The Intimate Audio DS-108 back loaded horn loudspeaker is UK built and uses the four-inch Fostex FE108EZ driver. Ian Ringstead puts these £1595 standmounters through their paces for Hifi Pig. 

Horn speakers have been around a long time and as I said in my recent review of the Ferguson Hill FH-007 they are unique in their sound presentation, but require careful and skillful design.

Duncan Saul, whose idea these speakers are, was encouraged by friends to pursue this design as they felt he really had something special and unique with his idea. I talked at length to Duncan and discovered his musical tastes are very similar to mine with a passion for 70’s prog rock such as Genesis, Yes, Wishbone Ash etc. Now horn design speakers aren’t what some music enthusiasts would choose for rock music, but Duncan liked the concept and as he wanted to produce a speaker he could listen to his favourite music on, then the DS-108 is the end result. 

Horn designs are complex and very varied and can cost a fortune; some will also take your living room over, especially in modern homes, so Duncan set about designing a reasonably compact room friendly model that had good bass output.

CONSTRUCTION

The unusual sandwich construction gives an amazingly strong cabinet structure without the boxiness sound of traditional four walled designs. Each and every pair is CNC cut, built and finished by hand in the UK.

The four-inch Fostex FE108EZ is an amazing driver with great midrange, a sparkling top end and credible acoustic bass. Amazing, considering the small 2.5-inch cone surface. Features include a unique Hyperbolic Paraboloid shell diaphragm, UDR tangential edge damping and ES cone manufactured from banana plant fibre. This all helps to produce a smooth and detailed sound. When I researched it I also discovered they aren’t cheap! The retail on a single driver is about £150 so Duncan hasn’t penny pinched on the parts cost and quality. Also this model has the latest addition of Taket Piezo Super tweeters which add extension and airiness to the sound, Wonderful sound can be heard from a wide range of genres, particularly female vocals, jazz and classic rock. These speakers are extremely valve friendly, perfect when partnered with a good valve amp.

Mounted on a 40 cm stand, this combination will fill a room with perfect imaging and atmospheric sound. Highly recommended is the granite plinth option, enabling the use of almost any stand, whilst retaining the isolation and levelling properties of the Viablue spikes. Duncan supplied a pair of Atacama 40cm stands which were ideal to place the DS-108 on and with the granite plinths worked very well.

I was sent a pair in piano white with a pale grey suede effect finish, but other options are available and bespoke finishes are not a problem if arranged in advance and agreed upon. They are reasonably slim and the drivers are mounted at the top of the cabinet with the ported front slit below running down the centre. The front baffle is finished off with a smart acrylic covering plate and a foam protective grille for the Fostex driver. The Fostex drive unit is very unusual in design and looks but I would recommend caution when handling the speaker and keep prying fingers, whether children or adults, away due to their delicate nature. This is especially true when unboxing them as your fingers could easily destroy the cone if misplaced.

As the Taket Piezo Super tweeters were fitted, connections on the back of the speaker were bi wire with four high quality binding posts and good wired jumper leads for single speaker wiring (I applaud this as so many companies’ penny pinch and put cheap nasty jumper links on their models). I chose to run them single wired as it was more practical, especially when I used a valve amp later.

Duncan had told me he had done a lot of experimenting with the design and trying different drive units. The back-loaded or rear-loaded horn loudspeaker system is like bass-reflex and double bass-reflex speaker types in that the sound radiated from the back of speaker transducer is utilized to enhance the bass response. The difference however is that back-loaded horn (BLH) speaker enclosures make among the most efficient use of the back wave from the speaker driver. The back-loaded horn speaker enclosure operates by developing the bass response using the back wave from the speaker driver and an expanding horn section. The remainder of sound spectrum (mid and high-frequency ranges) is radiated directly from the front wave produced by the speaker driver. Back-loaded horn speaker enclosures are generally amongst the most efficient enclosure systems and respond well to the subtlest components of music signals. For “tighter” sound reproduction, you can reduce the interior volume of the horn speaker cabinet using fill material.

As you can see designing a speaker is not easy and just building a cabinet and sticking a driver or two into it takes a lot of expertise and trial and error. I’ve listened to a lot of speakers over the years and none are perfect, but some manage to be really enjoyable. Once I’d run the D-108’s in after a few days, I settled in to get used to the sound this speaker had to offer. The Fostex driver is surprisingly good for its size and has a reputation for being an excellent full range unit to use especially in horn designs. Fostex have a fine reputation anyway as a professional audio company, so they know a thing or two about sound reproduction. To my ears all horns have sounded coloured and I certainly don’t profess to be an expert on them, it’s just my opinion. The D-108 initially did sound coloured to me, but as I acclimatised to their particular traits I became far more tolerant and grew to like them.

The addition of the Taket piezo super tweeter certainly made for an open airy top end. The bass end was also good given the size of the Fostex driver and went reasonably low in my listening room. Duncan currently has an add on sub woofer under development which matches the D-108 in looks and compliments it well as a stand. Those wanting more bass in a larger room can when the final design has been decided on. Duncan assures me he is pleased with the results so far, so it’ll be interesting to see the difference later this year. As it was I was happy with the bass provided in my room. As I like a lot of prog rock I tried many different albums from that particular genre of music with great results. Bands like Marillion and Genesis from their early years sounded tight and controlled with good clear vocals. A combination of good recordings on my Project Extension 9 being very well reproduced by the Fostex drivers of the D-108 and that super tweeter.

The back loaded horn cabinet design undoubtedly aids the bass output and allows the Fostex driver to work to it’s true merits of mid range clarity and sparkling sound. 

CONCLUSION 

As I said earlier it took me awhile to get used to the sound of the D-108, but once I had acclimatised I enjoyed what I heard. My review pair were in white with matching white granite bases (black is available as well). I personally liked the look of them and in a different colour scheme so might have my wife and friends. They certainly drew criticism aesthetically and most people didn’t like the style, but as I have said so many times before everyone is different and hifi designs have always polarised people’s opinions on looks and design. As the listener make your own decision.

Duncan and his team have come up with a very interesting design that I applaud them for and trusting their instincts, being brave enough to go with something different. When you see them in the flesh you appreciate the work that has gone into them and the parts costs are not cheap. Quality I am sure was uppermost in Duncan’s thoughts when designing these speakers. Go on the website when it is up and running to explore them more. I have seen pictures of the matching sub’s/stands and they complement the styling very well.

Pros: 

Very clear sound with good bass extension and a lovely mid-range that works well will all types of music 

Well made with high parts quality 

Bespoke finishes available 

Cons: 

The looks will divide opinions, but make your own mind up (I personally liked them)

Price: £1595.00

Options:

1. ST Pizeo-Electric Taket Supertweeter – £150
2. Viablue or Soundcare Super Spikes – £50
3. Granite Plinth x 2- £50.00
4. Acrylic Front protection panel and removable grill – £150

Specifications

 Ian Ringstead