By now the Gale Electronics factory had moved to Godmanchester and was producing the Gale 301. Initial price was 279 pounds. The reincarnated Gale company (DW Labs version eventually led by MD Alan Coleman) created the GS301, an eight inch two way. It featured a perforated metal grill, its larger stablemate was the GS302.
Frankly, this is an unusual design when one considers the emphasis put on midrange performance with earlier Gale speakers.
Essentially the low frequency unit is pushed to its upper frequency extreme- 3 kHz.
One might consider this a one way single driver speaker augmented with a super tweeter. Curious, as a similar woofer in the GS401 series is crossed over at 475 Hz. It would be very interesting to pull this crossover apart!
The Seas 19TNF/T H305 tweeter is rated to perform from 4kHz to 20 kHz, +/- 3dB. It is intended to be used with a 5 kHz crossover. Gale specifies the crossover point at 3 kHz.
This ferrofluid based model would more typically be used with a three or four way speaker system. rather than eight inch two way.
Excellent Repair Procedures resource: http://www.funkygibbins.me.uk/?page_id=3194
Per member Ian Simpson, “Interestingly the GS302 is not just a GS301 with extra room and ABR’s. The units are different.”
Member shs wrote, “Also refurbed a pair of 302s (unfortunately no photos). I remember the woofer certainly had a larger magnet than the 301, possibly had a larger diameter voice coil. The passive device certainly stood out, in that it didn’t have a separate chassis (cost saving?), it was assembled directly into the wooden enclosure, a little bit fiddly when replacing the foam edge and spyder, especially when bearing in mind the weighted diaphragm. Anyway, all part of the fun.”
A speaker enclosure using a passive radiator usually contains an “active driver” (or main driver), and a “passive cone” (or drone or passive radiator). The active driver is a regular driver, and the passive is typically the same or similar, but without a voice coil and magnet assembly. It is only a suspended cone, not attached to a voice coil or electrical circuit. The passive radiator usually has some means to adjust its mass, thereby allowing the speaker designer to change the box tuning. Internal air pressure produced by movements of the active driver cone moves the passive radiator cone as well.
Passive radiators are used instead of a reflex port for much the same reasons—to tune the small volume and driver for better low frequency performance. Especially in situations in which a port would be inconveniently sized (usually too long for practical box configurations). They are also used to eliminate port turbulence and reduce motion compression caused by high velocity airflow in small ports (especially small diameter ones). Passive radiators are tuned by mass variations (Mmp), changing the way their compliance interacts with motion of the air in the box. The weight of the cone of the passive radiator should be approximately equivalent to the mass of the air that would have filled the port which might have been used for that design. Passive radiators do not behave exactly as do (more or less) equivalent bass-reflex designs in that they cause a notch in system frequency response at the PR’s free air resonant frequency; this causes a steeper roll-off below the system’s tuned frequency Fb, and poorer transient response. Due to the lack of vent turbulence and vent pipe resonances, many prefer the sound of PRs to reflex ports. PR speakers, however, are more complex to design and likely to be more expensive as compared to standard reflex enclosures.
The frequency response of a passive radiator will be similar to that of a ported cabinet, with two exceptions. The system low frequency roll-off in a passive radiator design will be slightly steeper, and will have a notch (dip) in frequency response due to the Vas (compliance, or stiffness of the speaker cone) of the passive radiator. The goal in designing a passive radiator is to adjust the tuning so that this notch is below audible levels.
Gale GS210, 220, and Near Field Monitor
A series of smaller speakers for the cheaper end of the market were produced and badged as 210 and 220, along with these a project was started to produce a high power handling Near Field Monitor for studio applications to be called the NFM it was around two thirds the size of a 401A available in either chrome ends or black Ash finish. This final designated range was to be called the 500 and 520 although 600 and 900 ranges have been found but history not confirmed to date. An available working Near Field Monitor has not been found by our members to date.