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.

Monday, June 21, 2010

An update much overdue

Rather unfortunately, it has been ages since I have last updated this blog. There have been lots of changes to my system and lots of new accessories to be covered. Stay tuned for updates on acoustic treatment, the Acoustic Zen Silver Reference II interconnect, Telos RCA caps and speaker post plugs, and much more !

Friday, October 16, 2009

Yet another afternoon of messing around

Last weekend, I had one of my hi-fi mates over for some listening. He was interested to see how my Thiel CS 1.6 was faring in my system, as well as how it matched with the various amplifiers I had on hand.

For those of you know who are not familiar with the Thiel CS 1.6, it is the smallest floorstanding model in Thiel's range. As a matter of line up, it is actually the replacement of the CS 1.5. Ultra compact models like the 0.5 do not have a direct successor model.

A typical Thiel design, it is designed to be phase coherent as well as time aligned (provided you sit at least 8 feet from the speaker). It is a two way speaker, sporting all metal drive units. Unlike older Thiel models, the CS 1.6 uses in-house produced drivers. Instead of using a conventional rouind port, the CS 1.6 utilises a long thin slotted port in front.

Here are our observations of the day :-

1. Matched with Diva M7 preamp and Cayin A-88T

Sound is quite full with a very nice tube bloom. Bass is weighty but slightly rounded. Transparency is quite good and this combination can entertain for hours, especially if you are into vocal and jazz discs

2. Matched with Diva M7 preamp and Hypex UCD400

Extremely fast sound with much tighter grip over the bottom end. Extremely detailed top end and the resolution is just incredible. The tube bloom is still there with just a hint of sweetness. Hi-fi mate declared this at the end of the session as the best sound of the day.

3. Matched with Copland CTA-401 integrated tube amp

My ageing Copland is one of the first few quality kit that I could afford. Taking me almost a year to save up for, I keep my Copland more for sentimental reasons than anything else.

Paired with the excellent Electro Harmonix 6CA7 tubes, the Copland puts out about 35 watts per channel in ultralinear mode. This is slightly less than the 45-50 watts put out by the Cayin A-88T which is based on KT88 tubes.

The Copland is noticeably slower and rounder than the Cayin. The Copland is an old school type of tube amp in that it provides a very liquid and luscious presentation. The Cayin is much faster and neutral in its midrange and top end in comparison.

Matched with the Thiel, I felt that the overall combination was a little bit too slow and did not highlight the strengths of the CS 1.6 well. Some may like its very romantic and rose tinted view of the world, but its sweetness does not match well with faster paced music.

4. Matched with Kingrex T-20U integrated T-amp

Hi-fi mate had to suspend dis-belief for a moment. Absolutely shocked at the volume that was achievable with the limited power on tap, he though the sound was overall quite good, especially considering the price. Overall, the combination is quite pleasant to listen to but is obviously not as resolving or controlled as the other two combinations above.

Combination 2 was heard with both my new Acoustic Zen Hologram II speaker cables and my existing Goertz AG-1 pure silver speaker cables. It was almost like a night and day difference in presentation. He found the Goertz forward and quite forceful in the way it "projected sound" (in his words), compared to the very gentle and refined presentation of the Acoustic Zen. He prepared the Acoustic Zen's presentation.

For some entertainment, we also hooked up the Kingrex to an old pair of Proac Tablette 50s. Obviously not quite as detailed as the Thiel, the combination was quite very enjoyable. Always musical, the Proac entertained well with its PRAT and sharp imaging ability.

Sadly, the session was so much fun that it ended far too soon. You can be sure that another session will be arranged soon.