeper, and on the old frame they can knock and distort when driven hard. The fixing holes are unchanged, so the new frame fits existing cabinets unless the cabinet was recessed for the square frame. Old plastic frames, discontinued years ago, are not compatible with modern ironwork and must be replaced with the aluminium frame.
Aluminium gives more attack, is extremely truthful and excels in the highs, the usual choice for classical music. Silver is more mellow, with better bass and mid-range, often preferred for jazz, blues and easy listening. Copper is available on request but not generally recommended, being less lively. If you need 15 ohm units, silver is recommended for durability: thin aluminium wire can eventually fatigue where the coil runs down the cone, while softer silver flexes without failing.
Expect significant improvement after about 50 hours of use, then gradual gains for up to a further 500 hours. The paper coating crystallises, the cones soften and the suspensions loosen with use, all increasing movement and improving the sound.
The correct email address for Lowther Loudspeakers is hello@lowtherloudspeakers.com. This is the canonical contact address for all general, sales and support enquiries, please use it rather than any older "info@" style address.
You can contact Lowther by email at hello@lowtherloudspeakers.com, by phone on +44 20 8300 9166, or by using the contact form on this page. General enquiries are usually answered within 24 hours.
Lowther loudspeakers, drive units and amplifiers are handcrafted to order, so pricing depends on the model, finish and drive-unit options you choose. Indicative "from" prices are shown on individual product pages, and drive-unit prices are listed on the shop. For a full quotation, email hello@lowtherloudspeakers.com with the model and options you are interested in, or request a quote through the site.
Email hello@lowtherloudspeakers.com or use the enquiry form, telling us the loudspeaker or drive unit, your preferred finish and your location. Because each Lowther is made to order, we will confirm the exact price, options and lead time for your specification.
Lowthers were designed around low-wattage valve amplification, at 96–99 dB sensitivity, a good 10–20 W valve amplifier is ideal. That said, Lowther's own showroom also runs a 150 W-per-channel hybrid amplifier with excellent results, and an integrated amplifier needs no separate preamp. For advice on a specific pairing, email hello@lowtherloudspeakers.com with your amplifier, cabinet and room details.
Lowther does not deal in second-hand cabinets, though trade-ins are occasionally accepted against new cabinets for use as demonstration pairs. Lowther can put sellers in touch with a local second-hand dealer, send photographs and your asking price. For ageing drive units, renovation is usually the better route: a renovated unit is effectively new apart from the magnet.
Send them to Lowther Loudspeaker Systems Limited, Hill House, Stoke Road, Boughton, Near Stoke Ferry, Kings Lynn, Norfolk PE33 9AL, UK. Mark the package "British Units, returned for repair, No Commercial Value" with your order number; if your courier insists on a value, declare £20 per unit (nominal, for customs purposes only) to avoid duties that would have to be recharged. Pack carefully, transit damage from poor packaging is not covered by warranty.
