Thanks for the feedback, I am still in the research phase so haven't physically touched anything on site yet until I understand the components and how it is all fixed up. I have also downloaded all of the manuals and reviewed the Yamaha install guide. Another issue is that all of the speaker runs are hidden away in cable runs behind the walls and in a crawl space so also cant line each cable end with the amp binding post.
Responding to some of your questions.....
Note that 70V requires (3) amplifier channels, bridged. See the specs towards the end of the manual.
not sure what you mean here, the manual only shows 70v requiring two channels bridged and the HPF switched on with the speakers wired to the centre binding posts. I still have no idea as to why there would be additional wires connected to the remaining binding posts that shouldn't be in use if being bridged.
Also, as the amp pumps out L&R through its output they take up two channels on the amp. But as they are bridged only one of the inputs will be live, so I should look at combining the sound into one channel from the mixer into the bridged input.What input preamp is being used in this system (make and model) ?
the Numark RM6 mixer has a gain on each input (assume preamp stage) and then a zone level for each combined zone before heading to the amp. There is a mixture of line and level inputs going into the mixer.What, if any, processing is being used (equalizers, crossovers, etc) ?
None I believe, other than the HPF on the amp.Is there just (1) Yamaha amp ?
there are two amps (same model) running 12 channels. A bit more of a look identifies that the one amp is running the conventional setup (one zone) with the sub and the 25s in stereo mode (no bridge) 4 speakers (fl, fr, rl, rr) on their own channel. The other amp appears to be running the other zone with the 25t's on a 70v line. This amp has both the HPF and the bridge mode set to on.Is there just (1) subwoofer ?
Yes one sub, As its a passive sub I assume the binding posts for the fl and fr will run into the sub before branching off to the speakers.How many Control 25's are there ? Control 25T's ? Panasonics ?
As above regarding zone 1. Zone 2 has the Panasonics but they are the ones you get in a $200 dollar surround system.... they will be removed and binned at the first opportunity. There is a couple of 25t's but they have been disconnected as they 'don't work' and the wires switched into the Panasonics.Are the Panasonic spkrs 70V (this may be indicated on the input panel or by the presence of an external transformer on each speaker) ?
As above, they are not 70v or even PA grade components.
I have attached a photo of the rear of the amps.... Points of note.
- the 4 channels from the mixer (Zone 1 & 2, L&R) come into the top amp and are replicated via euroblocks to the respective channels.
The top amp has 6 channels bridged into 3 but has additional speakers wired up to the outer binding posts. Therefore the input and attenuation of the second channel should be redundant for the bridging. but could be used to replicate to the unbridged channels?
The bottom amp is running stereo and running the conventional setup which runs the 25's and the passive sub.
Both amps have HPF activated for all channels, even the on front channel to the sub
I have attached a photo of the rear of the amp, what my initial plan of attack is before getting into anything serious.Zone 1 - Lower amp - conventional set-up
confirm spec of speaker and ensure that 25's are in place rather than 25t's
stereo mode for all four channels.
HPF switched on for rear speakers.
HPF switched off for front speakers which run through passive sub.
reset gain structure and attenuationZone 2 - upper amp - 70v
confirm spec of speaker and ensure that 25t's are in place rather than 25's. remove Panasonic jobbies
bridge mode for four channels into two. need to review combined channels to mono rather than stereo
HPF switched on for all channels (as per Yamaha guidance)
remove cabling wired to redundant binding posts and check all terminations at speaker locations are not shorting.
reduce taps on speakers, fire it up and see what is working.
in this zone I would be looking to run the internal 2 restaurant speakers off one bridged channel and run the two outer deck speaker locations off another bridged channel (no speakers connected a present)
reset gain structure, attenuation and taps