Two Speakers to one amp output? Series/Parallel?

TomTesch

I'd like to hook up two CS400I speakers to one center channel output amp from a denon 4800. My amp is only rated down to 6ohms.. but would like to stay at 8ohms. I beleive this is possible through series/parallel combination but I am a little confused. Can someone in the know offer me a clear diagram of the positive to negative connections from amp to speaker and speaker to speaker. Is there a safe and effective way to do this with the CS400i? (I mean.. come on I have 8 speaker terminals to work with

Tritonman

A series connection would raise the ohm from 8 to 16 as your speakers are 8ohm to begin with. The quick and dirty explanation is series doubles the Ohm and Parallel halves the ohm.

Series - take the negative of one speakers terminal and connect it to the positive of the other speaker teminal. Use the remaining Positive and Negative of the speakers and plug those into your receiver. This will generate a 16ohm load.

Parallel - Wire one speakers positive to the positive of the other speaker. Wire the same speakers negative to the other speaker. Take the other speaker and plug its positive and negative into your receiver. This will generate a 4ohm load.

If your receiver can do 4 ohm then Parallel is ok. However..If all of your other speakers are 8ohm then the center channel will be effectively "louder" than all your other speakers due to more draw from the receiver. The same would go for the Series connection..just the reverse. Some receivers dont do well in a mixed Ohm environment either. So i would definately check on the specs of your receiver..plus you didnt state what model you have so I can only purely speculate.

TomTesch

I have the denon 4800 which isn't rated down to 4 ohms.. thus the problem. I was told that a combo series/parallel connection could keep me at 8 ohms.. What you told me was how to get to 16 and 4 ohms.... Is there a connection to stay at 8 ohms?

McLoki

TomTesch wrote:

I was told that a combo series/parallel connection could keep me at 8 ohms.. Is there a connection to stay at 8 ohms?

How would you feel about running 4 centers? (another (and better) option - get a decent mono amp that can handle 4 ohm loads)

Michael

thehaens@cox.net

Buy yourself an inexpensive Mono amp, (Marantz MA-500) comes to mind. Then use your pre/out on your receiver. Then you can run your centers in parallel. The MA-500 is good at 4 Ohms...

scott

You will not be able to stay at 8 Ohms with your configuration....

TomTesch

OK.. I quess hooking up 4 8ohm speakers in series/paralell combo will produce 8ohms. Since the CS400i has dual binding posts with the gold connectors.. could I just remove the gold connections and treat the 4 posts as 4 separate speakers? Would this produce 8ohms?

(I at least think I understand the wiring now a little better). Yea.. I'm running a separate two channel amp to the fronts right now using a spliter cable and not using the center channel amp from the reciever. I have another reciever/amp powering 4 surround back speaker for THX Surround EX.. but would like to move the front amp to the rear and just see if I could figure out some wiring for the center to power more than one speaker... and sell the rear amp. (& free up some space). The Denon 4800 has 125 wpc .. so it is decent enough in my opinion to power two fronts from one out (if possible). Plus save me $ dealing with another amp. I actually could run 4 fronts and have the speakers for it (in a dedicated movie room) .. do you think 125 wpc is enough though? Maybe worth a try.

unc2701

Unhooking the binding post straps won't change anything... The impedence only counts for the what the signal passes through- you have a 8 ohm tweeter and an 8 ohm bottom end- the straps make this a parallel connection. However, it's 8 ohm overall because the full signal doesn't pass through each one- if you graphed the impedence, you'd see a dip at the crossover point where the signal goes through both the tweeter & the bottom end.

I believe that you can make an impedence matching circuit, that will bring the 4 ohm parallel load up to 8 ohms, but it'll be inefficient, so you might as well put them in series.

Still the best solution is a cheap monoblock.

TomTesch

Thanks for the info! May just have to run another amp.

Phil Dawson

I also run a pair of CS400is in my system. What I did was split the signal out of the pre-pro and run it into a stereo amp. This works very well and I have power to spare. I have also forund that used stereo amps are easier to come by than single used mono blocks.
Good luck, Phil

emcclary

You can run your speakers in parallel if you want even though Denon does not give a rating for a four ohm load it will work with one. It isnt until the load drops to two ohms or less that you risk damage to your components. If you do a search of reviews for your unit you will see several tests where they use four ohm loads. The speakers will be "louder" tham your eight ohm loads so you may have to adjust your output levels for that channel to balance everything out.