Recent content by BPA

I agree with Timber, this guy has a very strange explanation of his dual layer carbon trap that is effective for low's mids's and high's. Also he the idea of "limp mass" vs "membrane" can be slightly deceiving. If a piece of material is 2mm thick and weigh's 6.1kg/m2 and is slightly flexible...

I realised this at the beginning of the build. I would measure and weigh the material and redo the depth calculations according to the density of the board. And that's where I noticed the boards were inconsistent in density, it is wood afterall. Other synthetic materials are far more consistent...

Very much agreed! Audio is such a subjective field and is about the listener! All I try and do in the rooms I design is let the listener hear honestly what the material is telling them so that they can work and enjoy themselves at the same time. Engineers aim to provide the end user with a...

Hey Timber, Yes, I started my quest by building one of Ethan's traps with 1/4" ply according to his spec that should treat 80hz. The effect was minimal at various locations, and I built two just to make sure that it wasn't a problem with the build/seal, it may be a problem with availability of...

Hey Nico. What is depth of the opening? I ask because if it is a single brick opening, you will have a very hard time minimising transmission regardless of any type of door you put in. To block sound you need mass. And (very) preferably an air gap. The principle of mass-spring-mass is what...

I'd love a link to the sub 100hz notes topic. This is news to me and might be a matter of understanding what is meant by pitch and timbre according to the links. I build studios for discerning engineers, so my experience in hifi is somewhat limited. I joined the forum as I was interested in...

Hey Atjan, Well the limp mass device is tuned. Depth of the box and mass of the "limp" cover dictates where it will be effective. And the placement of these boxes relevant to the mode in question. So if we are looking at a tangential mode, we will use it at the back wall parallel to the front...

Hi Phase, I don't see it that way. Using electronics to treat nulls and issues negates the need for high end speakers, and acoustics for that matter. I prefer to listen to audio as projected from my setup, rather than electronically correcting the system, I could buy a cheap pair of speakers...

Fun to be here! Well, introducing an absorptive element into a limp mass device would broaden the Q, but lower the absorption. Although from my experience the Q is broad enough to affect surrounding decays too. Chris Whealy has a great porous absorption calculator...

Hello everyone, New to the forum and first post. I have read through most of the posts and I would really like to offer my 2c worth. It seems most of the difficulty comes from nulls in the room, and while "super-chunks" do work to a certain degree, there are other ways of treating targeted LF...