Question 1

How do I measure the delay of a speaker using SonaVyx?

Accepted Answer

Step 1: Connect the measurement signal (pink noise or sweep) to the speaker. Step 2: Place the measurement microphone at the listening position. Step 3: Start the transfer function or impulse response measurement. Step 4: SonaVyx automatically detects the propagation delay from the impulse response peak and displays it in milliseconds and equivalent distance. Step 5: Record this value. Step 6: Repeat for each speaker (muting all others). Step 7: The delay difference between speakers is the amount of electronic delay needed on the closer speaker (shorter delay) to align it with the farther speaker (longer delay). SonaVyx status bar shows the detected delay continuously during measurement and stores it with each trace for comparison.

Question 2

How do I calculate the delay needed for a fill or delay speaker?

Accepted Answer

At the overlap zone between the main speaker and the fill speaker, the fill must arrive at the same time as (or slightly after) the main. Measure the main speaker delay at the overlap zone: say 35 ms. Measure the fill speaker delay at the same position: say 12 ms. The fill is 23 ms early. Set 23 ms of electronic delay on the fill to synchronize them. For Haas precedence (making the audience perceive the main as the source), add an additional 5-10 ms to the fill delay: total fill delay = 28-33 ms. Verify by measuring the combined response: the impulse response should show a single coherent peak (not two separate arrivals). SonaVyx delay finder gives you the exact numbers, and the magnitude response verification confirms correct alignment.

Question 3

What if the impulse response shows multiple peaks?

Accepted Answer

Multiple peaks in the IR indicate multiple sound arrivals at the microphone. The first peak is the direct sound from the measured speaker. Subsequent peaks are: reflections from floors, walls, ceiling, or nearby objects (common within 5-20 ms), arrivals from other unmuted speakers, and diffraction around obstacles. For delay measurement, only the first peak matters — it represents the direct sound arrival. SonaVyx identifies the first peak above the noise threshold. If early reflections are strong and close in time to the direct sound (within 1-2 ms), they can distort the peak shape. In that case, move the microphone away from nearby reflective surfaces. If another speaker is bleeding through despite being muted, it creates a false peak — ensure complete isolation by physically turning off unused speakers.

Question 4

How do I measure the delay through a DSP processor?

Accepted Answer

The DSP processing delay (latency) is the time the signal takes to pass through the processor. Measure it by connecting the DSP output directly back to the measurement input (electrical loopback through the DSP). The impulse response peak time gives the DSP latency. Typical values: 1-3 ms for most DSP processors. Some FIR-based processors have 5-20 ms of latency. This latency is constant and applies equally to all speakers connected to the same processor. If different speakers use different processors, the latency difference must be compensated. In practice, measuring the total acoustic delay at the listening position (which includes DSP latency) is simpler and more accurate than measuring individual component latencies. SonaVyx measures the complete acoustic chain delay.

Question 5

Can I use delay measurement to find the distance to a speaker?

Accepted Answer

Yes. Distance = delay × speed_of_sound. At 20 degrees Celsius: distance (meters) = delay (seconds) × 343. For example, a measured delay of 14.6 ms gives 14.6 × 0.343 = 5.0 meters. This is the acoustic distance, which follows the actual sound path (which may not be a straight line if the sound diffracts around objects). The accuracy depends on temperature: using 343 m/s when the actual temperature is 30C (349 m/s) introduces a 1.7% error (8.5 cm over 5 meters). For most purposes, this is negligible. SonaVyx displays both the delay in milliseconds and the equivalent distance in meters (at 20C). For temperature-corrected distance, enter the actual temperature and SonaVyx adjusts the calculation.

Question 6

How do I verify delay alignment after setting it on the DSP?

Accepted Answer

After applying delay corrections: enable both speakers (main and fill or main and sub). Measure the combined transfer function at the overlap zone. Check: the impulse response should show a single coherent peak (not two separated peaks). The magnitude response should sum smoothly through the crossover region without a dip. The phase of both speakers should track together through the crossover region. If you still see a dip at crossover, fine-tune the delay in 0.1 ms increments. If the phase is offset by approximately 180 degrees, try inverting the polarity of one speaker. SonaVyx before/after comparison stores the individual speaker responses and the combined response for verification. The delay finder confirms the actual arrival time difference after correction.

Question 7

What is sub-sample delay resolution and why does it matter?

Accepted Answer

At 48 kHz sample rate, each sample represents 0.021 ms (20.8 microseconds) or about 7 mm of sound travel. This is the basic resolution of digital delay measurement. Sub-sample resolution uses interpolation to estimate the delay more precisely than one sample. Parabolic interpolation of the three samples around the IR peak typically achieves 0.1 to 0.2 sample accuracy, giving approximately 2-4 microsecond (0.7-1.4 mm) resolution. This matters for high-frequency alignment: at 10 kHz, a full wavelength is 34 mm, and 1 mm of misalignment causes 10 degrees of phase shift. Sub-sample resolution is important when aligning tweeters in multi-way speakers or making precision measurements for speaker design. SonaVyx uses parabolic interpolation for sub-sample delay estimation.

Question 8

How do I document delay settings for a sound system installation?

Accepted Answer

Professional documentation should include: a system block diagram showing each speaker zone and its DSP delay setting, a venue plan showing speaker and measurement positions, a table of measured delays for each speaker at the alignment position (before and after correction), the combined measurement traces showing smooth summation at crossover, the temperature at time of measurement (affects speed of sound), and the DSP processor model and firmware version. Include notes on any compromises made (e.g., alignment optimized for the mix position at the expense of other seats). SonaVyx report generator compiles measurement data, traces, delay values, and verification results into a formatted document. Store the session for future reference if the system needs re-tuning after changes.

Delay Measurement Guide: Impulse Response, Fill Speakers, DSP Latency

Frequently Asked Questions