Posted by MARCOS AUGUSTO on September 16, 2002 at 23:07:42:
In Reply to: Re: Re: Re: M-1 Sensitivity posted by Roy on September 16, 2002 at 00:50:44:
Hey Roy,
i implemented crossing over my A-1's at 80Hz by using a pair of PARADIGM's X-30 crossovers which were reviewed by "AUDIO MAGAZINE" in the april '98 issue and found to be rather accurate, neutral- sounding and fully adjustable, especially considering their price (they only cost me $250 for the PAIR and packaged with EACH unit is an audiophile-grade subwoofer cable measuring 23 feet long!)
each crossover has a control for subwoofer level, a control for low-pass cutoff (variable from 35 to 150Hz), and a fully variable subwoofer phase control (which affects only ONE of the two mono subwoofer output jacks on the rear panel, that being the reason i purchased TWO X-30 crossovers, so that each one enables me to fully control left and right stereo subwoofers for the main channels,INCLUDING THEIR PHASE-RESPONSE !).
each crossover also has high-pass filters (with separate line-level stereo outputs jacks for 50,80 and 120Hz cutoff frequencies), which are located on the rear panel.
so, if you are planning on using just a single subwoofer while still being able to control its phase-response, obviously you don't need to buy two
X-30 crossovers, just one would give you all the controls you need...
although keep in mind that you only have THREE choices for high-pass stereo outputs to the main speakers at 50,80 and 120Hz frequencies, which, in my particular case with the A-1's, i figured 120Hz is somewhat high, 50Hz would be just right if i only used my A-1's to listen to music at moderate levels up to 90dBs as well as no home-theater "DVD bass extravaganza" application (which i do!), leaving me with just one choice, the 80Hz high-pass cutoff frequency, which, thanks to PARADIGM's prescience, turned out to be the standard frequency cutoff point for dolby digital...
insofar as to the subwoofers i purchased, they were the GENESIS TECHNOLOGIES 928 : each one has TWO 12" metal woofers servo-controlled for extremely low distortion, firing from opposite sides of the cabinet (also, because they use two "smaller" 12" metal woofers they are much "faster" than 15" or 18" woofers while still moving as much or even more air !)...
i set up each subwoofer right next to each A-1 as part of the main left and right front- channels, and i made sure to have one woofer firing towards the listener and the other woofer firing towards the front wall of the room. by doing so, i was trying to somewhat mimic the dipole radiation-pattern of electrostats...
actually i was always amazed with the bass that the A-1's are capable of reproducing, it is just that sometimes i tend to listen to "techno" music at levels over 100dBs as well as to DVD's which sometimes exhibit an overwhelming amount of bass, so i was beginning to feel concerned about somehow damaging my A-1's, therefore deciding to "liberate" them from reproducing low bass frequencies, while at the same finding a pair of fast, very low-distortion subwoofers that would be capable of keeping up with the A-1's while still being affordable.
...so far, i have been very, very pleased with my choice of the GENESIS TECHNOLOGIES 928 subwoofers.
the company went out of business late last year but has recently re-entered the market under new management while still keeping the original designer of the legendary GENESIS loudspeakers of years past.
....and, by the way, i understand that MARCHAND ELECTRONICS also manufactures highly regarded crossovers, albeit at much higher price levels than the PARADIGM X-30 i mentioned above.