Saturday, 11 December 2010

A Third Way






















Over the last thirty years speakers have evolved into two basic types, two way and three way. The former are by far the most popular because they are smaller, they only have one crossover and it is high enough up the frequency range not to be overly intrusive. 
Three way speakers have more problems and tend to be less well liked, unless they are in a large enough room not to boom and for listeners to be a good distance away from them. This is because they have a second crossover in the region of middle C, which is very intrusive. They harshen sound  and the phase distortion they produce causes discomfort.  Also passive crossovers are very lossy and make for boomy bass. 

Big passive three ways struggle to avoid boom and tizz and even small passive two ways have intrusive crossovers as the tremendous success of ADM9s has shown. They don't suffer from the unpleasant artefacts produced by a passive crossover.

We've called our forthcoming generation of speakers the Third Way because they are different and better.

1. ADM40s are floor standers approximately the same size as ADM9Ts on stands, each housing a purpose built 10" Sub driver in a sealed volume large enough to allow useful output down to 30Hz. 

2. Because the bass driver in the ADM40s crosses over to the mid at 100 Hz rather than 250-400 Hz in older designs, artefacts that are so intrusive at higher frequencies are inaudible and merging is seamless. 

3. This low crossover point means the ADM40s can have an unfiltered Low Frequency Effects input for an AV processor and a gain control (from handset) to adjust normal stereo bass levels to suit different room acoustics and or recordings. 

4. At the same time, applying a crossover to the lower end of the 6.5" mid driver reduces its cone excursion and intermodulation distortion, which in turn allows a worthwhile increase amplifier power for more dynamic range. 

5. ADM 40s will have a total RMS power per speaker of around 750 Watts and be able to produce instantaneous peaks of an incredible 3000 Watts or over 120 dB! To anyone considering one of a recent proliferation of "one box, audio only solutions"  with measly 25 Watt amps, this may seem ridiculous, but it isn't at all because modern movie and TV sound tracks (and the best music recordings) all have a dynamic range and bass extension that needs it! 

Needless to say this doesn't mean ridiculous SPLs are the norm, although ADM40s will play as loud as a Wagner Opera or AC DC without distorting if you want them to. Much more important is that that they avoid the inevitable (and irritating) congestion/distortion that lower powered amps produce on loud passages. With adequate power everything appears cleaner and more clear at all levels including normal family ones. 


Our next blog will provide a much overdue explanation of the need for more power where high quality sound reproduction is the objective.

None of the above is practical with big old, three way speakers, so if you buy a pair of them and they boom when you get them home, your money is wasted!

Conclusion

By combining the best of modern subwoofer and two way speaker technology in a compact active, three way, AVI have produced floor standing speakers that have the most dynamic range of any available, the cleanest, purest sound you will hear and without any ugly metal boxes or even a separate sub. 


ADM40s  will easily outperform more expensive, old fashioned three way speakers several times the size and price.