Yes, I agree that the
older numbering convention is pretty non-intuitive ( and that's what those 5642's of yours are / they're an older generation of Gauss ).
A Multi-Meter will confirm the 16 ohms impedance for you ( ie; it'll read @ 11- 12 ohms if your speakers are 16 ohm ).
They are the 16 ohm equivalent of the 8 ohm 4582 ( so 4562 ) . They use an alnico magnet.
They're a short coil version of your existing 4583's ( but still have the standard 4 1/8" diameter voice-coil ) .
re; Recones
- You might of noticed that the eBay link I posted some 6+ years ago now shows that company is no longer active ( at least on eBay ).
That's really a shame because the only other option ( for the DIYer ) is not a good option for any novice ( like yourself ).
Your latest acquisitions can be reconed into 4583's ( since they share the same 4 1/8" VC diameter ).
Gauss 4583 Recone Kit
or kept as 4582's ( which were more efficient / but have a lot less available cone travel, ie Xmax )
- the comparable JBL model to the 4583 is the 2234 while the older JBL D140 roughly equates to the Gauss 4582 ( the short coil really meant it was best suited for horn-loading or M.I. work ).
http://reconingspeakers.com/wp-conte...-2-300x300.jpg
I would suggest you find a reconing outfit with connections to these same aftermarket parts ( as used by the people in my new link ) and have pros do the work.
:)
PS; Glad to hear those other 4583s are still rockin for you.
Here's a link to the
"deep" VC SpeakerX supplies ( it comes from MWA, the lack of any former venting is a bit of a concern IMO );
http://reconingspeakers.com/wp-conte...-8-300x300.jpg