The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
Electric hot water heater's (in front corner of listening space) affect on acoustics
Old 19th October 2013
  #1
Gear Head
 

Electric hot water heater's (in front corner of listening space) affect on acoustics

My 2-channel critical listening space is out in my garage. I've implemented several fundamental acoustic treatments in the space (some bass trapping and early reflection absorption on side/back walls and ceiling) and bit by bit, as I find the time, I'm adding additional treatments to improve the room's response. One thing I've always been unsure about is the effect my hot water heater, which is located in the front right corner, is having on the acoustic response in its location. You can see it in the attached pic (though it is a bit hidden by a piece of fabric I've draped around it). I'm sure the hard sheet metal case the heater is constructed of is redirecting/deflecting a good amount of spectral content much the same as a poly diffuser may, but have no idea what influence it's having over the LF content that's building up in that corner. Above it you can see I've installed a superchunk (703) broadband corner absorber in attempt to absorb as much LF as I can.

My question is fairly trivial, really, as there is nothing I can do about the placement of the hot water heater as rerouting the plumbing to move it is not an option (and I really don't have a better place in the garage to locate it, anyway). Anyone care to share what they think the water heater's acoustic contribution is?

- Michael
Attached Thumbnails
Electric hot water heater's (in front corner of listening space) affect on acoustics-altec19ii.jpg  
Old 19th October 2013
  #2
Gear Head
 

Oh, and it might be worth mentioning that in the opposite front corner I've tried to create some symmetry by stacking a few hard plastic bass drum cases (also draped in fabric) and filled them with fluffy fiberglass (in plastic trash bags). They're a few inches larger in diameter than the how water heater, but I figured I'm doing pretty good just to get something in that corner that mimics what's happening in the opposite corner. I've also installed superchunk (703) broadband corner absorbers above the bass drum cases much like I did above the water heater.
Old 20th October 2013
  #3
Lives for gear
 

Filling those cases with sand would be more symmetric
It's most likely going to affect the lowmids (100hz-500hz), but it depends on the radiation of the cabinet. If they send a good deal of lowmid energy forward, then any effect the water heater could have would be less important. Have you measured the left and right channels separately?
Old 20th October 2013
  #4
Gear Guru
Damping

Strangely, sheet metal can be acoustically useful. Would it be possible to damp resonance of the casing by cladding it tightly with Fibre?
There are HVAC duct damping panels available with adhesive etc. etc.
DD
Old 20th October 2013
  #5
Gear Head
 

Quote:
Originally Posted by DanDan View Post
Strangely, sheet metal can be acoustically useful. Would it be possible to damp resonance of the casing by cladding it tightly with Fibre?
There are HVAC duct damping panels available with adhesive etc. etc.
DD
When I first started treating the room I didn't have the bass drum cases stacked in the left front corner, but instead had floor to ceiling superchunks there. In an attempt to get acoustic symmetry in the opposite corner I shrouded the water heater with three 703 panels.

*** Before I go any further I need to mention that the left front corner isn't the true corner of the room. The true corner is another four feet beyond the "faux" corner and is formed by two of the room's primary boundary layers, the front wall and the wall that has the garage doors. The "faux" corner is created by a "faux" wall that is built from a facing and backing of 1/4" plywood with a few inches of rockwool sandwiched inside the frame. Two of these 4'x8' "faux" walls are screwed to a row of plastic utility shelves which I have access to from the garage door. This "faux" wall allows me to still use some of the garage for utility by having the storage shelves accessible from the garage doors, yet hides the shelves and creates a similar acoustic response as the true wall (sheetrock) on the right side of the room. The actual corner of the room, the one that is created by the junction of the front wall and wall that has the garage doors, is treated with floor to ceiling 703 superchunks.

Anyway, after getting my first pair of dipole speakers a few years ago (Magnepans) and learning how critical the rear wave they propagate is to the creation of their unique sonic characteristics, I decided to take the 703 panels that were shrouding the water heater down. The result was a wider, deeper sound stage on the right side of the room. It was at that point I decided to recreate the sort of reflection of energy I knew was occurring at the water heater and introduced the stacked bass drum cases to the treatment scenario. Sure enough, the left of center response opened up to the rear and outboard of the left speaker. I have acquired other dipole designs since and in most cases prefer them to monopole designs, but since I rotate each in and out with regularity I kept the corners partially diffuse.

Again, my curiosity lies in what the sheet metal/fiberglass/water composition of the heater is likely doing with frequencies below 150 Hz. Looking over my OP, I see I wasn't very clear about that so sorry it took all this (extraneous) information to articulate it.

And Dan, your comments about sheet metal being acoustically useful intrigue me. I have read of one or a few here using thin sheet metal panels for LF absorption. Care to elaborate on your comment? And as far as resonances created by the sheet metal, I would think the internal insulation would largely prevent that. Wouldn't you?

- Michael
Old 20th October 2013
  #6
Gear Guru
Metal

Depending on how stiff the structure is and how intimate the damping fibre is, the metal may or may not vibrate at LF. Thump it and listen for resonance. If it does vibrate significantly, being damped, it will absorb LF. More likely, as you suggest, it is relatively inert, in which case it is disturbing the corner, probably in a good way.


DD
Old 20th October 2013
  #7
Lives for gear
 

Another option might be to install a timer on the hot water tank so it's completely shut off during certain times you plan on doing recordings. You can get a hot water tank timer for about $50-75 bucks at most electrical supply houses or maybe even Sears still sells them, that's where I got mine. If you're handy you can install it in a couple of hours, or get a pro to do it.

I have my tank on for four hours in the morning and four hours around supper time, and I have plenty of hot water, as the water stays hot for a long time. This will also cut down on your electric bills. I put mine in about 19 years ago and have saved a bundle off my electric bills over the years.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump