Connecting speakers in series or Parallel? Pros and Cons?

chamojesus

Hello, I recently purchase a set of 70-RT polk in-ceiling speakers for my back surround. I also purchased a set of the RC80i speakers to compare them side-by-side to the 70-RTs. I liked the 70-RTs better. However, I couldn't return the RC80is and I now have four in-ceiling speakers.

This is my setup:
Front RTi A1
Surround 70-RT
Center CSi A4
Sub PSW505
Receiver Denon 2113CI

My Question:
Since I have an extra set of RC80is, I have thought of connecting them to the 70-RTs in series or parallel to improve the sound ambiance. I know my Denon 2113CI is a 7.1 receiver and I could connect these two extra speakers for a full 7.1 surround sound. But I'd like to use the extra two channels to power two Bose 51 outdoor speakers as Zone 2, and keep my indoors surround to 5.1 (I believe I don't have enough space to justify the use of 7.1 (living room is about 14' x 14') and I really wanted the receiver to power two patio speakers).

A sketch of the setup I had in mind looks like this:

Would this be possible? Would it improve or hinder the sound quality? What about running them parallel instead of in series? I have read many threads on this topic and have heard mixed opinions about this. Any information on this setup would be appreciated.

mantis

No and No. You don't want to do either. Go buy a external power amp for your Outdoor speakers and use the internal amps for the speakers. You are in perfect placement according to your drawing for a 7 channel system.
If you run 2 pair of speakers off the Denon , you will be creating a 4 ohm load which will such the life right out of it. It will sound worse.

ZLTFUL

mantis wrote: »

If you run 2 pair of speakers *in parallel* off the Denon , you will be creating a 4 ohm load which will such the life right out of it. It will sound worse.

Just wanted to clarify that a bit. Running a pair of 8 ohm speakers in series would not present a 4 ohm load.

But Dan is spot on. Not a great idea with an AVR to get into multiple speakers on one channel either parallel or series. But to run them in 7.1 the way they should be would be a good idea.

chamojesus

Thanks Mantis and ZLTFUL. The whole reason for getting a 2 zone receiver, especifically the Denon 2113CI, was to control and listen to music from two different rooms using Airplay. If you think the setup that I describe above would actually make the speakers sound worse, I would rather not use the RC80is, and only use 5 speakers instead of 7 indoors. Unless you can think of other options. Thanks again.

TurboGTU

That's probably your best option. Like stated above parallel would put you at a 4 ohm load, not good for your amp. And series would put you at 16 ohms which would cause you to lose a lot of power that you would otherwise have, not worth it unless you have an amp that can give them enough power at that load.

Throw the unused speakers up for sale on here or craigslist, or do what I do and hoard them.

mhardy6647

The big problem with connecting loudspeakers in series is that the first speaker's impedance characteristics will impact the signal going to the second speaker (e.g., in the simplest, case, the VC inductance of the first speaker - if it were a single driver - would be in series with the second speaker). This may well have audible impact on frequency response characteristics of both members of the series pair.

tonyb

You can pick up a cheap 2 channel amp for those outdoor speakers. On my local craigslist, theirs an Audiosource amp, 50 watts per channel for 75 bucks. Perfect for what you need it to do.