Audio technology

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Studio-quality audio technology – for a tight budget, is that possible? Within certain limits, this question can definitely be answered with yes. Thanks to digital technology, the egg-laying jack-of-all-trades is actually no longer out of reach and can also be achieved with budgets below the five-figure euro limit.

Budget and purpose

The two all-important questions are: how big is the budget and what purpose should it serve? Is it primarily about speakers, one or several in a discussion group, or about musicians, singers, smaller ensembles? Is it a mobile or stationary installation? How are the rooms designed? What type of sound system is desired?

Cable goodbye...

Cables are a thing of the past, which is why audio transmission is predominantly implemented wirelessly. In addition to Bluetooth, for example for monitoring loudspeakers, various frequency bands are used, within which some can be used without a permit, while others are subject to a fee.

Frequency jungle

The choice of frequency range should be preceded by a few considerations: the greater the distance between the transmitter and receiver, the lower the frequency to be selected. As the frequency increases, the range or the ability of radio waves to penetrate obstacles decreases. In addition, some frequency ranges are not reserved for exclusive use for audio transmission purposes, which is why freedom from interference cannot be guaranteed. Finally, some frequency releases are time-limited, which encourages eager retailers to advertise special offers that appear extremely affordable and therefore lucrative. Unfortunately, the fact that the frequencies on offer have a near expiry date is often a different matter.

Bandwidth

The available bandwidth of a selected frequency also deserves special attention. If several transmitters have to share a frequency range, for example in the ISM/SRD band 863 - 865 with only 2 MHz, you may quickly reach the limits if a certain audio quality is required.

latency

The latency within the respective frequency range is another consideration. While in audio conferences it doesn't matter a few milliseconds if you hear the speaker 20 ms later than the word was spoken, this is out of the question for musicians or singers.

Recommendation

After weighing up all eventualities, only frequencies in the range of are ultimately recommended 470 to 608 MHz and 614 to 694 MHz, – at least until 2030, because then their approval will expire in accordance with the general allocation 34/2020,

Cheap or good?

Which manufacturer you ultimately award the contract to should not primarily depend on the price offer. The saying “If you buy cheap, you buy twice” and therefore more expensive, is certainly justified.
Even if the expiry date of the usable frequencies can encourage you to say that you have to invest again anyway, so it can also be something “cheap”, this may well be true in private and hobby use cases. But if you need equipment that you can rely on because it is used professionally, you should also take into account aspects such as service availability, warranty period, availability of spare parts, etc. and the associated price premium.
Manufacturers that have been established on the market for decades have sophisticated products, an extensive service network, available customer service and storage capacity in order to be able to deliver the necessary spare parts even after the warranty period has expired.

Used market

Used equipment as a happy medium? Why not! Assuming, of course, that it doesn’t involve a near “expiration date” as mentioned previously. Here you will usually get high-quality equipment at reasonable prices and still have a long service life. Dealers of used studio equipment usually only give a one-year guarantee, compared to three or more years for new equipment, but it's better than nothing.

Microphones

The choice of microphones depends on the intended use: speech, singing, which directional characteristics, lavalier microphone, head set, pickups for string instruments, guitars, etc.

A microphone can be designed as a dynamic or condenser microphone.

The dynamic microphone has a comparatively large membrane, is preferably used at high sound pressure levels (singing), is very robust and is more than resilient to feedback effects.

Condenser microphones are more sensitive and are more likely to be found in directional microphones. You need a voltage source in the form of a battery or so-called phantom power with 48 V DC (+/- 4 V DC) via cable. Battery-operated microphones can vary greatly in terms of their energy requirements. Two identical microphones do not necessarily have to have the same operating time.

The frequency response diagram of a microphone shows its sensitivity over the entire frequency range. The more linear the progression, the less correction is required when recording on the downstream mixer.

Speakers and singers usually appreciate head sets. The hands remain free, there is no need to maintain a constant distance from the microphone, and the speech/singing quality is always consistent. Lavalier microphones are used “occasionally”. The disadvantage is that sweeping gestures may touch the microphone, which can lead to unpleasant disruptions in the recording/transmission.

Polar pattern

The directional characteristic of a microphone depends on whether the audio source preferably comes from one direction and whether sideways noise is blocked out (cardioid, super-cardioid, hyper-cardioid, club), or with a central microphone all sources, for example arranged in a circle around it should be recorded equally (sphere), or the figure-eight characteristic for conversation partners opposite each other.

The sphere captures sound from all directions, has a strong tendency to feedback, but is not very sensitive to wind or popping noises and has a good bass characteristic.

The cardioid filters out rear sound sources very well, is less sensitive to feedback, but is more sensitive to impact and structure-borne noise and requires appropriate decoupling measures. In close-up conversations it tends to amplify low frequencies, which is why a switch for speech usually switches on a bass filter.

Please note that as the directionality increases (super-/hyper-cardioid), noises occurring in the opposite direction, as well as at right angles, also gain influence.

The club is the least sensitive to sound coming from the side, but is very sensitive to structure-borne and impact noise, which is why very good decoupling must be ensured.

Here are the different characteristics as polar diagrams:

Digital mixer

The dimensioning of a digital mixing console is usually the last hurdle on the way to professional audio mixing and recording. How many inputs and outputs are needed, should there be an integrated recording option, can digital, analog signals be processed, etc .?
In general, it can be said that it is better to oversize than undersize. To return to the jack-of-all-trades mentioned at the beginning, a recommended example is the mobile and stationary one Midas M32 live called. It has everything an audio heart desires, can be expanded in many directions and is hard to beat in terms of price-performance ratio at around 3,500 euros with a 48 kHz sampling rate.

If you need a 96 kHz sampling rate, this is it Allen & Heath SQ6 good advice, even if it is inferior to the above-mentioned 48 kHz mixer in some respects.

The purchase decision should always be based on the parameters that are relevant and essential for your own application, including prospectively.

Sound reinforcement

The circle closes with the design of the sound system. Depending on the sound-related spatial conditions, it may be advisable to obtain recommendations from a room acoustics planner. If you don't want to equip and sound a concert hall, but rather a meeting room, usually rented, for example, you want to keep your real estate investments within a very manageable limit. Consequently, acoustically corrective measures are limited to mobile sound absorbers or, simply, curtain materials to prevent unwanted sound reflections.

The choice of sound reinforcement systems should also be preceded by professional advice if you do not have the relevant specialist knowledge yourself. A cost-effective alternative may be to look around in similar rooms and listen to the systems installed there and talk to the operators. Again, preference should be given to well-known manufacturers of loudspeaker systems if you want to enjoy the investment for many years without regrets.

And now?

Now it is important to note down, based on the ideas above, how your own requirements are designed in order to be able to obtain targeted advice and recommendations on the one hand, and to be able to create a materials list within the available budget on the other. Then we go on the hunt for suitable equipment.