Omnitop JArray x8 and T48 x4

[Charles Jenkinson]

I wonder if it could be that cathedral roof, focusing a cancellation into the room centre. It looks about the right angle for anything hitting the roof.

[lancemhorsley]

Is it possible its being caused by the room?

It's possible, but a cancellation mode down the center of the room at shorter wavelengths isn't likely. You also can try aiming them straight out with no toe. You never know til you try what will work best.

Ok I will play with the tow angle next free chance i get.

I wonder if it could be that cathedral roof, focusing a cancellation into the room centre. It looks about the right angle for anything hitting the roof.

Its a 4/12 pitch and the building 80' wide. The side walls are 17' high and the center of the gable is 27'. Maybe that will give you a little more info about the room.

[Charles Jenkinson]

All I did (in my minds-eye, looking at your photo) was draw a perpendicular (square line) to the roof and draw it back to the floor through the line of the speakers. The roof line focusses reflections back toward the room centre-ish on the floor, moreso than a flat ceiling. Whilst the room dimensions could help with an acoustic analysis, I'm not suggesting mathematical analysis, someone else may though, ...whilst I have a predeliction to analysis, I'm trying to shake it off. I agree that the first course of action is to try toe angle (in the plan view) and the other option, though I don't have the plans and therefore don't know, is array vertical angle (in the side elevation view). The teaching to suck eggs part: I would change only one parameter at once, then assess the effect of that change, and to be sure fiddling with angles is easier than absorption in the roof, so must be the first call. There must be an optimum angle for toe-in based on the sideways dispersion - I had read somewhere (not on here(*)) that toe-in was necessary for all PA systems to avoid comb filtering. I'm not an authority/expert on this subject - these are just my opinions. It would be interesting to know what the troublesome frequencies are - is there any way of measuring it, with the mic in the positions you can hear the problem and comparing the graphs? Again, only an idea.

(*) It was the westhost page here (3/8 down the page): http://sound.westhost.com/articles/pa.htm

[lancemhorsley]

Next chance I get I am going to play with the tow angle. Hopefully later this week. I actually took pictures on sunday morning of what it looks like in smaart, but I did not have all eq turned on so I did not post it. I will post it anyways maybe it will be useful after all.

Thanks for website info!

[lancemhorsley]

So today I had a little more time to go adjust angles and I also had a helping hand. After an hour of adjusting and nothing changing I decided to check the polarity again. It was much easier with an extra person, and i'm not sure what I did wrong on sunday but it was definitely a polarity issue. The problem is resolved thanks to all your help. Thank you!! I just wanted to add it sounds pretty stinkin good!! a Huge improvement from our bose l1 setup. It really can not even compare, and my pocket don't feel as empty either!

[Bill Fitzmaurice]

It was much easier with an extra person,

+1, one guy switching wires while the other listens to the result is much easier.

[Grant Bunter]

So good to hear it's finally worked out well for you...

[biggerrigger]

Alright another Bose convert. Good job getting it dialed in and sounding sweet.

[Tom Smit]

Excellent!

[DJPhatman]

lancemhorsley, please post a new screen shot, post phase fix, from SMAART.

Glad you got the system all sorted out. Also, could you post a review? Comments from other listeners are welcome, too.

[lancemhorsley]

lancemhorsley, please post a new screen shot, post phase fix, from SMAART.

Glad you got the system all sorted out. Also, could you post a review? Comments from other listeners are welcome, too.

If I get a few moments tomorrow morning I will get check the center in a couple spots and post some pictures. I will also write a review here after our christmas bash! Im hoping a local system design and installer shows up so I can get his feed back.

Alright another Bose convert. Good job getting it dialed in and sounding sweet.

haha I will do my best to convert everyone! should not take much, one listen an its obviouse.