Brightness isn’t just caused by the equation of the speaker’s frequency response to room size and dampening ratio as Erik mentions, but also due to other forms of noise in the chain. This could be found through:
- Poor resonance control in the speakers, rack, and components where vibration induces slurring, peaks, and nulls of certain frequencies. Great resonance control will result in much improved image solidity, making for more audible, impactful bass /and less noise through the rest of the frequency spectrum so sonics are more effortless and easier to discern.
- Jitter and EMI are usual culprits that induce high frequency noise into a system to a point where people find their system to be bright, peaky, piercing, and /or fatiguing. In such case it may be improved by using better components or cables, or introducing technologies or accessories that are designed to lower noise floor.
- Poor speaker and amplifier matching is a common challenge I see my customers and others face. Often times, people think their amps can properly drive a speaker just by looking at the specs. Some speakers require a lot of power, and it’s easy for many that are uninformed to look at the speaker sensitivity to the watts of an amplifier and be done with it. Sometimes they get lucky, but in most times, amplifiers cannot fully handle the impedance set by the speakers. Klipsch are great examples, since I know that while they claim to be of high impedance, many of them actually have an impedance dip in the midbass. Regardless, a few may look at the Klipsch’s sensitivity (say high 90s dB) and nominal impedance (usually 8 Ohm or greater) and believe a low power OTL amp would work well. Well, they’re wrong, as the OTL amp can’t handle the impedance dips, and this further makes Klipsch speakers sound “bullhorn-ish”. Sadly, even many solid state power amplifiers don’t deliver the high current needs to truly drive and control smaller speakers, which tend to be lower in sensitivity and lower in impedance. I’ve in many times guided customers to better amplification that simply wakes the speakers up to the point where no subs or larger speakers are needed.
Case in point, Erik suggests a very good point on treating the room to address and optimize full-range frequency delivery, but it is one of many ways to address it. The whole system’s performance depends on any and all bottlenecks being addressed to a certain level.