Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: notesfiles Path: utzoo!watmath!clyde!floyd!harpo!seismo!hao!hplabs!hp-pcd!hpfcla!rmd From: rmd@hpfcla.UUCP Newsgroups: net.audio Subject: Re: More Magnapan info Message-ID: <13100008@hpfcla.UUCP> Date: Mon, 12-Mar-84 15:13:00 EST Article-I.D.: hpfcla.13100008 Posted: Mon Mar 12 15:13:00 1984 Date-Received: Wed, 14-Mar-84 19:24:42 EST References: <333@dual.UUCP> Organization: Hewlett-Packard Fort Collins Systems Division - Fort Collins, CO Lines: 35 Nf-ID: #R:dual:-33300:hpfcla:13100008:000:2033 Nf-From: hpfcla!rmd Mar 11 12:13:00 1984 I think that the low end rollof of the Magnaplanar MG-IIBs (the model I bought) is actually worse than the numbers you give -- at least for my listening room. However, I don't think that the effect on music is a significant as you seem to imply. The bass response of the Magnaplanars is deep enough to be quite enjoyable for most rock music and it is much more accurate and uncolored than most speakers. I think that most people who object to Magnaplanars are used to response peaks in the 80-100 Hz and 10-12 Khz regions (typical of many conventional speakers). I spent a lot of time measuring the room response of my MG-IIBs with a flat microphone and a signal generator. My goal was to match a subwoofer to the MGs. I found that the base response was relatively independent of speaker placement (contrary to Magnepan's literature) and that the MGs peaked slightly at about 65 Hz and then rolled off at about 35db per octave, becoming essentially unmeasurable below 40 Hz. I would consider them 'flat' to about 57 or 58 Hz. I didn't make any measurements at high frequencies. I finally came up with a crossover that cuts off the subwoofer at 30db per octave above 50 Hz. This high crossover rate results in a combination that is within .5db of the original MG response above 65 Hz and adds about 6db at 50 Hz. It turns out that with this crossover, much pop music is almost totally unnaffected by the subwoofer. Even songs like the Eurythmics' "Sweet Dreams" or the Beatles' "Come Together" with apparently loud and deep bass really don't have much below about 60 Hz. There are many pop recordings with bass content down to about 48 to 50 Hz and for these the subwoofer makes a noticeable (but relatively subtle) improvement. The only really striking difference is for classical music with a bass drum. This kind of music goes down to under 25 Hz. However, very few conventional speakers go down this low. Rick Dow inhp4!hpfcla!rmd