I agree with others that the speakers on their own may not be the issue, however, their positioning is likely a big part of the problem. As modern recordings go, you’re not delusional, the bass is often boosted in the mix. I’ve read reports that claim our ears develop greater sensitivity to high freqs as we age, not that we hear them better, but that they’re more likely to cause fatigue. I believe they we’re referring to the 4kHz to 8kHz range - not the 16kHz^ range that folks often describe as "air."
Rear ported/slotted speakers are just not very compatible with such wall proximity. 10" is just too close. DSP can do pretty marvelous things, but at that distance, it’s more like a bandaid on a hemorrhage. It’s best to mitigate problems where you can before you’re forced to process your analog signals. Because you can’t move them, you should seek out a transmission-line or sealed box speaker. I can concur with Wolf that Heresy IIIs work very well against walls, and they’re as detailed as any Harbeth for half the cost. If a lack of high freqs or "forwardness" really is a problem in your system, they can very likely solve it. This isn’t to say they’re fatiguing, but they can require careful gear matching. The ATCs are another good suggestion. But in the meantime, you can temporarily pull those Dynaudios away from the walls (a good 4’ or more) just to see how much it changes the balance. My bet is you won’t find the highs lacking in that condition.
Rear ported/slotted speakers are just not very compatible with such wall proximity. 10" is just too close. DSP can do pretty marvelous things, but at that distance, it’s more like a bandaid on a hemorrhage. It’s best to mitigate problems where you can before you’re forced to process your analog signals. Because you can’t move them, you should seek out a transmission-line or sealed box speaker. I can concur with Wolf that Heresy IIIs work very well against walls, and they’re as detailed as any Harbeth for half the cost. If a lack of high freqs or "forwardness" really is a problem in your system, they can very likely solve it. This isn’t to say they’re fatiguing, but they can require careful gear matching. The ATCs are another good suggestion. But in the meantime, you can temporarily pull those Dynaudios away from the walls (a good 4’ or more) just to see how much it changes the balance. My bet is you won’t find the highs lacking in that condition.