Differences between small vs. large mid driver


What are the advantages of using a small (3 - 4in.) vs. large (6 - 7 in.) midrange drivers?

What I notice is that expensive speakers tend to use smaller midrage drivers. For example, the more expensive speakers from Proac (Future One) and Meadowlark (Blue Heron)use small mid driver while the less expensive either use a large mid or two large driver for mid and bass.
andy2

Showing 1 response by gregm

While I agree with the gist of the above, I beg to differ slightly. Since I listen to large orchestral music, I need authority, dynamics -- the ability to excite lots of air.
So, for the ~100->8-10kHz part I would use a wide-range 8-12" (supravox, lowther, goodmans, etc). The trade-off here is beaming...
For the upper range, a super tweat to over 25kHz. The trade-off here is the difficulty to align the acoustic centres of tweet & wide-range (at 8kHz the lambda is very small => the margin of error is high).
For the lower register:
At least one 15" per channel for bass (two for open baffle).
At least one 18/24" per channel for 20-45Hz. The trade off here is cost and cost (cost of drivers, cost of amplification).

Overall, such a construction ideally needs a minimum of three amp channels per side. Passive filter for crossing to tweet; Leave the wide-range free on top, cut it with a soft LPin the bottom. Active or PLL for the rest.

Wishfull thinking, eh?