[bpape]

You've gotten some good advice. I will clarify one thing. The density of the material to be used for optimal performance in a given application depends on a few different things. The biggest of those things is how thick you'll be making them.

As an example, 705 is basically double the price of 703 (6lb vs 3lb). So, given a choice, I'd rather have a 6" thic absorber from 703 than a 4" thick absorber from 705. The 6" 703 will perform better and 25% less. Now, by the time you get to that stage, you can (with the same amount of 703 for the same height and size of absorber, you can build a solid chunk that will do MUCH better below 80Hz than 6" straddling. Why? Because at it's deepest point, it's a solid 12" thick.

Another example is when making reflection point panels. If your speakers are far away from the side walls, then your angles of incidence for the reflections are relatively steep. However, if you're close to the side walls, there are some really shallow ones. 6lb material has a tendency to allow high frequencies to skip off at shallow angles of attack - 3lb not nearly so much.

It would be great if there was a single best product for everything - unfortunately there isn't. The reason most people use 703 is because it's a good all around product that can be used for pretty much anything and the cost is at least somewhat reasonable.

I appreciate the kind words about our product. I'm more than happy though to help with DIY projects also.

Bryan