Amplifier for my homebuil JBL 4343 speakers

I am upgrading my crossovers to full range passive following the JBL crossover schematic but with appropriate upgrade of the coils and capacitors.   I currently only have an active crossover at the 300 cps crossover point with an Audire amp from probably around 1960 for the high frequency band and a new class D Crown XLS 1502 for the under 300 cps realm.  I cannot get the appropriate active crossover by JBL so am going to go passive with either one amplifier full range or two amps and the crossover bi-wired to have the amps on the passive crossover. One amp will control only the under 300 realm and the other the upper range above 300 cps. What I have been reading of the Lansing Heritage forum on that speaker that after the crossovers are upgraded with new caps and inductors, get a high-end amp like an Audio Research or some other high-quality amplifier.   This post was back around 2004 though, so I am looking for options but under $2500 though.  

Within my system I have both audio and audio video equipment including full 11 channel surround with atmos on a Anthem MRX 1150. All my initial audio equipment is located at the end of the room opposite this video equipment and my main audio speakers, the JBL 4343 pair are at the theater end.


The audio equipment including Accuphase CM 300preamp, Sota turntable with low output Hanna cartridge, Nakamichi tape decks, an Oppo 205 and DAT recorder/player are all 25 feet from my front speakers and movie screen to the Anthem AV receiver and it is set on non modified output for audio from tha audio end of the room. I have not heard any added noise due to the long run of normal RCA cables using very good Belden video grade cable. I feed the line out from the Accuphase, to the Anthem line in to get a relatively high signal from the preamp to carry well over that 25+ feet of audio cable.  My preamp is not equipped with balanced outputs nor do I have an amp other than the Crown equipped with the balanced inputs. The turntable to preamp RF noise pickup however can be touchy at 60 dB of preamp boost to run my Hana low output moving coil cartridge. Other than phono background noise from running that super high when on the record surface, the noise contribution of the long cables is well below my audibility. Recognize this noise is with 110 dB music peaks and 90 dB average level content. CD output is almost dead quiet across that 25 ft cable at that sound level.  

If a new single amp is used I feel it should be over 150 watts/channel. If a separate amp is used for each range, then maybe keep the Crown on the low frequency realm and add a real good amp capable of almost at least 75 watts per channel for the 300 cps and higher realm only.


Any amplifier suggestions? Not sure if a PS audio Stellar 300 amp selling in the $1500 range would be a good choice or something better is available. I think it would easily handle the JBLs at full range

 At least I could try that one in my setup before committing to buy it. I don't know the current realm of very good amplifiers that do not break the bank. The Stellar is supposed to be solid up thru 150 watts output having more even in reserve power so I think it may be adequate running the JBL 4343 speakers full range without any help on the under 300 cps range. (For theater I also have a pair of internally amplified, sealed box SVS 16 ultras, only for movies, but also run my 4343's full range. Not sure what else in the new amplifier realm is available.
My speakers are large (6 cubic ft each)and ported with upper drivers a mix of cones and compression drivers so 94 dB efficiency really do not need over 200 watts/channel for running the bass or the whole range.

 Any amp suggestions?


Showing 1 response by billshenefelt

Thanks  I am not the one building the new crossover.  I don't know if that impacts the drive voltages in the crossover but I have a test plot he ran on my homebuild for the 300 up crossover.