PG Music Home Forums General Discussion Recording, Mixing, Performance and Production Monitor isolation suggestions

Now that I have the KRK VXT 6 monitors, any suggestions on isolation? Mopads, Pink Pearl erasures, or any other items that might work for the DIY kinda thing. Monitors are 28lbs. a piece. Thanks

Are you having an issue with them vibrating items on the surface they are sitting on? If not, the isolation pads are a bit of hype that from a physics point of view can't really offer much difference.

I am going by what I have heard and seen on youtube, how the isolation cleans up frequencies mostly on the lower end. No vibrations, I don't crank them up loud enough for that, lol.

Believe what you wish to believe. They physics don't necessarily play out.

Several physics items are possibly at play:

1. Isolation pads COULD isolate speaker cabinet vibration from being transferred into the surface that they are sitting on, which could then in turn vibrate itself and create unwanted low end sound which would compete with that coming from the monitor speaker itself. Unless you have some flimsy panels on the desk somewhere, the likelihood of this is rather small, particularly if you are listening at low levels.

2. The isolation pads CAN make the monitors less efficient when the monitor itself is not fixed well to 'ground', in that when the woofer cone pushes against the air, it doesn't have the benefit of a solid connection, rather a more springy connection to 'ground' to push against except it's own mass, not it's mass and the mass of the earth. This is why you see the exact opposite of monitor isolation pads being sold in the hi-fi speaker market - metal inverted spikes designed to be placed under hi-fi speakers and 'pierce' through carpeting and pad down to a more solid foundation. I'm talking about items like this: http://www.oregondv.com/spikes.htm

However, with the weight of each of your speakers, which you said was 28 pounds each, there's likely enough mass there to not notice a big issue with low end punch if you did mount them on iso-pads.

You will likely have more of an issue with room acoustic cavity modes getting excited by your monitors, as well as comb-filtering that could result from having the speakers too close to reflecting surfaces.

The first issue is primarily caused by the geometry of the room, and where you place your monitors relative to the geometry of the room and the rooms natural frequencies. This article: http://ethanwiner.com/acoustics.html would be a great place to start to try to get an understanding of what the cavity resonances, also known as standing waves, are and why you should be concerned about them - Spend more effort working this out, than worrying about isolation pads. It's a much bigger issue than whether your monitors are on iso-pads or not, because it doesn't matter at what volumes you are listening, the standing waves in the room WILL get activated at nearly any playback level and will deceive you at your listening position.

Pay particular attention to Figure 11 and the discussion around it - highly important stuff there. Also down near the bottom of the article, maybe 3/4 down is a discussion of a tool for free download called ModeCalc - this will take the dimensions of your room and show you specific frequencies that are likely to be issues in your room, where you place monitors, etc. The physics are pretty simple, and this tool will yield quite accurate results unless your room has non-parallel walls, many large items breaking up the geometry of the room like bar-counters, big furniture, etc.

Also pay attention to the side-bar in the article about creating a reflection free zone. The advice in that section is quite good, and it's going to help you avoid comb-filtering. Key advice in that section for most home studio design is adding absorption to surfaces that could reflect mid and high frequencies from the monitors to the listening position. One trick not mentioned in that article is that you can do this by putting the absorption on any wall (and ceiling) where if a mirror was placed in the same position, you can see the monitors in the reflection of the mirror. This is ray-trace acoustics and spending the little bit of money that you would on monitor iso pads, on absorbing material like rigid fiberglass insulation, is going to be much better spent for most home studios which are often bedroom spaces, with rather narrow wall dimensions. I'm a bit lucky in my studio, I have 2' from my monitors to the wall behind the monitors, and 4' to each of the side walls - where the reflections off of those surfaces back to the listening position is significantly longer than the direct path from the speakers to my listening position.

That article is probably the most concise and honest article on home listening room and home studio acoustics that you can find. While the author has a company that sells acoustic treatment (RealTraps), he also offers up a host of practical and rather inexpensive acoustic treatments in this article that can be purchased mostly at home improvement stores and installed with a little bit of effort.

You just bought some nice monitors - make sure they play nice in your space. Iso-pads would be very low on the list, if at all, for getting the most out of your monitors. Most of the endorsees of these iso-pad type products have already gone through the rigor of having a treated space or had a ground-up purpose designed control/listening room built where many of the common issues of home studios can be avoided altogether.

I don't use Iso-pads.

I tried some firm foam and didn't hear any difference. I would only use a pad or something IF.... IF there were buzzes from the speakers setting on something....and then it would likely be a simple piece of cloth to dampen the rattles and buzzes.

I've heard both sides to the story and in reality, for the normal home studio, there's not enough of a difference to matter. Some folks swear by heavy mass such as concrete pillars so that the inertia of the speakers is NOT transferred into the stands as easily. That is the entire hypothesis for using the iso-pads. You only want the speakers and the box they are in creating the vibrations.


As I said, in my studio, and at the volume I work, the isolation did nothing for me that I could hear. So, IMHO, I wouldn't waste the time or money.

GuitarHacker gives good info.
To expand on this though .. I have found that putting sound treatments on the wall behind me (where the speakers are pointed at) DID make a noticeable difference.
Less 'room' and less standing bass. Cleaner.
YMMV
You need to experiment in your own unique room.

That said, when I mounted my speakers on the wall I did include pads between the speaker and the mount. Couldn't hurt.

Yes.... good point.

Room treatment..... or should I say PROPER room treatment will make a difference.

I have a room with acoustic ceiling tile, carpet on the floor, and various pieces of furniture and other things to break up the standing waves a bit. In other words, not just an empty square room. The walls are mostly bare, but there are also 2 open doorways on the opposite wall from the speakers......AND..... I have ARC.

Critter, did you read the Ethan Winer article link that I put in my post above?

I have my monitors on Wall mounted Swivel stands, if you go that way you will need a good sturdy pair like these:

http://www.andertons.co.uk/studio-furniture/pid25855/cid737/stage-line-past550sw-swivel-tilt-speaker-bracket.asp

I think they cure the isolation problem, and they also allow you to direct the sound to your ears. I mounted mine high up at first, but now they are at ear hieght so I can catch that sweetspot.

If you need to you can use rubber, similar to a mouse matt, to further isolate them. Here there is no need

Z

Three to five feet ahead and apart...at a slight v angle

Level to your ears

That's how my krks are setup and it works fine for me...

Also my pads are 2 padded stools I bought at Walmart they are exactly even height, sturdy and 9 dollars apiece.... (Silly stands for them are like close to 180 apiece what a waste of money!!!!

BX,

Nice hack. I paid over $100 for a pair of 40" RTA stands. For those on a budget—IKEA rules!

I went a step or two up from the mounts you linked, and still added the mat you describe. I may have called it foam in my previous post, but they came with a sound 'mat' material about 1/8" thick .. so I used it. Like I said; can't hurt.

You guys don't experience any issue with coupling the speaker vibration directly to the wall the mounts are screwed into?

My wife brought home two different types of foam from work, I cut them to fit the monitors, harder foam on the bottom, softer foam on top, each half inch thick, holy crap what a difference, no more booming bass and everything else is great. This changed everything, and for free.......

Then you had an issue with the surface the monitors were sitting on getting activated/vibrated by the monitors.

Yep, wood workbench converted to this, particle board top, etc. So far so good.............