Reader Query, April.

[Andrew]

I have a NAD Master series system consisting of an M15 pre amp, M27 power amp, M55 disc player coupled to a Mission Elegante speaker system (E82 fronts, E80 surrounds, E8c centre and E8AS2 sub). I also have a REL Q150E sub connected coupled to the front outputs (Lo level) positioned in the left corner facing into the centre of the room. The Mission E8AS2 sub is linked via the sub output and is positioned at the back left. Roll over frequencies are set at 100 Hz for both units.


Although the system sounds good, I believe that it could sound even better with the correct tweaks. My dilemma is that I have not found a supplier or installer in my area that seems capable of giving me good honest advice. (Cape Town). Not being an experienced reviewer, I am not sure how to describe the “deficiencies” that I feel are in my system. There is what I suppose is a ringing effect of the high frequencies which tends to detract from the cleanliness of the sound. Also at times is seems as though frequencies are competing against each other “smudging” the sound. I realise that the quality of the reproduction is only as good as the recording and have therefore attempted to find music that I like in the SACD’s and audio DVD’s format. (The choice seems to be very limited). The dimension of my lounge is about 5m by 4.2m with a low roof. The walls are un-plastered and the floor is covered with a plush wall to wall carpet. The furniture in the room consists of a plush leather three seater facing the front speakers (which are toed in slightly), a two seater on the right and 3 single seaters on the left. (All plush leather recliners). The windows are heavily curtained.

Even with the “high quality” recordings, I feel that the system is not delivering what it is capable of. At times the music seems to be rough and unclear. As if the system is trying to deliver frequencies that it is not actually capable of delivering. I have read every bit of advice in your magazine since subscribing a year or so ago but am unsure where to focus. I am prepared to spend money to optimise the system but I don’t want to throw money at the problem without understanding what I am doing.

One of areas of my system that I suspect is not up to scratch is the interlinks. I am using cables built for me by (a local AV dealer). They assure me that they are “good” cables but the two fronts are using an off the shelf splitter from the pre amp to the power amp for by-amping purposes. I am not sure what make the speaker cables are, but I paid about R150/m for them (Bi wire). The system is housed in an oregon pine home made cabinet that does not isolate the equipment very well.

Where should I be spending my money? The interlinks, the stand, the speaker cables?.....


Any advice you have would be greatly appreciated. (My budget for the tweaks is R10k tops)

Kind regards

Roland Cook

[Hennie]

There is what I suppose is a ringing effect of the high frequencies which tends to detract from the cleanliness of the sound.

It almost sounds like an acoustics problem. How bare are the walls? Do they have brick surfaces. How large is the heavily curtained area as % of the total wall area?

Clap your hands (a single, short, sharp) at the listening position and tell us what you hear?

[Hennie]

Another question: Is there a bare wall directly behind your listening position?

[Shonver]

Hi Roland

Have you had an audio consultant over to your place? It is difficult to do a diagnosis without experiencing it first-hand. Poor acoustics can result in a cacophony of sound and I agree with Hennie that this is the first place to look. However, the plush furnishings should help out here.

Where in Cape Town are you? (I'd love to hear this).

[Shonver]

More thoughts...

It is possible for you to debug your system on your own, to a certain extent. After doing the handclap test (and if the acoustics is not shown to be your main problem), I would set the system up as simply as possible, then add the tweaks gradually. I'd start with removing the biamplification. Use just one amp per speaker. I suspect that there is more than just acoustics problems, from what you describe.

[Hennie]

However, the plush furnishings should help out here.

IME leather does not help all that much at higher frequencies.

[Shonver]

IME leather does not help all that much at higher frequencies.

Hennie, I'm including the carpeting and curtaining in my "furnishings" statement. My own lounge has very little absorptive materials, and I (miraculously) do not have the same problem. So I reckon that with Roland's setup there should be less of an acoustics problem.

One more question, Roland: what kind of music do you listen to?

[Hennie]

Well I certainly would not advise the guy to do the clap test if I did not have a very similar sounding problem once, in an environment that from his description sounds very similar to the one I had. A clap test is simple to do, costs nothing and can tell you a lot. A short delay reflection from a wall directly behind the listening position can also have a similar effect. This is the best I can do without actually hearing the system.

[Shonver]

Well, first things first; let's hear the results of the clap test...

[RR]

Dear Mr Ro(w)land. 

Please suggest to Roland the following.

Get the REL Q150 out of the corner, only the ST range REL subs are meant to be in a corner. Place it either directly behind the left/right speaker or slightly inside (But not center). Face the driver towards the listener.

Secondly, turn down the REL sub roll off frequency to below 60Hz. Actually start very low (40hz)and adjust it incrementally until it starts sounding boomy, then turn it down a notch.

Secondly, switch off the Mission sub and sell it. It cannot hold candles with an REL, and will just muddle these frequencies. 1 x REL Q150 is enough for the room anyway.

Even though his main issues seem to fall outside the 'sub' category, it is amazing how much a bad sub setup can f.. up proceedings at higher frequencies as well.

[RR]

Also get some proper bi-amp interconnects. This is probably not the main problem, but good practice anyway and is sure to bring slight or even obvious improvements.

[Shonver]

Also get some proper bi-amp interconnects. This is probably not the main problem, but good practice anyway and is sure to bring slight or even obvious improvements.

Hey!! [gasp] Who are you and what have you done with Riaan??!!

[DRNB]

I agree with Riaan, get the sub out of the corner.

And what Hennie said..... but I would just like to add:
Early reflextions could very easily rip detial out of the sound. The time difference between the reflected sound and direct sound will not be heard as 'wrong' or an echo, but have a far greater effect than what one might think.

Put absorbent directly behind the speakers, and if your listening posision is close to the rear wall do the same there. Prefeably purpose made traps, but I guess carpeting and who know what else would also work. Also check refletion points on the side walls, and put something there. Floor bounce is something I have not figured out how to eliminate, since I like my tile floors with only a light rug over it .

[Timber_MG]

I would also assume that this situation calls for acoustic treatment. Depending on the character of the loudspeaker and room I would guess diffusion and some absorbtion (perhaps cleverly disguised as a painting pulled over a timber frame with fibre-glass insulation) behind the listener and perhaps elsewhere. I would also look at the toe-in of the loudspeaker and deal with side-wall reflections (the mirror trick) and perhaps look at furnishings to address such problems.

Two subs will almost always deliver a more balanced (and hence better sounding) output than a single unit in such a room (especially considdering the size) and it dominates the scenario. Taking them out of the corner in that small room might not be that easy but two subs in corners will be better than one well placed unit elsewhere.

[RR]

Hey!! [gasp] Who are you and what have you done with Riaan??!!

NEE MAN!!!!!

I did say "even obvious improvements" can be obtained.

Still, this will not be the main problem in the system, the main problem will be something along the lines that you and Hennie are suggesting, and my proposed sub changes will also go a long way towards getting some musicality in the system. I have respect for the Missions, they are good and can deliver the goods.