ISUB-12 & ISUB-18
Home Theater and Studio Powered Subwoofer Systems
As seen in Widescreen Review Magazine
The Bag End ISUB-12 & ISUB-18 Self-Powered Subwoofer Systems are used in both professional and home theater settings.
Bag End subwoofers are known for their quick, tight, and musically connected sound. Back in the 1980’s, Bag End implemented the Time Align and ELF (Extended Low Frequency) technologies into their ISUB-12 & ISUB-18 designs. Time and phase are important performance parameters for the accurate reproduction of the input signal by a loudspeaker. This technology was licensed from E.M. Long and Long/Wickersham Labs.
Behind the Technology
The ear/brain system may be even more sensitive to time cues than it is to amplitude variations. Certainly, paying attention to both factors in the design of a loudspeaker is necessary to fully preserve the original sound recording.
The time response characteristics of a subwoofer are very difficult to measure. As a result, they have been virtually ignored by most manufacturers. Most subwoofers don’t integrate well with the main loudspeakers. Bass often sounds disassociated from the midrange, and the basic character of all sounds is subtly changed when a subwoofer is added to a system.
Today the newer INFRA systems are an updated version of the original ELF systems. They utilize much of the same technology and the same fundamental thinking. Bag End INFRA systems include updated SMD (Surface Mount Device) technology and additional driver and cabinet configurations.
Bag End subwoofers do sound different, with a resonance-free clarity and startling pitch definition that is unmatched by most other designs.
It’s the frequency that takes the least energy to excite, and the system favors this frequency over others. When a complex transient signal enters a loudspeaker system it excites all frequencies… but at resonance the system plays louder and persists more in time as compared to the other frequencies. This is why it is desirable to reduce the influence of the resonance so that the loudspeaker is not creating additional sound that is not in the recording. It is useful to operate any transducer outside of its resonance, as is typically the case with a good loudspeaker, phono cartridge, and microphone design. A strong resonance in a loudspeaker can blur and mask the details in the original sound.
Widescreen Review uses the flagship 18-inch INFRA subwoofers ( ISUB-18) in two of our reference systems.
For complete article by Gary Reber see Widescreen Review link.