Question 1

What is a house curve and why do sound engineers use one?

Accepted Answer

A house curve is a target frequency response that deviates from flat to compensate for the way humans perceive sound in a venue. At the mix position (typically 15-30 m from the speakers), high-frequency air absorption and audience absorption naturally attenuate the treble. A flat measurement at this distance may already sound bright because the microphone captures the direct and reflected energy differently than human binaural hearing. A house curve typically has: +2-4 dB at 60-100 Hz for bass warmth, flat from 200 Hz to 4 kHz for clarity, and -3 to -6 dB at 10-16 kHz for natural treble. The exact shape varies by genre, venue, and personal preference. SonaVyx provides 12 built-in target curves including several house curve variants.

Question 2

What is the X-curve and where is it used?

Accepted Answer

The X-curve (ISO 2969) is the standard target for cinema sound system calibration. It specifies flat response from 40 Hz to 2 kHz, then a smooth rolloff of -3 dB per octave above 2 kHz. At 8 kHz, the response is -6 dB relative to the midrange. The rolloff compensates for the high-frequency energy contributed by screen reflections and room reverberation in large cinema spaces. Without the X-curve rolloff, cinema soundtracks mixed in small dubbing stages sound harsh and bright in large theaters. The X-curve is measured with pink noise at the primary listening position using slow averaging. It applies to the steady-state room response, not the direct speaker response. SonaVyx includes the X-curve as a target for cinema calibration work.

Question 3

What is the B&K house curve?

Accepted Answer

The B and K (Bruel and Kjaer) house curve is a widely referenced target for live sound system tuning, based on research by Bruel and Kjaer engineers into preferred spectral balance in performance spaces. It features: flat response from approximately 60 Hz to 1 kHz, a gentle downward tilt of about -1 dB per octave from 1 kHz to 16 kHz, and a slight low-frequency rise of 2-3 dB below 60 Hz. The total high-frequency rolloff is about -4 dB at 10 kHz relative to the midrange. This curve sounds natural and is less fatiguing than flat response at typical concert SPL levels (95-105 dBA), where high-frequency sensitivity increases. Many live sound engineers use a variation of the B and K curve as their personal preference target. SonaVyx includes the B and K curve as one of the built-in target presets.

Question 4

Should I use a different target curve for different music genres?

Accepted Answer

Yes. Different genres have different spectral expectations. EDM and hip-hop benefit from more bass emphasis: +4-6 dB below 100 Hz relative to flat, with extended sub-bass down to 30 Hz. Rock and pop work well with the B and K curve: moderate bass warmth, clear midrange, gentle treble rolloff. Jazz and acoustic music prefer a flatter response with less bass emphasis but preserved high-frequency detail. Classical music in a concert hall target: essentially flat, letting the room acoustics provide the natural spectral balance. Speech (conference, worship): flat through the 200 Hz to 6 kHz range for maximum intelligibility. SonaVyx target curve selector lets you choose a preset or create a custom curve by adjusting the bass and treble contour to match your genre and venue requirements.

Question 5

How do I create a custom target curve?

Accepted Answer

Start with a flat reference and adjust based on the application. For live music: add +3 dB shelf below 120 Hz for bass warmth. Keep 200 Hz to 4 kHz flat for clarity. Add -3 dB shelf above 8 kHz for high-frequency comfort. For monitoring: start flat and adjust based on personal preference and room interaction. The deviation from flat should not exceed ±6 dB anywhere. A useful technique: listen to well-mixed reference tracks through the system. If the bass sounds thin, raise the low-frequency target. If the highs are harsh, lower the high-frequency target. Then EQ to match your adjusted target. SonaVyx allows custom target curves: import an FRD file defining your target, or use the built-in presets as a starting point and modify them.

Question 6

What target curve should I use for a studio control room?

Accepted Answer

Studio control rooms should be calibrated as flat as possible within the room acoustic limitations. The target: flat from 40 Hz to 16 kHz (within ±2 dB) at the mix position. No intentional house curve is applied because the goal is to hear the mix accurately so that it translates to other playback systems. However, the low-frequency response depends on the room and monitoring setup: in a small room with boundary bass buildup, the target may include a gentle cut below 80 Hz to compensate. Some mastering engineers prefer a very slight high-frequency rise (+1 dB at 10-15 kHz) for detail, but this is personal preference. ITU-R BS.1116 and EBU R22 provide reference listening room standards. SonaVyx flat target curve with RT60 verification provides the reference for studio calibration.

Question 7

How do NC curves relate to EQ target curves?

Accepted Answer

NC curves and EQ target curves serve different purposes. NC curves define maximum acceptable background noise levels per octave band. EQ target curves define the desired frequency response of the sound system. They are related because background noise affects the perceived tonal balance: if the background noise is high at low frequencies (common with HVAC), the sound system needs more low-frequency energy to maintain the perceived spectral balance. Some engineers adjust the target curve based on the measured NC spectrum: if NC is 40 at 125 Hz but only NC-25 at 4 kHz, the system target may include 2-3 dB more bass to maintain the signal-to-noise ratio across the spectrum. SonaVyx displays both the NC measurement and the system target curve so you can make informed target curve decisions.

Question 8

What is the Harman target curve and does it apply to room speakers?

Accepted Answer

The Harman target curve was developed through extensive listening tests by Harman International researchers. It defines a preferred in-room frequency response for loudspeakers: slightly downward-tilting from bass to treble, with a gentle slope of about -1 dB per octave from 20 Hz to 20 kHz when measured in-room. This curve accounts for the room gain at low frequencies and the natural high-frequency rolloff in a typical listening environment. It was primarily developed for home listening rooms and headphones, not large venues. For PA systems in large venues, the room interaction is different (longer distances, more reverberation), so the Harman curve does not directly apply. However, the principle of a gently tilted target rather than flat is universal. SonaVyx target curve options include variations inspired by the Harman research for near-field and mid-field monitoring setups.

EQ Target Curves: House Curve, X-Curve, B&K, Harman, and Genre-Specific Targets

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