10" bass driver for studio monitors

A solidly built bass driver with a low Qts most suitable for bass reflex enclosures. When used for sealed or dipole operation, bass extension will be limited somewhat. But low Qt drivers offer superior cone control in all cases and so are preferrable except where cost is a major consideration.

A coated paper cone of relatively low mass and a powerful motor combined to give reasonable efficiency of about 89dB/w/m. The paper cone also helps to minimise the severity of breakup modes in the upper registers but typically limits high frequency pistonic motion compared to a stiffer cone material.

The driver also claims to have dual spider, extended voice coil and symmetrical magnetic structure for reliable operation and low distortion at high excursions, although no evidence of any these claims were found.  

The frequency response test is of 2x B250.8 in parallel in a 60L sealed enclosure with centre to centre spacing of 280mm. Amplitude response is smooth up to around 300Hz where it begins to drop away. This is caused by interference effects between drivers and should not be taken as a deficiency of the driver itself. The phase response is smooth up to around 300Hz-400Hz where a few ripples begin to show. The first breakup mode occurs at around 800Hz and as such the driver should be rolled off well below this frequency.

The bass driver in a system is responsible for producing the fundamental tones of most instruments including the human voice. Listening to the B250.8 reveals few surprises. Solid bass performance giving life to lower register instruments. Punchy bass with plenty of extension even in a relatively small sealed enclosure. As suggested by the measurements, the driver is best suited to bass duties and sounds soft and unconvincing higher up. I recommend not using the driver above 300-400Hz for best performance. Using the driver in a ported enclosure will additionally assist low frequency extension at the risk of increased group delay.

A key aspect when considering which drivers to use is the quality of support for the product. Warranty and the availability of spares in years to come are particularly important. Unfortunately Volt in the UK fail badly here. There is no advice provided to prospective users and the staff at Volt come across as abuse and unhelpful. Thus I would recommend staying  clear of this company's products and looking at other similarly performing and far better supported drivers.

Better value can be found elsewhere. While the B250.8 performs well, it's price is excessive and the lack of decent support make it a risky investment.