Why do some amplifiers throw a bigger soundstage than others?

I like the way a seasoned amp maker put it:

Competently designed speakers can sound different from each other.

Competently designed amplifiers can sound different from each other, but less so.

atmasphere

11,504 posts

03-07-2024 at 12:37am

…impedance issues in the bass region, which has nothing to do with presenting a sound stage.

@atmasphere is this statement meant to rule out bass as being important to listener perception of soundstage? That would seem doubtful… query not intended as a challenge for which I have empirical grounds, just interested.

atmasphere

11,504 posts

03-07-2024 at 12:37am

…Our OTLs are known for a very good soundstage and yet they have a high output impedance so can’t deliver the power into lower impedances. Our class D can- but the sound stage of our class D vs our OTLs is nearly identical.

And this would make that potential discrepancy even more interesting.

crustycoot

572 posts

03-06-2024 at 10:50pm

…I also believe the preamp is more instrumental in establishing soundstage than the power amp is in my experience.

Not sure you intended it but, that’s gonna be the pun to beat today.

atmasphere

11,505 posts

03-08-2024 at 12:15am

”is this statement meant to rule out bass as being important to listener perception of soundstage?”

@benanders Yes. Bass (20Hz to about 150Hz) is important if you want to get the tonality right but it has little to do with imaging and sound stage- the lower the frequency the more this is true. Below 80Hz in most listener’s rooms the bass is 100% reverberant (which is why subwoofers don’t have to be in the same location as the main speakers if crossed over below 80Hz).

@atmasphere I’d assumed that has more to do with a discrepancy between wavelengths and reflection time vs. boundary dimensions, than with how we perceive bass overall (granted, research indicates certain higher frequencies are disproportionately influential on our sense of spatial scale). Should spatial perception x what you describe differ for, say, bass in outdoor setups (I am sorry - I realize this is slightly tangential from the OP query)?

You can try a simple experiment to show how this is so. If you use midrange drivers and tweeters as speakers you’ll find they can image nicely, but if you use only woofers that are rolled off at a normal crossover point you’ll find the image very indistinct or non-existent, depending on the woofer.

This made me chuckle at myself. Bass in my setup comes from stereo subs that can go up to ~180 Hz (I keep them crossed at 100 Hz). When I was setting them some years back, I did play them without the towers but directed my attention to measurements vs. room modes (vs. listening impressions); I admittedly wasn’t focused on soundstage of given tracks. “Tell me you already knew something but didn’t know how to say it ‘til just now.”

I’ll aim to give that simple experiment a whirl this weekend if time permits. Thanks again.