[JakeJ]

Hi gang,

Been searching and Googling but do not find any tips, guides, or general help in tuning the CSS passive radiators used in the RM-30 M.  Any instructions, input, opinion?

TIA

EDIT-
I did find the PR on Creative Sound Solutions website and deduced that adding weight lowers the Fs.  Does this mean adding weight lowers response as well?  I would have thought the opposite.  My PR's have 9 washers each. That seems like a lot to me.

What do my fellow VMPS owners have to say?

[John Casler]

The PR "reacts" to the internal cabinet pressure variation caused by the active woofers.

Adding mass (washers) slows that reaction, and thus lowers the frequency.

When we used the CSS PRs in the Subs (IIRC) we started with 3-4 washers

Since the 6" woofs of the RM30 will not cause the same amount of pressure variations, I would begin with 2-3 washers and then add and listen.

Once you hear the bass you like, you can also take some "putty" and place it inside or even outside, the center cap, and pinch away for fine tuning.

[JakeJ]

Thanks, John.

Still lovin' the RM-40's.  I moved the RM-30's into my office to make space for a project in the HT room.  I haven't really played with tuning them much so now they are "on their own" so to speak and I want to dial them in to the new room.  Yeah, I'll have to do it all over again once the construction is complete but that's OK.  626r's are pulling rear duty temporarily as they can be moved easily for the project.

[G E]

The PR "reacts" to the internal cabinet pressure variation caused by the active woofers.

Adding mass (washers) slows that reaction, and thus lowers the frequency.

When we used the CSS PRs in the Subs (IIRC) we started with 3-4 washers

Since the 6" woofs of the RM30 will not cause the same amount of pressure variations, I would begin with 2-3 washers and then add and listen.

Once you hear the bass you like, you can also take some "putty" and place it inside or even outside, the center cap, and pinch away for fine tuning.

Similar to my experience. In addition changes in upstream electronics made a difference necessitating a washer adjustment.

Adding or subtracting 1 washer can make a dramatic change in bass sound.

I have fine tuned by adding putty to washers, the inside of the cap, and outside the cap. Right now my cap is off.

Removing washers is kind of a pain. Use one of those magnets on an expansion stick to make it easier.