ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  
previous: lonzo If an amp has a 4 ohm spkr out and ... -- 1140168861 View Thread

Re: 4 ohm or 8 ohm - Difference in Sound?

2/17/2006 7:43 AM
R.G.Re: 4 ohm or 8 ohm - Difference in Sound?
This is covered in the Tube Amp FAQ at GEO - http://www.geofex.com.  
 
The differences are caused by two things - the difference in drive level and the source impedance of the amplifier.  
 
A 4 ohm speaker output has 0.707 times the voltage of the 8 ohm output nominally, and half the impedance as seen by the speaker. A speaker driven by half the impedance of the amplifier may have a tigher bass, depending on the amount of impedance the power amplifier has and how much feedback it uses.  
 
The 4 ohms will be a little quieter because it's driven less hard.  
 
In addition, any speaker artifacts of breakup will be less because the speaker is driven less hard.  
 
So there will be a sonic difference. It's not so much that the amp reacts differently as the speakers react to a different drive voltage and source impedance.

 
Replies:
Dave H [QUOTE]The 4 ohms will be a little ... -- 2/17/2006 9:12 AM