new construction and absorption

[Mike L]

I am doing a new construction living area in which my audio gear will be included.  While in the process of insulating the room with Roxul I noticed the impact it had on my radio.  When I stood by a wall that was not insulated the radio sounded the same.  However, when I stood perpendicular to a Roxul insulated wall it was like I went deaf in the ear towards the wall.  I was surprised at just how much the Roxul absorbed.

I am unsure if all of this absorption is good or bad.  If this is a good thing I will insulate an interior wall as well, thus making the whole room encased with the Roxul.  However, is it possible for a room to be too dead?  Will most of the absorption be nullified by the vapour barrier and drywall?  Not sure what to do here.

Thanks,
Mike

[bpape]

DEFINITELY insulate the rest of the walls.  If not, you'll get a huge resonance at the cavity resonance.  Insulated walls tend to absorb centered around 80-125Hz assuming single drywall.

The rest can be dealt with via positioning of speakers and seating, and proper room treatment.

Bryan

[Mike L]

Thanks.

[Carlman]

It can be too dead.. when you have no reflections and just absorption.  When I had open walls and just fiberglass insulation, it made me feel like I had a cold/sinus problem and things were unnatural.  It was fun to come down and hear it.. but weird. 

Your brain needs some reflections to figure out spacial cues.  All the insulation behind your walls becomes bass trapping when sheetrock goes up.  So, the effect you're experiencing now will completely go away.  However, all is not lost, you'll be starting from a solid foundation.  You'll still need to do bass traps and panels to make the walls seem like they dissapear.  There are many ways to do that.. and many preferences on what sounds 'right'.

-C

[richidoo]

I like anechoic listening. The recorded spatial cues are sufficient to alleviate the stuffy feeling, and the clarity and music connection is intense. But it's not for everybody....

[Mike L]

You guys are scaring me now as I am afraid when I am done there isn't any turning back. 

[bpape]

If you do standard construction with insulated walls and single drywall, it's no different than any other room - just quieter and no resonances from the wall cavities. 

Double drywall helps more with Green Glue in terms of isolation (both sound getting out and sound getting in) and drops the resonant point of the wall by about 35Hz. 

Next step is paying attention to the door, any holes (outlets, can lights, hvac, etc.) to further the reduction in transmission both in and out of the room.

Don't be scared - it's well worth it.  Ask Carl

Bryan

[richidoo]

No ignore me. Listen to Bryan.  I was just commenting on Carl's observation, and I took us off topic.

You're right that once the walls are sheetrocked you won't be taking out the insulatoin again, but there is no downside there. Insulation is always better than no insulation except for cost. Everything else is after sheetrock and changable.

Stuff the walls so the in wall cavities don't resonate. After sheetrock it will be very lively again, because sheetrock will reflect frequencies from mid bass on up. So you may want to add some topical treatments or cushy furnishings and surfaces inside the finished room to bring down the echo and tune the room to your liking.

[Carlman]

The only thing to be scared of are the bills! 
I like a dead-er room than Rich so I'm surprised he likes anechoic..   I think ultra-dead (non-reflective) is awesome to 'visit' but not live with.  I thought about it, though.  The experimentation and possibilities are seemingly endless.

You have to decide what's important to you and go with it.  Your overall goal will guide you to sonic nirvana.  Bryan's right, I'm quite pleased.  He helped me understand what I was compromising when I made choices along the way which was helpful.  It'd be good to know how you rank these:
Cost/Budget

Sound:
Isolation (people, equipment, outside world)
Room orientation
Specific frequency issues (I hate a peak at 100Hz, I'd like to avoid it)

Comfort:
Looks
Lighting
Seating (how many in the room at a time, how many in the sweet spot)
Access (in and out of the room, around the room, etc.)

Other factors:
WAF, Children, pets, etc.

[lonewolfny42]

Don't be scared - it's well worth it.  Ask Carl...

Carl's room is great....it definitely is well worth it !!!

[richidoo]

With anechoic, its only fun it there are NO reflections. Not possible in a shared living space.  If not totally dead, then I like it pretty lively, at least on the front wall.