The Concept of Audio-Visual and Home Theater Consulting services.

When one takes a look at the modern Home Theater concept, it becomes very apparent, that the last two years have sprung some important changes. We call it the “Avid Revolution”. Many of the options that had previously been available only in professional grade equipment (such as room acoustic calibration), are now available to home users. New formats that offer many useful options, like Tivo, are becoming main stream. New types of connections such as the i-link (digital audio in full resolution for all formats, including SACD and DVD-A) or DVI / HDMI (digital video for all HDTV resolutions) are conquering the market, just like the compact disk with recorded digital audio did some time ago. The list continues with developing digital amplifiers, new sound formats as Dolby Pro Logic IIx, and more. One of the most important manifestations of the Avid Revolution is the improved quality of audio-video signal, which is directly linked to the growing increase in the use of new digital connections (the critical links are shown in red in the above linked photograph).

As an example of this evolution in multi-channel audio signals connections please take a look at this sound signal path. (Older analog connections with additional analog-digital conversion are shown in red as well). We had to convert the High-resolution digital signal in the DVD player to an analog, transfer it to the receiver or amplifier in the analog form, then (path #1) listen to it without any bass management or time alignment (getting phase distortion between speakers and without possibility to use subwoofer) - (path #3) convert it again into a digital form and process it through a Digital Signal Processor (DSP) to get the necessary adjustments and then again convert it to analog (to the lower resolution CD signal at Path #2). All those processes are not perfect and at each stage we got we got added distortions. With today’s latest technology and the right know-how we can transfer (i-link, path #4) an audio multi-channel signal through one cable in its original digital form to the receiver, process it through DSP and avoid 2 unnecessary conversions. The same applies to digital video interfaces DVI and HDMI. The last one, HDMI, provide an opportunity to transfer high-resolution multi-channel audio signal as well as video digital signal ... a feature that will be fully implemented in 2004-2005.

But how do these devices work? In the era of analog stereo amplifiers we had several manufacturers, making amplifiers with different level of distortions, depending (mostly) on the circuit design approach and the quality of elements. To choose the best sounding amplifier used to be an art form. Equipment has become increasingly complicated, and producers started using chips (modules), like in a puzzle game ... take a look at our one year old collection of database of main chips in the modern receivers / processors ... they are more or less the same (just different quality) and represent a cross section of most available devices. The main chips are Operational amplifiers, commonly used as a replacement to the transistors, ADC & DAC (analog-digital and digital-analog converters) and DSP (digital signal processor). to this category, like digital interfaces, however, for i-link they are almost the same, and are not used for multi-channel analog signals. Then we have the modern receivers / processors, with less dependency on the circuit design (with the exception of some High-End devices with class A output stage and differential connection of 2 to 6 DACs per channel), but with much more dependency on the quality of the used chips which is due to the fact that their circuits (surrounding elements) are usually the standard ones as recommended by chip manufacturers, with some limited changes.

As a general rule, consumers rarely have an opportunity to listen to all the devices in all possible configurations with the different speakers, different transports, etc. Nonetheless, the above mentioned suggestions, users information, understanding of schematic diagrams, as well as the specifications, datasheets and the audio signal processing in analog and digital domain provides the necessary foundation for the prediction of the sounding quality of a particular device with reasonable precision. This is particularly true when we are able to narrow the possible choices of devices.

This may sound like we are trying to open "a can of worms", but this is a can that has already been opened a long time ago by tweakers. Ultimately, the definitive test will always be one’s own eyes and ears (since no one can listen to or watch specifications on a datasheets).

That is where we at Alex Hardware can truly make a difference. We can “lend” you our eyes and ears and save you a HUGE amount of time and money by helping you to make the most informed decision and the best choices. Based on our Extensive Professional Experience and using our vast database of knowledge and proprietary know-how we can predict the performance of different equipment in specific environments. By so doing we will greatly assist you in making the most cost effective purchase and installation that will produce the finest quality your money can buy.

The following is a general example of our added value services – a DVD player (AV receiver, AV processor) X can produce an excellent picture), but sounds a little bit too unnatural. Player Y has an excellent sounding, but worse picture for the same price. Player Z has both, excellent picture and sounding, but cost 10 times more then the first two. Which one to choose? We can explain you why they have such a difference and what is the "bottleneck" in the first player, how it may be modified and sound as good as, or even better then player Z? Even the finest player Z can be modified to be even better. You don't want any modification? We can recommend a good working device without it, in the price range that you are looking for. We have in depth understanding and can provide you with detail explanation of the reason why a particular device sounds so good or has such a good picture. The same apply to all components of any entire audio-visual system of your choosing, including loudspeakers, room acoustic and interconnections.