Phil Leigh;544239 Wrote: > I've been thinking about Darren's comments on the DSP x-overs... > > I'm not sure of the block diagram of the Meridian DSP speakers, but > with any multi-way speaker the driver sensitivities are usally > different by a small number of dB. One of the benefits of (any form of) > active crossover is that this can be taken care of - and response > flattened - in the x-over at line level. > > Given that the DSP's have digital x-overs... and that a digital x-over > (unlike an analogue one) cannot boost (>0dB!)... > > IF the drivers need to be adjusted for relative sensitivity (which is > almost certain) then there are 2 ways Meridian could do this: > 1) by altering the relative ANALOGUE gain of the power amps, post > x-over > 2) reducing the level of some of them DIGITALLY by different > amounts... > > If they used method 2... then regardless of what you put in, you won't > get 96dB of SNR/Dynamic Range out on redbook material. > > Hypothetical example - let's say the bass and tweeter have > sensitivities of 90dB but the midrange has one of 87dB. > > The Bass and Tweeter will need 3dB of attenuation. This is ignoring any > additonal DSP (ie attenuation!) required to flatten the in-band > frequency response of the individual drivers themselves. > > They could be using a hybrid approach with make-up gain in the analogue > power amps as well as DSP attenuation. > > Therefore the problem/issue that mswlogo is describing may well be > confined to/exacerbated by the Meridian implementation. > > This is all speculation - but it would explain the differences in > opinion/findings in this thread! Exactly, thanks Phil. I think even with analogue boosting each crossover band, which is best case, you're still left with DSP EQ in-band - shifting bits down (in some or perhaps much of the frequency range). Darren
-- darrenyeats http://www.amazon.co.uk/gp/richpub/listmania/byauthor/A3H57URKQB8AQO/ref=cm_pdp_content_listmania/203-7606506-5721503. (Inguz bass EQ'd) SB3 -> (pre bypassed) Krell KAV-300i -> PMC AB-1 (caps bass EQ'd) Desktop -> Genius Slab SW-flat2.1 700 Sennheiser HD 25-1 II ------------------------------------------------------------------------ darrenyeats's Profile: http://forums.slimdevices.com/member.php?userid=10799 View this thread: http://forums.slimdevices.com/showthread.php?t=77725 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
