Re-post re QED Transmatch

Technophobe

Hi

Had previoulst posted this elsewhere but got no replies..>Am at point of needing to order a solution so was hoping someone here would be kind enough to offer an opinio

I have a query for the more knowledgeable (than me) about the QED Transmatch Speaker switch product….

http://www.aqsound.com/en/product/QE...roduct_details

I have a bedroom that will have 2 pairs of ceiling speakers and an en suite that will have 1 pair of speakers with a WIW room that will probably also have 1 pair with the remaining pair yet to be allocated (or just reduce to a 4 way switcher)….

This “Transmatch Speaker Switch” will be connected to a SONOS ZP120, which I understand is the amplified version with all the speaker pairs then obviously connected back to the Transmatch..

What I wanted to know is

a) does this sound okay in practice?
b) I presume the buttons on the front are to turn on/off the various speaker pairs? Simple as that?
c) Can all the “pairs” of speakers be listened to/playing at the one time or is there a limit to what you can do?
d) What is the difference between Speaker A and the other 4 called 1B, 2B etc ?

If anyone has any better product suggestion to achieve this with the Sonos, then please advise also…

Thanks for all the help in advance…

cnocbui

a = yes

b = yes

c = yes...maybe. The sonus has a total powerr output of 2x55W into 8 ohms so there would probably be enough volume for some background music with all pairs on, but don't expect to be able to support a party in each room.

When you wire speakers in paralel, which is what the QED does, you decrease the resistance with each pair you switch in. So, if all your speakers have 8 ohms resistance, the amplifier section of the Sonus will 'see' an 8 ohm load with one pair, 4 ohms with two, 2.7 with three, 2 with four and 1.6 with 5 pairs.

Most amplifiers do not like driving a small load like 1.6 ohms so I think the B1 to B4 spec implies the switch adds resistance for speaker pairs 2-5 so the amplifier does not blow up.

This implies the best sound quality will be obtained using the 1st pair (A) on their own, with degraded performance with more pairs switched on.

I think the QED will do what you want, just make sure you don't get 4 ohm speakers, get 8 ohm ones.

5 way 'Transmatch' speaker switch. 'A' pair switching for best sound quality. 'B1' to 'B4' Transmatch converts a net 2 ohms load back to 8 ohms for safe amplifier operation. Impedance loading with all pairs selected of 4 ohms (using 5 pairs of 8 ohm speakers)

Technophobe

Hey cnocbui...

thanks for the reply.....

All that is very useful to know....
My understanding now is that the more speaker pairs on at the same time, the less the effectiveness of each of the additional sets switched on? Is this correct??

"c = yes...maybe. The sonus has a total powerr output of 2x55W into 8 ohms so there would probably be enough volume for some background music with all pairs on, but don't expect to be able to support a party in each room"

...:) So if I reduce my requirements to omit the ones in the WIW, it will help too and dont worry, unless my parties are going REALLY WELL, I hope not to need music playing loudly in my en-suite....;)


thanks
technophobe