The RMB 40/4 Loudspeakers (£3000) are a distinctive and interesting design, Dave Robson takes a listen.

These striking and unconventional looking RMB speakers are born and raised in Ilkley, North Yorkshire. They are the creations of Richard Best, a man who has Mechanical Engineering in his blood, but who has been busy planning, designing and testing his speaker line for some time. Richard hand delivered the 40/4 speakers personally. He was compelled to tell me about his speakers and that they were an early pre-production model, and that there are some small changes to things like the felt diffuser ring on the bass driver phase plugs and speaker grill fixings will be much improved on production models. Although everything else sound-wise will be identical. Richard also gave me a “user pack” which comprehensively tells one about how to set up the speakers and to glean the very best of their performance. Richard also supplied the speaker cables, DNM Solid Core Resolution, which he told me where paramount to reproducing the best sound from the speakers and had been used in the development of the 40/4.

CONSTRUCTION

These RMB 40/4 speakers are constructed from 18mm high-density birch plywood, there is heavy and complex bracing internally holding the cabinets together. Listening tests in the early research and development stages found the plywood sourced from Europe outperformed material from elsewhere around the globe. Such is the lengths Richard went to in an effort to perfect the sound of his speakers. There is also felt wadding internally in critical areas for added damping.

The speakers are a 3-way design, each speaker consists of two aluminium and magnesium bass drive units measuring 170mm. These both have 39mm Voice Coils. The mid-range and high frequencies are handled by a 54mm hand treated mid-range dome and a 26mm fabric dome tweeter. The tweeter has had some in-house modifications to lift performance and operates above 6.5khz. The speakers have an enclosure at the top which houses both the Tweeter and the Mid-range drivers. This keeps the top and bottom sections of the speaker separate. At the rear of this enclosure, the back is made from 3mm thick alu / plastic / alu sandwich material commonly used in the sign making industry.  It is stiff, lightweight, with a durable finish and is able to withstand extremes of exterior temperature and sunlight and this is screwed into the wood with standard cross-head screws.

The cabinet has two bass ports located at the rear, on the lower half of the speaker and situated towards the floor. Efficiency is measured at 89db and amplification above 40 watts per channel is recommended.

Speaker wires are connected to the rear by terminal sockets by decent quality gold – plated brass, of a design which has minimal metal mass. The removal of the wire links would enable the speakers to be bi-wired, although according to their designer brings no sonic benefit.

The supplied finish of my pair of speakers is classed as “Natural” and there are three other standard finishes or “Tints” are available; “Whiskey”, “Chestnut” and “Black Ink” and all are available as a no-cost option and topped off with a clear lacquer, Richard will also look into bespoke finishes as requested. Each speaker has two grills one covering the top enclosure and one covering the lower two bass drivers. As mentioned above there will be some modifications to the magnetic fixings as the glue on this early sample has corroded the metal, this will not be a problem with the standard production models. It is recommended that listening should be carried out with the grills off. This then has the magnets on show, I would prefer not to be able to see these magnets, and would look to design them to be invisible or have the magnets incorporated into the grill somehow, as I think it detracts from the handsome looks of the RMB 40/4.

Standard m6 Spikes are supplied and fitted via screw in sockets on the foot outriggers.

Size H/W/D 121cm, 25cm and 38cm respectively, and weigh in at 22.5kg each.

SOUND QUALITY

Thankfully my pair of speakers are ready run in and I could get to grips with listening tests virtually from the off, I gave them a couple of days to acclimatise in my listening room playing several albums from my little “regular” collection, thus allowing me to bond with their sound characteristics.

I followed Richard Best’s instruction manual as to positioning as much as my room would allow. Toe-In is recommended and having the tweeters aimed either side of my head I set about putting in my first few CD’s.

I was quite worried as my smallish listening space doesn’t react well to big drivers and rear bass ports. I’ve come quite accustomed to performing juggling acts with foam boards and bass traps to accommodate different speakers though! How surprised was I when the first few CD’s where played, no bloom, no buzz, no bloating or any other signs of problems in the bass department. Quite a lot of my collection consists of Blues, Rock and Acoustic style guitar music and playing Robert Cray (Sweet Potato Pie) and Peter Greens Splinter Group (Destiny Road), Fleetwood Mac (Rumours), Derrin Nauendorff (Natural) and Steely Dan (Gaucho) brought about nothing but tuneful and syrup like bass riffs that where easily followed and led the way forward to heightened enjoyment of what was to come from the rest of the albums.

As all good speakers should, the RMB speakers managed to disappear from the audio party in front of me. Soundstage was perfectly formed, the vocals sitting central in the music and the rest of the instruments and sound spread out in isolation and coming from exactly where I was expecting them to be. The detail of the Harmonica conveyed in the instrument solo during “You’ll Be Sorry Someday” (Peter Green), has you sitting in a smokey old jazz club, the accuracy of ambiance transferred from the speakers to your ears is quite strikingly real. All that was missing was the smell of damp-course failure, stale beer and cigarette smoke (or vape odour as it is now). The mid-range was also just as detailed, with the ability to create that “in the room” presence and realism of vocals, with backing singers clearly ensconced either to the left or right in the background and this was delivered somewhat effortlessly from the 40/4. This sound was growing on me immensely. Needing to change CD’s to move the review onward became difficult, as I just wanted to hear track after track of my favourite albums. High frequencies are handled with the same ease, even when the volume is pushed nothing becomes grating, it just comes out the speakers at a higher volume as perfect as it does at lower levels. There is a level of delicacy here that is quite pure and clean. Don’t get me wrong, these babies can rock when asked to. At lower levels, the sound has a very clean and polished sheen that makes listening at this and any level a complete pleasure. Even some recordings that are less than perfect seem to be cosseted by the RMB 40/4, and thus made to sound listenable. The albums you have become used to flicking past can get an airing and the abilities of these speakers make the experience once again enjoyable. I’m thinking that these speakers are not too system dependent either, their easy-going sound doesn’t seem phased by any genre of music I tried with them. Rock, Jazz, Vocal, Acoustic, Soul, R&B and Big Band the RMBs just lapped them all up. Nothing seemed to phase these speakers at all. I can’t really find a negative to say, if I had to put a single stamp on their sound I would struggle, I’d be picky to say they err on the side of warmth, but that’s about it!

CONCLUSION

I like these speakers, no I actually love them. From their design to their effortless sound, the RMB 40/4 fulfill every need I have for music. The long listening tests and constant development have paid dividends. A few niggles to iron out in the design as mentioned above, but that takes nothing away from the sound these speakers make.

AT A GLANCE 

Build Quality:

Solid build and nicely finished, Richard has already stated the retail speakers would have a few improvements. Speaker grills, speaker grill attachments, and spiked outriggers could be improved on a little further. I would also look at custom finishes as the design and shape could offer may options.

Sound Quality:

Effortless, smooth and delicate delivery but can still throw a Rock party if needed.

Value For Money:

Sonically superb for the price. You need to add on the price for the recommended DNM speaker cables.

Pros:

Fantastic sounds, fantastic looks, and design. Easily integrated into many rooms and systems.

Cons:

Shape and design may not be to everyone’s taste. Grills and their coupling method would be better concealed, and the sheer see-through grill cloth could be somehow bettered. The Spiked feet could also do with a little improvement to make leveling them easier and look a little more upmarket.

Price £3000 

David Robson

Review Equipment:

Oppo 205 UHD (used as CD transport). Mytek Brooklyn DAC/Pre (Fitted with Sbooster Linear Power Supply). Nord Ncore NC500 Power Amplifier. Chord Shawline digital coax RCA’s. Gekko Silver Lining XLR’s.