Laser beam LP problem

Configuring your Home Theater
Post Reply
Message
Author
Keryn O'Shea
Posts: 216
Joined: Sat Jan 26, 2013 5:50 pm
Location: Brisbane, Australia

Laser beam LP problem

#1 Post by Keryn O'Shea » Wed Apr 25, 2018 12:04 am

My HT has a tiny sweet spot, which is the chair directly in front of the TV. I'm always saying "sit here, it's much better", is there a way to help with the seats either side to have a similar stage?
Things I think I'm doing wrong for the room.
- Too close to TLAHs (8 feet, they just sound so good in 2.1 listening to music though)
- The room won't allow front or back surrounds, which is why there are heights and sides. And the sides aren't really ideal surrounds. the roof is sloped making using the 2x4 SLA surrounds hard.
- 6 woofer center, I couldn't buy GT-302s for a while. A 9 driver/tweeter center is coming soon.

Any advice appreciated

Can 4x4 SLAs be spiral arrayed? Or would a set of 6x4 mains help?

Can midbasses be arranged in a cab like a 90 degree melded tweeter array?
Attachments
20180425_132944.jpg
20180425_125958.jpg
20180425_125853.jpg
I'll fit this next panel, then off to bed...

CoronaOperator
Posts: 1485
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Laser beam LP problem

#2 Post by CoronaOperator » Wed Apr 25, 2018 12:41 am

For staging there are roughly 3 rules:

1: below ~100hz we can't really tell where the sound is coming from as long as the timing isn't out too much, ~25ms or about 25 feet.
2: between ~100-3500hz our ears use timing between L/R (which sound hits our ears first) as our primary location method, even a 1ms difference here can move the sound stage over about a foot.
3: above ~3500hz the relative spl between L/R is our primary location device.

What I would try is to swap your L/R speakers to get the mids closer together and the tweeters further apart. Then I would try a pretty heavy toe in. The trick to the tweeters is to get the same volume level from both at your ears in the outer seats. By using a heavy toe in you are putting the closer speaker off-axis which reduces the volume level of that speaker (in the higher freq) and the far speaker on axis. You should find a sweet spot where at the outer seats you get the same volume level from the tweeters from both speakers. I would also consider spreading your mains out further apart if layout allows.

Your brick veneer walls are not helping matters and reflections from them could be/are messing with your perception of where the sound is coming from. I would consider some DIY sound baffles hung on the walls and some heavy drapes for the windows. Proper sound treatment (fiberglass/rockwool panels) makes a world of difference, sometimes even more so than the speakers themselves.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

User avatar
Bill Fitzmaurice
Site Admin
Posts: 26427
Joined: Tue May 02, 2006 5:59 pm

Re: Laser beam LP problem

#3 Post by Bill Fitzmaurice » Wed Apr 25, 2018 7:01 am

Your mains are much too close together. Arranged as they are you'll never hear them as left/right, only as a bit left of center and a bit right of center. Eight to ten feet is the usual spread for best results. Your surrounds should be up near the ceiling, aimed at the ceiling, the way the surrounds in the SLA plans are.

Keryn O'Shea
Posts: 216
Joined: Sat Jan 26, 2013 5:50 pm
Location: Brisbane, Australia

Re: Laser beam LP problem

#4 Post by Keryn O'Shea » Wed Apr 25, 2018 4:39 pm

Thank you for taking time to help gentlemen
CoronaOperator wrote:
Wed Apr 25, 2018 12:41 am
What I would try is to swap your L/R speakers to get the mids closer together and the tweeters further apart.
Understood and worth trying man!
CoronaOperator wrote:
Wed Apr 25, 2018 12:41 am
I would also consider spreading your mains out further apart if layout allows.
Bill Fitzmaurice wrote:
Wed Apr 25, 2018 7:01 am
Your mains are much too close together.
Roger, If I move the TV to the right as far as lined up with sitting in the recliner nearest the door (its centred on the inside seat atm), I should be able to move the r/h main/height to be 9-10 feet apart from the l/h. Then on movie night we'll just move the other single seater in front of the door.
Does it matter if the centre cab is above or below the TV as long as it's aimed at ear level?

RE building and fitting 4x4 SLA surrounds, as for the roof being pitched, which part of the ceiling would I best start looking to fit them?
I can give my cousin the 6x4 centre and 2x5 as he's been hassling me for a while for some BFM.

I'll study up on HT sound treatment, cheers!
Attachments
20180426_070601.jpg
20180426_070204.jpg
I'll fit this next panel, then off to bed...

User avatar
Bill Fitzmaurice
Site Admin
Posts: 26427
Joined: Tue May 02, 2006 5:59 pm

Re: Laser beam LP problem

#5 Post by Bill Fitzmaurice » Wed Apr 25, 2018 5:30 pm

Keryn O'Shea wrote:
Wed Apr 25, 2018 4:39 pm
I'll study up on HT sound treatment, cheers!
+1. It appears that everything you could do wrong you are. The surrounds don't go on or in the ceiling, they go on the walls aimed at the ceiling.

Keryn O'Shea
Posts: 216
Joined: Sat Jan 26, 2013 5:50 pm
Location: Brisbane, Australia

Re: Laser beam LP problem

#6 Post by Keryn O'Shea » Wed Apr 25, 2018 7:38 pm

Bill Fitzmaurice wrote:
Wed Apr 25, 2018 5:30 pm
everything you could do wrong you are.
:lol: Well I'm glad there's room for improvement, and look forward to hearing it set up properly!

Once these TLA Pros are done, I'll cook up a better center + some SLA surrounds and get cracking. Understood the surrounds are fitted to the wall aiming at the ceiling, should they be level with the bricks or the angled ceiling? And in line with the mains opposite the room?
I'll fit this next panel, then off to bed...

User avatar
Tom Smit
Posts: 6595
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Laser beam LP problem

#7 Post by Tom Smit » Thu Apr 26, 2018 12:16 am

Remember Geogolf, way back in, what, Win3.1? Anyway, try aiming the satellites such that it reflects off of the ceiling and aimed at the listening position.
TomS

User avatar
Bill Fitzmaurice
Site Admin
Posts: 26427
Joined: Tue May 02, 2006 5:59 pm

Re: Laser beam LP problem

#8 Post by Bill Fitzmaurice » Thu Apr 26, 2018 7:07 am

Tom Smit wrote:
Thu Apr 26, 2018 12:16 am
try aiming the satellites such that it reflects off of the ceiling and aimed at the listening position.
Not necessary. The whole point of aiming them at the ceiling is to spread their output throughout the room and reduce the ability to directionally locate them, which should be vague. The pinpoint imaging desired from mains is detrimental with surrounds.

T_Gowan
Posts: 96
Joined: Sun Sep 09, 2007 7:10 pm
Location: Allenford, Ontario, Canada

Re: Laser beam LP problem

#9 Post by T_Gowan » Thu Apr 26, 2018 10:21 am

Hope I'm not intruding, I have a 7.1 receiver but never bothered with the mid surround it that's the proper term. Is it worth it and if so how do you aim them.
DR200 x2
T24 16" x2
T39 20" x2
DCX2496
DEQ2496 x2
Mackie DL1608

User avatar
Bill Fitzmaurice
Site Admin
Posts: 26427
Joined: Tue May 02, 2006 5:59 pm

Re: Laser beam LP problem

#10 Post by Bill Fitzmaurice » Thu Apr 26, 2018 10:29 am

It's not the proper term. If you mean the center channel it is critical. If you mean the side surrounds they don't add much unless you've got a very deep room. IMO the diminishing returns sets in very quickly beyond 5.1. I think Atmos is silly, only existing to convince owners of perfectly good systems that they need to 'upgrade'. My 5.1 might not be the be-all, but it's still enough to get a 'holy crap!' out of everyone who hears it, as for most people even a soundbar would be an improvement.

T_Gowan
Posts: 96
Joined: Sun Sep 09, 2007 7:10 pm
Location: Allenford, Ontario, Canada

Re: Laser beam LP problem

#11 Post by T_Gowan » Thu Apr 26, 2018 10:33 am

I always had my rear surrounds set high and pointing down at the listening position. So it would be better to have them mid wall or higher pointing up? Narrow or wide spread?
DR200 x2
T24 16" x2
T39 20" x2
DCX2496
DEQ2496 x2
Mackie DL1608

User avatar
Bill Fitzmaurice
Site Admin
Posts: 26427
Joined: Tue May 02, 2006 5:59 pm

Re: Laser beam LP problem

#12 Post by Bill Fitzmaurice » Thu Apr 26, 2018 12:39 pm

Pointing down they'll be loud below them, faint away from them, so whichever you're closest to will be dominant. Aimed upward they'll be at a more uniform level across the LP. The higher they're placed the better. That will best replicate what you hear in a theater, where the rear speakers would be quite a ways in back of you.

Keryn O'Shea
Posts: 216
Joined: Sat Jan 26, 2013 5:50 pm
Location: Brisbane, Australia

Re: Laser beam LP problem

#13 Post by Keryn O'Shea » Sat Apr 28, 2018 2:07 am

[/quote]
Bill Fitzmaurice wrote:
Thu Apr 26, 2018 10:29 am
I think Atmos is silly, only existing to convince owners of perfectly good systems that they need to 'upgrade'.
Bill Fitzmaurice wrote:
Thu Apr 26, 2018 10:29 am
as for most people even a soundbar would be an improvement.
Haahaa, Excellent!

My sons and I went to the AV repair guys today to pick up a Denon AVR2805 which was playing up, they're 6 and 8yrs old and in the adjacent showroom was some Klipsch and Jamo gear, they were quizzing the retail guy about the subs they had...., "Is that a sub? It's TINY!, you should see Dads Tuba, it'd eat all these for beakfast!", and "Where's the rest of your speakers?!". The guy had no Idea what Connor was talking about :D . It's been a while since I checked prices.... holy :shock: ! Talk about tricking people out of their cash!
Tom Smit wrote:
Thu Apr 26, 2018 12:16 am
Remember Geogolf
Memorable character?
I'll fit this next panel, then off to bed...

User avatar
Tom Smit
Posts: 6595
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Laser beam LP problem

#14 Post by Tom Smit » Sat Apr 28, 2018 1:09 pm

Keryn O'Shea wrote:
Sat Apr 28, 2018 2:07 am

Tom Smit wrote:
Thu Apr 26, 2018 12:16 am
Remember Geogolf
Memorable character?
Wow! I wish I could remember the correct name! :oops: We had it on a computer, way back in the days of Windows 3.1 or earlier, where the angles were calculated of how to shoot the ball. It may have been pool or golf.
Anyway, it was something that I should not have used as an example since Bill pointed out that the ceiling reflections should be diffused.

Me --> :owned:
TomS

Post Reply