Amplification; Choosing A Power Amplifier; Gain Settings; Recommended Amplifiers - Martin Audio THV User Manual

TH Series
Amplification
Choosing a power amplifier
Martin Audio loudspeakers are capable of recreating musical dynamics accurately and with incredible impact if powered
correctly. Martin Audio loudspeaker power ratings are quoted for AES power ‐ a long‐term average power rating with a much
closer relation to a music signal than other measurement standards such as RMS, and Peak power – a short‐term burst capability.
Moving coil loudspeakers can be run up to their AES power rating continuously and up to the higher Peak power rating for
transient musical peaks. All TH Series speakers have a peak power rating four times the long‐term AES rating. Ideally you should
use an amplifier that can deliver the full peak rating without risk of clipping. This however may be beyond the budget for many
so a good compromise is to aim for an amplifier that can deliver at least twice the AES rating.
This should be acceptable for many applications but be aware of the limitations particularly if the system is used with
uncompressed live music. In particular it is vital to avoid amplifier clipping, this is possibly the biggest single cause of damage to
speaker drivers. The clipped waveform has a colossal harmonic output at ultra‐high frequencies all being delivered at the full
power capability of the amplifier so speaker damage is extremely likely.
The amplifier selection table below will assist in choosing an amplifier to suit your application at an acceptable price point.
Gain Settings
The vast majority of professional and even budget amplifiers on the market these days have a standard front to back gain
regardless of their output power capability. The industry standard gain figure is 32dB which is a gain of X40. This figure is a good
balance between enough gain to run that majority of systems without having to drive mixers and any other processing equipment
at a level so high that there is a risk of clipping, and not too much gain which would raise the noise floor of the system. When
using a DX0.5 or other system processor which has a limiter function you should always use the limiter settings shown in the
parameter chart (see the chapter on the DX0.5 Speaker Processor). The limiter threshold is calculated to allow the maximum
level from your system without damage and is based on a known amplifier gain setting‐ 32dB by default. For that reason it is vital
that if the amplifier has front panel gain controls they MUST be set FULL UP. Lowering them does not offer more protection for
your system, it just changes the gain setting of the amplifier so a greater input level is required to obtain the maximum power
from the amp. This will make the limiter in the system controller useless as the gain is no longer at the setting for which the
threshold has been calculated. For optimum performance always observe the following;‐

Use a DX0.5, DX1.5, DX2 or high quality loudspeaker processor

Use the published Parameters for the TH range

Use an amplifier with a gain of 32dB (X40)

Always run front panel gain controls full up

Avoid amplifiers that only quote a sensitivity rating; "xxdB for maximum output" (i.e. no published gain setting)
Recommended Amplifiers
Model AES Power
Rating
THV LF 750W
THV HF 300W
THV LF 750W
THV HF 300W
TH Series User Guide V1.0
USER GUIDE
Peak Power Ideal amplifier rating
Rating
4Ω
3,000W 6,000W
1,200W 2,400W
3,000W 6,000W
1,200W 2,400W
Minimum rating
8Ω 4Ω
3,000W 3,000W
1,200W 1,200W
3,000W 3,000W
1,200W 1,200W
Martin Audio amplifiers
8Ω
1,500W iK42
600W iK81, MA5.2K, MA3.0
1,500W iK42
600W iK81, MA5.2K, MA3.0
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