Originally Posted by stereo2.0
I think if all else is equal, then there are no reasons left for them to sound different. Peter Aczel from the Audio Critic used this same argument to explain why both cheap and expensive amplifiers can sound indistinguishable if operated under the same conditions.
However, just like the more powerful amplifier, the bigger sub will indeed sound better than the smaller one when asked to provide more output than what the little one was designed to supply. Tom Nousaine came to the same conclusion when he tested the entire size lineup of one Velodyne subwoofer model. The smallest sub sounded just like the largest until levels were increased.
This is good information and helps answer my question...thanks.
So, to summarize so far:
The main characteristics that make up Sub Sound Quality are:
1. Flat Frequency Response (Reference FR)
2. Extension (obviously, this is related to FR, but wanted to break it out separately)
3. Output (also related to FR)
4. Distortion or 'Audible Noise'
5. Group Delay (Transient Response) - the subs ability to stop and start a given frequency (tight vs loose sound)
6. Power Compression - As dynamic content changes in the source, the subs ability to maintain a consistent (flat) FR, maintain phase, etc.
So back to my theoretical question:
If two different subs with different designs, drivers, and amplification have the exact same FR, Extension, Output, Distortion, Group Delay, and Power Compression characteristics, will they sound exactly the same?
I believe the answer is Yes
So, what does this all mean?
Any differences we hear when we compare the sound quality of subs fall into one of these 6 major categories. The characteristic that we 'hear
' the most is the frequency response of the sub. Assuming that we can setup the 'right conditions' in a room so that frequency response is as flat as possible for all subs, we can then compare them based on the other 5 characteristics. Output and Extension are really a function of FR, and so these can be easily represented in graphs, etc.
It’s at this point where it will be easy to determine where the subs rank against each other; the flattest response and deepest extension for your desired output will have the best sound quality (assuming the other characteristics are within reason).
But perhaps the subs all have negligible differences for FR, extension and output, which one has the best SQ? You can then look at Distortion, Group Delay, and Power Compression.
Unlike FR, these cannot be adjusted with an EQ and are fixed characteristics based on the flat FR. Because these are fixed, you will have the most variability among these characteristics across the sub's frequency response. Each sub will have its own recipe for these characteristics and all with their own advantages and disadvantages based on their 'recipe'.
Assuming that Distortion, Group Delay, and Power Compression are all within ‘reason’ AND they all have negligible differences for FR, extension and output, I believe it is at this point that subjectivity and preference come into play. Since each of the subs will have its own recipe for distortion, group delay, and power compression across their frequency response, it now becomes a matter of taste.
And it is at this point where subjective comments have some meaning.
Comments? Again, I’m no expert and could completely be way off base…but it sounds intuitive.