***Working Man's DIY Dedicated Home Theater*** - Page 6

Thanks!

i'm thinking I want these behind the seating probably on the ceiling.....

Hello Mr Rose Surprised you have time to post what with that shiny new projector goodness calling to you.

Yeah i think the bigger they are the lower theyre effective. That comes from the acoustic engineer Dr. Gobigergohome's paper on sound wave propogation in a closed system with single non-acute incidence diffusion.

AND this is what i ended up with after a bit of cutting and trying to maximize the material I had......

WooHoo the Deco-Fusers are done!

Drum Roll Please(Cark Griswold Style)

My crappy pics don't show off how cool looking they are. I haven't listened to a flick with them yet. I'm sure the difference will be subtle if any, but we all know its the sum of all those subtle things which make big differences.

I ended up putting all three on the ceiling above and behind the main seating addressing all the primary reflection points from the surrounds.

Thanks for the kind words sir! The pics are crap though, this room is haaaard to photo its designed not to reflect light you see......

Anyways they were so crappy that it bothered me enough to lug a shop light up there for some lighting and about 30-40 pics later and 30mins of playing with the settings on the camera I got three which were marginally better.......

If only I had a friend who could take good pics...........

And a few more not so great......

Hmmm what was that guys name.... Dan I think.... Last I heard he had caught sub sickness. Hes probably off daydreaming down in his theater about things that go BOOM!

Meanwhile The Dude Abides......

Aaaaah football, nothing like seeing ALL the dirt on the jerseys!

i did some optimization of the acoustic treatments I already have with great success. The waterfalls look much better and overall imaging sound is better. I'll post some images to help demonstrate what i mean. But now, back to football and beeaz!

Ill have what he's having!

Sorry to hear youve been diverted mate but that is the nature of the beast......

Thank you very much man, we do what we can with what we have.....

i just realized i have the theater pumping, the living room, and then the kitchen that way I dont miss a play on the way to the fridge.....

While I had some time and before I forget, here are a couple waterfalls of before and after the treatments were moved. The decay times were considerably reduced and after a little brief listening I consider it a major success, especially considering it cost me nothing.

It also further allows me to assess the affects of treatments as you move them around the room.

Basically I did not have enough treatments to treat all the primary reflections and behind each of the mains and center. So making the best of what I had and working off of previous reading I moved the treatments from behind the main L and R speakers and placed them to address all the primary reflections from the C, L, and R.

They are as follows:

2x4 OC703 2" with 4" air gap

• Both side walls
• Ceiling
• Back Wall

Center speaker has a large window behind it which was filled with fluffy pink and covered with poly batting then burlap.

3 of 4 corners treated with Bass traps 4" OC 703 2' wide across corners

Here is the before waterfall:


Here is the after:



Notice the after has much less decay out to where the graph cuts off. I delibrately cut off the bass region. I still have much work to do there and since I didn't add any treatments that region didn't change much.

Here is the final response plot I've still got some work to do below 200 so I left that part out......

Yeah theyre white, havent got to that yet.....

I do the science when i don't have the cash to start a new project.

I can swing a can of high temp paint though, for less of an "old school" look.

I basically confirmed what i already knew. In my room addressing ALL the primary reflection points was paramount to having treatments behind the mains. Moved those two to the ceiling and back wall for an audible and measurable improvement.

All in all cost me less than $10.

Now i gotta shuck out 5 more bucks for a can of paint!!!

Hi Cuz,

Well my understanding of it is that what you see deepest in the graph is the initial FR. Then the software continues to monitor as the sound decays which is what we see on the waterfall. Now if there are room issues or modes those regions will continue to ring after the signal stops and the "waterfall" does not drop off as fast as it should. I think generally you want the waterfall to drop below the noise floor of the room in less than 300ms and obviously less is better.

Now factor in audyssey. Audyssey corrects(among many things) for ringing by notching or EQ depression. So Audyssey will often in fact make your FR more jagged trying to correct ringing which can be far more detrimental than a 5db valley in response.

Ok bring it all full circle. With less ringing Audyssey does less EQ depression and notching. This should produce a flatter reaponse which is what were all after, right?

How does it sound. Counter intuitive actually. The sound of the mains is much fuller and far more articulate. It is easy to tell that the sonund stops sooner which lends itself to the "faster" description even though i dont like fast or slow when describing sound. What im really referring to is how fast the sound stops.

More of the same effect i got when i first installed acoustic treatments.

I like it.

Yeah, thats why i tapdanced the response on how it sounded.

I watch a movie last night on the new setup and calibration. Most of the difference was noticed in the front stage obviously. Most notably improved was center channel clarity and detail.

Pretty much spot on John. I use rew which plays a user definable sweep and measures response and then its decay. For this test I tested all channels driven. However if i had all my treatments constructed and were going full bore I would be testing each channel independently. There is a way to measure each channel with the ETC function i think which gives a spectral reading of sound arrival over time. With this you could calculate the wave path length and isolate specific detrimental reflections and address them.

What im doing is highly simplified since i dont have any more acoustic treatments to address those problems. Just picking the low fruit for now.

Hi Cuz,

I agree his site has some good reading. Lots of free info on the basics and even some free diy solutions. I actually used his suggestions for the basic treatements I already have.

Keep us updated on how your treatment reboot works out.....