"Headroom" is something that MOST audiophiles don't seem to understand.
The term simply refers to "having more power than you normally need - in case you need it once in a while"...
And that really is all there is to it.
Which, as you might notice, also doesn't seem to make much sense.
(In the old days there was also a bit of "you never want to crank anything all the way up because it starts to distort a bit when you do."
However that really is not true for modern gear - which tends to remain very clean until you finally get it to overload. )
The simple fact is that typical music is extremely dynamic...
Which is a technical way of saying that the level bounces up and down a lot...
So sometimes, for short periods of time, you may have big peaks that require WAY more power than what you're using on average...
And how much this is a factor depends a LOT on what music you listen to and how it is recorded.
On a good recording of the 1812 Overture those cannons are a LOT louder than the flutes.
On typical pop music the variation is much smaller.
And, if you don't have that power available when you do need it, those peaks may clip...
What you normally experience as "insufficient headroom" is simply the fact that loud peaks occasionally clip...
And, if it only happens once in a while, you usually don't hear it as "hard clipping"...
This is especially true for things like drums... where clipping changes the loudness more than what the hit actually sounds like.
You simply hear the fact that those peaks aren't as much louder than everything else as they should be.
And you experience this as "limited dynamics".
For various reasons most modern amplifiers are not capable of delivering peaks that are many times higher than their normal full output.
The design considerations and limitations that made this a good idea for older designs simply no longer apply as much.
If you're really interested the reasons mostly involve efficiency...
A Class A/B amplifier is most efficient at full power - up to around 70% - and less efficient at lower power.
So, if you have two Class A/B amps, both rated "200 watts continuous", but one rated "300 watts peak" and one rated "600 watts peak"...
The one with the much higher peak rating would be MUCH less efficient when running at 150 watts...
So it would need much bigger heat sinks, and a much bigger, more expensive power supply, and would heat up the room a lot more as well...
(This was far less true in the old days... and is also not entirely true for designs that use other classes - like Class H.)
There's also the simple matter of economy...
Back when a 30 watt amplifier was "a big expensive amplifier" there was a good reason to over-design it so it could deliver 100 watt peaks...
Nowadays really powerful amplifiers are far more economical than they used to be...
So, if you think you might need 100 watt peaks, you simply build or buy a 100 watt amplifier...
Or a 200 watt amplifier... (which probably costs a lot less than that 35 watt amp cost in the "good old days").
(In "2020 dollars" an XPA-DR2 probably costs less than a good quality 35 watt/channel amp cost in "1950 dollars".)
The simple reality is that something like a TA-100 actually outperforms a 1950's amp that cost as much as a car back in those days.
(We live in a fun world.)
The answer to your question is simply this....
If you're playing something very dynamic at the same level on both amps....
And your average level is about 30 watts (which is quite loud)....
And a peak comes along that is ten times that (300 watts)....
Like those cannons...
Either an XPA-3 or an XPA-DR3 will handle it just fine....
But, if a peak comes along that is twenty times higher (600 watts)....
Like those cannons on a really great recording...
It may clip a tiny bit on the XPA-3....
But it WON'T clip on the XPA-DR3....
Which will make it sound a little bit better....
And "more dynamic"....
And that's "more headroom"...
If budget is stretched already don't feel bad about the the PT-100 as it is a great preamp, in the future you could always save up and move to something else if you feel the need, don't get stuck on balanced XLR connections, they are nice but not an absolute must, as I mentioned from owning one myself the PT-100 is a very capable preamp especially given the price.
Also the DR-2 runs 250 watts more than the XPA-2 so will only give you about 2.5db higher of headroom, the XPA-2 is already a very capable amplifier and the DR-2 will set you back another $600 so you have to calculate the worth of that extra bit of headroom
A bonus with the current promotion if you buy the DR-2 you would get $319 in Emobucks towards the purchase of the PT-100 which is $299 so you would essentially get it for free
Chad
Thanx!!
But help me out; 2.5 db higher of headroom?? What does that mean?
The extra power is'nt for me about loudness, more about controlling the speakers, so sound stands out clearer. 250 watts more, is both control when playing loud but more importantly the damping (not sure thats the right word, but stopping the speaker again - does that make sense?)
I was looking on the dr2 because of the great reviews, but also because my last buy was a compromise and i dont want to do that again - i will rather buy the right, so i can build on that later.
As to the emobucks, I live en denmark (europe) so shipping and tax would eat that right up.
and yes I agree that shipping cost sucks but at least it's $319 towards everything which is better than $0
