Kentia Palm

[junker]

So, yesterday I had to take back a wool area rug that i had bought for my new place to tame the brightness from the hardwood floors. Unfortunately, it going to be some work to find the right type of rug, so I decided to look into adding a plant behind the speakers in the room's corners.

So, I headed over to Home Despot and found out that most palms are outdoor plants, that is, except for the Kentia Palm (Howea forsteriana). Problem is, this is by far the most expensive palm. They were the classic parlor plant in Victorian England. The seeds are tightly regulated and pretty much only come from Lord Howe Island near Australia. And those seeds are difficult to germinate. Not to mention it is very slow growing.

Kentia Palm

How to Care for Kentia Palm | Home Guides | SF Gate

The nice thing is that is can handle low light, humidity, and temperatures, as well, as dust, and somewhat rough handling. Once I found out about them, I googled it and found a relatively local Palm Nursery built on the land of an Victorian orchard/ranch house from 1880-1890. She also does weddings out of the place. Honestly, I think they run this place to keep Orange County from taking it by Imminent Domain. Gave me a great price of $150 per plant in a 15 gallon container. Home Despot had them for over $300 each. Guess they didn't look as big with all of the other, much larger Palms, but I clearly was being optimistic! Also, winter is not ususally the best time to buy palms.

Performed a bit of bonzai shaping with a bungee cord to keep them from spreading out much more, and I think they are a great indoor. So, since I have never heard of them before I thought I'd post them here in case any of you were wondering what would make a good indoor plant to absorb and diffuse sound from behind the speakers. I just hope you have a bigger place than me...

[KahunaCanuck]

Looks good! Did you notice a difference in the sound after installing them??

[junker]

Originally Posted by KahunaCanuck

Looks good! Did you notice a difference in the sound after installing them??

Yeah, I've been moving speakers and the plants around - and draping them a bit more gracefully. Keep in mind I have all hardwood floors and a glass Noguchi coffee table so it doesn't sound carpeted, but it has seriously knocked back the room's reverb and gave me a few Feng Shui points. I figure it looks a bit better than panels or at least the triangle corner pieces.

It's one of those things that I'll want to play with a bit. I'll definitely try to follow up with more details when I get my better amp installed here in the near future. That Rotel has always been a thorn in my side, so I've got to get that out of there first. Let's just say it doesn't sound nearly uncarpeted as it did before.

[junker]

I'd say the sound affect of the palms is a bit like this, with an umbrella drink...

[GIK Acoustics]

Originally Posted by junker

I thought I'd post them here in case any of you were wondering what would make a good indoor plant to absorb and diffuse sound from behind the speakers.

Just to clear a few things up: while I'm absolutely certain the plant did affect the sound and likely break up anomalies such as flutter echo, a palm tree wouldn't be a great absorber and would not diffuse by any means. It is a common misconception that random objects offer any notable diffusion. Diffusion must be calculated to perform well, or it could actually be detrimental. Things like a plant can be helpful in combating harmful reflections and echoes, not by absorption or diffusion, but by (very uneven) scattering. Also, diffusion behind a speaker wouldn't be very beneficial at all. Most diffusors don't offer any helpful amount of diffusion above around 800-1200 Hz. Since only frequencies under 300 Hz or so start to become omnidirectional, not much would be affected behind the speakers at all. A much more helpful place would be in a directional path for the frequencies of interest, where it would (best) return diffuse reverb back to the listening position. Just to restate - I'm sure your plant positioning has been helpful, but it would be best not to assume it is absorption or diffusion that is the helpful factor.

Anyone interested can read more about diffusion (along with common misconceptions) here: How Diffusion Works - GIK Acoustics

[junker]

Originally Posted by GIK Acoustics

Just to clear a few things up: while I'm absolutely certain the plant did affect the sound and likely break up anomalies such as flutter echo, a palm tree wouldn't be a great absorber and would not diffuse by any means. It is a common misconception that random objects offer any notable diffusion. Diffusion must be calculated to perform well, or it could actually be detrimental. Things like a plant can be helpful in combating harmful reflections and echoes, not by absorption or diffusion, but by (very uneven) scattering. Also, diffusion behind a speaker wouldn't be very beneficial at all. Most diffusors don't offer any helpful amount of diffusion above around 800-1200 Hz. Since only frequencies under 300 Hz or so start to become omnidirectional, not much would be affected behind the speakers at all. A much more helpful place would be in a directional path for the frequencies of interest, where it would (best) return diffuse reverb back to the listening position. Just to restate - I'm sure your plant positioning has been helpful, but it would be best not to assume it is absorption or diffusion that is the helpful factor.

Anyone interested can read more about diffusion (along with common misconceptions) here: How Diffusion Works - GIK Acoustics

How about having 15 gallons of soil behind the speaker and toward the corner?

Acoustic are definitely interesting! Thanks for the reference. So, frequencies above 300 cycles per second are where reflection start to play a significant role?

Do you recommend any computational modeling tools such as Cara or AudioCad?

[GIK Acoustics]

Originally Posted by junker

How about having 15 gallons of soil behind the speaker and toward the corner?

Now that is a more interesting question! I don't think the air flow resistivity would be low enough to be a good absorber, but only testing would be able to tell!

Originally Posted by junker

Acoustic are definitely interesting! Thanks for the reference. So, frequencies above 300 cycles per second are where reflection start to play a significant role?

Yes - I agree! A lot of fun to read about.

I'm not sure on the exact frequency. If I remember correctly, roughly 300 Hz is where it stops becoming as directional, and under roughly 150 Hz is, for most purposes, omnidirectional. So, usually the frequency accepted as the point where it becomes omni is about 200 Hz.

Originally Posted by junker

Do you recommend any computational modeling tools such as Cara or AudioCad?

I don't have a lot of experience with modeling software so I'm unsure of what to recommend. I can recommend that you find one that offers BEM (boundary element method) calculations, as they're the most accurate that I know of (but also can take quite a long time to compute).