Hi Cyrus,
that's what is nice about using these SP-1's as the actual over all size is very similar to the foot print size of the MBL's so nothing is really exposed. Looks like they were designed for them.
Looking at the picture of the Sistrum platforms, the brass points you see actually screw together and where they are positioned is a long slot. This slot is the actual area of adjustment, you just position the brass point where you desire it for size and tighten it up, it's that easy.
Measurement of mine;
The front brass point I have positioned at 1 1/2 inches and the two back brass points I have positioned at 3 inches.
Installation and how I did it;
with the front brass point removed, I tilted the speaker forward (I had assistance) my helper held it in that position (wife) not hard to do at all. Just a pointer here make sure you have her put on those fancy gloves that came with the speakers that way no bracelets, rings, other jewellery or fancy nails become issues, ha! ha!. Gotta have a laugh right? I then carefully slid the platform underneath the speaker from behind with the two brass points all ready installed. I slid it under positioning so the centre of the points were 2 1/2 inches from the back and sides. By doing this the front was centered but I did check to confirm. I then tilted the speaker backwards onto the two points already in position, tilted the speaker back a little bit and with my helper (wife) steadying the speaker. I then pushed down on the front of the Sistrum platform as it will be up against the bottom of the speaker and installed the last point. I positioned that point again at 2 1/2 inches in from the front of the speaker base and centred.
I have to say it was pretty simple after I put some thought into it and figured out the measurements, the first time arround went well. I rocked the speaker a bit just to assist in settling better into the carpet (no carpet you will not need to do this, if you are wanting to protect your floors just tilt and install protective couplings under the points)
Prior to critical listening right away your speakers need to settle in, I know this seems all so weird but read more about this. I have found using any of these platforms underneath speakers and amps is when this is most apparent. It takes time for total settling in, some things that may occur, images can be out of focus, centered image may not be centred and off to one side, bass wooly. It all happens just like flicking the light switch on, it's all so really weird.
Oh and if you need to reposition your speakers, it's easy just pivot the speaker on the brass point. You do not have to do anything but just make sure to hold unto the speaker firmly.
Hope this helps, any more questions let me know.
You are going to be in for a real tweet, let me know what your thoughts are.
I have lost count now how many others have tried with other speakers and have been absolutely blown away, getting to read what they experienced has been a blast and that's what this hobby is all about.