Sennheiser HD 660S2 Open vs STAX SR-X9000

Every tracked fact about the two, side by side - prices, history lows, ratings and measured tuning. No verdict: which one to buy is the visitor's decision, always.

Not this pair? Swap either side:

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Open head-to-head

Sennheiser HD 660S2 Open Back Headphones Sennheiser Now ₹27,990 at Concept Kart At its lowest recorded price ★★★★★ 4.8 4.8 · 34 reviews Full prices & history

STAX SR-X9000 Earspeakers stax Now ₹5,89,496 at Apos Lowest on record ₹5,89,310 on Sunday, 1st Nov, 2026 Full prices & history

What is being compared

Both sides are headphones. The rows below are the facts each store publishes for this shelf - driver setup, impedance, sensitivity, back design and connectivity. A dash means the listing does not state that spec.

Spec Sennheiser stax

Sensitivity — 100dB

Connectivity Wired Wired

Back design Open-back —

Measured tuning, side by side

Both curves are real community measurements (gold: Sennheiser · ink: stax). Each is level-aligned to its own 200 Hz–1 kHz mean, so rig offsets don't skew the comparison.

Sennheiser stax

Tuning distance ±1.89 dB RMS 89% match - Very close. Computed on a shared 40-point log grid, 20 Hz–10 kHz. A measurement-space fact, not a promise two ears agree.

Bass · 20–250 Hz Level Average level difference in this band, both curves aligned to their own 200 Hz–1 kHz mean. Plus means Sennheiser plays louder there on the measured files; minus means stax does.

Mids · 250–2,000 Hz Sennheiser −0.4 dB Average level difference in this band, both curves aligned to their own 200 Hz–1 kHz mean. Plus means Sennheiser plays louder there on the measured files; minus means stax does.

Treble · 2,000–10,000 Hz Sennheiser −0.7 dB Average level difference in this band, both curves aligned to their own 200 Hz–1 kHz mean. Plus means Sennheiser plays louder there on the measured files; minus means stax does.

What a curve cannot seeBuild, driver QC unit-to-unit, comfort, isolation, accessories, warranty and resale value sit outside the graph - usually what the pricier one is charging for.

Price over the last 30 days

Daily lowest price across every tracked store, from the site's own price history. The line is one product's own range - the two cards are not drawn to a shared scale.

Sennheiser HD 660S2 Open Back Headphones Now ₹27,990 at its 30-day median Lowest on record ₹27,990 on Wednesday, 7th Oct, 2026 In stock at 6 tracked stores

STAX SR-X9000 Earspeakers Now ₹5,89,496 at its 30-day median Lowest on record ₹5,89,310 on Sunday, 1st Nov, 2026 In stock at 1 tracked store

Price gap right now ₹5,61,506 95% of the dearer one's price.

Stores with it in stock 6 vs 1 Active stores carrying each one right now - more stores usually means easier replacement and a steadier price.

The decision, factually

Cheaper right now Sennheiser HD 660S2 Open Back Headphones Lowest current price across all tracked stores - ₹27,990 vs ₹5,89,496.

Deepest discount ever seen Sennheiser HD 660S2 Open Back Headphones From each product's own recorded price history.

This page reports facts and expresses no opinion on which to purchase.

Keep going

EQ preset: Sennheiser EQ preset: stax All Headphones More comparisons