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Following the last-minute cancellation of the 2018 Los Angeles Audio Show, scheduled to be held this coming weekend in Irvine, two Southern California audio retailers have stepped into the breach with AudioCon-June. Jason Lord of The Source A/V Design Group (3035 Kashiwa Street, Suite 101, Torrance, CA 90505. Tel: (310) 534-9900) and Sunil Merchant of Sunny's Components (1370 E. Cypress St, Covina, CA 91724. Tel: (626) 966-6259) are holding weekend-long free events. The events run 10am–6pm on Saturday June 9 and Sunday June 10 and you can find full information here and here.
The Acustik-Lab SR Bolero loudspeaker ($1580/pair) debuted at the 1988 SCES in Chicago. I must own up right from the outset that I know nothing about the Swiss SR Trade (Acustik-Lab) company. I do know, however, that Audio Advancements' Hart Huschens was getting an intensely musical sound from their little Bolero speakers, driven by the German Klimo Kent tube amplifiers, at the 1988 Summer CES. I immediately asked for a pair for review; in addition, Mr. Huschens sent along a pair of the matching Bolero Forte woofers ($920/pair).
SR's Bolero is a well-made two-way minimonitor using drive-…
Sidebar 1: System Details
The review procedure followed, with minor changes, that established for my previous loudspeaker reviews: Each pair was used with a pair of VTL 100W Compact monoblocks, connected with Monster M1 speaker cable, while the preamplifier was a combination of the Mod Squad Line Drive Deluxe AGT and Vendetta Research SCP2 phono preamp. Source components consisted of a Marantz CD-94 CD player used to drive a Sony DAS-R1 D/A converter, a 1975-vintage Revox A77 to play my own 15ips master tapes, and a Linn Sondek/Ekos/Troika setup sitting on a Sound Organisation table to…
Sidebar 3: Measurements
I estimated the voltage sensitivity (using 1/3-octave pink noise centered on 1kHz) and measured the change of impedance with frequency, while the nearfield low-frequency response of each speaker was assessed with a sinewave sweep to get an idea of the true bass extension relative to the level at 100Hz.
The Acustik-Lab Bolero's modulus of impedance with frequency is shown in fig.1. Typical of a 4 ohm design, it stays below 8 ohms most of the time, the only exceptions being in the region of the tweeter resonance and the twin reflex humps in the bass. The…
Do-It-Yourself (DIY) loudspeaker projects are quite common in the UK, where details about several excellent designs, including a recent one by Martin Colloms, have been published for public domain consumption. Stateside, the situation is rather grim, where only an occasional subwoofer project (always popular) makes it into the commercial magazines.
Whatever this imbalance may say about American audiophiles, it speaks well for the British attitude toward good sound; home construction offers the audiophile a ticket to kilobuck sound quality at a fraction of the cost. Generally, there's a…
Sidebar 3: Specifications
Description (Bolero): Two-way, reflex-loaded, stand-mounted loudspeaker. Drive-units: 1" hard-dome tweeter, 5.25" plastic-cone woofer. Crossover frequency: approximately 3kHz. Frequency response: 50Hz–19kHz ±3dB. Sensitivity: 90dB/W/m. Nominal impedance: 4 ohms. Amplifier requirements: 10–60W.
Dimensions: 14.125" H by 7.75" W by 9.4" D. Weight: 17 lbs each.
Price: $1580/pair (1989); no longer available (2018).
Description (Forte): Drive-unit: 6.5" doped paper-cone woofer. Crossover frequency: approximately 150Hz. Measured –6dB point: 32Hz.…
J. Gordon Holt reviews the Dahlia, from February 1986 (Vol.9 No.1):
Visibly, there is nothing to distinguish Dick Olsher's Dahlia design (see later) from hundreds of other small speakers—except, that is, that it's uglier than most such. Although our samples were superbly finished (Dick Olsher bought them from a professional cabinet maker), the enclosures' dimensions were apparently chosen according to acoustical dictates rather than aesthetic considerations. The resulting shape is rather squat, like a kneeling dwarf.
Since I haven't tried putting one of these together according…
The Dahlia Debra: Dick Olsher updates his DIY loudspeaker design, from June 1987 (Vol.10 No.4):
Since the publication of the Dahlia do-it-yourself speaker article in February 1986 (Vol.9 No.1), I've been inundated with requests for clarification of construction details and additional information. I'm very pleased that the Dahlia has been received so favorably and wish I could personally acknowledge each and every one of your letters. To have done so, however, would have kept me very busy for a long time, and would have precluded additional research work on my part. Instead, let me take…
Martin Colloms offered a different tuning of the Dahlia in August 1987 (Vol.10 No.6):
In Vol.9 No.1, Dick Olsher offered a neat two-way loudspeaker design which exploited the virtues of the Son Audax 8" bass/mid unit, a TPX-coned unit which I also favor. As Dick could not avail himself of measurement facilities to determine the flatness and balance, his crossover was more or less to "book." Having tried his network, I found the resultant sound rather forward and lightweight compared with neutral, commercial, BBC-balanced references, while the bass, in my opinion, was not fully…
Sidebar: Specifications
Description: Two-way, do-it-yourself dynamic bookshelf system with 1" soft-dome tweeter and 8" TPX-cone woofer in vented enclosure. Impedance: 8 ohms. Rated frequency range: 60Hz–18kHz. Nominal impedance: 8 ohms. Rated power: 50W maximum.
Dimensions: 14.5" W by 20" H by 12" D.
Price: approx. $200 for parts (1986).