Hardware Reviews

Proac Response D2R for the joy of ribbons

Proac Response D2R speaker review https://the-ear.net

Proac Response D2R standmount speakers

Since enjoying the Proac Response DB3 speakers around a year ago I have been eager to try some of the brand’s more up-market products having enjoyed them at various hi-fi shows. When the opportunity arose to listen to the D2 in my own system I jumped at the chance, even more so when learning that it would be the version with the true-ribbon tweeter, the D2R which is offered alongside the soft-dome D2S variant. This is the current version of the speaker that launched the Response range over 30 years ago and is an important part of the company’s history.

Celef into Proac

Running a successful hi-fi shop in Borehamwood, Stewart Tyler decided he could design and make loudspeakers which customers would like. His key aim was to build a compact speaker with good bass extension, smooth and extended high frequencies with a clear and uncoloured midrange. Developing the bass extension and diminishing cabinet colourations would be his biggest challenge. He had the novel idea of loading the reflex port with small tubes (akin to plastic straws), each of which would add its own friction at high levels without any significant effect at low volumes.

In 1973 Stewart launched a company under the brand name Celef Audio (derived from the drive units he was using: ‘Cel’ from Celestion and ‘ef’ from KEF). In 1979 Proac (Professional Acoustics) was introduced and the Celef brand name was gradually phased out.

Over the years Stewart investigated all types of tweeters: ribbon, dome, electrostatics and less well-known types. Finding a tweeter with the fewest drawbacks was his long-term ambition. He died in 2021 although Proac remains very much in family hands. It was following the launch of the Response Range in 1989, to wide critical acclaim, that the company went from strength-to-strength.

Proac Response D2R speaker review https://the-ear.net

D2R design

The Response D2R is a compact two-way standmount loudspeaker with front-facing reflex port intended to give potent bass for the cabinet size. And the front port allows them to be sited closer to the rear wall. This model dates back a while and has been offered with a soft-dome tweeter for around 20 years before this new variant with the true ribbon HF unit, as used in Proac’s floorstanding models, which promises extreme transparency and pinpoint imagery. Rather than an off-the-shelf ribbon, the parts are assembled by Proac using their own design of front plates. The ribbon part is made from very fine corrugated aluminium, lighter than a human hair, with rear chamber damping and alnico magnet.

Looking conventional from the exterior, the cabinet combines a rigid and well-damped marine plywood cabinet with high-density fibreboard front and rear baffles. This combination helps to eliminate cabinet resonances without using internal bracing. It houses a 64mm diameter plastic port, 130mm deep and tuned to 45Hz. The loudspeakers are all proudly British-made at the company’s factory at Brackley and the cabinets also UK sourced.

The mid/bass driver is made to Proac’s specifications by SEAS in Norway and is a 165mm glass fibre cone unit with rubber surround, Excel ceramic-ring magnet system, and copper phase plug. The front baffle has the ribbon tweeter offset to help prevent phase anomalies while improving the imaging.

Ribbon or dome?

There are pros and cons to both dome and ribbon tweeters. To reproduce high frequencies in a natural uncoloured way the tweeter diaphragm has to be extremely light, allowing it to start and stop very quickly. Any addition, overhang or distortion is sonically evident, and low distortion is Proac’s key concern.

Proac Response D2R speaker review https://the-ear.net

 

Dome tweeters are exceptionally good and found in the majority of loudspeakers, reproducing harmonics in a faithful way with excellent dispersion. The ribbon diaphragm is probably the lightest possible and reproduces very high frequencies accurately. Unfortunately, a ribbon tweeter does not have the dispersion of a dome tweeter, therefore loudspeakers with a ribbon tweeter create more of a listening hotspot for best performance. Proac therefore offers this model with the (cheaper) soft-dome option or the ribbon one on test here, so that customers can decide for themselves.

In the 1970s Celef Audio made a loudspeaker called RT1 which used a ribbon tweeter from Decca, the ribbon was loaded by a large horn to add efficiency. This ribbon suffered from both inconsistency and power handling issues although these have been largely eradicated so that today’s ribbon tweeter is efficient and can handle the power output needed.

The main driver hands over to the ribbon at a higher than average 2.8kHz crossover point, this reduces its power handling and compensates to some extent for the different dispersion characteristic relative to the cone. The crossover network uses high-grade components on a dedicated circuit board, with multi-stranded oxygen-free copper cable making connections to the drive units. There are two sets of terminals per speaker, catering for bi-wiring/bi-amping options although I left the sturdy wire links in place throughout the review. Likewise, I did not employ the removable and acoustically transparent Crimplene grilles.

Proac Response D2R speaker review https://the-ear.net

Sound quality

I am a big fan of well executed AMT designs, using the ‘hybrid-ribbon’ or Air Motion Transformer, and was hoping for even better results from Proac’s implementation of a true ribbon in the Response D2R. I was not disappointed; the sound was of exemplary quality from what is clearly a very well-engineered loudspeaker that presents a relatively friendly load to the amplifier, the nominal 8 Ohm impedance not going below 6 Ohms, with a not too shabby 88dB sensitivity for the box size.

Sitting atop filled Custom Design stands and with Hegel’s new H600 streaming integrated amp to hand (providing 300W/ch) it seemed churlish not to give the Proacs an airing with this £10,500 power house. Wow! The 2019 country album Hearts of Glass by Beth Nielsen Chapman where the discordant, plucked waltz and breathy vocals appeared to have greater definition than I recall on lesser systems. The softer edge to 1993’s Rage On Rage was more ethereal in quality, more sublime in enjoyment and with better transient response than I’ve heard it. There was an almost eerie amount of texture to the music and oodles of emotional engagement.

Switching to Shostakovich’s Twenty-four Preludes/Ashkenazy where the sheer transient ability, not to mention speed of attack and decay, was remarkable. Sometimes the music fails to move with as much fluidity as we witnessed here where the pianist’s extrovert manner is fully exposed for the benefit of listener’s enjoyment. Piano can be a difficult instrument to reproduce accurately and this excellent recording is oft marred by limitations in the electronics/loudspeakers. Here, though, it was simply a delight to be immersed in the accomplishment of this talented performer.

Atoll and Proac

Switching to the newly-arrived, and more modest, Atoll SDA300 Signature streaming amp (£3,995), the listening panel immersed themselves in Love Affair’s song Everlasting Love from 1968. There was a thought that the midband was slightly recessed on this historic recording, and we began to appreciate the monitor qualities of the D2Rs and their ability to dissect a recording. If soft-dome tweeters are prone to ‘fizzing’ and metal domes all-too-often ‘zing’ the tweeter here created a simply glorious treble. The sound was sweet, detailed and luscious. In fact, the detail was immense and brought back happy memories of Fountek ribbons in speakers of yore. The full orchestral backing and real driving rhythm on this stereo version had the panel in raptures.

Proac Response D2R speaker review https://the-ear.net

The enjoyment continued with the 2023 remaster of Starbuck’s Moonlight Feels Right with its amazing instrumental break, although one panel member noted that the treble was a tad detached at times. I found the integration to be spot-on which just shows how personal tastes vary when it comes to loudspeaker preferences. The glistening synth and marimba sensation captures the essence of mid-70s soft-rock and remains oddly timeless even though it’s inextricably tied to its era. The arrangement is outstanding with swirling synthesisers and the almost Zappa-esque xylophone solo which is dazzling, it certainly had feet were tapping.

Next up were the Pet Shop Boys with the 2010 remaster of Suburbia, and another chance for the Proacs to reveal their ability to retrieve immense detail from the effects on this track. The soundstage had width and depth beyond the cabinet extremes, as a well-engineer loudspeaker should. The throbbing basslines came across strongly and with control. The D2Rs are not for LF junkies, who would probably need to add a subwoofer to satisfy their cravings. But, how much better not to swamp everything with over-blown and unnatural bass as besets too many modern loudspeakers. The Proac D2Rs deliver as much bass as they can given the cabinet volume and deliver what’s on the recording as faithfully as possible.

Before departing, the panel selected a stereo version of My Name is Jack by Manfred Mann, from the band’s second incarnation with Mike D’Abo on lead vocals, after Paul Jones had left to pursue his solo career. Once again, the ribbon tweeter shone through in a track that can seem lifeless and lacklustre on lesser speakers. There was a real sparkle to the treble which increased the overall enjoyment, with the presence region response again showing the D2R’s monitor leaning pedigree that’s reminiscent of classic BBC designs.

I had no desire to remove the Proac D2Rs from my system and used them for the next few weeks listening to a lot of live radio with a mix of classical and speech material. During which they showed themselves to be a high-quality transducer capable of top-quality sound reproduction. The standouts were the treble from that ribbon coupled with an uncluttered, natural-sounding midrange which handled the human voice so well; something many loudspeakers, even at this price-point, fail to achieve. I was also struck by the dynamic abilities of this compact cabinet and the D2Rs ability to re-create tonal colours so believably from so much music.

Looking conventional from the exterior, the cabinet combines a rigid and well-damped marine plywood cabinet with high-density fibreboard front and rear baffles. This combination helps to eliminate cabinet resonances without using internal bracing. It houses a 64mm diameter plastic port, 130mm deep and tuned to 45Hz. The loudspeakers are all proudly British-made at the company’s factory at Brackley and the cabinets also UK sourced. The mid/bass driver is made to Proac ’s specifications by SEAS in Norway and is a 165mm glass fibre cone unit with rubber surround, Excel ceramic-ring magnet system, and copper phase plug. The front baffle has the ribbon tweeter offset to help prevent phase anomalies while improving the imaging. Ribbon or dome? There are pros and cons to both dome and ribbon tweeters. To reproduce high frequencies in a natural uncoloured way the tweeter diaphragm has to be extremely light, allowing it to start and stop very quickly. Any addition, overhang or distortion is sonically evident, and low distortion is Proac’s key concern.

Conclusion

Clearly Proac have a superbly designed and well-engineered loudspeaker in the Response D2R. To hear ribbon tweeters executed so well is a delight. This comes at a cost but creates a treble that is just so detailed, so sweet and so moreish that it’s justified. Combine this with the elegant cabinets, clarity of midrange and timing of the bass output, and the model is a winner in more ways than one.

The D2R is something of a crossover loudspeaker with some of the key monitor qualities of studio designs but with many hi-fi credentials, which makes listening to music such an enjoyment rather than an analysis of the performance and/or recording.

Removable magnetic grilles are set to be introduced and a new, premium finish of Liquid Amber added to the range in a manufacturer’s clear endorsement that the superb D2R is here to stay. For music-lovers that can only be good news. Combining excellent overall transparency, featuring a ribbon tweeter creating an open and extended top end, and a characteristic rich, midrange along with deep, well-defined bass notes means that the D2Rs are very highly recommended.

Specifications:

Type: reflex loaded 2-way standmount loudspeaker
Crossover frequency: 2.8kHz
Drive units:
Mid/bass: Proac 165mm (6.5”) Excel magnet system, glass-fibre wave-cone and copper phase-plug
Tweeter: Proac ribbon, alnico magnet
Nominal frequency response:  30 – 30,000 Hz
Nominal impedance: 8 Ohms
Sensitivity: 88dB @ 1W/1m
Connectors: bi-wire binding posts
Dimensions HxWxD: 430 x 203 x 260mm
Weight: 11kg
Standard finishes: black ash, mahogany, cherry, walnut, oak, silk white
Premium finishes: rosewood, ebony
Warranty: 5 years

Price when tested:
Standard finishes £3,410
Premium finishes £3,995
Manufacturer Details:

Celef Audio International Ltd
T 01280 700147
http://www.proac-loudspeakers.com

Type:

standmount loudspeakers

Author:

Trevor Butler

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