More Power or use subwoofer to boost bass for music

This has always been there achilles heal. They lack in the low octaves.

Only if driven by amps that can't handle their loading (impedance +negative phase angle) in the bottom end with copious amounts of current,  which nearly all the mid/upper end models have.

Cheers George

Cheers George

BHK Labs Measurements: Parasound Halo A31 Three-Channel Amplifier

1% THD 232.8W @ 8 ohms, 352.0W @ 4 ohms

10%THD 285.0W @ 8 ohms, 422.9W @ 4 ohms

heaudio
This is a misinterpretation of how an amplifier will behave or at least an interpretation without adequate knowledge.

Once again it’s you that has the inadequate knowledge sunshine, those wattage figures from 8ohm to 4ohm clearly show a lack of good current delivery in this amp especially even though it’s not shown for obvious reasons down to 2ohm where these speakers need power.

xcool OP Just found proper test on the A31 as I thought not much current ability into low impedances. The 4ohm wattage should be a lot higher, and they didn’t do the 2ohm as it would have been trouble (bang maybe). Not the amp for these speakers.

 Cheers George

BHK Labs Measurements: Parasound Halo A31 Three-Channel Amplifier

1% THD 232.8W @ 8 ohms, 352.0W @ 4 ohms

10%THD 285.0W @ 8 ohms, 422.9W @ 4 ohms

xcool OP

The combined impedance and -phase angle graph shows these 804’s are a hard load in the bass from 60hz to 150hz where all the power is needed
https://www.stereophile.com/images/913B804fig1.jpg
Yet the frequency response shows that they have a slight rise in that area, and should give big bass if driven well. https://www.stereophile.com/images/913B804fig4.jpg

The second page of the Stereophile review often complains about the lack of bass from the 804 D’s. And looking at what they drive them with, it was the same amp as you a 3 channel HT Parasound A31 that has trouble doulbing wattage from 8 to 4ohms, let alone down to 2ohms
https://www.stereophile.com/content/bowers-amp-wilkins-804-diamond-loudspeaker-page-2

I think your amp just like the reviewers, is not up to driving the bass with good current delivery, try something that can, and you then won’t need any subwoofers and the problems they bring to seamlessly blend in to the mains.

Cheers George

Guys!, his amps aren't up to it in the bass with that kind of load, sure they're 250w at 8ohm, but they start s*****g themselves even into 4ohms let alone 2ohms!! which is the kind of load the 804 d3's give in the bass.

232.8W @ 8 ohms, 

352.0W @ 4 ohms

Look at the Stereophile 804 review, the reviewer used the same amps and complained also about the bass also.

Cheers George