Audio Database


1,950yen(1958 release)

The 16cm most typical full-range speaker unit of a Diatone.
Although P-610 is the first model and the fine partial model change was carried out after that, while it had been a form at the time of a release mostly, it was sold till 1996.

P-610 has obtained success of the industry beginning to the BTS standard which NHK defined.

The matching transformer is attached to P-610 which is an initial model, and use by two kinds of impedance, 6ohm and 600ohm, is possible.
For this reason, the marks of the attachment hole of this transformer portion remain in P-610 series put on the market after that.
Moreover, only impedance differs from P-610 A/P-610B.

In order to enlarge effective magnetic flux density in a magnetic circuit, malleable iron was used, and the dumping which was excellent as aperture class of 16cm, and high efficiency are acquired.

The consistency vibration type of the design of an orthodox approach was used for the corn part, and it has acquired the characteristic of the broadband with the single corn with corrugation and free edge.


Rating of a mode
System BTS-6121 success single corn type full range
Aperture 16cm
(400Hz o'clock)
At usually, the time: 6 ohms ±0.6ohm
At the time of attached output-transformer wearing: 600ohms
Maximum permissible input 3W
Output sound pressure level 97 dB/W (with 50cm)
Play frequency band 80Hz-10000Hz±5dB (survey data attachment)
The minimum resonance frequency 80Hz±8Hz
THD 5% or less (Input 1W, 100Hz or more)
Magnetic flux density 10000gauss
Effective oscillating radius 6.5cm
Equivalent mass of a vibration system 6.5gr
Equivalent Q0 of a vibration system 0.8
Voice coil diameter 1.92cmphi
The total magnetic flux 8.5x104maxwells
Permanent magnet 30phix25
The diameter of baffle opening 135mm
Dimensions Width 173x depth of 94mm
Weight Nothing [ transformer ]: 0.75kg
Gross weight: 1.2kg (transformer included)