series vs parallel in a home system

[myname159753]

ok, i came to this forum hoping that you guys probably know enough to answer my question

i bought a 360 watt (peak) sony shelf system that has 2 speakers and a subwoofer which each recieve 120 watts (peak) each.

The speakers are rated to handle 120 watts at 6 ohms each

i later bought 2 other larger shelf speakers that are rated at 120 watts (dont specify if it is peak or rms) at 8 ohms each

I originally just plugged them in parallel style by shoving the additional speaker wires into the same places as the original 2 speakers were plugged in.

i now know that this is decreasing the resistance, it worked pretty well but i know wonder if connecting them in series style would be better.

when they are connected in parallel i can turn up the volume to around 20 out of 30 (shakes the house a lot) before they start to sound bad. I have only had it that loud for short periods of time >30 mins. But i was wondering if it would be bad for the amp/reciever to do that for a long time.

so baisically my question is, will they still be able to get as loud in a series setup? and which way will be able to be the loudest for a prolonged period of time (like 4-10 hours) without screwing up the reciever?

Any imput would help

thanks

[Frank Berry]

I would not operate your Sony system with both sets of speakers attached in parallel.
Some Sony models have a nasty habit of "releasing smoke" without warning when powering additional speakers.
When wired in series, the speakers won't play as loudly but the amplifier won't blow up either.

[anatech]

Hi oh numbered one.

Frank is not kidding. Pick one or the other speaker. In series they may not sound good. In parallel the magic smoke will come out.

This system will not put out anywhere near those ratings so don't worry about the power rating so much.

-Chris

[Stocker]

I'm vote #3 for not using them parallel-wired. Unless you don't mind if you do let the smoke out. Does the amp. get hot that way? I imagine it would, but it wouldn't have to, to go pop.

[tinkerbell]

Originally posted by myname159753
before they start to sound bad. I have only had it that loud for short periods of time >30 mins. But i was wondering if it would be bad for the amp/reciever to do that for a long time.

not a good idea to play music so loud that the speakers "sound bad"

if they sound 'bad' ie distorting, then damage maybe occuring inside the amp or inside the speakers...

turn down -> sound better -> more enjoyment

[anatech]

Hey tinkerbell,
If the music is that loud, it will be a self correcting situation at some point.

-Chris

[amplifierguru]

Here's a suggestion.

Assuming the new bigger speakers are a) 8 ohm and b) more efficient, how about you wire them as the main system speakers giving a lighter load to the amplifier for cleanness. The replaced pair you could runlong cabling , add some series resistors, say, 22ohm and mount them in the littlest room ( americans euphemistically refer to as the bathroom) which because of it's tiny size should give plenty of decibels despite the attenuation and enjoy music's laxative effects, while still meeting your amplifiers 6 ohm design spec.

[Brian Donaldson]

I remember the days when a 100 WPC amp could put out 100WPC RMS @ 8 ohms from 20hz -20khz @ less than .5% THD and 160 WPC @ 4 ohms from 20hz -20khz @ less than .75% THD with no fear of releasing the magic smoke. It might warm the power cord a little and dim the dial backlights a tad, but no fear of damage to the reciever. (I can't promise safty of the speakers though)

My old Pioneer SX950 that I found in the trash due to a frayed power cord survived countless college parties and even a pitcher of beer spilled in it, but it did ruin a few pair of speakers along the way.

[mastertech]

when you connect something to something electrical you sould at least know
what you are doing, speakers and amps are not an exception to this rule, read the specs of both the amp and speakers and connect accordingly

[anatech]

Hi Brian,

Those days are long gone. I don't see them coming back either. Only certian brands of higher end gear and DIY will equal those feats. (long live my Marantz!)

-Chris