• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

Paradigm Servo 15 upgrade to Monolith


Standard Member
Hi :hiya:

I'm upgrading much of my gear and wondered if it would be worth changing my Servo 15 to a Monolith? The Servo is a great window shaker but gets a little too much, and seems a sloppy with music tracks. Room size is about 7m x 3.5m and space is not an issue (the Servo is also huge). Would I be wasting my money?

Expert opinions gratefully received!




Hi Rob, by all accounts the servo 15 was a bargain and still are and from past comments from other owners I wonder if something like the monolith to be a sidweways move, are you using any EQ as it may not be intagrating as well as it could be with you're system ?


Distinguished Member
Welcome to the forums :smashin:

Whilst it's reasonable to assume that a smaller sub might time better with music (indeed the Monolith is extremely good in that sense, although my secondhand one was duff) I'd be tempted to stay with your Servo and spend the dough on getting it right, myself.
Maybe some Eq, for example?


Distinguished Member
I'd imagine it to be a sideways step.

If you are suffering sloppy music bass from a servo controlled sealed sub, have you considered that some sort of bass EQ might improve things drastically?

It's not guaranteed, but with your 3.5m dimension repeating in the 7m dimension of your room you'll potentially be getting a peak in the response at 25Hz along the length of the room, with a potentially larger peak at 50Hz across the room as the second harmonic of the length ways mode combines with the fundamental of the shorter dimension.

It's no surprise that the 50Hz mode could make most musical bass sound 'ploddy' and tuneless with a very one not quality and that's before you also consider the other harmonics of both the modes at 75 & 100Hz and then start looking at the tangential modes at 55 & 110Hz....:boring:

Baffled? Well I've prattled on for the fun of it but there's a very handy room mode calculator here that helps you visualize whats going on. Where you spy a very similar frequency repeating, that can double your trouble. Type one dimension in at a time to see which frequencies relate to which dimension.

It's not guaranteed that all of the frequencies will be peaks as that calculator can't predict variations caused by where your sub is and where you sit - some of them could equally cause dips (a suck-out) in the response too. But if you have the de rigeur Radio Shack SPL meter and some freely downloadable test tones burned to a CD, you can measure your rooms actual response and see where the trouble really lies and whether EQ will help.

The good news is that EQ devices can cost* less than the change of sub you are proposing.:)


*I'm excluding your sanity from this equation.;)
Last edited by a moderator:


Standard Member
Thanks for the replies, its kind of what I thought...I'm not using any form of EQ its literally straight out the back of my Denon 2802.

Can you point me in the right direction of a suitable bass EQ device?

I'm probably going to upgrade to a Denon 2309, so whether the bass might be a bit more controllable from there I'm not sure.

Thanks again, Rob

The latest video from AVForums

Is 8K TV dead? Philips OLED+907, Pioneer LX505 AVR plus B&W 700 S3 Reviews & Visit + AV/HiFi News
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom