Plantronics BackBeat 500 On-Ear Bluetooth Headphones Measurements

Measurements Wired

Click on graphs image to download .pdf for closer inspection.

Raw frequency response plot show very little change with positioning on the ears. I do think these pads work very well.

Bass boost of 5dB is good, but boost goes to high coming down to it's midrange minima at around 400Hz where is should be down by 150Hz. This was evident in listening but subjectively not quite as much as measurements might indicate.

The rise to the 3.5kHz peak starts Nicely at around 600Hz, but begins to rise too quickly 1kHz-2kHz, which can be seen as a small plateau there in the compensated curve. After 2kHz the curve begins to fall away from target; the peak at 3.5kHz should be about 3dB higher and subsequent treble remains about 3dB low until 12kHz where it's level is about right. Subjectively I heard this as a papery or cardboard character.

30Hz square wave has good shape. The nice linear waveform top coupled with low distortion in the bass are indicative of the solid, punchy bass heard.

300Hz square wave clearly shows lack of a quick rise and initial transient height echoing the under powered treble, as does the rising wave form top subsequently.

Both 300Hz square wave and impulse response show a pretty minimal level of noise subsequent to the initial transient. Distortion is remarkably low. I did hear these cans as quite clean.

Impedance is ruler flat at 36 Ohms. This is a good sign that the acoustics around the driver are behaving well.

Isolation is about average for a sealed on-ear at -20dB broadband.

Needing 94mVrms to achieve 90dBspl at the ear, the BeackBeat 500 is a little inefficient and may not quite play loud enough for some on portable devices.

Measurements Bluetooth

Click on graphs image to download .pdf for closer inspection.

The picture significantly changes without the wire. Bass boost rises to 10dB centered at 45Hz, which is 5dB too much. Fortunately, it now extends less into the midrange coming to baseline now at around 200Hz. The rise to 3.5kHz again starts well at 600Hz, but now rises fast to the peak, which is now at proper height. Now the plateau between 1kHz and 2kHz on the compensated curve is a dB or two more prominent than in wired mode. This matches well with the subjective impression of a more shouty sound with Bluetooth. A peak is now clearly appearing at 7kHz...not good.

30Hz squarewave is significantly swayback, likely due to phase shift through coupling caps in the electronics. 300Hz square wave shows better height on initial transient, but it's very sharp shape is not optimal and is likely due to the 7kHz peak.

Distortion plots are a little higher overall due to noise from the electronics, but this level shift is minor...I didn't hear any noise.

Plantronics obviously does some tuning with the electronics. I think they would have been better off just leaving it alone; the wired performance of the native drivers and acoustics is markedly better.

Oh well.

Plantronics, Inc.
345 Encinal Street
Santa Cruz, California 95060

gibtg's picture

Thanks Tyll for taking the time to review some more reasonably priced offerings!