In 2016 the original Little British Monitor project launched on KickStarter to great success - Over 300% funded and awarded 'Project We Love' status.
Little British Monitor - MK2
Today, the LBM returns a more mature, refined product boasting better performance than ever before!
What is 'LBM'?
The Little British Monitor is a hand-built, desktop sized, aptX Bluetooth enabled, fully active, monitor-speaker with transmission-line bass loading. What a mouthful! The design goal was rather more simple - build the best loudspeaker possible in a small size of just 12cm x 12cm x 20cm (2.8L).
Equally suited to the quality conscious recording engineer, musician or music lover. The LBM is small enough to be used in almost any location, yet capable enough fill the space with clean dynamic sound.
Campaign Update - New Feature!
While this campaign has been running, I've been working behind the scenes on adding a new function. The LBM MKII will now feature a variable 'boundary adjustment' dial. This allows the balance of the speaker to be adjusted for placing it near a boundary such as a wall or large desk, or to use them in a more open environment. Placement can make a huge difference when it comes to loudspeaker sound and this feature should allow more flexibility.
Why is LBM special?
The LBM is an audio engineering tour-de-force with sound quality its primary goal. Most desktop sized loudspeakers use thin particle board or plastic cabinets, budget drivers with single component crossover circuits and class-D amplifiers. The LBM is elevated above these products by the detail of its acoustic and electronic design.
Topping it off, a matching desktop stand has been designed that features constrained-layer damping to isolate and dissipate vibration in the LBM structure.
A Twist - DIY or Buy
As well as a fully complete and luxuriously finished product, the LBM is available in the form of a build-it-yourself DIY kit that provides the user with a highly rewarding experience and a final result to be cherished. The build-it-yourself kit is an ideal gift for any hands-on person or as a project to complete with a friend (or by yourself).
> Download the build guide < (54MB)
The details of design and construction set the LBM apart from other desktop sized loudspeakers. Let's get stuck in and find out which areas received special attention, and why they matter.
Micro Transmission Line - New to the upgraded LBM is a bass porting technique called a 'transmission line', capable of more extended and tighter bass than standard port tubes. Usually only found in select large and expensive speakers, this carefully specified path inside the cabinet provides more efficient coupling between the woofer and the air. Placement of acoustic material inside the transmission line helps maintain ideal control over the woofers motion.
Transmission lines are notoriously difficult to design well. When the original LBM was conceived, I had simply deemed it impossible to engineer a transmission line so tiny. Yet, after much trial and error adjusting geometry, damping and drive electronics, I am proud to say the result is rather impressive. This probably makes the LBM MKII the smallest loudspeaker available with a transmission line!
Little Feet – Custom designed vibration damping and isolating stands named ‘Little Feet’ are available to match the LBM. If a speaker is placed directly on a desk or shelf, energy will travel into that surface and make unwanted noise. The Little Feet help stop this happening to get the best from the LBM wherever you place them.
The support plate uses 'Constrained Layer Damping' - two steel layers laminated using a specific acrylic adhesive. This composite rapidly dissipates structural energy as heat, acting as a sink for unwanted vibration. The plate is de-coupled from the stand body with neoprene, creating a filter where energy above the tuning frequency will not easily pass. A lot of care has gone into creating Little Feet as the perfect accessory for the LBM.
Note: The Little Feet are an optional accessory and not included with the LBM.
Cabinet Resonance – To ensure the listener hears only the sound of the drivers, a loudspeaker box should not resonate or vibrate. The BBC research department studied many materials and concluded that Birch plywood dissipates structural borne energy faster than any other. British loudspeakers following the BBC tradition have been recognised across the world for their clean and natural sound.
The LBM is therefore built from 9mm Birch plywood, cut on CNC machinery and assembled with traditional joinery techniques. The internal baffles of the transmission line further strengthen the enclosure. The outside is veneered with real Walnut or Oak and finished with a clear satin lacquer.
Driver Distortion - Good drive units are where quality sound begins. Music should be reproduced without adding any noises that detract from what we want to hear. The tweeter and woofer in the LBM were chosen for their superb performance after testing many potential candidates.
The Tweeter has low distortion comparable with the best high end units, yet is able to reproduce more of the music range than most. Thanks to this the LBM remains clean and dynamic even when the woofer is working hard. It can also be used close-up, ideal for smaller spaces.
The 3" woofer in the LBM can move twice as much air as many similar size drivers thanks to it's 'long throw' capability. Combined with a powerful magnet system and supported by the carefully designed transmission line, the LBM punches fast and tight with a minimum of distortion.
Class A/B Amplifiers - Practically every current compact speaker uses class-D digital amplifiers. These are power efficient, but not designed with ultimate sound quality in mind. Testing a number of affordable class-D amplifiers revealed excessive distortion through the mid-band that would negate the use of high quality drivers.
The LBM deserves better. Class-AB analogue amplification has been used in top of the range equipment for years and now also finds its place in the LBM. Class-AB amplifiers require a bigger heatsink and power supply, but reward the user with significantly better sound.
Fully Active Design - Good drivers and amplifiers mean nothing if they are not working together as a cohesive whole - this is the role of a crossover circuit. The LBM crossover is fully active; the same kind of signal-level crossover used in professional studio and concert loudspeakers.
Do not be confused by the difference between powered and active speakers. A powered speaker has a basic crossover that is connected after a single built-in amplifier. This crossover creates distortion and also prohibits the amplifier tightly controlling the drivers.
A true active loudspeaker has an advanced crossover that separates the frequency range adding minimal distortion before it is amplified. Each driver receives its own dedicated amplifier in precise control of the driver. This is a huge advantage, resulting in the LBM playing louder and cleaner than more basic systems.
The LBM is not just a tiny, fully active speaker - it also incorporates aptX bluetooth reception to enable wireless streaming of music from almost any device nearby. aptX is a feature that streams lossless quality from supporting sources.
One of the challenges integrating wireless devices in high quality audio equipment is electrical noise. It is very difficult to keep sharp power pulses drawn by the the processor and transmitter out of the audio signal. This has been addressed in the LBM MKII by use of a regulated virtual ground circuit, which provides significant isolation between the bluetooth processor and critical audio circuitry, resulting in an improved noise-floor.
Steel and Connections
New to the LBM MKII is a stainless steel rear panel with professionally printed labels. This brings a neat and stylish appearance, though good looks are not the only purpose. Stainless steel is exceptionally stiff, giving less unwanted vibration. Users felt the original LBM ran warm (due to the 4x class A/B amps), so with the entire panel now made of metal the running temperature is significantly reduced.
As well as an upgraded internal bluetooth receiver, inputs now include high quality RCA sockets allowing connection of the best external sources. A 3.5mm jack aux input makes connection of portable devices and streamers easy. Finally, a volume controlled subwoofer output has been added, which is actively buffered. All inputs are selected from a pleasingly tactile analog rotary control.
Oh, and the volume control has been moved to the top of the panel for easier access.
The LBM is accurate and true; a straight edge by which decisions in audio production can be reliably made. Many speakers have exaggerated bass and treble to sound more impressive than they really are, but the LBM does not need to pretend. Recordings are reproduced the way they should be.
The DIY Kit
The kit will come as the following components:
- Back panel with tested main PCB and heatsink installed
- Connectors, wires, switches and knobs
- Front panel with tweeter installed
- Cabinet body as flat-pack panels
- Transmission line panels
- Power supply
- Miscellaneous parts
The cabinet body will be shipped as a flat panel cut from Birch plywood. V-grooves are cut across the panel that allow it to fold in the shape of a box. The DIY LBM will be provided with original Birch finish, so the builder can decorate their creation and make it their own.
A full construction guide can be downloaded >HERE< (54MB)
(Improvements to the DIY Kit are already planned, the instructions will be updated before shipping)
What's happened since 2016?
After shipping the final rewards for the LBM MK1 project, my life and business have undergone many positive changes. Thank you KickStarter backers! My wife and I were able to make a deposit on our first home, with an ideal location to build a dedicated workshop, as well as a great spot for paint spraying and home office. I have gradually been building and equipping the workshop with all facilities needed for efficient high quality production. Amidst these developments, I have continually worked on improving the original LBM design.
The main requirement to create upgraded LBM is production of a new set of assembled PCBs, power supplies and rear panels. This will accommodate new connections, improved bluetooth and generally make production more streamlined. KickStarter is also simply a great platform to unveil the new and upgraded LBM which I am very proud to show.
Click here to view >Prototyping Gallery<
As detailed above, I am equipped with all the facilities needed to produce the LBM cabinetry in-house and assemble the production versions.
PCBs will be fabricated by a company in China, which I have chosen because they offer machine 'pick and place' assembly of the boards for greater accuracy than hand soldering (still common for small runs), as well as automated optical inspection 'AOI' of the finished circuit.
Metal panels will be cut by a local company with whom I have a face-to-face relationship. Label printing is handled by a UK company I have used before. These companies produced the samples shown in the photos.
I'm happy to hear from retailers interested in selling the LBM. I would suggest working on a commission basis, holding a set for demonstration purpose, while shipping direct from my location, as the LBM are small and easy to ship internationally. However, discussion on this point is welcome. Please expect to be vetted before any agreement is made, you should have an established business.
Risks and challenges
In 2016 I completed a successful KickStarter project for the original LBM and have since gained much experience in fulfilling a project such as this. I own all equipment and facilities required to create the final production LBM cabinetry and handle assembly. Risks are therefore very low.
Issues I faced during the original project were mainly:
1) The PCBs were hand assembled by the supplier and they did a poor job, which wasted a lot of my time to correct and lost about 20% of circuits.
I have since learned more about PCB production and made contact with a new fabricator that offers superior assembly facilities and machine automated inspection of the final product.
2) I required more space and facilities to produce the rewards efficiently.
I have invested heavily in a new workshop and equipment to become more productive and improve quality.
3) I needed to devote a lot of time to assist people with DIY kit troubleshooting. The complexity of wiring and assembly was too great for many beginners.
This time the electronics skill requirement is significantly eased, by providing the main PCB pre-assembled on the back panel and using PCBs, ribbon cables and plug-in wiring to make easy connections.
A final risk is that I am just one guy. If I fall sick or am unable to work then production will be delayed. On the other hand, this is also why the LBM are a unique hand-made item direct from the hands of the designer himself.Learn about accountability on Kickstarter
- (27 days)