Audio Alto R101 Speaker by Terry London
The allure of single-driver designs has always enticed me to bring this type of speaker in-house for reviewing over the past ten years. This “allure” revolves around perfect impulse response, time and phase correct, single-point imaging, filter-less (no cross-over) connection to the source, and extreme efficiency. However, there is “no free lunch” with any design including single-driver designs. The drawbacks that are often encountered are, restricted high-frequency extension, limited power handling/ultimate dB levels, the need for horn-loading the driver which leads to colorations, and finally the use of behemoth sized enclosures to use the back wave pressure in a transmission line to get reasonable lower end extension. I had never found one that I would want to keep as a long-term resident in my stable of speakers in my two systems.
I had received some emails from readers inquiring what I knew about a company located in Slovenia, Audio Alto, that manufactures a full range of electronics and speakers, specifically their model R101 speaker, which is a single-driver design, (retails for $3,999) that had received very positive reviews in Europe. The designer/owner of Audio Alto, Sasa Burian has a reputation for being a very creative designer with talent at producing extremely high performing musical speakers for different size acoustic environments. After doing research on the Audio Alto R101 speaker, I was intrigued to setup a review on this “petite” floor-stander, as you will see later based on its diminutive size, and contacted Alex Siufy, Alma Music and Audio, located in San Diego, California. This company imports this speaker into the US. In a conversation regarding this speaker, Alex shared with me that on a visit to Sasa’s home in Slovenia he was so delighted with the performance of the R101 speaker that he was highly motivated to bring it to music lovers here in America.
The Audio Alto R101 speaker is built around a special metal membrane 4.5 inch full range driver that covers 36 Hz to 23,000 KHz (+/- 3dB) up to 102 dB volume levels. It is ported on the bottom which allows great flexibility regarding how close you can place it towards the front wall without getting any smearing of the low frequencies. The R101’s sensitivity is 85 dB and it’s a 6 Ohm load. My Triode Lab SET 2A3 four-watt amplifier drove the R101 with ease and great results. When teamed up with a high power solid-state Class A amplifier (Threshold 550e) the speaker had no difficulties handling the much higher current and wattage. Another feature is a switch on the back plate that allows you to pick three settings of -2dB/0dB/+2dB in the frequency range of 1,200 Hz to 20000 KHz. This feature is terrific at getting the right tonal balance in your room based on where you place the R101s and your specific taste. With my final position, a slight toe-in, two and half feet off the front wall, five feet apart, three feet off the side walls, the 0dB setting got me exactly the balance I wanted. The demo pair that was shipped to me was clad in a beautiful oiled Walnut wood veneer. There are other options of wood veneers or different paint colors. Two aluminum front spikes adjust the rack angle and the speaker rests on a rear acrylic elliptic stand. Next to the switch is where a single pair of high-quality speaker wire posts is located. The driver can be covered with an invisible magnet held black grill cover. I found no difference in the performance of the R101 with the grill covers on or off, so this would be based totally on which physical appearance you like better. Now, on to the matter of what I mentioned above regarding my use of the descriptor “petite.” The Alto Audio only weights 33 pounds per speaker. Secondly, the dimensions of this floor-standing speaker are only 40.5” high x 10” wide x 4” deep. This is a tiny speaker. Everyone who saw them commented how “cute” and attractive they were. Then they were beguiled by the large sound-stage they created, the soothing tonal quality, the clarity of the vocals, and finally how they produced real punch along with enough bass to anchor the music. All this “big sound” coming from two 4½” drivers housed in diminutive enclosures!
One of my favorite jazz piano players is Larry Willis, who just recently passed away a few weeks ago. His final recording, “I Fall In Love Too Easily” was recorded at the Rudy Van Gelder Studio. This CD has reference level clarity, spatiality, and very natural timbres on all the acoustic instruments used on this disk. The Alto Audio R101 speaker captured the acoustic space of where this music was recorded. Being a small single driver design the R101 completely disappeared and created a large realistic sound-stage with the band members spread through that space with great accuracy. What surprised me was there was no roll-off in the high-end frequencies. The cymbal playing of the great Victor Lewis was created with purity, all the sparkle and simmering hits were intact, and the decay trails were easy to hear as they drifted into silence. This was the first single driver design I have ever had in-house that could reproduce the high end in this remarkable fashion, without sounding etched or bright.
For years, I have been listening to the albums of one of the Hammond B3 jazz organ masters, “Big” John Patton. He recorded many outstanding Blue Note albums either as a leader or a sideman. Of all his recordings one of my “best picks” is his 1968 Blue Note “Understanding: Harold Alexander/Hugh Walker”, this disk was recorded by the great Rudy Van Gelder at his studio in Englewood Cliffs, New Jersey. I believe that Big John Patton was maybe the finest of all the great B3 masters regarding his footwork on the bass pedals producing tight and powerful bass patterns to setup the PRAT of the music. I wanted to see if the R101 could even come close to reproducing not only the extension of these bass notes, along with the tautness and timbres of these low bass runs. Well, the Audio Alto R101 did pretty damn well! To my surprise they got most of the fundamentals, along with the punch and tone I’m used to when listening to this recording on my Tekton and NSMT speakers. No, they won’t pressurize your room were your thumped in the chest, but if setup correctly in a small environment the speaker gives an amazing foundation to the music at reasonable loud dB levels. Another shortcoming of single driver designs, back loading the rear wave of the driver in a very large transmission line baffles taking up a lot of space or having to load them in the corners of the room was negated by this extremely tiny speaker. It can easy be placed in a small acoustic space unobtrusively, and still get you reasonable bass performance.
One strength of all well designed and built single-driver speakers is a purity of tonality/timbres/colors and see through transparency allowing all the micro-details to be heard easily emerging from the background ambience, particularly in the midrange band, because of the absence of any cross-over network coupling the driver directly to the amplifier. I expected the Alto Audio R101 to be superlative in this particular fashion and it lived up to my expectations. Peggy Lee’s album Black Coffee will test a speaker’s ability to render the nuances, very special tonality, and the emotionality of her voice on this recording. If the speaker, and the upstream gear, is not up to the task I hear a drying out of her voice’s subtly huskiness and it will flatten out her sultry delivery where you miss the emotional connection to her performance. The R101 was a direct conduit to Ms. Lee’s unique timbres and voluptuous tone color and allowed me to relax into the music as she effortless floated into my listening space right between the speakers.
If you enjoy your music in “tight quarters” and are a fan of tube-based SET or low powered solid-state class-A designed amplifiers, the Alto Audio R101 speaker might be a perfect partner for your system. It offers reference level purity of tonality/timbres. It creates a realistically sized soundstage with air around individual players. It has an overall ease and liquidity that just draws you into the music, and very surprisingly will play at relatively loud dB levels without straining or breaking up. I don’t play music much over 85 to 90 dB levels and in my listening space this was loud enough for me on most music selections to get the micro-dynamics I want even if it was big band or symphonic pieces. If you want to listen to Rush at over 100 dB levels, the R101 speaker is not for you. I also found that both the top end extension (airy/fully extended) and the bottom end bass range (taut/tuneful) was quite the surprise to me based on past experiences with other single-driver designs. It is a very physically attractive minute speaker that because of its size, the downward firing port and the ability to change the dB levels in the midrange and upper frequency ranges gives you the ability to totally dial-in its performance based on your room acoustics and personal taste. I give credit to Sasa Burian for creating a wonderfully musical speaker for smaller acoustic spaces and Alex Siufy for having the fine taste to bring it to the US for listeners to enjoy.
Impedance 6 Ohm
Frequency range 36 – 23.000 Hz +- 3 dB
Sensitivity 85 dB Phase shift above 100Hz from +28 st. to -2 st.
Room size up to 35 m2
Dimensions (W x D x H) 260 x 105 (with base 200mm) x 1030 mm
Weight 15 kg Finish (upon order) various colors, veneers and leather
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