HELP: Insulating speakers in cabinetry?

[HTnewbie]

Summary: Need advice on sonically insulating/isolating speakers in a wall unit.

I am in the process of finishing an A/V installation in a great room adjacent to our kitchen. The site is far from ideal but it is where the family spends much of our time so I have to make do. I have a space in the basement that will ultimately become a dedicated theater but that is out in the future. Importantly, wife approval factor is also very important.

We have designed and installed a built-in “entertainment center”. Fortunately, I had a great deal of influence in the design and sizing of the unit (see photos attached). The LCR and sub will be located in the spaces covered with grille cloth (yes, I am fully aware of all the compromises this entails, especially the sub’s placement) Given the dimensions of the RPTV and the equipment stack, I was not able to dimension the speaker holes to the dimensions of the speakers. Thus, as you see, there is much dead air around the sub and the mains. The sub space is also open in the back the center portion of the wall unit (i.e. behind TV, etc.)

I am no acoustics specialist but I have read enough to believe that I should consider filling that dead space behind and around the speakers with insulating material. I have used the egg crate acoustic foam (PartsExpress) to insulate my in-ceiling surrounds and rear surrounds and have extra pieces that I can use. If there is better material I am open to suggestions.

I am also wondering if I should “isolate” the mains and/or the sub from the wood surfaces to reduce vibration transmission. As it is, I need to raise the mains about 1.5” to center the coaxial drivers in the speaker doors. There are a variety of products out there but I would appreciate some advice. Note that the sub does not have much room above so anything under it must be less than 1.5” high.

Here is the basic equipment involved in the cabinetry:

Yamaha RX-V2500
Bagend MM-8H (LCR mains)
Bagend Infrasub-12 Home (I-12)
Samsung HL-R6168w

Thanks.

Tom

 

[mtrycrafts]

Summary: Need advice on sonically insulating/isolating speakers in a wall unit.

I am in the process of finishing an A/V installation in a great room adjacent to our kitchen. The site is far from ideal but it is where the family spends much of our time so I have to make do. I have a space in the basement that will ultimately become a dedicated theater but that is out in the future. Importantly, wife approval factor is also very important.

We have designed and installed a built-in “entertainment center”. Fortunately, I had a great deal of influence in the design and sizing of the unit (see photos attached). The LCR and sub will be located in the spaces covered with grille cloth (yes, I am fully aware of all the compromises this entails, especially the sub’s placement) Given the dimensions of the RPTV and the equipment stack, I was not able to dimension the speaker holes to the dimensions of the speakers. Thus, as you see, there is much dead air around the sub and the mains. The sub space is also open in the back the center portion of the wall unit (i.e. behind TV, etc.)

I am no acoustics specialist but I have read enough to believe that I should consider filling that dead space behind and around the speakers with insulating material. I have used the egg crate acoustic foam (PartsExpress) to insulate my in-ceiling surrounds and rear surrounds and have extra pieces that I can use. If there is better material I am open to suggestions.

I am also wondering if I should “isolate” the mains and/or the sub from the wood surfaces to reduce vibration transmission. As it is, I need to raise the mains about 1.5” to center the coaxial drivers in the speaker doors. There are a variety of products out there but I would appreciate some advice. Note that the sub does not have much room above so anything under it must be less than 1.5” high.

Here is the basic equipment involved in the cabinetry:

Yamaha RX-V2500
Bagend MM-8H (LCR mains)
Bagend Infrasub-12 Home (I-12)
Samsung HL-R6168w

Thanks.

Tom

You don't have a crucial, must do before listening, issue here. Use the left over foam to raise the speakers. After the unit is up and running, properly tested , see if the cabinets are resonating enough to interfere with what you hear. I think it will not.

 

[gene]

Ray offers some basic tips here:

Subwoofer Cabinetry Installations


I used this stuff from Knox Foam cut to order on an RBH T-3 system install into a built in wall unit and it worked great!

Try to get the speakers flush with the cabinet so it better simulates a 2pi environment. use foam to the left/right sides of the speakers to eliminate any gaps between them and the cabinet. if the speakers are ported, plug the ports and cross them over at 80Hz or so.

As for the sub, treat behind the sub with at least 6 inches of foam to fill that empty cavity. Hopefully your sub isn't rear ported?

 

[HTnewbie]

Gene:

Thanks for the suggestions. Part of my problem is that I am trying to anticipate problems I may not actually have. I need to finish making my speaker cables this weekend (pre-Christmas w/ 4 kids and wife...hmmmmmm). Once everything is connected, I will let the Yammie do its thing with YPAO and see how it sounds. It's a very tough space with lots of hard services on the one hand mitigated by an opening to a kitchen to the right of the unit and an opening to a breakfast room behind the listening area.

Thanks again.

Tom

Oh yeah, the sub is front firing with no ports - I made the selection partly based on that.

On another forum someone suggested OC703 or 705 - do you have any experience/opinions on fiberglass insulation vs. foam?

 

[HTnewbie]

Gene:

I had read Ray's sub tips late last year when this project started and have applied all that I can. I hope a 12" 400watt sub is sufficient for the space.

I also have two 18" versions of the BagEnd subs for my next HT project. Unfortunately, I could not use them in this room due to space limiations and WAF. As it is, she has no clue as to how loud this system can be.