Which is better for studio monitoring?

The ATH-E70. Its three balanced armature drivers and maximum-isolation housing are built for hearing detail over loud sources. The IE 100 Pro is fine for casual monitoring but its single dynamic driver separates instruments less.

Which is easier to drive from a phone?

The IE 100 Pro. At 20 ohms it plays loud from a phone or laptop jack. The ATH-E70 at 39 ohms benefits from a dedicated player or amp.

Does either have a microphone?

The ATH-E70 has none. The IE 100 Pro has no mic on its stock cable, but Sennheiser's optional IE PRO Bluetooth connector adds one for calls and webcasts.

Which isolates noise better?

The ATH-E70. Its housing and Comply foam tips are tuned for maximum passive isolation. The IE 100 Pro isolates well with foam tips but is less aggressive.

Is the ATH-E70 worth stepping up to?

If you monitor professionally or want triple-driver detail and isolation, yes. If you want a simple wired IEM you can also use wirelessly, the IE 100 Pro covers more everyday use.

Both have detachable cables, so the cable is the replaceable part on each. The ATH-E70's balanced armature drivers have no moving diaphragm, while the IE 100 Pro uses a dynamic driver; neither has a water-resistance rating.

Sennheiser IE 100 Pro vs Audio-Technica ATH-E70

The IE 100 Pro is the simpler buy: one 10 mm dynamic driver, a 20-ohm load that any phone or laptop drives easily, and a detachable cable you can replace. The ATH-E70 is the step up for monitoring: three balanced armature drivers, 39 ohms, and a housing built for isolation, but it has no mic and no wireless option. Owners rate the Sennheiser well overall; the Audio-Technica earns its keep with detail and isolation rather than convenience.

Choose the Sennheiser IE 100 Pro if you want an easy-to-drive wired IEM with a replaceable cable and the option to add a Bluetooth connector later.
Choose the Audio-Technica ATH-E70 if you monitor on stage or in the studio and want triple-driver detail and strong passive isolation.

Prices

Sennheiser IE 100 Pro: $64.99 at eBay (last seen Nov 8)
Audio-Technica ATH-E70: $439.00 at B&H Photo-Video-Audio (checked today)
Difference: the Sennheiser IE 100 Pro is $374.01 cheaper than the Audio-Technica ATH-E70 at the latest prices (Nov 8 and Nov 10)

	Sennheiser IE 100 Pro	Audio-Technica ATH-E70
Driver design	Single 10 mm dynamic driver	Three balanced armature drivers (low, mid, high)
Impedance	20 ohms, easy to drive from a phone or laptop	39 ohms, better suited to a dedicated player or amp
Microphone	Available through the optional IE PRO Bluetooth connector	None
Wireless option	Optional Bluetooth connector sold separately	Wired only
Cable	1.3 m detachable cable, 3.5 mm jack	1.6 m detachable cable with A2DC connectors and memory loops
Isolation	Passive, shaped housing with silicone and foam tips	Passive with maximum isolation housing and Comply foam tips
Frequency response	20 Hz to 18 kHz	20 Hz to 19 kHz
Weight	Not listed, similar in-ear build	9 g without cable

Spec	Sennheiser IE 100 Pro	Audio-Technica ATH-E70
Headphone Cup Type	In-ear	In-ear
Body Part Use	Ear	Ears
Noise Cancellation Type	Passive	Passive (maximum isolation)
Connectivity Technology	Wireless, Wired	Wired
Compatible Devices	Tablet	Low-output device like a portable player
Ports And Interfaces	3.5 mm Jack	A2DC connectors
Cable Length	1.3 m	1.6 m (5.2')
Earpad Material	Silicone, Foam	Comply foam, Silicone
Water Protection	Water Resistant	No
Waterproof	No	No
Water Resistant	No	No
Driver Size	10-mm	Triple driver (low/mid/high)

Spec	Sennheiser IE 100 Pro	Audio-Technica ATH-E70
Frequency Response	20 Hz to 18 kHz	20 – 19,000 Hz
Headphone Impedance	20 Ω	39 Ohms
Color	Transparent, Black, White	Black
Impedance	20 Ω	39 ohms
Sensitivity	115 dB	109 dB/mW
Sound Output	Stereo	Stereo
Wireless Type	Bluetooth	—
Bluetooth Version	5	—
Max Battery Life	10 h (SBC)	—
Recharge Time

Sennheiser IE 100 Pro vs Audio-Technica ATH-E70

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Sennheiser IE 100 Pro vs Audio-Technica ATH-E70

Prices

Audio-Technica ATH-E70

What separates them

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