Skip to content
Specdex
Compare now
Sennheiser HD 660S — Open-back
Sennheiser

Sennheiser HD 660S

Open-back

90
/ 100
From $499
VS
Sennheiser HD 660S wins by 3
Sonos Ace — TV Audio Swap · Dolby Atmos · Wireless Home Theater
Sonos

Sonos Ace

TV Audio Swap · Dolby Atmos · Wireless Home Theater

87
/ 100
From $449
Specdex verdict

Sennheiser HD 660S takes it — here’s why.

In our weighted Specdex score, Sennheiser HD 660S lands at 90 and Sonos Ace at 87. That puts Sennheiser HD 660S ahead by 3 points — a narrow margin driven mostly by its strengths in the categories below.

Pick Sennheiser HD 660S if…

  • ✓Reference-level detail
  • ✓Well-regarded in audiophile community
  • ✓Long-term ownership appeal

Pick Sonos Ace if…

  • ✓Unique TV Audio Swap with Arc soundbar
  • ✓Great ANC
  • ✓Spatial audio
Share this comparison: Share to Reddit X / Twitter

Winner by scenario

Derived from the sub-score breakdown · not a separate test

Sound quality

Tie

Tuning, detail, and staging

Effectively tied — neither pulls a 2-point weighted lead.

Noise cancelling

Sonos Ace

ANC strength for commute and travel

Sonos Ace leads on anc (90 vs 0).

Comfort

Tie

Long-session wearability

Effectively tied — neither pulls a 2-point weighted lead.

Value for money

Tie

Specdex score per dollar at MSRP

Effectively tied — similar score-per-dollar at MSRP.

Sennheiser HD 660S 90
vs
87 Sonos Ace

Score breakdown

Sennheiser HD 660S
90
anc 0
sound 90
comfort 88
battery 100
features 50
Sonos Ace
87
anc 90
sound 90
comfort 88
battery 84
features 92

Specs side-by-side

Sennheiser HD 660S versus Sonos Ace — full spec comparison
Spec Sennheiser HD 660S Sonos Ace
Type
Open-back
—
Driver
—
40 mm dynamic
Battery
—
30 h
Weight
—
312 g
Codecs
—
aptX Lossless via Snapdragon Sound

Sennheiser HD 660S

Pros
  • +Reference-level detail
  • +Well-regarded in audiophile community
  • +Long-term ownership appeal
Cons
  • −Requires amplifier (most)
  • −No active noise cancellation
  • −Impractical for commuting

Sonos Ace

Pros
  • +Unique TV Audio Swap with Arc soundbar
  • +Great ANC
  • +Spatial audio
Cons
  • −Swap feature only works with Arc/Arc Ultra
  • −Sonos app issues
  • −Heavy

FAQ: Sennheiser HD 660S vs Sonos Ace

Which is better, Sennheiser HD 660S or Sonos Ace? +

Sennheiser HD 660S scores 90 on our weighted rubric — ahead by 3. Your best pick depends on the sub-scores above.

Is Sennheiser HD 660S worth the price? +

At $499, Sennheiser HD 660S delivers a Specdex score of 90 — strongest in battery.

Is Sonos Ace worth the price? +

At $449, Sonos Ace delivers a Specdex score of 87 — strongest in features.

Does Sennheiser HD 660S or Sonos Ace last longer? +

Based on our long-term update and support ratings, both ship with multi-year support. Battery and reliability scores are visible in the breakdown above.

Which is better for noise cancelling, Sennheiser HD 660S or Sonos Ace? +

Sonos Ace — leads on anc (90 vs 0). ANC strength for commute and travel.