Johnny TN Posted April 4, 2004 Share Posted April 4, 2004 Ok dont say the ones in the academy...looking for other opinions..not necessary Klipsch..I want to add 2 8" woofer to my center channel plans of : AA Crossover K55V / K400 midhorn K77 horn tweeter Electromagnetically shielded a plus, but not 100% necessary.. TIA, Johnny Quote Link to comment Share on other sites More sharing options...
Malcolm Posted April 4, 2004 Share Posted April 4, 2004 What's wrong with the ones from the Academy? Last time I checked, you could still get them from Klipsch. FWIW I considered building something similar some time ago. My choice in 8" would be a pair of old alnico magnet EV SP8b or University C8W. Just be aware that these are not particularly high power speakers. And, of course, you will have to do something to match the output levels of the woofers to the rest of the system. If you would consider 10" woofers, CTS made some decent ones with large alnico magnets in the early 70s. Might be more difficult to find than the 8" woofers I mentioned above. And if space is not a issue, a pair of the 12" alnico magnet woofers used in the Heresy up to the mid 70s would make a killer center. Quote Link to comment Share on other sites More sharing options...
Johnny TN Posted April 4, 2004 Author Share Posted April 4, 2004 EV's you mentioned are 16ohm right...dont I need 8 ? thanks for the recommendation though..I would be nice to get something w/alnico Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 5, 2004 Share Posted April 5, 2004 Wiring two 16 ohm speakers in parallel will result in a net of 8 ohms. If you find a 4 ohm woofer that meets your needs, then you can wire two in series to get 8 ohms as well. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 5, 2004 Share Posted April 5, 2004 How low do you want your center channel to reproduce? How large of an enclosure can you live with? Fwiw, the voice coil couldn't care less if the flux ( energy in the magnetic gap ) is produced by ferrite, alnico, neodymium, uraunium or unobtainium. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 5, 2004 Share Posted April 5, 2004 Take two Eminence beta 10b ( 16 ohm ) and wire in parallel you get an 8 ohm impedance and has a high enough sensitivity. ( 101 db sensitivity with 2 in parallel ) They are 10" though, if you want 8", the beta 8" is only available in the 8 ohm version, so if you wire these in parallel, you get a 4 ohm load for the crossover. This requires changing out some values of inductor and capacitors to get the same crossover point for a 4 ohm speaker, as you would with the 8 ohm load on the network. The Eminence beta 10b sells for $51.47 each at parts express, their # 290-411, and the beta 8 sells for $ 47.06 each # 290-404. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 5, 2004 Share Posted April 5, 2004 Oh, and these are DEFINATELY not shielded! Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 5, 2004 Share Posted April 5, 2004 Just ran some numbers in the parts express box program. Looks like 2 beta 8" in a 4.06 cu ft ported enclosure would be quite nice. Of course you could make a smaller enclosure, but this would be the maximally flat response. The numbers are as follows, 4.06 cu ft enclosure ( internal measurements are 30.97" x 19.14" x 11.83" ) with 4 2" diameter ports 1.83" long. Tuning frequency comes in at 52.17 hz with a theoretical f3 of 45.32 hz. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted April 5, 2004 Share Posted April 5, 2004 In a sealed enclosure of 1.62 cu ft, the beta 8 barely makes an f3 of 92 hz, so you may consider building the ported enclosure instead, if this isn't low enough for your needs. ( a heresy goes lower ) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.