Vincent Brient of totaldac renown in France has been incredibly busy with his d-1 series of R2R ladder DACs, and streamers for the last few years, (which have received critical acclaim in the high-fidelity press. I have a d-1 integral on loan for review: Part One HERE) but it seems he has been just as busy on the loudspeaker front, and for considerably longer: Introducing his d150. It’s been seventeen years to be exact that Brient has been painstakingly labouring on this set of horn-loaded, full-range drivers, and separate sub-bass cabinets. Upper frequencies are handled by an undisclosed high-efficiency paper cone loaded down to 150 Hz via a large solid wood horn, and an undisclosed 15-inch paper woofer handles everything else down to 40 Hz.
Questions for Vincent Brient on his new d150 horn loudspeakers:
RA: How long have you been working on the design of the d150? What made you choose the configuration you finalized, and why did you want a separate bass-reinforcement cabinet, and why is it not an active bass system?
VB: “I started experimented with big horns 17 years ago. After many experimentations with different technologies I wanted to use a single driver from the treble to as low of a frequency as possible. I also wanted a small paper cone for its natural sound (a bit like wood is used for violin or piano, despite new materials). I wanted no whizzer, so a small full-range driver was the solution. To get a real body in the low mid a horn was necessary. Horn loading the low mid and not really loading the treble, so I then just had to take care of the bass below 150Hz, with 98dB efficiency to match the horn. A 15inch high-efficiency was the best solution I tried. No 15inch high efficiency driver makes 25Hz with real level and dynamic, so I added the optional subwoofer with the matching efficiency. Very few hifi speaker can make 25Hz with a real dynamic anyway.I didn’t want to use a small bass driver boosted by an internal active amplifier because these solutions are much less dynamic and distorted. I wanted to get real dynamics on the whole spectrum, not just the correct quantity of bass.”
RA: Are the tweeter, and mid/bass driver proprietary designs by you, or are they a collaboration with an established driver manufacturer? Are you building the horn, cabinets, and crossovers in-house at your factory near Mont Saint-Michel?
VB: “Driver types are not currently published except the sub-bass driver, it is the American Aespeaker TD18H+. I built the first pair of horns myself, and a wood specialist in France is building the next pairs. The cabinet is also designed, and completely built in France, in a factory which specializes in wood work. The final assembly and crossover is built by totaldac, near Mont Saint-Michel.”
RA: These speakers have a very unique look, do they come in separate sections like some other large horn-loaded loudspeakers?
VB: “Each part is less than 60kg, and there are three parts: the horn, the bass cabinet and a large external crossover box.”
RA: Wooden horns, paper cones… these would not be considered “cutting edge” design components, but rather, traditional in many respects. How did you decide on using such natural materials, and not more exotic ones?
VB: “I don’t know anything better than very thick wood to build horns. The other materials often used for horns like metal, plaster or glass fibre are first lower cost to build, and not better sounding in my opinion. I also don’t know anything better than a good paper cone (I don’t mean that all paper cones are good), especially for the mid-band, and treble. The paper dome has to be very small to make good quality treble, in this case it makes just tweeter if no big horn is used. The big horn is mandatory to make the correct body down to 150Hz. I tried many solutions but didn’t find anything better than small paper cones. I didn’t want a compression driver, didn’t metal dome, didn’t want a ribbon, didn’t want plastic, didn’t want carbon…”
RA: You chose a high-efficiency design (98dB) which allows for a wide range of amplification to be used, especially with the easy eight-Ohm (seven-Ohm minimum) impedance load. At this efficiency level single-ended triode amplification would be an obvious choice (to me) for pairing the d150s with. What amplification did you use to voice your design? Was it a tube amp, OTL? Did you experiment with solid-state designs as well during the prototype process? Do you have a favourite power tube: 300B, GM70, EL84, etc.?
VB: “A tube amplifier is indeed a possible choice, I have for example 300B and KT88 amplifier, I had 845 triodes, 6C33 OTL. Currently I use the Absolare Integrated Signature amplifier with tubes in the input stage and a transistor output stage. This allows a great dynamic and bass control, still with an open and natural sound.”
RA: Is the d150 the start of more speaker designs? Do you have any plans to also prototype amplification or pre-amplification designs? Analog Cables?
VB: “Another speaker is in development, a rather small column speaker made in the same spirit but in a much smaller scale. So the top of the line will be the d150. I am not planning releasing preamps and amplifiers. I already make and sell digital cables but the other cables I use are from partners I am also a retailer for, such as Echole, Bibacord and Esprit.
Thank you for your time, and quick response on these questions Vincent, my congratulations on this achievement.
d150 speaker specification ($40,400 USD, $52, 800 CAN,€38,000):
-40Hz-20KHz frequency bandwidth (25Hz-20KHz with the subwoofer option).
-150Hz crossover frequency making the speaker close to point source.
-860mm diameter wooden horn made of 100m thick wood.
-15inch bass driver.
-selected drivers allow gentle crossover slope to get the smallest phase shift and allow to use very high quality filter components.
-use of paper cones only and without whizzers for the most natural sound.
-easy 8ohm impedance, 7ohm minimum impedance, to be used with all kind of amplifiers, from small triodes to transistors.
-dimensions: 1.45m heigh, 0.86m diameter round horn, 0.72m max depth .
-weight: each part is less than 60kg for an easy handling.
-made in France.
d150 subwoofer specification ($6,380 USD, $8,345 CAN,€6,000 per unit):
-18 inch driver from AESPEAKER -25Hz-50Hz pre-set filter embedded in the d150 speaker.
-use of paper cone for the most natural sound.
-easy 8ohm impedance.
-recommended amplifier: 200W and above.
-dimensions: 0.48m wide , 0.29m deep, 1.9m heigh.
-made in France.