Performance Tests

Performance tests are designed to verify that the unit is performing within the specifications.

Necessary Equipment:

1. Lock-In Amplifier

Freq Range	0.1 Hz - 100 kHz
Output Ampl	4 mV rms - 1 Vrms
Output Z	50 Ω
Recommended	SRS SR850/830/810

2.50 ΩTerminator

3.50 Ω, 20 dB Attenuator

The instructions here apply to SRS DSP lock-ins (SR850/830/810). Other lock-in amplifiers may be used. However they will require substantially longer time constants to arrive at accurate measurements.

1)Connect the 9-pin power cable from the rear of the lock-in amplifier to the SR554. Connect the 20 dB attenuator to the lock-in reference output and a BNC cable from that to the SR554

(A) input. Connect another BNC cable from the SR554's (A) output to the lock-in’s (A) input. Set SR554 to buffered mode (X500), (A) input.

2)Power on the lock-in in the default condition. (SR810/830 Power on Setup, SR850 Power on Bksp) This places the lock-in in a known state. The power LED of the SR554 should light.

3)Set the input to DC coupled, grounded shield. Set the time constant to 300 ms (1 s for 1 Hz measurement), 12 dB/oct filter and turn on synchronous filtering (if available). Set the display type to magnitude (R) and the reference sinewave amplitude to 10 mV rms.

4)For each frequency, the following amplitude should be observed, ± 5%.

Frequency	Amplitude
1.0 Hz	31 mV
10 Hz	252 mV
100 Hz	438 mV
200 Hz	442 mV
500 Hz	439 mV
1 kHz	414 mV
10 kHz	96 mV
100 kHz	11 mV

5)Disconnect the lock-in reference from the SR554 input. Connect the 50 Ω terminator to the SR554 (A) input.

6)Set the lock-in to measure noise.

7)For each frequency and time constant, the following rms noise voltage should be observed (±10%). Set the lock-in sensitivity to about 5 times the expected reading and allow it to settle (10-20 time constants) before making readings.

Frequency	Time Constant	Noise Voltage
1.0 Hz	3.0 s	480 nV
10 Hz	1.0 s	260 nV
100 Hz	0.1 s	460 nV
200 Hz	0.1 s	460 nV
500 Hz	0.1 s	460 nV
1 kHz	0.03 s	420 nV
10 kHz	0.03 s	120 nV
100 kHz	0.03 s	60 nV

SR554 specifications

SRS Labs SR554 is an advanced audio processing solution that aims to enhance audio quality across various media platforms. Recognized for its innovative approach to sound enhancement, the SR554 incorporates a variety of technologies designed to create a richer, more immersive listening experience.

One of the standout features of the SRS Labs SR554 is its Superior Sound technology, which employs advanced algorithms to optimize audio output for different types of content. Whether users are listening to music, watching movies, or playing video games, the SR554 intelligently adjusts the audio output to suit the specific requirements of each medium. This adaptability is crucial in today’s diverse audio landscape, ensuring that users enjoy the best possible sound quality regardless of the source.

The SR554 also integrates SRS's renowned TruBass technology, which enhances low-frequency audio signals to produce deeper, more resonant bass without sacrificing clarity. This feature is particularly beneficial for genres such as hip-hop and electronic dance music, where bass plays a pivotal role in the overall impact of the audio experience. By creating a more balanced and full-bodied sound, the SR554 caters to audiophiles and casual listeners alike.

Additionally, the SR554 is equipped with SRS Virtual Surround technology, which simulates a multi-channel audio experience from standard two-channel setups. This feature provides users with an enveloping soundstage, making it ideal for home theater systems and gaming setups. By creating a perception of height, width, and depth in sound, the SR554 enhances the realism of audio playback, making users feel as though they are part of the action.

Compatibility is another key characteristic of the SR554. The solution supports a wide range of audio formats, ensuring that it can seamlessly integrate into various devices and platforms, from smartphones to high-end audio systems. This versatility allows users to experience enhanced audio quality no matter how or where they choose to consume their media.

In terms of user customization, the SR554 offers an array of adjustable settings, allowing users to tailor their audio experience according to their preferences. This tailored approach means that whether someone seeks a more vibrant sound or a subtle auditory atmosphere, the SR554 can be fine-tuned to meet those needs.

In summary, the SRS Labs SR554 stands out in the crowded audio enhancement market through its innovative technologies geared towards delivering superior sound, enhanced bass, and immersive audio experiences. Its adaptability, compatibility, and customization options make it a compelling choice for anyone seeking to elevate their audio experience across a wide range of media formats.