Jeg har lest flere steder på forumet at BAM vil forårsake en del ulemper i form av effektsug etc... Her kan du lese hva konstruktøren selv skriver... interessant
imho, there is no downside to the bam. the eq is in a very narrow bandwidth from 30 to 60 hz and centered at 35hz with a 5.2db boost. up 2db at 45 and 1 at 60, gone at 30. when you filter out all of the energy under 30, how much power are you saving? alot depending on the material. and a 5.2db boost over a very narrow band in less than a doubling of the power in the range and not 3.5x. so if one tries to make a box big enough to go to 32 like a competitor's speaker with a similar woofer, the usable sensitivity goes down to 84db from the vsm's 89. now there is another 5db. and with the bigger encloser the woofer has less pressure on it so the mids suffer, the woofer is more easily unloaded causing reduced playback loudness potential and much increased distortion. with the bam in, you can use a much lower powered tube amp than with a speaker using the same woofer in a large cabinet and the impedance of the vsm will undoubtedly be flatter and easier on the amp. impedance fluctuation causes increased or decreased output at a given frequency depending on whether you use ss or tubes.
the bandpass is a must for all speakers...period. the more uniform the speaker and the more continuous it sounds, the more resolution it has. then things like rfi and emi in big cities is obvious and detrimental to the overall sound.
when you play any woofer or midwoofer below its fs, you do so with increased im distortion in the usable bandwidth. this makes the mids sound fuzzy and destroys the contrast. and when you play a woofer below its fs, the excursion takes the woofer out of linear drive in the magnet and the distortion goes way up and the maximum output level is greatly reduced. hook a voltmeter/impedance to a woofer and push the cone in. now it is taken out of linear drive and the impedance skyrockets. think what this is doing to the amp and what it causes. this causes 2nd and 3rd order harmonic distortion and the usual chugging or booming of typical speakers. all speakers would benefit by bandpass filtration...period!
anyone who does not see this is stuck in the forest and cannot see the trees. one listen and you hear that so much is improved in the sound that you cannot live without it.
there this one made it.
best,
b