Axiom Home Page Forums General Discussion Advice from Axiom Owners Crossover on the EP subs.

I tried to get a refund for it and they just laughed me out of the store . So I gave it to my daughter and she cut holes in it for an art project at school.

Ha ha, nice refund attempt. I always have to work up the nerve to try for any kind of refund.

So I simulated bass traps as best as I could. You can see pictures of the mess I created in my basement below. I even managed to get carpet from one of my neighbors. Randy, my wife is really PO'd at you because I told her this was your idea .

The blue trace in the graph is no treatments with a 40Hz cut-off. The red trace is with the treatments and an 80Hz cut-off. I've explained what the 80Hz cut-off does in other posts. The bottom line is that the treatments really amounted to nothing in the frequency domain.

However, the time domain is a different issue. I don't hear as sharp a "snap" after I finish clapping my hands. Also, I can turn the volume up higher before sound starts to get muddied. And there is no question that the bass is tighter!

Maybe I will go for some artificial treatments after all .

Here's more to show that I don't think I need side-wall treatments.

I measured the direct distance from my speakers to my listening position and all of the major reflection distances (see spreadsheet). I then used the reflection coefficients for the materials that caused the reflections and the distance of the reflected path to calculate the reflection SPL. I then figured out the reflection delay. This is all according to the Master Handbook of Acoustics.

I used the attached chart from the book to figure out which reflected paths cause me grief. Grief = echo + imaging effects such as shifting and spreading as opposed to spaciousness.

The only areas that could be cause for alarm are the floor and the ceiling between the listening position and the speakers (shown in yellow on the spreadsheet).

Not sure I would say there is no difference. For one, these are not true bass traps. You need at least 4" thick material like 703 spanning across or filling the corners.

If you look across the entire spectrum I see many nulls that have been improved. Overall, it seems to be a flatter outcome.

Ok, that's what I thought. They're not very good simulations. And yes, you're right. There are some nulls higher up that got knocked up. But the nulls below 100Hz have nothing to do with the "traps". They are purely due to the 80Hz vs. 40Hz cross-over on the Denon.

That could be, but I'd bet if your room was treated properly even those freq's would get better and flatter.

Mojo, since we're on pic mode tonight, thought I'd take a quick snap of some fledgling treatment.

I haven't run any frequency sweeps, but I can tell you those little corner thingies really help tame the echo in here. When I first put all these up, I felt I was in a loony bin cell. Maybe I am. . .

Those tube amps look awesome man.