Ohms difference question

[Q00 0]

Im not sure where to put this so if its inappropriate i hope the mods will help me move this thread.

 

Im asking on behalf of a friend. He is contemplating changing his amp for his 120w, 6Ohm speakers. He wants to get a 2ndhand 50w stereo amp but its output is using 8Ohms. Will there be any problems with this setup?

[Mackie 0]

Usually an intergrated amp/power amp is specified to handle a range of impedance and rated as so (for eg):

 

100WRMS/channel into 8ohm; 200WRMS/channel into 4ohm

 

Anyhow, impedance of speakers changes constantly during playback and on this notion, your pal can still connect his 6ohm speakers to the new amp although it's specified for 8ohm. However, do be careful of driving the speakers to obscene loudness for the amp might clip very quickly. This simply means the amp has run out of juice driving the lower impedance load at high volume level. The resultant distortion can burn out the tweeters and retire them permanently.

[kahchun 0]

To help you further, maybe you should tell what amp and spks is he using now and what he's changing to?

[Q00 0]

Thankyou guys for helping me. I went over to his place only to discover that he had wrongly wired his spks into his subwoofer output. So i guess there is the problem rite there. Obviously there was a huge improvement and he decided not to buy the new amp. Im surprised that there wasnt any damage to his speakers.

[seiko_citizen 0]

how can you tell if the wiring has been wrongly wired? does it play up? or must you just be careful when you connect it

[Q00 0]

Well...i was just checking if there was anything wrong with the amp when i realised that he had wrongly connected it when i compared it with the manual. It does play up but it sounds horrible. My friend was wondering what was wrong with the sound which was why he asked me over.

[Mackie 0]

I wouldn't say that the speakers were "wrongly" connected to the sub as most if not all subs do offer speakers binding posts to facilitate this method of connection. When doing so, one actually employs the sub to handle low frequencies below the crossover point (usually 80Hz with home theater speakers) and the speakers for all above.

 

The caveat is to integrate the sub and speakers to sound like one, not forgetting the phase shift/cancellation that may arise if the sub and speakers are placed far apart from one another.

 

I prefer not to connect my speakers meant for music thru the sub unless U have a quality one like a Rel etc. Even on my home theater system, I prefer to connect the speakers and sub to AV amp which serves as bass management center. Hooking up the main speakers to your sub means the latter will take over bass management.