{"product_id":"sennheiser-hd-660s2-headphones","title":"HD 660S2 Headphones","description":"\u003c!-- ***** Generated by Builder.io on Wed, 24 Sep 2025 13:01:44 GMT ***** --\u003e\n\u003cstyle type=\"text\/css\" class=\"builder-styles builder-api-styles\"\u003e\/*start:h47494*\/.css-h47494{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-items:stretch;-webkit-box-align:stretch;-ms-flex-align:stretch;align-items:stretch;}\/*end:h47494*\/ \/*start:j5317t*\/.css-j5317t.builder-block{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;position:relative;-webkit-flex-shrink:0;-ms-flex-negative:0;flex-shrink:0;box-sizing:border-box;margin-top:20px;line-height:normal;height:auto;margin-right:200px;margin-left:200px;}\/*end:j5317t*\/ \/*start:1qggkls*\/.css-1qggkls{outline:none;}.css-1qggkls p:first-of-type,.css-1qggkls .builder-paragraph:first-of-type{margin:0;}.css-1qggkls \u003e p,.css-1qggkls .builder-paragraph{color:inherit;line-height:inherit;-webkit-letter-spacing:inherit;-moz-letter-spacing:inherit;-ms-letter-spacing:inherit;letter-spacing:inherit;font-weight:inherit;font-size:inherit;text-align:inherit;font-family:inherit;}\/*end:1qggkls*\/ \/*start:1mvsfya*\/.css-1mvsfya.builder-block{height:0;width:0;display:inline-block;opacity:0;overflow:hidden;pointer-events:none;}\/*end:1mvsfya*\/\u003c\/style\u003e\n\u003cdiv class=\"builder-component builder-component-b2285df7cf414b3a883b5e8c234ec512\" data-name=\"product-description\" data-source=\"Rendered by Builder.io\"\u003e\n\u003cdiv class=\"builder-content\"\u003e\n\u003cdiv data-builder-component=\"product-description\" data-builder-content-id=\"b2285df7cf414b3a883b5e8c234ec512\" data-builder-variation-id=\"b2285df7cf414b3a883b5e8c234ec512\"\u003e\n\u003cdiv class=\"builder-blocks css-h47494\"\u003e\n\u003cdiv class=\"builder-block builder-7865402d7c784d75b43fdfd352185a88 builder-has-component css-j5317t\"\u003e\n\u003cp\u003eSennheiser’s HD 660S2 headphone delivers even better sound, comfort, and versatility than the original HD 660. Sennheiser HD 660S is the ideal open, dynamic headphone for the passionate audiophile.\u003c\/p\u003e\n\u003ch3\u003eDive Deeper Into Your Music!\u003c\/h3\u003e\n\u003cp\u003eEnjoy your music on a completely new level. An intimate, relaxed sound signature combines with outstanding precision and exceptional comfort — and now, extended sub bass — for a deeply moving experience. The extremely precise yet non-fatiguing sound of the HD 660S2 delivers even more impact with extended sub bass.\u003c\/p\u003e\n\u003cp\u003eWith an optimized surround, transducer airflow, and coil, our engineers doubled the sound pressure at the lowest octaves. You can feel the lowest note on the piano (27.5 Hz) or the kick of the bass drum (45-60 Hz) as if you were there.\u003c\/p\u003e\n\u003cp\u003eThe relaxed tone and open-back design make this extremely comfortable headphone great for long sessions. With warm tuning, smooth treble, and strong bass, the standard-setter for extended listening is now the standard-setter for extended bass as well.\u003c\/p\u003e\n\u003ch3\u003eSound for the passionate music enthusiast\u003c\/h3\u003e\n\u003cp\u003eMade for the demanding listener, the Sennheiser HD 660 S surpasses the exceptional performance of its predecessor, the legendary HD 650. With a crisp bass, excellent mid-frequency response, and a gentle, pleasantly natural treble, the HD 660 S has an expressiveness that immerses you in every emotion and nuance of music. Still, it always stays exceptionally accurate and transparent.\u003c\/p\u003e\n\u003ch3\u003eAudiophile Sound\u003c\/h3\u003e\n\u003cp\u003eBreathtaking resolution and precision take you closer than ever to instruments and vocalists. Yet the sound is natural and balanced, never harsh or brash. Sub bass expands the entire sound. In doubling the sound pressure at the lowest frequencies, we’ve retained extraordinary precision and balance throughout the sub-bass, mid-bass, and beyond. Extension on the low-end changes everything — by creating more space for the sound. Against a deeper backdrop, highs feel more brilliant, the soundstage deeper, and emotions stronger.\u003c\/p\u003e\n\u003cp\u003eThe velour earpads of the HD 660S2 can only be described as a tactile pleasure. With just the right amount of tension for proper acoustic positioning and supple padding, the headband won’t draw attention away from your music, either. With an open-back design, the HD 660S2 gives your ears an extremely comfortable climate, even for super-long sessions. Low total weight and ergonomic headband rule out any potential discomfort. Combined with excellent build quality made in Ireland, the listening experience is as physically pleasing as the warm, non-fatiguing sound at its heart.\u003c\/p\u003e\n\u003ch3\u003eImprovement of a Legend\u003c\/h3\u003e\n\u003cp\u003eThe Sennheiser HD 660 S Headphones have been created to enjoy music in supreme quality and from many different audio sources. High-end Sennheiser headphones have inspired generations with their balanced, natural reproduction. Recognized as benchmarks for neutral audiophile sound, the HD 600, HD 650, and HD 660S share visible and audible DNA with the HD 660S2.\u003c\/p\u003e\n\u003cp\u003eThe revised coil of the HD 660S2 matches the 300-ohm impedance of the legendary HD 600 and HD 650. This new coil also provides higher magnetic force and electrical dampening for a cleaner impulse response. The surround is also more compliant, dropping the resonant frequency to 70 Hz. Altogether, these measures result in even greater precision, speed, and resolution — with double the sound pressure at the lowest frequencies\u003c\/p\u003e\n\u003cp\u003eSignificantly increased the compliance of the surround, dropping the resonance frequency from 110 Hz to 70 Hz. --\u0026gt; bass drops off below the resonance frequency in open headphones, so a lower resonance frequency increases the bass. Optimized airflow around the transducer and decreased air leakage between the front and back of the transducer. Air leakage introduces an acoustic short circuit, decreasing acoustic pressure for low frequencies. The coil in the HD 660S2 was revised to match the legendary HD 600 \u0026amp; 650, resulting in an impedance of 300-ohm: Better electric damping and lower weight with improved detail retrieval. The Result: Sound pressure at the lowest octaves has doubled\u003c\/p\u003e\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eHD 660S2 headphones\u003c\/li\u003e\n\u003cli\u003e6.3 mm cable (1.8 m), 4.4 mm cable (1.8 m)\u003c\/li\u003e\n\u003cli\u003e6.3 mm to 3.5 mm adapter\u003c\/li\u003e\n\u003cli\u003eCarry pouch\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cdiv class=\"builder-component builder-component-b2285df7cf414b3a883b5e8c234ec512\" data-name=\"product-description\" data-source=\"Rendered by Builder.io\"\u003e\n\u003cdiv class=\"builder-content\"\u003e\n\u003cdiv data-builder-component=\"product-description\" data-builder-content-id=\"b2285df7cf414b3a883b5e8c234ec512\" data-builder-variation-id=\"b2285df7cf414b3a883b5e8c234ec512\"\u003e\n\u003cdiv class=\"builder-blocks css-h47494\"\u003e\u003cimg src=\"https:\/\/cdn.builder.io\/api\/v1\/pixel?apiKey=48d1cdcd52ec4d289f1ef8c4f75da167\" aria-hidden=\"true\" alt=\"\" role=\"presentation\" width=\"0\" height=\"0\" class=\"builder-block builder-pixel-569p90el8z9 css-1mvsfya\"\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Sennheiser","offers":[{"title":"Default Title","offer_id":51621414207802,"sku":"HD660S2","price":679.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0834\/0245\/7402\/files\/sennheiser-hd660s2-01__55304.1681226026.1280.1280.jpg?v=1719254634","url":"https:\/\/www.moon-audio.pro\/products\/sennheiser-hd-660s2-headphones","provider":"Moon Audio","version":"1.0","type":"link"}