Ohm Question? (1 Viewer)

[Bill Griffith]

If you have 2 sets of speakers, (Theoretically identical)

One set is 4 Ohm

the second set is 8 Ohm

given the same power to each which will put out the bigest Db if either.

 

[Jeff Braddock]

Well Bill, I am probably wrong, but I will take a stab at it. With all things being equal, including sensitivity, power delivered, etc, it looks to me that they would be equal in output (assuming everything was the same, including placement). Now let me qualify that with what I understand about this stuff (which ain't much )
If these 2 identical sets of speakers were hooked to an amplified that delivered x watts/channel, the 4 ohm speakers would receive more power than the 8 ohm speakers because the 8 ohm speakers would be offering more resistance than the 4 ohm speakers. But, since the power delivered in your hypothetical situation is the same, I believe the output would be the same.
I am sure I have only muddied the issue with my dim understanding and poor writing skills. Hopefully someone who knows their stuff and can express said stuff will reply.

 

[Holadem]

Sensitivity is the measure of how loud speaker will go for a given power input.
Impedance (ohms) is a measure of the demand a speaker puts on the amp. If you keep increasing the volume, at some point, the amp powering speaker A (4 ohms) will start clipping before the one powering speaker B (assuming the amps are the same of course). Below that point, both speakers will have the same output. After that point, speaker B will be louder AND cleaner... until you reach it's amp's clipping point. All this assuming equal sensitivity.
Sensitivity and impedance are probably related somehow.
Bottom line, impedance is not where you should be looking if you are concerned about volume.
--
Holadem

 

[John F. Palacio]

If you have 2 sets of speakers, (Theoretically identical)

One set is 4 Ohm

the second set is 8 Ohm

given the same power to each which will put out the bigest Db if either. ]

Being that sensitivity is SPL out/power in; The answer is: They will both be the same.

Now, using both speakers with the same amp the 4 ohm variety will produce 3dB higher level because the amp will be producing twice the power (assuming the amp is capable of holding maximum output voltage into the 4 ohm load)

In other words amps are mostly a constant voltage device, so the lower the impedance of the load the more power the amp can produce, within the output device limits.