Author Topic: Acoustic concerns for speakers lying on the ground  (Read 4805 times)

byc

  • Guest
Acoustic concerns for speakers lying on the ground
« on: November 16, 2009, 07:29:40 PM »
Hi there,

My friend and I have set up a theater in his backyard, and for front speakers we're using three EV ZX1-90's.  Right now they are lying on their sides on the ground in front of the screen, and they tilt up about 10-15 degrees.  They don't sound bad by any means, but I'm always looking for ways to improve things, and I'm assuming, although I know very little about acoustics, that it's a bad thing having them on the ground.

I think I can raise them about 6 inches before they start to obstruct the screen, so I'm looking for suggestions on what sound absorbing material I might put beneath them (if that's a good idea).  I'm thinking they could sit on some sort of pads that extend out couple of feet in front.  I was looking at this material: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-515, but one reviewer mentions that it's only good for high frequencies, so perhaps I could layer it on top of something else that can handle lower frequencies?  The speakers are set to run as "small", so below 80Hz should not be a problem.

Am I close to being on the right track?  If I'm crazy, that's cool, I've heard it before! :)

Thanks so much for any advice you have.

Randy S

  • Senior Soundproofing Technical Specialist
  • Global Moderator
  • *****
  • Posts: 787
    • Super Soundproofing Co
Re: Acoustic concerns for speakers lying on the ground
« Reply #1 on: November 16, 2009, 08:22:10 PM »
Ahhhh.... The beauty of "Free Path", not an easy set up where there are no walls to add reflections, you've probably noticed that they don't sound very good — thin and dull, with very little bass.
Raise the tweeters/ speaker to ear height when your seated and angle the speakers 110* torward center on the left and right side. You can place the speakers on our SSP Foam mat however the stands seen in your link might be ideal if more height is needed...
Good Luck, Your taking on a great challenge when working with sound outside.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

byc

  • Guest
Re: Acoustic concerns for speakers lying on the ground
« Reply #2 on: November 17, 2009, 02:07:36 AM »
Hi Randy, thanks for your help.  Unfortunately, I can't get the horns up to ear height since they have to stay below the screen, and I'm actually trying to optimize for 3 different ear heights (We've got 2 rows of raised platforms for seating, plus the ground for a total of 3 rows).  So all I can do is raise the speakers about 6 inches off the ground and angle them up a little bit.  Luckily the cabinets' design makes them sit at pretty much the perfect angle.  I will definitely try toeing in the left and right like you say.

I guess what I really want to know is should I be concerned with reflections from the ground immediately in front of each speaker?  Are those reflections a bad thing?  Would the SSP Foam be the best solution for that?  For all frequencies?  Or is the best solution to just raise the speakers as much as possible and live with the results?

Thanks again!

Randy S

  • Senior Soundproofing Technical Specialist
  • Global Moderator
  • *****
  • Posts: 787
    • Super Soundproofing Co
Re: Acoustic concerns for speakers lying on the ground
« Reply #3 on: November 17, 2009, 04:48:56 PM »
Well you want the ground reflection because it is the only reflection you have.
Why would you not place the speakers on either side of the screen instead of below it? then toe in.

This is not my area of expertise but why dont you give me a call and we can toss a few ideas back and forth. My contact info is below.

Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

byc

  • Guest
Re: Acoustic concerns for speakers lying on the ground
« Reply #4 on: November 17, 2009, 08:49:21 PM »
Well, since the center speaker has to stay below the screen, I was thinking it would be best to keep them all on the same plane?  Plus, if I put the L and R to the sides, the L will have free air behind it, whereas now it has the screen behind it.  So from what you're saying, wouldn't that be a bad thing?  One less surface to reflect off?

Anyway, thank you for answering my main question.  I was confused about whether the ground reflections were good or bad.  I will raise them as much as possible and see how that sounds.