Today I want to discuss how an Audiophile can evaluate speakers in a Surround Sound situation with input from Floyd Toole and Dr Groh.
ChatGPT (Edited)
"I’ve been thinking about the intersection between Floyd Toole’s loudspeaker research and some of the points raised in the recent Huberman interview with Dr. Jennifer Groh. Groh discusses how the auditory system naturally processes sounds from multiple locations simultaneously. This raised an interesting question for me:
If speakers do not meet Toole’s criteria for accuracy, but still produce a strong emotional experience in a surround-sound demo, is there still a justification for choosing the Toole-approved speakers?
After looking closely at both perspectives, here’s how I see it.
1. What Dr. Groh’s work shows
Her research explains how the brain is designed to analyze complex auditory scenes—multiple sources in different spatial locations. The auditory system integrates timing differences, level differences, spectral cues, and reflections to form a spatial map. So the brain is perfectly capable of handling multi-source playback.
But this relates to perception, not to evaluating the accuracy of a loudspeaker.
2. What Toole’s criteria predict
Toole’s controlled blind-test research shows that listeners—ordinary and trained—strongly prefer speakers that measure well:
Flat and smooth on-axis response
Smooth off-axis response
Predictable, consistent directivity
Low distortion
Matched performance across units
These characteristics hold up even when people are listening casually or “emotionally.”
Accurate speakers tend to be preferred more often, across rooms and listening scenarios.
3. Why surround demos can mislead
In a multi-speaker surround environment:
- Spatial cues dominate perception
- Speaker–speaker interactions mask tonal flaws
- Room acoustics multiply
- Emotional engagement increases due to immersion, not accuracy
A speaker that fails Toole’s metrics can still sound exciting or enveloping when combined with other speakers and room effects. But that impression doesn’t reflect the quality of the speaker itself.
This is why Toole emphasizes single-speaker evaluation:
- otherwise you cannot attribute what you hear to that specific speaker.
4. A common claim:
- “My speakers sound better in my surround setup.”
This is something we see often:
- Listeners using objectively poor-performing speakers sometimes report that they sound better in their 5.1 or Atmos setup than speakers that meet Toole’s criteria.
From a perceptual standpoint, this is completely understandable.
Surround playback can:
- Add a sense of envelopment that masks coloration
- Increase apparent clarity via directional cues
- Distract from frequency response irregularities
- Create an emotional impact that overrides tonal accuracy
The result can feel superior even when the underlying speaker is objectively inferior.
But again, this is due to the system, the room, and spatial effects, not the speaker’s inherent acoustic quality.
5. Should you still choose the Toole-approved speakers?
It depends on your goal:
If the goal is: accuracy, neutrality, predictability, and long-term consistency
→ Yes, there’s strong justification for choosing speakers that meet Toole’s criteria.
They provide reliable performance across rooms, content types, and listening positions, and maintain timbral consistency across all channels in a multichannel system.
If the goal is: maximum emotional impact in a specific surround setup
→ Then you may prefer non-Toole-compliant speakers, even if they measure poorly.
But that preference is heavily dependent on the particular room and multi-speaker interaction, and often doesn’t generalize outside that context.
6. Bottom line
Toole’s work answers:
- Which loudspeakers will most listeners prefer when evaluated fairly and in isolation?
Groh’s work answers:
- How does the brain naturally interpret complex, multi-source auditory environments?
Both are true.
Groh explains how we perceive complex soundscapes.
Toole explains how to evaluate loudspeakers accurately.
So even if some listeners claim their poor-measuring speakers sound better in their surround setup, this doesn’t contradict Toole’s research. It simply reflects how immersion and spatial cues can overshadow timbral accuracy.
There remains strong justification for choosing speakers that meet Toole’s criteria if the goal is accurate, reliable reproduction."
