# Primacoustic London 12A kit... experiences?



## Danny_Owen (Jul 15, 2010)

My studio is in big need of some acoustic treatment- I've just ordered the Primacoustic London 12A Kit: http://www.primacoustic.com/bw-lon12a.htm as I know someone who can get me a very good deal on it. Just wondered if anyone has had any experience with them and what their thoughts were? I went into a room with very similar treatment at Reelsound in Pinewood studios, and the imaging was fantastically clear, I'm hoping these will do a similar job!

If you have had any experiences please share them 

Thanks

Danny


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## misterbee (Jul 15, 2010)

I have a pack of the control columns and they work nicely to deaden reflections. The only problem I have with them, is that they stink.


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## artsoundz (Jul 15, 2010)

ya know/....if you can screw 2x2's together and wrap fabric over rigid insulation then you can build these things for a fraction of the cost. 

the stink probably comes from the fireproofing on the fabric.


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## Danny_Owen (Jul 15, 2010)

Lol, not the answer I was expecting, I guess I'll have to get an air-freshener! Good to know they work well though

If I wasn't getting these at such a good price I might consider making them, but I have a hell of a deal, the price I'm paying is very worth letting them do the work I feel


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## wst3 (Jul 15, 2010)

As you have already made your purchase I'll try to fashion a solution around it. I suspect you will get many suggestions about DIY solutions, and in general I think they provide a bit more flexibility, if not some cost savings.

The kit you purchased is pretty flexible already, and it will provide a certain amount of instant gratification - which is also nice<G>!

So, room treatment ideas for a pre-configured kit...

1) You still need to identify the problems - which will usually fall into the following broad categories: low frequency modes, bad early reflections, bad reflections, and inadequate sound field build-up (aka poor reverberation time.)
Note that a small space can not be statistically reverberant... so be careful not to chase that problem - it is a red herring. These problems will appear as one or two symptoms, poor balance across the frequency spectrum, and poor imaging. Sadly, no single problem maps to a single symptom!

2) start with the simplest solutions... and the single biggest bang-for-the-buck solution is placement of the loudspeakers and listener. So play around a bit with different arrangements of these two elements. In all but the smallest spaces you can usually find an optimal configuration that will start to reduce both the perceived frequency response and imaging problems.

3) pick exactly ONE design philosophy. Mixing and matching does not work! The major schools of thought can be divided into three categories:
- make the front of the space more reflective than the rear
- make the rear of the space more reflective than the front
- make the space disappear entirely (aka the non-environment approach)
All three approaches use the control of reflections to tame the space. At first glance this may seem a bit backwards, but if you can minimize troubling reflections you can reduce the impact of the room modes - and by the way, you can not change the room modes with acoustical treatment, you can change the reflection patterns, so best to start with something you can control. (aside, if you are building from scratch you can control, to some degree anyway, the room mode spacing, and in that case you do want to start there!)

4) find all the problematic reflecting surfaces, and don't overlook things like monitors, racks, the desk (in the old days the desk was the console<G>), etc. Before you apply a treatment, try to relocate the offending surface (obviously doesn't work for walls!)

5) Once you have the early reflections controlled you should already experience an improvement in the stability, and probably clarity or definition, of the stereo image. This is a good place to switch gears...

6) If you have the ability to measure the room mode problems by all means do so, not that it'll help much with mitigation, but it'll give you a yardstick to see how much improvement you've effected.

7) start with the corners, and apply broadband trapping there. The information that comes with the kit will provide ample detail. Now go listen... did it get better? If it didn't you may need more than a kit can provide, but I'll be surprised if you don't notice an improvement.

8) now, based on the approach you selected in #3 above, apply additional absorptive tiles to the front or rear of the space. 

IF you are deadening the front, and you have sufficient distance from the back of the room to the listening chair (usually 10 ft - 12 ft) apply diffusion to the rear of the room. Otherwise stash them away for a bit.

If you are deadening the rear of the space then just stash the diffusers.

Do not forget to treat the ceiling above the listening space and/or the floor beneath as part of this step.

9) After a critical listen you may decide you need even more absorption. This is where most folks get into trouble. Since the 'reverberation' in a small space is not statistical you can not treat it with statistical means. You have to place absorption where it will actually help. There are two popular approaches, and which one works is a coin toss, even if it should not be<G>!

Start by placing the absorptive tiles on the side walls in a staggered pattern, so that they are not directly across from each other. This runs the risk of distorting the stereo image, but in my experience it usually works better than the alternative.

If that does not work then you need to place them tiles so that they are directly opposite each other. And sadly, you will probably need to try both approaches. The effectiveness of one or the other is tied to the room dimensions, but there are no hard and fast rules.

That's it in a (large) nutshell<G>! One caveat - if your room treatment is effective you run the very real risk of unmasking other problems, specifically noise problems. Nothing you can do about that, it's the natural and appropriate consequence of fixing one problem.

If that happens you will need to investigate noise sources inside and outside the space, but that's a topic for another long-winded post!

Prime Acoustic is a good outfit, and their products are well made. I am not a big fan of the 'kit' approach, but I appreciate that it can help, and it can save people money, and I think their kits are reasonably well thought out, and presented.

Have fun with this project...


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## misterbee (Jul 15, 2010)

artsoundz @ Thu Jul 15 said:


> ya know/....if you can screw 2x2's together and wrap fabric over rigid insulation then you can build these things for a fraction of the cost.
> 
> the stink probably comes from the fireproofing on the fabric.




Since I can't get OC703 here, I priced it up, and by the time I'd added shipping, fabric, wood and varnish, it wasn't worth making my own. 


The smell comes from the fibre glass. I've smelled it before on wall batt insulation too. It dies down, but when the room gets humid which it can in the summer, it all comes back.


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## Danny_Owen (Jul 15, 2010)

Thanks for that very detailed response wst3 

I have indeed already been moving around my room trying to get the best spot, and since I've moved my listening position and set up I think my mixes have improved a lot, so this really is that next stage. I can still do some more work on the early reflections I'm sure, so I'll probably give that a go before the panels arrive.

I'm going to do the 'make the front space more reflective than the rear' approach, mainly because I have windows that stretch across the entire width of the room (which I am facing), so it's impractical to but anything on there, so I aim to deaden my back wall and the side walls. I'll try and get some pictures up here later to show what I intend to do and see if I'm going about it the right way. I think I get it, but it'd be good to have other people's opinions. 

Ahh, luckily England is only humid for about 2 or 3 months a year, so I'll largely get away with it  still, thanks for the warning. It'll be interesting to see what difference it makes, can't wait!


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## Danny_Owen (Jul 25, 2010)

These arrived and I've put them up. Instantly noticeable results, these things are impressive. The smell isn't nearly as bad as I was expecting, they've been out of the box for about 5 days now and it's not that strong, it just smells... well, how I'd kind of expect a studio to smell.

I can now walk anywhere in the room and the frequencies remain practically identical, the first time I've ever had this. I had to start using the room EQ on my Adam A7's to compensate for the change in frequencies from how it was before, but it sounds great now. Every instrument is a hell of a lot clearer in terms of panning and frequency. In addition it's allowed me to relatively turn down the sub a little, making it more neighbor friendly.

Thanks for the advice on placement, I think I've got the best design I could have got out of the room with this kit now.

Good product, got the thumbs up from me  Will be seriously considering the Recoil Stabilizers as well now


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