Why do some amplifiers throw a bigger soundstage than others?

As a monoral signal has no separation, by the same token, it would seem to me that an amp with better channel separation would throw a wider soundstage than one with poor separation.

BUT, perhaps a bit of out-of-phase channel crosstalk could make the image wider? 

Also, one would want both channels to be/track as identically as possible, to keep the soundstage from shifting about.  If a channel lacks what the other has, it can't really produce mono for a proper center image at that frequency/volume.  This would apply anywhere along the audio chain.

I must admit that it is fun imagining my large deep soundstage emanating from my reference system. So damn good that I suspect it ain’t real - its a repeating simulation.

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).

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.

I would think that class A amps with less negative feedback would have a bigger soundstage, that could be one of the reasons many tube amps have a great soundstage.

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.