Speakers at any price point are always a matter of trade-offs, and the lesser the budget, the more compromises the designer has to make. Designed by Andrew Jones of TAD fame, the Pioneer SP-BS21-LR is a compact rear-ported mini-monitor utilizing a 1" soft dome tweeter and a small 4" woofer. According to online resources, Jones tried to maximize the sonic results with a custom cabinet, a multi-component crossover design, and OEM drivers. Efficiency is an extremely low 84dB, meaning some good solid-state amplification may be the best thing around when driving these speakers. Prices for the pair range from $49 or more, depending on the vendor. This is hardly the dollar amount that audiophile wonders are made out of, but more on this later.
Small stands or placement on a large bookshelf would be suggested. I use mine sitting on a table in a small recording studio, suitable for playback while playing synth, or for monitoring mix-downs. I basically wanted something cheap, fairly neutral - or at least with a coloration that was easy to hear around - and enough toughness to handle a sudden sonic overload. The SB21s delivered this at a price point that made my wallet breathe a sigh of relief. Using the Dun Mei LM3886 amplifier, sonics for mix-downs was surprisingly good, sounding much like my Sennheiser 570 headpones. The treble was smooth, the midrange fairly good, and the bass had a nice growl. I was curious enough to give these a listen with some more serious amplification.
I pulled out a B&K ST-140 down from the shelf. Preamp duty was done by my retired Audio Research SP-7. Signal source was a Sony SCD-CE595 SACD player. Wiring was Belden interconnects and Canare speaker wire. Hardly a upscale system, but better than your average receiver.
First up was a SACD - David Bowie's Scary Monsters - a classic 1980 gem that was the last burst of Bowie's creativity before his plummet to more pedestrian pop. Through the Pioneer Speakers, the sound was quite dynamic with good (for the speaker size) bass definition. It is also clean and with an easy, non-aggressive treble. Soundstaging depth is fairly flat, but left-to-right sound placement was quite good. Sure, the sonic results weren't close to my Magnepans or even my lowly KEF speakers, but any problems were sins of omission. Some detail was missing and the more dynamic parts of the music were slightly congested, with a bit of wooden chestiness. There was also some minor 'blurriness' to the images, but I've heard much worse at higher price points. A few more discs later, and my thoughts were extremely positive about this speaker. Sonically it reminded me of some older Dynaudio kit speakers I once owned in college, or even of some older Wharfedale Diamond Vs.
When I finally came upstairs, I mentioned to my wife that I was listening to the Pioneer speakers. She looked surprised, commenting that she could feel the bass coming through the floor. She thought I had been listening to the Magnepans! Not bad at all for just a 4" woofer.
So highly recommended - but within their limitations. A perfect dorm or teenage speaker, it will also work well for a second system. I would also recommend some amplification that can deliver some current, since the low-efficiency will eat up power.
