Will the Cinema 70s damage the Motion XT B100?

No. The Cinema 70s is rated for the Motion XT B100's 4 Ω load as it comes.

What impedance setting should I use for the Motion XT B100 on the Cinema 70s?

None: the Motion XT B100 is 4 Ω, and the Cinema 70s needs no change for it.

Is the Cinema 70s powerful enough for the Motion XT B100?

More than you need. From a seat 2 m away, loud 95 dB movie peaks take about 7 W per speaker, and the Cinema 70s is rated 50 W per channel. Cinema reference level, 105 dB peaks, takes about 64 W.

Does the MartinLogan Motion XT B100 work with the Marantz Cinema 70s?

Verdict

Yes

The Motion XT B100 is 4 Ω, and the Cinema 70s is rated for speakers down to 4 Ω, so it drives them as is.

Speaker load

4 Ω speaker, rated down to 4 Ω

Power

50 W

More than you need. About 7 W gives 95 dB peaks at 2 m

How to connect them

Connect the Motion XT B100 speakers to the Cinema 70s's front terminals with speaker wire.
Run Audyssey MultEQ XT with its microphone at your seat.

Plan the Motion XT B100 and Cinema 70s in your own room.

Draw your room in 3D, place both, and see every connection checked and how loud they play at your seat. Designing is free.

Build it in your room

The specs that decide it

MartinLogan Motion XT B100

Impedance: 4 Ω
Sensitivity: 93 dB
Recommended amplifier power: 20–250 W
MSRP: $850 each (MSRP, September 2026)

All Motion XT B100 specs and pairings

Marantz Cinema 70s

Amplifier channels: 7
Height formats: Dolby Atmos, DTS:X
Lowest speaker impedance: 4 Ω
MSRP: $1,300 each (MSRP, September 2026)

All Cinema 70s specs and pairings

Questions about the Motion XT B100 and Cinema 70s

Does the Motion XT B100 work with the Cinema 70s?: Yes. The Motion XT B100 is 4 Ω, and the Cinema 70s is rated for speakers down to 4 Ω, so it drives them as is.
Will the Cinema 70s damage the Motion XT B100?: No. The Cinema 70s is rated for the Motion XT B100's 4 Ω load as it comes.
What impedance setting should I use for the Motion XT B100 on the Cinema 70s?: None: the Motion XT B100 is 4 Ω, and the Cinema 70s needs no change for it.
Is the Cinema 70s powerful enough for the Motion XT B100?: More than you need. From a seat 2 m away, loud 95 dB movie peaks take about 7 W per speaker, and the Cinema 70s is rated 50 W per channel. Cinema reference level, 105 dB peaks, takes about 64 W.

Swap one of them

MartinLogan Motion XT B100 + Emotiva XPA-2 Gen3Works
MartinLogan Motion XT B100 + Denon AVR-X3800HNeeds a setting change
KEF Q6 Meta + Marantz Cinema 70sWorks
KEF Q750 + Marantz Cinema 70sWorks

References

Specs verified against the manufacturer's published data. Last checked September 15, 2026.

Brand names are trademarks of their owners. Not affiliated with or endorsed by any manufacturer. 3D models are our approximations. Prices are manufacturer list prices (MSRP) as of the month shown. How we earn from buy links: affiliate disclosure.