Archive for October, 2009

Mounting amplifiers upside down!

Wednesday, October 28th, 2009

Sounds dumb isn’t it? Yea, but some people still do it, mostly not due to stupidity but because of space constraints.

Amplifiers come in different designs, but all designs use a heat sink to dissipate heat, some coupled with either a fan or two for additional cooling. Some amplifiers have no fan at all but depend solely on sufficient heat sinks to handle the heat.

Having said that, common sense tells us that to let the heat sink do it’s job, it must be ventilated and heat should not be trapped on it, around it or channeled to it from hot surfaces, devices or heat from the sun. If you feel there is insufficient ventilation, by all means add a fan or relocate it to a cooler spot, an area which does not absorb or trap heat.

The reason why I bring this up, is that lately we have seen a few cases of overheated amplfiers, and in extreme cases damaged pcb boards, severely premature amplifier life and “pregnant” or buldging capacitors as part of the consequences. Particularly in scorching summers or hot climate countries all year round, where additional care must be taken to keep your gears cool and within operating range.

Last week, I solved yet another “ignorant” install, failing to understand the very basics of car audio safety and maintenance. The amplifer in question was a Zapco Reference 1000.4, a high powered 150watter x 4 running only the fronts (there is another amplifier for the subwoofer).Firstly, this is a very slim unit and secondly, it has no fan in-built. The amplifier was mounted upside down just below the rear parcel shelf in the trunk.

In a hot country like Malaysia, heat builds up considerably fast in the cabin space and equally fast in the enclosed trunk space. Your dashboard, just beneath the windscreen and the rear parcel shelf, just below the rear screen soaks up the direct sun when you park outside in the open. 

Since the amplifier is mounted right below the rear parcel shelf, heat is transferred to it direct from the mounting screws and gets trapped with little air movement. This results in the amplifier getting extremely hot (untouchable) even after 5 minutes of normal use.  Naturally, the amplifier shuts down thanks to the build in thermal proctection.

During the mornings and nights, the amplifier could play a little long before turning off by itself. The installer failed to address the problem and blamed the amplifier for being faulty. 

Another bad but not as seriously faulted install that I have seen many times is one amplifier mounted vertically on the rear seat and just below it, mounted  flat/horizontal on the floor trunk another amplifier for subwoofer duties. Naturally, amplifiers run hot and heat goes up, especially when you are running your subwoofers hard or for long-hours! The heat passes through the amplifier above it. Not a big problem but could be avoided if you care for your gears.

Love your amplifier, maintain it well and it will serve you for years. Use a fan if you have to (note: fans can induce external noise and also noise into your system) but better still use our common sense.

Audio Creations Customized Crossover Network

Monday, October 12th, 2009

 

In an ideal and simple form, we could use full-range speakers to wonderfully playback music in our home and car hi-fi. However in reality, most full-range speakers in exception to a few expensive and exclusive speaker drivers are not capable of reproducing the full frequency spectrum faithfully without signs of strain.

Instead of using full-range speakers, some car manufacturers adopt co-axial speakers that promises to give a step up in sound performance. The co-axial speakers are sold in pairs, each consisting of a high frequency driver, called a tweeter, attached to a cone, called the mid/woofer. As a complete whole, it plays the full range of frequencies from the highs, lows and the frequencies in between in which we call midrange.

The speakers will be fed with high level music signal by the player’s in-built amplification or a dedicated amplifier. In the case of a 2-way co-axial, a small capacitor is placed before the fragile tweeters to only allow the high frequencies to enter the voice coil and diaphragm. The midrange and low frequencies are filtered away to protect the tweeters from being damaged. This is the simplest form of a crossover, called a high-pass filter.

In most cases the bottom cone will still be fed with the entire music material and the effect you get with the extra tweeters, is a sparkle in the highs which translates to a slightly better separation and clearer reproduction. Some manufacturers introduced 3-way or 4-way co-axial speakers or 6×9” speakers, with large peak power ratings but sad to say most are hypes without much substance.

2-way separates or components were then introduced that comprises of a pair or tweeters and a mid/woofer. Tweeters came in all types of size and shapes, with ½”, ¾”, 1” and even 1-½” dome variants, using all sorts of materials from silk domes, aluminum/metal domes, beryllium and even diamond, each with it’s own character and capabilities. Common mid/woofer sizes are 4”, 5”, 5.25”,6”, 6.5”, 7” and 8”. These come with engineering designs of all sorts, various build quality, and cone materials such as paper, polypropylene, aluminum, Kevlar or hybrid materials. 3-way separates goes one step further by introducing a dedicated midrange driver that is usually 3”, 4” or 4.5”. In true high-end cases, a 5” mid-driver is used but one has to take into account the complexity of installation and space constraints. 3-way separates introduces better division of duties, where highs are dedicated to the tweeters, mids to the midrange, and lows to the woofer. Properly set-up and implemented, they can sound a step up in performance compared to a typical 2-way component.

Why Audio Creations Passive Network?

Anyone can build a crossover, seriously! However, it is the level of importance one place in building that really matters. The knowledge of how the transducer/driver will respond to different crossover points and crossover designs cannot be merely studied by reading but it has to be experienced.

A speaker is only as good as how it is being installed and the crossover being used. The crossover is the heart of any speakers. Speakers do not sound polished by themselves, they need to be controlled and guided to perform their best. A good speaker driver is like a good athlete – Just like a dancer or a gymnast require a coach to bring out the best in them. That is why we call them raw drivers.

Unlike home audio loudspeakers that have the enclosure to bring out the best of the drivers, the car environment is limited to doors, kick panels and pillars for mounting and placement. Thus, even the best install will leave much to be desired and countless hours of tweaking is required to bring the best out from the speaker drivers.

Isn’t using an electronic crossover an easier solution? Electronic crossovers are flexible and useful but the quality of sound and tonal character again leaves much to be desired, leaving the reproduction to sounding dry, clinical, thin and uninvolving. My partner actually calls it ”boring music”, which is exactly what it is. Equalizers will help in the aspect of fine tuning and tweaking but being electronic and limited to the quality available for car audio use, the more natural and analogue method still boils down to the use of custom crossovers like you see in any home audio loudspeakers.

Many available electronic equalizers are not useful/powerful enough in the first place. At Audio Creations, on top of using high-end capacitors and coils as NATURAL equalizers, we still use equalizers, but only analogue units. We use them for serious fine tuning and not a quick fix or a mask to problems. The major bottlenecks like the power supply and the passive network has to be addressed early on. Once solved, they make a  solid foundation of a good sounding kick-ass system.

At Audio Creations, we manufacture crossover networks using capacitors, inductors and resistors from highly regarded companies like Duelund (Denmark) and Mundorf (Germany), which we have tested and proven countless times to provide the best reproduction available from any high quality speaker drivers. We also use premium V-Caps (USA) in our applications.

Our custom crossover comes complete with high-end parts soldered with 4% silver solder or highly recommended Mundorf silver/gold solder, wired with Transparent Cable or highly recommended Van den Hul CS-122 and encased in a tasteful but simple enclosure (classy enclosures can be requested). We restrain from any form of connectors to avoid sound degradation and therefore prefer to hard wire all connections. We fully emphasize that cables from the amplifier and to the speakers from the passive network should be soldered and heat shrinked for a safe and sure connection. Five cents connectors should be avoided at the speaker ends.

Bring your speaker performance to a level that justifies the price you paid for them. Visit us and learn more about Audio Creations custom crossovers.

Audio Magic Stealth Mini Reference – Do your hi-fi a favour with proper power conditioning

Monday, October 12th, 2009

The quality of power (by our local utility provider) that we feed our equipment has always been a major hindrance to a good sounding system.

Apart from room acoustics, power supply plays big importance to any hi-fi system so much so that no system or equipment should be judged without proper power conditioning.

With power quality problems, there will undoubtedly be a bottleneck to what your gears are truly capable of. To the novice end-user, it may be difficult to grasp because to us it is only common sense that the music signal only passes through equipment, interconnect, speaker cables and speakers, so what does power have to do with anything.

Bad power introduces noise to the system and noise kills music! Music sounds edgy, messy (worsen when more instruments are being played) and not poised to begin with. Background hiss and grit robs music enjoyment and we are not able to play loud because it gets irritating.

At Audio Creations, we were taugh by our high-end customer friends some years ago that power conditioning brings a system to a different level altogether. Since then we have tried/loaned various power conditioners to learn what it is all about.

At Audio Creations, we use Audio Magic power conditioners. Why, and not try others? We have and we like how the Audio Magic sounds… because it does not alter the character or inject any false promises or hide/mask problems from the hi-fi system. What is does, as should any good power conditioner, remove EMI/RFI from the power line so that background can be pitch black and quiet for the music to flow our naturally without sounding held back, muddled out or cluttered. Nor should it amplify or inject any additional frequencies or sound to your system that makes it sound unnatural.

With good cleansing effect, your power line can give quiet and full sounding supply to your equipment without sounding thin and cluttered. Your system becomes more musically involving. Highs, mids and lows should tighten up, giving it a step up in control and definition.

A good power conditioner should also not limit power or current. Most high-end power amplifier makers suggest that their amplifiers be plugged directly to the wall. This is because the  majority of power products out there are current limiting ,which robs the dynamics and power from the amplifier. The Audio Magic Stealth Mini Reference has a duplex (two dedicated outlet) for your power amplfiers. 50 watters, 100 watters, 200 watters, 400 watters and up does not matter, this power conditioner does not hold anything back.

Stealth Mini Reference

Stealth Mini Reference

Features:
1. Large ga. silver conductors
2. Cryo treated parts to help stabilize resonance
3. MST treatment to enhance the crystalline structure of the parts to give maximum conductivity
4. QP pulse generator and QP passive Disrupter to remove EMI and RF
5. SonicCraft super audio capacitors
6.Leviton hospital grade duplex’s
7. IPF super filter with ERS paper for further RF and EMI suppression
8. 20amp mini breaker-detachable power cord inlet

A recent review in the Star by Sujesh Pavithran tells us a better story:

Other well known recent reviews or feel free to google for older reviews:

SPECIAL PROMOTION

Come get yours now. Special promo price extended since 1997 – Audio Magic Stealth Mini Reference RM3,888 (Retail RM4,500) . SOLD OUT!!!
We are now officially announcing that price will be up by 30-40% come December 2009.