Lectrosonics SMV User Manual download pdf (Page 4)

SMV Series

LECTROSONICS, INC.

Variable 1.8 - 4v

+6V

+5V

Regulator

Servo Bias Input

The voltage and current requirements of the wide vari-

ety of electret microphones used in professional appli-

cations has caused confusion and compromises in the

wiring needed for wireless transmitters. To address this

problem, the unique Servo Bias input circuit provides an

automatically regulated voltage over a very wide range

of current for compatibility with all microphones.

Digital Hybrid Wireless

Technology

All wireless links suffer from channel noise to some de-

gree, and all wireless microphone systems seek to mini-

mizetheimpactofthatnoiseonthedesiredsignal.Con-

ventional analog systems use compandors for enhanced

dynamic range, at the cost of subtle artifacts (typically

“pumping”and“breathing”).Whollydigitalsystemsdefeat

the noise by sending the audio information in digital form,

at the cost of some combination of power, bandwidth and

resistance to interference.

Digital Hybrid systems overcome channel noise in a

dramatically new way, digitally encoding the audio in the

transmitter and decoding it in the receiver, yet still send-

ing the encoded information via an analog FM wireless

link. This proprietary algorithm is not a digital imple-

mentation of an analog compandor but a technique that

can be accomplished only in the digital domain, even

though the inputs and outputs are analog.

Because it uses an analog FM link, the Digital Hybrid

system enjoys all the beneﬁts of conventional FM wire-

less systems and it does away with the analog compan-

dor and its artifacts.

General Technical Description

No Pre-Emphasis/De-Emphasis

TheDigitalHybriddesignresultsinasignal-to-noiseratio

highenoughtoprecludetheneedforconventionalpre-

emphasis(HFboost)inthetransmitterandde-emphasis

(HF roll off) in the receiver. This eliminates the potential

fordistortionofsignalswithabundanthigh-frequency

information.

Low Frequency Roll-Off

Thelowfrequencyroll-offcanbesetfora3dBdown

pointat35,50,70,100,120and150Hztocontrolsub-

sonic and very low frequency audio content in the au-

dio.Theactualroll-offfrequencywillvaryslightlydepend-

ing upon the low frequency response of the microphone.

Excessivelowfrequencycontentcandrivethetransmit-

ter into limiting, or in the case of high level sound sys-

tems, can even cause damage to loudspeaker systems.

Theroll-offisnormallyadjustedbyearwhilelistening

as the system is operating.

Input Limiter

ADSP-controlledanalogaudiolimiterisemployedbe-

foretheA-Dconverter.Thelimiterhasarangeofmore

than 30 dB for excellent overload protection. A dual re-

lease envelope makes the limiter acoustically transpar-

ent while maintaining low distortion. It can be thought of

as two limiters in series, a fast attack and release limiter

followed by a slow attack and release limiter. The limiter

recovers quickly from brief transients, with no audible

side effects, and also recovers slowly from sustained

high levels to keep audio distortion low while preserving

short term dynamics.

1 2 3 4 5 6 7 8 9 ... 27 28

Comments to this Manuals

No comments

Lectrosonics SMV User Manual Page 4

Comments to this Manuals

Related products and manuals for Accessories communication Lectrosonics SMV