January 2020

ProAc Response D2R Standmounted Speakers
Updating a true classic loudspeaker.
Review By Phil Gold

  When I moved to Canada in 1980, I bought Meridian M2 Active Speakers which I had originally heard in Edinburgh while I was attending the festival. They were so outrageously good I kept them for a very long time. Only when I found the ProAc Response 2 did I feel passive speakers had caught up and even overtaken the old M2s. That would be around the early nineties.

The Stewart Tyler-designed Response 2 also lived in my system for a long time, finally giving way to a pair of Wilson Benesch Act 1 speakers when I moved into a larger home. The Act 1 was ultimately replaced by the YG Acoustics Carmel, then the Carmel 2 and now the Hailey 2.2. Each new speaker was a considerable step up over its predecessor.

What a delight to have a chance to experience the very latest iteration of the ProAc Response 2, possibly the first such pair in North America. There have been many changes along the way, so let's chart them first.

The original Response 2 featured a 6.5" polypropylene bass/midrange and a 0.75" ScanSpeak dome tweeter in a rectangular cabinet sitting atop metal stands. The most distinguishing feature was a front facing port, stuffed with what appear to be drinking straws to modify the airflow and prevent port turbulence. The tweeters are offset towards the inside to reduce cabinet edge reflections. The walls are 1" MDF and the dimensions 18" x 9" x 11" (HxWxD). My pair was finished in walnut and the quality of fit and finish was outstanding. ProAc claimed a response from 55Hz to 20kHz (+/-3dB), with a sensitivity of 86dB/W/m into 8 Ohms. These speakers were imaging champs, quite high in resolution, not too extended in the bass or the treble, and really good for small scale classical music or jazz. Most of all, they were very alive and musically involving.

Stewart Tyler On The Drinking Straws In The Response 2's Port:
The straw ports bring back many memories. My grandmother used to make all of them, and I can remember sitting with her as a small child helping her and my father. (I have pictures of this somewhere!) The idea of using straws came about when Celef Audio first started, and I wasn't happy with the quality of the bass produced and I decided to experiment with different materials inside the port to see if I could improve this. After trying lots of different things without the desired result I was at a children's party when I noticed the plastic drinking straws. I tried these and found that I got the result I was looking for. The Straw ports were discontinued as drivers got better. The air movement in the port started to make the straws make small resonances. The bass quality became better as time went by and the straws were no longer needed. This is when we discontinued the straw ports.

The Response D Two (or D2 and now D2D), introduced in 2008 and still in production, uses a 6.5" glass fiber cone woofer with an Excel Magnet system and a copper phase plug and a 1" silk dome air cooled tweeter in a slightly smaller cabinet (17" x 8" x 10.25"). The straws are gone, and the bandwidth has increased to 30Hz to 39kHz with a higher sensitivity of 88.5dB/W/m, making it more amplifier friendly. The walls are now much thinner following BBC design principles. The carcass is made from 15mm thick marine ply which is heavily damped, while the front and back panels are made from 25mm thick HDF so ProAc can apply a high quality edge to all the drive units fitted. Resonances are cancelled out by the use of different types and thickness of wood used together. The cabinets are made in the UK.

The Response D2R replaces the silk dome tweeter from the D2D with a very costly ribbon tweeter used in some ProAc floorstanding models (D20 R and D30 RS). The tweeter obviously has very different characteristics from the silk dome, so the crossover has been completely reworked in this version. Ribbon tweeters, by virtue of their low moving mass, are very fast in their reaction to transient changes and it is quite a difficult task to integrate them seamlessly with moving coil woofers. Fortunately, this woofer is designed and built in house, giving maximum flexibility to ProAc's design team. The Response D2R was first shown in 2018 and is just now reaching the US and Canadian markets, through ProAc's US distributor, the Sound Organization and the new Canadian distributor, Crown Mountain Imports. It lists at $1000 more than the standard Response D2 ($4500 versus $3500).

ProAc uses computers to take measurements on the speakers to make sure they have a uniform frequency response. But they still spend a great deal of time listening to and tweaking the crossover network. This together with the measurements tell them when a speaker is ready for production. Sometimes this can take many months before they are satisfied that a speaker is ready to be launched and put into production.

Stewart Tyler On The Ribbon Tweeter In The D2R:
There are lots of ribbon tweeters on the market made from a variety of different materials for different levels of power handling, we source different parts to complete the ribbon unit that we use.  The ribbon of our tweeter has an Aluminum corrugation making it very reliable and able to take a fair amount of power. The tweeter also has a protection device allowing the ribbon tweeter to perform very well without the damping effect that you may get from other ribbon tweeters. We listened to and modified many different tweeters which took a great deal of time until we were happy with the makeup of the current Ribbon tweeter we use. Every pair of speakers built has a full power handling test before it leaves the factory and undergoes a strict quality control inspection.

This is a high performance component, so it deserves to be fed by a high quality system. I used my reference gear – EMM Labs XDS1 SACD Player, EMM Labs DV2 Integrated Converter (DAC with digital volume control) and a Soulution 511 Stereo Amp, all supported by Nordost Valhalla 2 power cords, interconnects and speaker cables.

ProAc recommends a slight toe-in for the Response D2R, and I experimented with distance from the wall and toe-in until I found a sweet spot. I found the D2R unusually sensitive to positioning, and compared to Totem's "The One", the D2R preferred a slighter toe angle, a greater spacing between the left and right, and a position closer to the wall. Your mileage may vary. In fact I found that when I optimized the location for one type of music, it was not always best for another genre. But moving speakers around in real time is not really an option.

The treble is remarkably smooth and detailed, and mates very smoothly with the midrange. Any problems I had were related to the bass, and this is often the case with ported designs. The port is front mounted and quite large. This serves to boost the frequency response in the deep bass, compensating for the small size of the box and bass driver, but it comes at a price. Deep bass definition is not as precise as a sealed box design can offer, and the low frequency response is less flat and drops off more sharply below the port frequency. The interaction between the speaker and the room varies considerably with speaker positioning and toe-in, whereas each of my sealed-box YG speakers was much less fussy about precise positioning. ProAc recommends a good deal of experimentation with positioning.

I found the D2R performed exceptionally on most well recorded material, be it classical, jazz, rock, folk. But on a few of my recordings, the bass energy could overwhelm. One example of this was the album Across the Digital Divide by Bela Fleck and the Marcus Roberts Trio [Rounder 11661-9142-2]. My initial notes read "sweet but bass heavy – not precise – in contrast to the superb open top and fast midrange". I had started out where the Totems were. I was able to improve the sound here by angling the speakers more to the listening spot and bringing them further into the room, but further investigation showed the best position was closer to the wall, further apart and angled close to parallel. That was where I found my sweet spot and I stuck to this for all my listening. The bass was still a bit soft, but the integration was much improved, and I no longer felt this was a speaker of multiple parts. But I also never felt the bass was as fast, free and pitch accurate in my room as the bigger YG Carmel 2 or YG Hailey 2.2, both much more expensive floorstanding speakers.

What Stands to Use?
I still have the original Target HR60 stands I used when I owned the Response 2 speakers, and they served me well for this review. But I hear from reliable sources that the Response D2R is very sensitive to the stands used. With the very best stands, the bass is said to snap into place and display the same speed and timing as the midrange and treble. Unfortunately, ProAc do not manufacture a matching stand, so you will need to work with your dealer to find the best combination. For sure you need high mass and rigidity, and a height of at least 18". You might try the Target MR60B which are even heavier and more rigid than my HR60s. Or the Foundation Audio 22" or 24" Designer II stands which come already filled with mass loading material. Make sure the tweeter is at the same height as your ears when seated in the listening position.

My findings are based on the Target HR60 stands.

Many affordable speakers have a very good midrange. You usually have to spend a lot more money to get an extended and unfatiguing treble. And then it's a lot more money again to get extended, pitch accurate, fast bass. That holds true not just for speakers. The same applies to power amps and even to DACs. I've found it's also true, but to a lesser extent, for preamplifiers. You show me a component that does all three well, and integrates well between all three, and I'll show you either a megabuck price tag or a component of exceptional value. That's the pot of gold at the end of the rainbow we are all looking for.

Why do we need an extended and unfatiguing treble? It's not so much so that we can hear the extremely high notes clearly. It's so that we hear the overtones above the fundamental tones of the various voices and instruments in the mix. These overtones give each instrument or voice its specific color and richness.

And why do we need deep pitch accurate bass? Some say you can do without it, and for some types of music, you probably can. But to get the sound of a full orchestra into your living room, or the full punch of a swing band, or to get the most of heavy rock, you simply must have that powerful bottom end. Not the one note bass of a low-fi big speaker, but bass that can start and stop on a dime, bass that has a strong thwack to it, that is as tuneful as the midrange. Then the music comes to life as it does in a good venue.

OK, I'll get off my high horse now. Having positioned the ProAcs, let's really put them through their paces on a bunch of recordings. A really expensive speaker may work well on everything you feed it, but real world speakers are of necessity compromises. What works well, and what doesn't?

The Listening Notes
Paul Simon's last album, Stranger to Stranger [Concord 0888072398030] has two versions of "Wristband" – the studio recording and an even better live version, taken from the Prairie Home Companion. On this bonus track the D2R offers exceptional clarity to Simon's vocal line, superb percussion and even catches the audience well. Imaging is lovely. Transient response is very strong, without ever sounding brittle. That ribbon tweeter is really strutting its stuff here.

Keb' Mo' eponymous album is available bat as a CD and as SACD [MOFI UDSACD 2054]. Although "She Just Wants to Dance" shows a hint of heaviness in the bass, "Am I Wrong" is better balanced and the old Robert Johnson song "Come on in My Kitchen" just nails it. Strong bass support and a forward presentation coupled with a strong wide image brings the music to life. The CD layer actually offers greater dynamics, while the SACD layer shows more nuance and detail. Both great.

Now we'll switch to Jazz. Portrait in Jazz, the 1959 Bill Evans album [Riverside RISA-1162-6] featuring Scott LaFaro on bass and Paul Motian on drums, is demonstration quality in every way. "Autumn Leaves (take 1)" offers a master class in jazz. The percussion is just about perfect through the D2R, as is the piano tone and the bass playing, but the real magic is in the way the three are captured in space, the way they react to each other, the way they swing. This speaker really brings out the differences between a good recording and a great one. Switching over to the big YG Hailey we hear more definition in the bass, stronger dynamics overall, but the D2R is still exceptional here, particularly for a bookshelf model.

Five years later, Jazz was changing. Nothing shows those changes more than the Free Jazz on Out to Lunch by Eric Dolphy [Blue Note RVG Edition 724349879324]. "Hat and Beard" sounds tremendously alive, rich and colorful. It's also forward, dynamic, full depth, full width, with a stable image. The bass is well handled here. Fast and with full pitch accuracy. Freddie Hubbard's trumpet is fantastically well reproduced. The same goes for the percussion, even the difficult to reproduce brushwork. The bell rings loud and clear, with no signs of compression. Altogether, that's quite an achievement.

Diana Krall lies half way between Jazz and Pop, but on her Nat King Cole tribute album All for You [Justin Time JTR84582] she's all Jazz. She gives up the keyboard for just one track on this album, to let the great Benny Green solo on "If I had You". Her voice is ideal and we have a thrilling reproduction of Benny's piano. Those deep notes ring true without compression – in fact all the registers of the piano have strong weight. Good as this is, the YG Hailey 2.2 brings a new level of bass articulation and Krall's voice is gritter and warmer by turns. There's more there, there. On "Boulevard of Broken Dreams", the D2R is beautiful and gentle, the bass just a little loose.

And now the toughest test for a small speaker – large scale classical music – Mahler no less. A live recording of the third symphony, conducted by the 88 year old Bernard Haitink on June 16th and 17th 2016 in Munich. Part of a box set Bernard Haitink Portrait [BR Klassic 900174]. I love Mahler, but the Third was never a favorite of mine. Not until this simply spectacular performance made sense of it all for me. I had intended to listen to a short extract, but I couldn't stop listening until the end of the 35m 49s first movement. The D2R offers extraordinary sounds emerging from a black background. It's visceral and hugely atmospheric. The brass instruments cut like a knife, the winds are stunningly realistic in tone, while full orchestra comes with extreme power. The image is wide, deep, and coherent. Yes, it was still slightly lacking in deep bass definition, and consequently the level of menace that the YG Hailey brings to the party is missing. But what I liked best was the interplay between the sections of the orchestra, and between the solo instrumentalists. It seemed like a conversation to me, something you can only appreciate when you have tonal accuracy, spatial specificity and high resolution, as the D2R offers. Mahler would have approved.

I like to test speakers with a wonderful recording of Haydn String Quartets Opus 20 by the Quatuor Mosaïques on original instruments [Astree E8786]. It's common for this to sound edgy and jarring in the wrong hands. That's not the case here. The gut strings produce a fine astringent sound. The tone color and imaging are first rate, although I find the excitement dialed back a little.

There is an awful lot to like here. Not just the sound quality but the reasonable efficiency and easy load the DR2 places on the amplifier (20 to 150 Wpc recommended) means it should fit well into most good systems, silicon or vacuum tube based. There is a good range of real wood veneer finishes available: Black Ash, Mahogany, Cherry, Walnut, Oak and Silk White. Rosewood and Ebony can be ordered at extra cost. You'll need good stands, and your dealer can recommend something suitable. Preferably very heavy and rigid, and sitting on small quantities of Blu Tack. The D2Rs come with removable grills – supposedly acoustically transparent – but my experience is that they sound best without.

Listen to these at the showroom of your choice, but since they are room critical, please also try these at home before committing. And throw a good variety of the kind of music you prefer at them. As you can see from my notes, they respond best to acoustic music, and they are transparent and unforgiving enough to reveal the strengths and weaknesses of the rest of your system and how well each track is recorded. With the right music and partnering equipment, they can be sensational.

Zoe Tyler-Mardle, ProAc's Sales And Finance Director, Writes:
ProAc started as a company named Celef Audio International Ltd. After trading for some years, we decided to make a move to make a more upmarket, better quality loudspeaker. We named this brand ProAc which stands for Professional Acoustics. ProAc was born in 1979 and the Tablette was one of our early models. This model in particular has been a best seller over the years, and we are currently on the 10th version of the Tablette.  Soon after this, the Celef brand took a back seat as ProAc became more popular. It was decided to stop manufacturing the Celef branded models and to concentrate on the ProAc line. Celef Audio International Ltd is the parent company of the ProAc brand which sells today. 

We have always been a family run business with various members of the family working over the years. When the business first started it was Stewart (my father), his parents and his wife. They worked full time jobs in the daytime making speakers in the evenings from their home. Sadly, today Stewart's parents have passed on, but the team is still made up mostly of family members. I run the day to day business and have worked with Stewart for over 25 years. My brother Tristan also works with us. The design team is made up of Stewart, myself, Stewart's son in law John, who has worked with Stewart for 30 years since leaving school, and now Stewart's grandson Tom. We also have four other members of staff who do a fantastic job and have all been with us for over 20 years. Although relatively small compared to some of our competitors - there are not many that are still owned by the original owners/designers – we continue to strive to achieve the ultimate in sound reproduction.

Specifications
Type: Stand-mounted loudspeaker
Frequency Response: 50Hz to 30kHz
Nominal Impedance: 8 Ohm
Recommended Amplifier: 20 - 150 watts
Sensitivity: 88.5dB/W/m
Tweeter: ProAc ribbon with rear chamber damping & alnico magnet
Bass/Midrange Driver: 6.5" ProAc unit with Excel Magnet System
Cone material: Glass fiber weave cone with copper phase plug
Crossover: Finest components on dedicated circuit board
Internal Cabling: Multi-strand oxygen free copper
Connections: Split for optional bi-wire or bi-amp'ing
Dimensions: 17" x 8" x 10.25" (HxWxD)
Weight: 24 lbs. each
Mode: Stand mounted on rigid high mass stands
Grill: Removable black acoustically transparent crimplene
Standard Finish: Black Ash, Mahogany, Cherry, Walnut, Oak and Silk White
Optional Finish: Rosewood, and Ebony
Price: Standard finish $4500, optional finish $5200

Company Information
ProAc Loudspeakers
Highpoint House
Riding Road
Buckingham Road Industrial Estate
Brackley
Northamptonshire NN13 7BH
England

Voice: +44 01280 700147
E-mail: zoe@ProAc-loudspeakers.com 
Website: www.ProAc-Loudspeakers.com