November 2015

A little over a year ago, I seemed to run into Bluetooth minispeakers everywhere. Somehow, I missed the Koss BTS1. Koss is known for making affordable, high-quality headphones -- they have dozens of models -- but the BTS1 ($59.99 USD) is their only Bluetooth speaker of any size. Since the various Koss headphones I’ve tried over the past six months have all proved splendid, I jumped at the chance to review this tiny speaker.

Koss BTS1

In the box

The little BTS1 -- it measures just 4”W x 3”H x 1”D and weighs a mere 5.8 ounces -- is displayed in a half-clamshell case of transparent plastic. It’s easy to see the speaker before removing or purchasing it. A small cardboard box built into the clamshell contains the accessories: a USB-to-USB-Micro charging cord, a 3.5mm-to-3.5mm cable, a soft carrying case, and odd-sized (4.4” x 2.4”) instruction and warranty booklets.

Though so small, the BTS1 feels solid in the hand, and seems of very good build quality. Its front is all gray grille, and centered behind it is the Koss logo in ghostly white. Also behind the grille are LEDs: blue to indicate Bluetooth functions, red/magenta for off, and orange to indicate charging. As in so many Bluetooth devices, turn-on and turn-off are also indicated by sounds: ascending and descending musical scales.

Koss BTS1

The body of the BTS1 is white plastic with gracefully rounded corners, and the right side and bottom are smooth and uncluttered by controls or jacks. Along the left side are 3.5mm input and output jacks, and a USB Micro charging port. The output jack can be used to daisy-chain another BTS1. Along the top edge are three buttons: one for On/Off and Bluetooth pairing, flanked by buttons for Volume Up and Down.

The back is framed by a ring of gray, nonskid rubber, so that the BTS1 can be placed on its back for maximum sound dispersion without bouncing around. There’s also a little pull-out, easel-type stand so that the BTS1 can be stood up and leaned back at an angle for listening. The BTS1 is also weighted stably enough that it can stand on its bottom edge, without the stand.

Koss BTS1

Koss claims a playing time of five hours from a fully charged battery; I found that to be about right. Five hours is less than many other Bluetooth speakers offer, but the BTS1 takes very little time to charge -- and if you run out of juice, you can use it wired.


The BTS1 paired easily with all of my Bluetooth devices. Its range was about the norm for my house, with its many interior walls: about 21’. Unobstructed, the distance would no doubt be greater.

All of the controls worked as they’re supposed to. The volume and play controls are arranged so as to preserve the BTS1’s smooth surfaces, but protrude just enough that they’re easy to press.


Of course, the BTS1 is not a full-range speaker. Basically, it covers the midrange and highs very cleanly, and can play at good volume levels in an average-size room. I found that its sound could be quite good with recordings that have little bass content. The Boston Camerata’s A Medieval Christmas (16-bit/44.1kHz ALAC, Nonesuch) came across quite well, with chorus, upper reeds, and tambourine all sounding natural and tonally complete.

Koss BTS1

J.S. Bach’s Brandenburg Concertos, with Reinhard Goebel conducting the Musica Antiqua Köln (16/44.1 ALAC, Archiv), were quite listenable because the bass is not heard very well (it doubles the cello line, which can be heard). The BTS1 was well suited to recordings of solo guitar, lute, or banjo -- Ronn McFarlane, on his Between Two Hearts: Renaissance Dances for Lute (16/44.1 ALAC, Sono Luminus), was heard to great advantage through the Koss. Except for the Beatles, most rock came across as much too tame, robbed of its punchy bass. Jazz was variable, depending on the instrumentation and complexity of the mix.

In sum

For what it is, the Koss BTS1 has a lot going for it: It’s good for background listening with music you’re already familiar with from having heard it through bigger, better speakers. It’s sturdy -- you can throw it in a backpack or gym bag without fear -- it gives you a choice of three different listening positions, and it plays at respectably loud volume without distortion. At $59.99 it’s good value for dollar.

. . . Rad Bennett

Associated Equipment

  • Apple iPod Touch (third generation)
  • Astell&Kern AK Jr digital player

Koss BTS1 Bluetooth Speaker
Price: $59.99 USD.
Warranty: One year, limited.

Koss Corporation
4129 N. Port Washington Avenue
Milwaukee, WI 53212
Phone: (800) 872-5677