First up I'm in Melbourne eastern suburbs.
Please check the rules again: That needs to go in your profile.
I was told that I'd likely need something like a Polyester 30Kg m3 type of treatment to get any decent results.
There's the issue: Decent results for what?
The density that you actually need depends on two things: First, the type of absorber that you are using, and secondly, the reason you are using it! Ie, the frequency range that you need to deal with. In fact, it's not even the density that matters per se, but rather the factor known as "Gas Flow Resistivity" (GFR), which is measured in the rather obscure units of MKS rayls. Most manufacturers of thermal insulation don't bother measuring that for their products, since it has little to do with thermal insulation, the primary purpose of their product, and is mostly useful only in acoustics. So you usually can't find that for most products. But there's a reasonably usable relationship between GFR and density, for each type of absorber material. In most cases, higher density is better for dealing with higher frequencies only, and lower density also extends that down to lower frequencies. The thickness of the material also governs how low down the scale it will absorb: the thicker it is, the lower it goes. Spacing it away from the wall has a similar effect. There are equations and rules-of-thumb for figuring out what treatment you need, based on the acoustic response of your room and the purpose of the room.
Currently my speakers are on the window side, and I'm using a 132hz EQ cut on my output to remove a large freq bump coming off the studio desk. When I remove the desk the 132hz problem goes away..
That's fairly typical. The desk / console usually does cause one or more "bumps" in the response, as well as comb-filtering and general unevenness in the lower mid range. Treatment won't do much for that, since it is caused by reflections from the desk/console surface itself. But treatment will help with smoothing out the bass response of your room, which is the key to everything, and it will also help with reflections off your first reflection points. What might help with the console bump, is to set up your geometry better.
I'm even happy to pay for some advice if it's needed..
For advice given on the open forum, that isn't necessary. That's what the forum is all about! Helping out folks for free, when they need a little nudge to get them going in the right direction, or when they have hit a wall in their research or design that they are working on. There's no need for paying for that (although donations to the forum are always welcome! There's a donation button at the top of every page... ) But if you wanted someone to design your entire studio for you, or maybe do the detailed layout and treatment plan for you, or to tweak the room tuning to perfection, then it might be an idea to hire John or someone else to to that. There's a few of us here that do offer design and consulting services but you should always contact John first, since it's his forum! Also, beware of random people contacting you off-line, via PM, to offer services: No forum member should do that, and it's a large red flag that you are probably being scammed, or that you are talking to an unethical, immoral designer. It's John's forum, he runs the place and pays for it, so you should only contact him initially. If John isn't able to help you (sometimes he's too busy) then either he or I can send you a list of people that we trust are able to help you, and you will contact them: they won't contact you, unasked. If you do get an unsolicited offer, then please let me know so I can deal with it.
But you might not need paid services at all. If your needs are fairly simple, and you aren't in a hurry, and you are prepared to put in some effort of your own to research what you'll need to do, then the open forum is a great resource, and free! If you aren't sure which way to go, then feel free to PM me.
- Stuart -