Αν και δεν βλέπω τίποτα συμβουλές για το θέμα (υποθέτω ότι τέτοιο παλιό passive Super Woofer δεν θα έχουν πολλοί) νομίζω ότι είναι χρήσιμο, για ενημέρωσν των μελών, να παραθέσω εδώ την αλληλογραφία μου με τον Graham Hartle που σε καποιο αγγλικό forum (δεν θυμάμαι ποιό...!) διάβασα ότι είναι ειδικός στα Jim Rogers. Λοιπόν να τα e-mails (έχω περικόψει τα άσχετα):
=============ΑΡΧΗ ΑΛΛΗΛΟΓΡΑΦΙΑΣ===========
========>Messenger to Graham============
I own a pair of the JR 149 loudspeakers and the non-powered superwoofer.
I learned that there is a special amplifier designed by Jim Rogers for the sub. I drive the JR149 directly by an 100 Watt AV amplifier (Pioneer 916s) but it cannot handle the sub as well. When playing loud with the sub connected (either in line to the JRs 149s or directly throught the "2nd zone" speaker outputs) the message "overload" appears on the Amplifier screen and then it shuts down. I can drive the sub by my old Sanyo Pluss P55 power amplifier but is there any better solution?
========>Graham to Messenger============
Is it the passive or active version? in the passive version connections from your main amp go into the woofer two blk two red lefthand and right hand then ther are a further four connections for your JR149 with a variable senstivity switch. Please advise which version you have and wether the bass unit is the original or has been modified.Then i can give you further advice.
============>Messenger to Graham============
It's the passive version and the bass unit is the original. The subwoofer is the one shown in the picture I sent you in my first message.
============>Graham to Messenger============
Well first of all what is you main amp in the whole of the system because the amp that Jim Rogers did was an active amp and had a built in butterworth filter if you are using a separate amp to drive just the woofer and a separate amp to drive the 149's you have it connected wrong.First of all your main sytem amp should have from the speaker outs 2right +red and two left _ black to the JR sub,Then the other four connections on the sub should be the leads running to the JR149's. Please advise and then i will give more help.
=============>Messenger to Graham============
I have an integrated AV amplifier PIONEER VSX-916s, which currently drives the 149s (from the speaker outs 2right +red and two left _ black go to the Left ancd right 149s). This amplifier has pre-outs for 7.1 channels (2xfront, 2xsurround, 2xsurround back, 1xcenter and 1xsubwoofer). I have connected 2 RCA cables from the Front-Left pre-out of the Pioneer to the input of the left channel of the power amplifier SANYO PLUS P55 and same for the right channel. This seems to work but the SANYO gets hot!
Alternatively: This PIONEER AV Amplifier can use the two Surround Back speaker outputs as "zone 2" outputs (having exactly the same output as the Front speaker outputs - no surround signal). I tried to drive the 149s from the Front speaker outputs and the subwoofer from the Zone-2 speaker outputs, not using at all the SANYO power amplifier. It works but, when trying to play loud, the PIONEER shut down after displaying a short message (i think "overload"). The same happened when I used the normal way of connecting, i.e. the Front Left and Front Right speaker outputs of the PIONEER are connected to the Left and Right inputs of the subwoofer and then the 149 are connected to the subwwofer "out" terminals as you suggest below.
I guess that the PIONEER amplifier cannot drive properly the subwoofer - that's why I used the SANYO for this task. But I understand that subwoofers have differences: the amplified should be suitable for low frequencies (maybe high current?) and that's why I am trying to find such and amplifier. Perhaps it would be better to forget the JR subwoofer and use a powered subwoofer - any advise?
=============>Graham to Messenger============
there really should not be a problem sound like the pioneer has a fault. The JR in passive version has a built in filter same has if it where active but you get a better damping factor with active but if you have connected the amp correctly you should have no problem as the filter is doing the job in the JR splitting the signal so any amp should be able to drive it.Unless there is a fault in the JR sub.
==============>Messenger to Graham============
Still I am looking for a suitable amplifier for the JR Passive Super Woofer. Do you know its characteristics (Impedance, Maximum Power?)
==============>Graham to Messenger============
What i would do personal is scrap the passive crossover and buy an active BK module the 100watt version would be suitable and you could wire a cable directly to the JR bass unit bypassing the JR crossover.This module has avariable crossover point and its own built in amp with volume control for just over 100GBP brand new They are excellent.
=============>Messenger to Graham============
It sounds very interesting and correct. What is the BK module (I understand it is an active crossover+a 100W mono power amplifier)? Where can I find it? Any site to see it on the Internet?
=============>Graham to Messenger============
www.bkelec.com is the site you require the module is the BSBP 100/8 117.88GBPounds you may have to make a small wooden cabinet sometimes it comes packed already in a wooden crate which you can adapt i use theses modules in my own design which is built in to the JR subwoofer cabinet.
========TΕΛΟΣ ΑΛΛΗΛΟΓΡΑΦΙΑΣ===========
Μάλλον σας κούρασα αλλά κάποιοι μπορεί να το βρούν ενδιαφέρον. Επίσης το site που δίνει μπορεί να φανεί χρήσιμο σε αυτούς που, σαν και μένα, δεν πιστεύουν παρά μόνο σε αρχές φυσικής και σε αυτό που ακούνε τα αυτιά (δικά τους και άλλων).
Λοιπόν περιμένω συμβουλές: Να ξηλώσω το passive crossover ή όχι; Είναι εντάξει να τροφοδοτώ τα ΔΕ-ΑΡ ηχεία με πλήρες φάσμα από τον ενισχυτή (τα δηλώνω βέβαια σαν μικρά) και ξεχωριστά το superwoofer; Αν ΝΑΙ είναι καλύτερα να στέλνω από τον Pioneer το σήμα του sub woofer (LFE) ή πλήρες φάσμα (δηλ. την έξοδο second zone); Αν στέλνω τα δύο κανάλια του second zone (για να κρατήσει το superwoofer μόνο τα μπάσα) είναι εντάξει να ενώσω τα "+" και τα "-" μαζί;
Μάλλον μπερδεύτηκα...! Κανένας να με ξεμπερδέψει;;;;