[Google Pixel XL Guides, News, & Discussion] chdloc:
Supporting plots done with stock mixer can be found here.

Pixel "frequency response" at 20 mV output voltage. Note that the 2.3 dB level drop to to the presence of the IE800 has been compensated for (with this output voltage my IE800 delivers around 90 dB SPL):

[IMG="Pixel_power_spectral_density_20mV"]https://lh3.googleusercontent.com/wKyiMrRHzCHuzhwsT7ViIZWIeSddu6XmUf4TlNsF1c-KFcdngkm4NxZRi5lC8UqklAS4jHajLcpsPiQFkpxz_P2LBnU1TNUmz2m5_j6cNxwu8QrexGmTLPM2xHKCpashJR4qMxOCMBUe5i8HZnwerLS4Ygm-MNe0kMjhLVAvliv9uydQTLT7ZZgTbRSRtWekp0nc3KlUFGMwRhBLk0Qg1FwcGFjttfg89Bgb6F_gaKqOF8CI2qC2PXGKK1bdgo6LFsYFxdxCVFgrQs7OGG-h7q4OJFXI6rLr6dXk-vXvzHXfB_ZfZ5WznvRtv7seN9oeX8ugIYOuu-YKN2oRn48U0ncVWYwg86kDA1Mk0mtSCfiyeztNUmkC883BRqxhAdnRtE4dyd_B8WOrR1fNDCQ1orFy1ihVFPJ_Zee72xVCMGXtkDAzM9yPnliOZn5zHxysOIrUQnu9xWxSgjqKlHquJxa9e_0Fl7-BP8B0dR5iLqegO0xtSXGFRs1hOHz9iIIaSiV8dmAoazIEugUj78aZdbCdycL5GTnlCj_xuR_TVaXpbqGc8TCSOr7LsO4n5ve-gxB24iaD=w2560-h744-k[/IMG]

Pixel "frequency response" at maximum output voltage (0.427 Vrms). Note that the 2.3 dB level drop to to the presence of the IE800 has been compensated for (with this output voltage my IE800 delivers around 115 dB SPL):

[IMG="Pixel_power_spectral_density_maxvol"]https://lh3.googleusercontent.com/QbaDsy-73Gu7eCjAjZjgXP-STdL5sMSr0bobuXcGPGoaG8HvMlDk4cgu4KxrmEfpYKnOeZNAAWHdB6awai-XWjyc05r7IhOCZrPxM8KIxrkKheMX4RvJIw7qsLe9skgQUg_zAR5O1WI8bdMvWvVLzk83VnnyXPDUxt6WwtTA45e7TYoV3KynvzT3uRpLyYbmk5MEnAHxLFZqMhyRd4eXs1wevP3CQx1eum1sdSIPXA-dLY57BSmBJ3rzVTV-7QO5PlNbJSLqO3assf_J4IILnl4fUMVJVcYF_OI2bShLGSz5mGWGwy2yxwanJ3peS8wBfrTOZYo0mfnzbHPbdLrDQ2n9N7U-vqBL83purC3XGlTG7u3yDwsGHMFCGIB-HW6BQ1_ohTVTyLLHSnIFuBU9opu2vHP4HLmzN4gx3oUiCcnT7UJKHdGf7V_LnmxuBICby_vsP24KkA7ihM-s8IZ-lyQgzvi1Y1lyz_WWyH7xhzn2c4hD8eYDUAAIGVNGw4dQjSwVn4dIuPtVT17qoJ3ssSgBBd9P1GNNY7U48ASbV0y7DkT7ty0CyfgOqee42FNTgIx7QJ83=w2560-h744-k[/IMG]

Pixel THD+N at 20 mV output voltage (only the left graph is relevant):

[IMG="Pixel_THDN_20mV"]https://lh3.googleusercontent.com/wgTllarzJxx8oGZnPWXw45CAfWaTPUCfTjyIZzEIbRhUAaunGQGTX2UrH3zzPFRXlP7yKtNNz5RI1amaahUyskCtyqZN2YjIEyySajdIGyoPt1EKyhfzhx7r5rgG3xoKE4k_KJE3Ct9TVjVl6evd5IQGfVU9DHooAZFxxefE89gSfpXcVrKth7XjdjEqvUmMEQrnypH-vb7Wte3HA5iMRe5WqPRjEa1CUr4Dbcc7lBXa4GardoxlvL35clIx4DfCHiYPBaOUCgfcjFt6LiWR1YC05Wb5WZ_egnIutImaDuOB50qKHKYRxpdnGslzXh-LT0rZn34S1x3p-ePcWhiMqjLw8-AUaGJAfdv2DfTylqcv2bnuu-JFz16kqkdvBzJpbp-aBmPZOYPtUnpy-fDPuUqotpGQAYjaElFR7SOi-P0s041j6T7i7-Jd5AGWlMXx82kLGDyqDSBicqo_agpw2d06pwMen7gcTZytcnQmJEfcIzS37OuvBOTVbRk5gAI5q_spFX4Q_uuqemRyTOheIFooO8usMYxG5tZlEAh1woQYmTDO_WJWNUy9gWW9oiI3Kc7W4tjR=w2560-h744-k[/IMG]

Pixel THD+N at maximum output voltage (only the left graph is relevant):

[IMG="Pixel_THDN_maxvol"]https://lh3.googleusercontent.com/3ks5xb8V4UbfAtiDadanXpXQV0zVluJaipL_en0WzyWCXnKMN20WS2KXldNC6fk8u9sjGeXiQA1io2yTLR-su9QxuD9uKJbKN7GJcdxjNe294UkrhfYlVAaJZeQVFIJc6G6cEg6tu2Y_YSPDZXm1iA4ODrIy2GypOuGN5kJO5M93yqVFnQg47Quc3TnGyn6Y63NacITu4TaHpMRpUI_KgyAHOB4vfB8upqwSxyjYp_Jv96PvOTIto_DETUSrY2geUc4QgdLAQoy2GkoHK99vaM7JY5Bb5UIZIaJnyXDzOD3_Za8h1Q3P--7Iprb4IZYhFwIy5gpBji1wbKMffEM6vuhm_D_nBoOCF96OL5GadZs9SyXiC4Wn2DzIkj8aS3SHKXGTZvnNj7m0_9OdDr24TA3t-pn2jNeh7VEnCJgXXRbGc5SLpOMQuOn9eHGpE6SebxTW8xpOICf0FCspzLu5PXzW1wV5m4RdmSnFjimtScmEQkV4pq1eUmFiKk0sn0qMOjkRQVhrfO0OLLUj-0-soDdS1hgALSYvwq70FuqX3Vtq6ZC7nGghsvWOYWohEsTJo-pKchKa=w2560-h744-k[/IMG]

iPhone 5s THD+N at 20 mV output voltage (only the left graph is relevant):

[IMG="iPhone5s_THDN_20mV"]https://lh3.googleusercontent.com/bKmQ_9cRY1rJIJMzZkjx16ruxq3xNliw-WzIZW9SXIQpDHxtstaOAibjzw-YHOSDLrYUC0UUaRjPWBkFgfGOj98lMBUFEnQXkqPYX_Q1HDq3U_YJIrSyCjbyBIGincG9w6hY1En0bvTK8SXhRp-4oSlZdTkVizIlp71ykLxXGUZ5-KG_KxcFr7kuoLcXRHonF-JjEmjKhtFJ0xTdGGhAkuG3fYxq_xPwe83vXCFxe4ho22dI1huf1e7hYoiQS3wFXnCKVIbJ3exYtxseKWBjoDAKF-u1qNL4krmS3rbXpAXWYTif45eZ-SrJ90f94Q2R0w_wj04lBozeZOIPJRgBWC4b7RdzchdAVDha05y27MxX-qDvaWKR-xCLUhZudpzNwj1DSK8jDNmPG9e3NxHUBp4JQROszMuEvOYYuMHTUebuH2SXWDsmYdiQn7FXsNXJFdKlRFkukRQSSRmCQkY0bcI-Q6FDboRP8FgIl37CrwcYcvlBLgmWOVxYTVhjLXz_svPuw-xp-MWdDmx_eU8a7Z6QI_xiURUuqoXxQjHYUxrOMq0Iq9v2JkLa8vN2vHhkbImKnQYI=w2560-h744-k[/IMG]

iPhone 5s THD+N at maximum output voltage (only the left graph is relevant):

[IMG="iPhone5s_THDN_maxvol"]https://lh3.googleusercontent.com/MwZAyn9aEh7XthqZkv7bW9M2hRSOkNz9vOuDq35490a4BExMUWAzIDItrPpRFaeDIJhHi_B6g48pARyyF-0Z_ec7REYHOYSczI9MQAcasBSfHT_TNZQyBiNApIK-FhoascP95Ge5MlS4ONbOkdSMtRr6OIgVlS1-Ii8K-eNZynoU2TdVHP_Jtk1dEYRclLqcbmhtIVIScKSW48bNg6WyqD3iZkKAj92jGFf-DBgYsPZa2k1c2x8eZqJfG0TFX_2WCFLPCG6v0WPTCIVPypWttLZ_3lKCErI86pe7ZPDVy-I9RFwWXqo5Q-9MAqXZqNRKQ2X3hyqG0DGpdRtH5zyr8t77ECDwpomuTBQhXM6g_GkyYNbBk3YnnPSZK0WLUO-gAv7-WFsLuniG0dwKxSavefmbsP_8s2Ko-2w-QjKAVpZqN_rdxWZsBLoMgqlJl0gXX70ShgvGEfsUhETjgTvn8mmXuqajEzGIFDaXdC9TOQ73eAgfQfbDM59LjSIWRnj9JBx6goiFAzi5zcaX1AXdkupKmuwGK5PE-i7gi2EdAQVmJqQXFeDPzcZFzkpMHtqOsRC5l7AE=w2560-h744-k[/IMG]