Hello,
Thanks for your post. The selection of 85 Hz for the crossover frequency is the result of many comparative listening tests we did few years ago. It is also a choice related to the main loudspeaker LF extension which should be in all cases lower than the selected subwoofer crossover frequency.
Concerning the 'standard' 80 Hz crossover frequency you mention, our first generation of subwoofers were released in 1994. These products were the 1092A and 1094A. At that time such 'standard' frequency of 80 Hz was not popular or even mentioned at all. Later, with the strong development of multichannel audio systems, various frequencies became common in consumer equipments, such as 60 Hz, 80 Hz, 100 Hz or 120 Hz.
The following research paper is an interesting reading on the subject: (
http://www.aes.org/e-lib/browse.cfm?elib=12156)
The choice of 120 Hz is the defacto in 35 mm film mixing and Dolby is the main actor in that scene and advocating for many years for the 120 Hz. Some years ago, Dolby also released some guidelines for 5.1 mixing that said: "Dolby generally recommends limiting the signal to 80 Hz in the console to ensure best uniformity no matter how the program is delivered." This is implemented during the production stage so that the consumer reproduction quality using such 80 Hz crossover can be controlled. Additionally, the 80 Hz crossover frequency is recommended by both Dolby and THX standards, which is the reason why consumer related people are so accustomed to it.
However, the difference between 80 and 85 Hz is very marginal and as our professional monitoring systems and subwoofers are not dedicated to consumer use, such issue of a necessary compatibility with typical consumer decoder 80 Hz crossover setting is not really an issue. Genelec provides full bass management in its subwoofer and the most important issue is the perfect acoustical integration between the sub and the main loudspeakers.
Hope this clarifies your question.
Best regards,
