Tricks, Tips & Tweaks

Some tweaks to improve sound quality & disregard myths.

Below are a few hints for those of you who would like to get the best out of your A/V or HiFi system and have an open mind (worshippers of What, Which or Whose Hi Fi Magazines had better leave now)

Bi-Wiring

This’ll upset any audiophiles who slipped through my front page warning! For general home use, bi-wiring speakers offers absolutely no benefit whatsoever except for doubling the thickness of the speaker wire (which is why most people can hear an improvement). Those little electrons don’t magically split into various frequencies and follow the path to the correct speaker (tweeter, woofer or whatever) so don’t waste your time and money.

Bi-wiring does work, however, when using separate amplification for various drivers. This is used mainly in super top end home systems using bi or tri- amplification and in most professional sound re-enforcement systems. The reason it works well there is because each amplifier can be matched to the driver in terms of frequency and damping. It also reduces cross harmonics since an external crossover circuit separates the various frequency bands and points them to the matching amplifier/driver configuration. Bottom line? For normal home systems, use better speaker wire – it’ll give you the same effect.

Speaker Cables

Ah, my pet subject. I guess having formal qualifications in both metallurgy and electronics (albeit 30 years ago) I can get a fairly good handle on how those nasty little electrons wizz through cables from amplifier to speaker. Lets dispel some myths first:

Forget uni-directional speaker wire; the signal to the speaker is alternating current and as such “vibrates” through the wire rather than travel linearly along it. If a speaker wire has a directional arrow on it, ask the salesperson “why” and “how” it works.

Thin wires for high frequencies and thicker wire for the lows – give me a break! The “skin effect”, which is the name given to the phenomenon of high frequency AC signals traveling only on the outer skin of the conductors, only occurs to any significant effect in the megahertz region (just a tad higher than the 20kHz of standard CD’s or even 192kHz DVD-A/SACD/Whatnext Formats), and unless you have superhero hearing ability you won’t hear this.

OFC or Oxygen Free Copper is a must

Well actually it is, but the very nature of copper wire manufacture means that virtually ALL copper wire is 99.9% + oxygen free, so the differences between different OFC’s (99.9% or 99.9999%) is relatively moot.

I won’t go into the whys and wherefores of single crystalline structure wire, capacitance, inductance etc. except to say that an electrical engineer and audio specialist far more qualified than I, one Jim Rowe, who for many years was editor of Radio, TV and Hobbies, held a double blind test using engineers and musicians whereby a high quality set of speakers was set up with an amplifier using several sets of speaker cables of about the same gauge.

After several hours of listening and switching cables, no listener could accurately say which cable sounded better (or even different) from any other. You may go into a so-called “audiophile” store and swear blind that the super duper, silver coated, multi strand, variable thickness wire being demonstrated sounds better than the plain Jane standard wire but you’re the victim of psycho-acoustics. In other words, you’re being conned into spending way more money than needs be (not to mention lining the pockets of the “audiophile” store – you ought to see the markup on this stuff).

The long and short of all this is quite simple – you need the wire to easily handle the current flow to the speakers, commensurate with the output of the amplifier. Obviously, the longer the run of wire, the thicker it needs to be. So for those short runs (1 to 2 metres) don’t go overboard and pay more than $6.00 a metre for good quality 12 or 14 gauge (AWG) thickness speaker wire when connecting a medium to large sized floorstanding speakers. If you’re running over 10 metres length per speaker definitely stick to the thicker 12 gauge (AWG) speaker wire for larger speakers.

The exception is for surround speakers in 5.1 or Atmos speaker systems where the speakers are designated as “small” in the AV Receiver settings. This is because all frequencies from around 8o Hz and below are typically sent to the LFE channel (subwoofer), and as such the current sent to those surround speakers is significantly less since the lower bass frequencies are responsible for most of the energy transmitted through the speaker wire.

So for a good connection to your speakers, count on spending around $6.00 to $10.00 per metre for your main speakers and $2.00 to $6.00 per metre for surrounds. If Alan Audiophile tries to tell you otherwise ask for a demonstration to justify the $20 per metre wire he’s likely to try to flog you – and make sure when you’re listening, that both sets of cables are heard at the same volume level (the louder sound always sounds superior to the ear).

Making the most of your room acoustics

It doesn’t matter how good your speakers are or how much you spend on them, they’re always going to sound bad in an acoustically challenged room. To me, it just seems crazy to buy a pair of $10,000 speakers and not treat the room to provide the best environment for that investment, be it for stereo or home theatre sound. We had that problem when we moved to our new premises at Dural, as the rooms were almost square (the worst case scenario for creating standing waves for bass) we had almost no bottom end and the room echo was so bad the top end on all speakers sounded harsh.

An acoustic treatment kit transformed the sound of our sound rooms. It’s from a company called Primacoustic. Although we don’t sell them, they’re available as a kit to suit most rooms from 12 to 50 square meters (our rooms are around 30 square meters and it works just great). You can buy individual tiles, or you can buy a full kit. It not only dampens the echo; many of the kits include larger  ‘bass trap’ panels which improve boomy bass so it sounds tighter and more defined, and can help with the problem of standing waves. If you can’t install an acoustic treatment kit see our section below on Room Furnishings.

Don’t sweat too much over the amplifier choice

Not so much of a Tweak but an observation. Many customers come into the store sweating over which receiver or amplifier to incorporate into a system – more so than the speaker set-up – wrong way around! They speakers are responsible for around 75% of the total sound performance so the time and effort should be spent determining which speakers are the best for your particular needs. The receiver should lock itself into place depending on the features required, technical specs of the speakers and main intended use. For example, in a similar price range Denon may be better for music but Yamaha may be better for home theater (although this isn’t always the case).

Any good HiFi dealer should be able to suggest the correct Amp/Receiver to match the chosen speakers, although you need to make sure there is no hidden agenda with the suggestion (such as that dealer importing the products recommended). If you need a reasonably honest opinion just e-mail or call us and we’ll give you a relatively unbiased answer (I say relatively ’cause there are some brands I just dislike regardless).

Room Furnishings

Ever wonder why, after purchasing HiFi from an up market “Audiophile” store, the system never sounds quite as good at home? Go back to the store and check their furnishings and dimensions. I’ll bet there’s no parallel walls in the room (hence no standing waves and better bass), I’ll also bet that if you clap your hands in the room there’ll be no “slap” echo (high frequency bounce). The reason for this is that the furnishings will be soft and hence absorb the higher frequencies. You can make the most of your system at home by realizing what’s happening to the sound as it bounces around the room.

If you have lots of glass windows, try for curtains rather than hard blinds and make sure you have some form of soft floor covering. If you have slate, tiles or polished wood, even a scatter rug in the center of the room will make an incredible difference to the sound. These sound absorbing soft furnishings will ensure you get an intimate sound rather than the nasty echoing that’s so annoying. If you’re building a dedicated sound room from scratch, do what the pro’s do and ensure there are no parallel walls (check out the inside of your local cinema when you visit next); this will give you the ultimate in room acoustics. Finally, use a cotton bud to gently remove any wax lurking in your ears (I find an extra 4kHz of top end after a good clean out).

Speaker Placement

Usually not a lot of thought goes into where the speakers are placed and once plonked down, they very rarely get moved. Speaker placement is critical and needs to be addressed to get the most out of your system. To understand the basics of speaker placement it’s important to remember that the higher frequencies travel in a straight line (much like a flashlight beam) whereas the lower the frequency, the less directional the sound until you get to the point where the sound is omni directional (the point at which the wavelength is longer than the distance between your ears – usually around 120 Hz). With these points in mind, it becomes obvious that the tweeters in the speakers should be close to ear height when listening, or at least angled towards your ears to form an equilateral triangle; this will ensure that you’re seated within the sound stage and it’s reasonably stable.

The distance of the speakers from the wall will determine the quality of bass. As the lower frequencies are omni directional, they will “creep” around the speaker box and tend to cancel themselves out to some degree, or instead create a boomy and ill defined bass sound. As the speaker box moves further away from the wall, this will “tighten” the bass although it may diminish it’s impact. As the speaker box gets closer to the wall, the bass will reflect off the wall and be re enforced, this tends to give a stronger bass albeit “sloppier” or less controlled. The secret is to move the box in and out from the wall until the best compromise is achieved. With a subwoofer/satellite system the distance from the wall is no longer a major issue as most of the frequencies concerned are handled by the subwoofer. I may come back to this subject in more detail at a later date but all this thinking is giving me a headache so I’m going home for a bourbon and coke!

Cabling/Interconnects

Regular readers will know that I’m not a great fan of the smoke and mirrors tricks associated with expensive interconnects, most dealers push them ’cause it’s an easy sale with plenty of profit. Good analogue/RCA interconnects, however, are important and most systems can benefit by upgrading from the crappy leads that come standard with your CD player or other source. As usual, some of the Pommie magazines go over the top and suggest spending 10% of the system price on interconnects (Darwin was correct in regards to isolationist inbreeding – that’s why we came to Australia to evolve the gene pool). I would generally look at spending 10% of the SOURCE equipment on interconnects i.e. –  if your CD player was $1000 then you would need to spend around $100 on a good quality RCA cable to connect it to your amplifier.

Remember also to keep your cables as short as possible, the longer the cable, the more likely it is to pick up extraneous noise.

In terms of cabling for home theatre and video, the vast majority of connections are made via HDMI cables these days. HDMI uses a digital signal path which is made up of ones and zeroes. With HDMI you either get the signal 100% or you don’t get it at all – there’s nothing in between. One particular HDMI cable won’t magically give you better picture quality than another. The main thing to be concerned about with HDMI cables is the bandwidth rating. Most will be rated to 18GBPS (gigabits per second) as a minimum – all the cables we sell are. This will support your 4K TV and 4K video sources like 4K Blu-ray and 4K Netflix etc. Some of the latest cables will be rated to 48GBPS which will support 8K video.

For cable lengths below 10 metres you don’t need to spend a fortune. $30 for a 1.5m or $40 for a 3m cable should be sufficient (you may pay slightly more for 8K rated cables). These shorter length runs very rarely have any issues.

For longer cable runs of 10 metres or more (eg from a ceiling mounted projector to an AV receiver), cheaper HDMI cables tend to fail and not pass through the picture, especially higher resolutions like 4K. In this case it’s better to spend a bit more on a HDMI cable that is certified to carry its stated bandwidth and deliver the picture. We’ve seen many instances where a cheap and long HDMI cable has been installed in the ceiling, only for it to fail and not pass through the picture.

Same applies to digital cables for audio connections. The most common are called digital optical cables (also referred to as optical fibre or Toslkink), and less common is digital coaxial. Being a digital connection they both sound the same, but the digital optical connection is found on more products. The most common use currently is to connect a TV to a stereo or surround sound receiver if you’re not using HDMI. $30 to $50 should be all you need to spend on these cables up to 3 metres in length.

Subwoofer Settings

It’s can sometimes be a challenge to get a subwoofer to seamlessly integrate with the main speakers, especially when it comes to music reproduction. Most surround sound receivers give the option of sending the bass information to the main speakers, the subwoofer or both. I’ve found that, regardless of the size of the main speakers, the best result is when the setting is on “both”.

Adjusting the position of the subwoofer in your room can also significantly improve the amount of bass you hear in your listening position. If you have the option to do it, we highly recommend trying the subwoofer in a couple of different positions to see if it improves the bass impact that you hear and feel. Even moving it 30-50cm one way or another can make a noticeable difference.

In theory the subwoofer can be placed anywhere in the room, but for optimal music reproduction I suggest the sub be on the same wall as the main speakers. And if it can’t be placed between the main speakers, make sure that it is no further away from the closest speaker than the distance between the speakers (trust me on this one). As a rule of thumb for the initial set up, place the phase switch (if available) at zero, the level to around 50% and the crossover all the way up when used in a system with a surround sound AV receiver connected. When connected to a stereo amplifier (via RCA cable) adjust the crossover to slightly above the stated lower frequency limit of the speakers (you’ll find this in the speaker specifications). For example, if your speaker has a lower frequency limit of 60Hz adjust the crossover on the subwoofer to about 70Hz so there’s a slight overlap. Tweak the settings from there, until it sounds good to your ears then leave it alone.

Please note when using the auto calibration feature included on most AV receivers it will often turn the subwoofer level down too low in the AV Receiver settings, quite often down to -10. After you’ve done the auto calibration check the subwoofer level setting in the AV receiver and adjust up if needed. The default level in most AV receivers is zero, so turn it back up to this level and see how it sounds – you can always adjust up or down slightly from here.