what is headroom??? (1 Viewer)

[Greg Bright]

Usually one will hear something out of the ordinary (not on the recording) from the speakers. Sometimes a tweeter will get fried. The sound will usually compress and sound strained. Really loud peaks won't get that much louder. Actually headroom is also a function of the loudspeakers as well. How efficient they are will in part determine the headroom of a system. High-efficiency speakers can give almost any system lots of headroom. Just ask the tube amplifier guys.

 

[Justin Ward]

Definetely. I've got Adire Audio HE 10.1s (95.5 db/w/m) powered by 30 clean watts per channel and the headroom is amazing. It sounds so effortless and I've never had the amp run out of juice.

 

[Kevin C Brown]

I agree that there are many definitions and ways to look at "headroom". And like I mentioned further up above, "dynamic headroom" was something that all the magazines that tested amps ... earlier ... did. I keep wondering about why it's not tested for now. (If I can get get motivated, I'll ask one of the mags that are still around, or maybe an amp manufacturer. Just curious.) One possible conclusion is that from the 70's and '80's to now, in general, amps are a lot more powerful. So it's possible that the dynamic headroom of an amplifier just doesn't matter as much as it used to.

Here's actually one recent example. I don't have the numbers at hand but here's the gist: I have a Proceed BPA 2. 2 channel amp, rated at 125W/ch. It actually tests to about 140W per channel into 8 ohms, and 240W or so into 4 ohms.

There is also the HPA 2, which from memory is rated at 250W/ch. I asked Proceed (now Harman) once about the specifics of each amp. The interesting thing is that, obviously, the HPA 2 has much larger transformers (they are both dual mono designs). From memory, the transformers in the HPA 2 are about 80% larger than the BPA 2. But ... the BPA 2 has about 50% more capacitor storage than the HPA 2. So my conclusion at that time was: cool. The HPA *is* a more powerful amp, but the lower power handling capacity of the BPA 2 is somewhat offset by an increased ability to handle transients.