Wednesday, June 23, 2010

Acoustic Treatment

The listening environment is one of the most important "components" in the hi-fi chain that is often overlooked. How a speaker interacts with the room it is placed in will have a dramatic effect on how it sounds to the listener.

In space scarce Singapore, most of us (except for the really lucky / well-heeled ones amongst us) have to make do with placing our audio setup in either the living room or a fairly small spare bedroom.

The typical public housing flat bedroom in Singapore measures about 3 x 4 meters. This necessitates keeping the system small, choosing speakers that do not acoustically overload the room, or resorting to room treatment methods, or a combination of all of the foregoing.

Why does the typical audiophile neglect room treatment ? Laziness ? Cosmetic issues ? Possible irate spousal response ?

Anyway, I have just revamped my listening room and taken the opportunity to acoustically treat my listening room. Unlike American homes, walls in Singapore are almost always built from brick, concrete and plaster. This results in hard reflections and a bit of bass boom.

Room treatment options in Singapore are quite scarce. Professional products are expensive due to the economic inefficiency of shipping large heavy items from American and European audio manufacturers.

DIY is an option, but lack of a garage makes construction a bit tricky. Materials such as wood and rockwool are available but require a bit of effort to track down and transport.

In consultation with Joamonte (resident acoustic treatment expert - you will find him on Singapore hi-fi forums like Echoloft (gone with the wind) and Xtremeplace, treatment was only done on one side of the room, directly behind the system. The treatment consisted of a combination of diffusor and absorption panels.



According to Joamonte, treatment of all the early reflection points could result in the system sounding too dead.

Acoustically, my listening room is not particularly troublesome. It is modest sized (about 3 x 3.5 meters), and has a fairly high ceiling. It is a regular rectangle shaped room, but is acoustically not fully closed on one end, as the wall is made out of plasterboard.

Nevertheless, the room is a little live sounding, and imaging and staging is not as sharp as it should be.

A total of 8 diffusor panels and 2 absorption panels were deployed. The two absorption panels were placed in the corner of the room, at ear level. The diffusor panels consisted of both an early model sold by Joamonte and his current production, which utilises plastic wells placed in a frame. Not much low bass treatment was required as my system does not go very low, probably no lower than 40 Hz.





























































Verdict :- Great stuff. Soundstaging and imaging are much improved. The tonal balance of the system was not affected much. Some of the obvious improvements were,

Midrange, especially female vocals – female voices were less sibilant and the level of grain was reduced.

Background – much quieter, with very low level detail retrieval becoming much more obvious. Most importantly, the lowering of background noise did not affect the “air” of the system.

Air / Ambience – The sense of air around instruments, and the fade / decay from the initial transient note of percussion and brass instruments were more prominent and longer. This seemed odd as I would have thought that acoustic treatment could have the unwanted effect of reducing this.

The panels were made by a carpenter to Joamonte’s specifications. He has also made some measurements of the room to demonstrate the difference between the treated and untreated room.

It is amazing how spending a relatively modest amount (S$1,600) could change and improve the system tremendously. Instead of spending money on expensive cables and footers, perhaps some attention should be paid to acoustic treatment.

Here are the measurements of the room with and without treatment.

4 comments:

ck said...

Hi Eric

A very nice blog for hi fi nuts! Keep the new articles coming ^_^

Thanks to you i've got in touch with Joamonte. Hopefully he can help solve some of my room acoustic problems.

Eric said...

Hi CK,

Glad you like my blog and hope that Joamonte is able to help you with your acoustic problems.

Properties said...

Hi Eric...How do I get in touch with Joamonte. My living room needs treatment. Cheers..Mike

Eric said...

Hi Mike, you can contact Joamonte by dropping him a private message on www.xtremeplace.com