Speaker stand height

I have a pair of PSB Stratus Minis on their factory 25" stands, but these seem too tall for my room/listening position. My listening chair is somewhat low and laid back and this i do not want to change. So I was thinking of buying lower stands so that the speakers are closer to my ear but am worried about messing up the overal tonal balance of my PSB's. Should i Be worried about the sound changing too much with lower stands, or will it simply give me more bass and a more direct sound?

btw iv'e experimented with putting these speakers on 10" concrete blocks, with a title to compensate for the height, and this seemed to make the sound much fuller. This was many years ago though and my memory could be fooling me.
You must know where the acoustic center of your speaker is. It may be the tweeter in the 2 way, or the midrange in a three way. This should be the ear height level.

Then the distance between speakers should be the distance to your ears-an equilateral triangle. A nice long metal tape measure work great for this.

Mass is your friend in stands; hollow metal or wood can ring a lot, adding its own a resonant frequency to the speaker output. Knock on the stand with your knuckle and hear if it rings. If yes, dump it. Try concrete blocks if you don't have anything else and hear the difference.

I have heard that it is ok if the tweeter is above your ear level ,but not below. Is this true?
Isn't it important to optimize speaker height for bass response? If you get floor bass reinforcement and bass cancellation right, you can then, if needed, tilt the speaker so the tweeter is on your listening axis (assuming that's the correct orientation for the individual speaker).

Sit in your comfy listening position, have someone measure the distance from the floor to your center ear. That is the height of your focal point of your speaker. Average is around 38 inches. Your PSB's are designed so the focal point should be the center between the top of the woofer cone and the bottom of the tweeter cone, That spot is the focal point of your woofer. In the example of 38 inches, that spot between your woofer and tweeter would need to be 38 inches off the ground.
Use a laser pointer, adjusted on the inside of the cabinet level with the focal point, turn your speakers in full tow making the laser point at your ears. Imaging should be excellent. If you have a brightness, start turning your tow outward exactly the same on left and right channels until sound is smooth. It is possible that at some point you may start losing center image, or dips in frequency, so stay keenly aware of image and frequency responce.
Todd, tweeters dispersion patterns are typically the same above or below ear level, but in a two or three way, The problem is that that farther your other drivers are off, the more their dispersion patterns and frequency response is off also, so if the tweeter is designed to be on top and is below, your frequency curves change even more on the drivers below. For that reason, most recommend to keep the tweeter at or slightly above, but overall it is a rule of thumb rather that a law, based on the speaker that you are using. If I recall, the Stratus mini, the tweeter is on bottom, so that theory wouldn't work. Don't forget, sometimes a little tilt either way makes a world of difference.