Will the BasX A-700 damage the Signature Elite ES90?

No. The BasX A-700 is rated for the Signature Elite ES90's 4 Ω load as it comes.

What impedance setting should I use for the Signature Elite ES90 on the BasX A-700?

None: the Signature Elite ES90 is 4 Ω, and the BasX A-700 needs no change for it.

Is the BasX A-700 powerful enough for the Signature Elite ES90?

Comfortable. From a seat 2 m away, loud 95 dB movie peaks take about 41 W per speaker, and the BasX A-700 is rated 110 W per channel. Cinema reference level, 105 dB peaks, takes about 401 W.

Does the Polk Signature Elite ES90 work with the Emotiva BasX A-700?

Verdict

Yes

The Signature Elite ES90 is 4 Ω, and the BasX A-700 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

110 W

Comfortable. About 41 W gives 95 dB peaks at 2 m

How to connect them

Connect the BasX A-700's inputs to the pre-outs of your receiver or processor: a power amplifier has no volume control of its own.
Connect each Signature Elite ES90 to one of the BasX A-700's channels with speaker wire.

Plan the Signature Elite ES90 and BasX A-700 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

Polk Signature Elite ES90

Impedance: 4 Ω
Sensitivity: 85 dB
Recommended amplifier power: 20–150 W
MSRP: $449 a pair (MSRP, September 2026)

All Signature Elite ES90 specs and pairings

Emotiva BasX A-700

Channels: 7
Lowest impedance: 4 Ω
MSRP: $501 each (MSRP, April 2024)

All BasX A-700 specs and pairings

Questions about the Signature Elite ES90 and BasX A-700

Does the Signature Elite ES90 work with the BasX A-700?: Yes. The Signature Elite ES90 is 4 Ω, and the BasX A-700 is rated for speakers down to 4 Ω, so it drives them as is.
Will the BasX A-700 damage the Signature Elite ES90?: No. The BasX A-700 is rated for the Signature Elite ES90's 4 Ω load as it comes.
What impedance setting should I use for the Signature Elite ES90 on the BasX A-700?: None: the Signature Elite ES90 is 4 Ω, and the BasX A-700 needs no change for it.
Is the BasX A-700 powerful enough for the Signature Elite ES90?: Comfortable. From a seat 2 m away, loud 95 dB movie peaks take about 41 W per speaker, and the BasX A-700 is rated 110 W per channel. Cinema reference level, 105 dB peaks, takes about 401 W.

Swap one of them

Polk Signature Elite ES90 + Denon AVR-S570BTNot recommended
Polk Signature Elite ES90 + Yamaha RX500ANeeds a setting change
JBL Stage 250B + Emotiva BasX A-700Works
Klipsch R-50M + Emotiva BasX A-700Works

References

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

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