Dan Worth takes delivery of the latest offering from Russell Kaufman’s British based company Russell K in the form of the SE version of his RED 150 floorstanding speakers costing £6000 – £6500 depending on finish.

A rendezvous with Russell Kauffman is always a well constructed, well thought out event, with a strong itinerary and a clear focus – in reality, this is never how the day turns out! During an initial lunch date when Russell arrived with the new 150SEs we planned that I would have around three weeks to gather my opinions on his new floorstanding loudspeakers, however at around the two week mark it became apparent that we would have to postpone our three weeks meet-up as he was suffering from a rather sore bout of gout! Over the next few weeks, I had some good listening time with the Red 150SE  speakers, while I waited for Russell to regain his composure.

There were a few minor hiccups within my system which raised their heads during this review process until I felt the Red 150SE sounded as they should do and how I had remembered them sounding on the couple of occasions I had heard them previously. These hiccups were of a system nature (which I soon worked out) rather than being the fault of the 150SEs. Basically, I had been playing with mains cables, filters and isolation products with which the 150SEs weren’t comfortable with but over the period of an afternoon I reintroduced the system configuration that I knew was solid and worked – this soon brought about an invigorated change to the presentation and normal service was resumed.

The tricky thing is, being a reviewer, as well as a hobbyist and general tinkerer, at times our core system that we have spent so long to synergise can be in many pieces due to work being done on modifications. At other times other pieces of kit may have migrated into the system by way of personal testing or work-based reviewing. Like many others, I love to play around and understand what effect changes of components and other accessories can bring to the picture and I’m learning constantly the effects of changes through experience. I digress somewhat, suffice to say the Red 150SEs once again had their cohesive integration and smooth detailed presentation I had heard before.


I discussed the white paper for the Red 150SE with Russell and my biggest interest was the design of the cabinets, along with the differences to the standard 150 loudspeakers. They are built with three separate internal chambers, each shelf has a predetermined number of 10mm holes drilled into them to finely tune the frequency response of each chamber and to work with the crossover design.

The bottom-most chamber has at its rear an internal port which has a very particular length but had to be re-engineered many times in order to fine-tune the lower-end response to Russell’s own taste (after measuring) and to achieve the company’s house sound. The front of this lower chamber has two open ports that are of different lengths, again for fine-tuning of the bottom-most registers, but another time-intensive labour of love for Russell to keep basslines “controlled, bouncy and interesting”.

Crossover design isn’t overly complicated, although it has been executed with some refinements over the standard 150 to accommodate the brand new tweeter on the SE model. Even with these additions, the filter isn’t overpopulated with one inductor on the bottom bass driver to allow for a claimed in-room response of 21hz at -12db. So on paper at least, these diminutive floorstanders do have interesting capabilities.

Interestingly, Russell chooses his tweeters after playing them without a crossover and at full range at low volumes to listen for any nasties. This seems to work well for him and the new tweeter on the 150SEs has a less resonant front baffle and is clearly more refined and open and with better top-end extension, voicing and control over the standard model.


The Red 150SE loudspeakers are designed by ex Morel Technical Director Russell Kaufman and are a modern take on a classical looking speaker. The overall shape and size isn’t imposing at all and would be at home in any environment. This said they do look robust enough to give one reassurance that they will indeed be able to cover a wide range of frequencies. The beautifully finished walnut veneer the review samples is complimented very well with the piano black CNC’d front baffle. They have an all MDF construction and wood and metal plinth rather than the MDF plinth found on the standard 150 version. This metal plinth allows them to isolate better and they also look more elegant than the standard version.

The speaker cable terminals are quite high up the rear of the speaker, as they are directly attached to the crossovers. I personally would prefer them lower down but it’s not uncommon for terminals to sit in this position. They are also oriented so that I accidentally wired them out of phase whilst I wasn’t paying attention properly, my spades also had to be attached horizontally rather than vertically which I felt was odd…but neither here nor there I guess in the grand scheme of things.

There is a range of cabinet finishes including real wood veneers and deep lustre piano gloss finishes, which are extremely high quality and have several interlacing layers of lacquer.


One of the first most notable traits of any of Russell’s speakers is that they allow the listener to comfortably sit down and relax into a lengthy listening session with absolute ease. I’ve always had a fondness for his speaker range and have previously reviewed both the Red 50 and Red 100. Each speaker has a presence that is larger than its physical form and with a smooth and detailed personality which is never forward or hard sounding. At the same time they don’t do pipe and slippers, they are kind of like the mature friend you have during your later teenage years, he does everything you do and enjoys life but at the same time he has a more level head and knows how to reign everyone else in if things get a little too excitable – an old head on young shoulders I guess would be a good analogy.

During my first listening impressions with Chris Jones’ “Moonstruck” album, I had the opportunity to really understand how much deeper and fuller the 150SE sounded in comparison to the Red 150, with the bassline of “Long After You’re Gone” sounding incredibly deep, extended and well-controlled. Notes rolled throughout the room with an air of subwoofer-ness, with only the bottom-most octaves rolled off more substantially. Obviously, the physical constraints of this admittedly accomplished design dictate that bass needs to end somewhere, but there is a lot of information being contributed to the music by these modestly sized boxes!

The richness of the midrange, with the addition of the extra internally tuned chamber and bass driver, was another step up in performance over the standmount 100s, conveying a clearly defined link between the lower-mid and upper-bass giving the listener a more spacious presentation and a clearer and more defined vocal. The vocal delivery of the 150SEs isn’t clouded or blurred and this due to the clever design of the cabinet and well-implemented crossover. The 150SE with their separate bass driver that is designed to be out of series with the mid/bass driver allows for far greater expression of vocals and James Taylor and Chris Jones sounded more soulful, textured and full-bodied, leaving bass lines to carry along the backing track rather than influence vocal presentation.

The different crossover point of the new tweeter on the Red 150SE is a clear step up from the 150 and one of the overall design’s biggest assets. It really proves that Russell has a good ear for driver selection and minimalistic filter integration, as well as fine cabinet tuning. The result is a top-end that is engaging and tactile, but tactile at a pace that was relative rather than being inherently fast giving a speaker that is simply musical! I much prefer the 150SE over the 150 and although id say that it is a combination of its parts, the new tweeter is a revelation and has clearly defined this model as the more sought after version. The new tweeter is so refined and clearly has less distortion than its predecessor. The overall clarity and quality of the driver give incredible refinement and insight into the music, which in turn gives better symmetry to the overall presentation of the musical picture.

I listened to the whole of Bliss’ “Quiet Letters” album, which is as much an album to test soundstaging and separation as it is for me to gain an idea of the ability of a speaker to convey a wide frequency range. The Red 150SEs did show that they can stage brilliantly. Let’s face it, for £6000 you want to be surprisingly impressed now and again, but even after owning very good speakers for a long period of time, the more intricate inner detail was something I hadn’t previously heard. Smooth and musical can often be perceived as boring but over time it’s greatly appreciated for longer listening sessions and the Red 150SE allow for hours of a non-fatiguing listening, but also have the ability to give a good hour of lively music to get you going before you go out of an evening. It was a shame that I didn’t have a good strong ultra-linear valve amp here while I had my time with the 150SE because I’d imagine that they would sound fantastic together. However, my Gamut power amp along with the Audio Music valve pre sounded fantastic with the 150SEs giving a  powerful and controlled presentation that was beautiful on mids and smooth and resolute in the treble.

With these attributes in mind I felt that the Red 150SE could well be a speaker capable of handling some Dance, Pop and Rock music – no they don’t have the ultimate pace of a PMC, but their naturally controlled presentation was great for Rock music and never pinned me to the ceiling with that wonderful new tweeter staying in control and the amount of detail they conveyed worked equally well with well-recorded dance music. Pop was a joy to listen too and the vast range of music within a chart based playlist allowed me to really appreciate the abilities of the speakers allowing each its own unique character rather than a samey same approach where a speaker is so specifically voiced that every piece of music has an overall expression rather than the ability to convey its own flavour.


If your in the market for a well priced more high-end speaker that doesn’t dilly dally around trying to be one thing rather than another and allows you to either relax late at night listening to some glorious vocals or alternatively have a quick livener before an evening out then this speaker should be considered. The Red 150SE from British brand Russell K is a flexible, none-imposing and great looking loudspeaker at home in any environment.

With a huge range of standard and custom finishes, great sonic attributes and thoughtful design they deserve a place on your demo list if you are in the market for a speaker at this price-point.

Music flows tastefully from the Red 150SE, even if your selection of genre is somewhat questionable, and their ability to keep you interested in your collection for many years to come is surely an attribute that should be of interest to anyone. There are choices in our life that allow us to experience differences in products and ones that we select for quick fixes for certain characteristics even if we trade-off other characteristics, such as detail, dynamics, bass, soundstaging, speed and accuracy, but there comes a time where you simply want to forget about all this and just own a speaker that does music and does it well.

The Red 150SE isn’t a fit and forget speaker, they are a speaker which will keep impressing over time and so come highly recommended.


Build Quality: Classy and brilliantly fabricated design with a high precision finish.

Sound Quality: A good all-rounder, with great communication of music keeping the listener interested. Fantastic frequency response from a modestly sized cabinet and a very special top end.

Value For Money: Not a cheap speaker by any means, but at this price point you expect something special and the Red 150SE will keep you satisfied for years to come 

Price: £6000-£6500






Dan Worth

Manufacturers Technical Specifications: 


Dimensions  H- 950mm (1000mm including plinth, base and spikes) W-240mm D-250mm

Construction 16mm MDF all sides apart from front baffle which is 19mm.

Totally undamped cabinet

3 acoustic loading bracing shelves with multiple apertures, mounted below the tweeter, below the bass mid driver and below the sub bass driver

1 bracing shelf mounted near the bottom of the enclosure containing an internal port

Internal port vents into a small chamber containing 2 asymmetric length reflex ports tuned as a system to 21Hz

Drive units

2 x 6.5” Bass units with impregnated paper cone and curved optimised acoustic profile

High power Ferrite magnet driving a 25mm voice coil with aluminium former and Faraday distortion cancelling copper ring

25mm soft dome tweeter

Double Ferrite magnet system

Copper Clad Aluminium voice coil wire on a Fibreglass Former and Faraday distortion cancelling copper ring


All drivers connected in positive phase

Sub-bass driver starts roll-off at 80Hz 6db/Oct fed by “Enclosed Field Iron Core Inductor”. Features high power without saturation, very low DCR and almost no stray magnetic field

Bass/Mid driver crossover frequency 2200Hz nominal 12 db/Oct. Utilises an “Enclosed Field Ferrite Core Inductor “in the signal path. Very low DCR nominal stray fields

Tweeter attenuation by misaligned Zobel network as opposed to conventional L-Pad

All Drivers have only one component in the signal path

Phase optimised through the crossover region

In-room usable frequency response 20Hz-22KHz (dependent on the room)

Sensitivity: 87db 1 watt 1 Metre

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