Hey there! Like you, many guitarists have embraced the versatility and power of digital amp modelers like the Kemper Profiler. It’s a fantastic piece of gear, and it’s understandable why you’d consider it a top investment for your sound. Moving from digital processors to a Kemper opens up a world of tonal possibilities, and it’s great you’re diving deep into understanding how it all works, especially concerning Guitar Speaker frequencies.
You’ve hit on a really interesting point regarding frequency response, particularly the common understanding that guitar speakers operate within a limited range, roughly from 80Hz to 5-6kHz. This is a crucial piece of the puzzle when we’re talking about crafting guitar tones, especially when using a Kemper straight into a PA system. Let’s break down where those higher frequencies come from and how to approach EQing your Kemper for live and studio scenarios.
The Role of Guitar Speakers and Frequency Range
Guitar speakers are indeed designed with a specific frequency range in mind, typically around 80Hz to 5kHz or 6kHz. This range is tailored to reproduce the frequencies that are most crucial for electric guitar tones. Think about it: the fundamental frequencies of a guitar in standard tuning, even down to a low E string, fall well within this range. Guitar speakers are built to handle the power and frequency spectrum of a guitar amp, focusing on the mids and upper mids that give guitars their punch, clarity, and distinctive character. They are not designed to be full-range speakers like those you’d find in a hi-fi system.
Microphones: Capturing the Extended Spectrum
This is where microphones come into play and bridge the gap to those higher frequencies you’re hearing in your Kemper profiles. When creating a Kemper profile, microphones are placed in front of a guitar cabinet to capture the sound. Crucially, good quality microphones have a much wider frequency response than guitar speakers themselves, often extending well beyond 20kHz.
Microphones don’t just capture the frequencies produced by the speaker; they also capture the nuances of the cabinet, the room acoustics, and, importantly, the full frequency spectrum coming from the amplifier’s output section. Even though a guitar speaker might roll off frequencies above 5-6kHz, the amplifier itself might be producing harmonics and overtones that extend much higher. The microphone will pick up these higher frequencies, along with the speaker’s response, and these become part of the profiled tone.
Think of it this way: the guitar speaker shapes the fundamental tone, but the microphone captures the complete sonic picture, including the air and energy around the cabinet, which contains frequencies beyond the speaker’s limitations. This is why profiles can sound so detailed and capture the “magic” of a particular amp and cabinet setup.
Kemper Profiles: A Full Spectrum Snapshot
When you profile an amp and cabinet with a Kemper, you’re not just capturing the speaker’s frequency response; you’re capturing the entire system – amp, cabinet, speaker, microphone, and even a touch of the room. The Kemper meticulously analyzes the sound captured by the microphone across a broad frequency spectrum. This is why your Kemper profiles contain frequencies well beyond the typical range of a guitar speaker. It’s capturing the miked sound, not just the speaker in isolation.
This is also why you can often hear differences between profiles even when they are of similar amps and cabinets. Microphone choice and placement, room acoustics, and even subtle differences in the amp’s components can all contribute to the final profiled tone, and these nuances are often reflected in the higher frequency information captured by the microphones.
EQing for Live and Studio: HPF and LPF Considerations
Now, let’s address your question about High Pass Filters (HPF) and Low Pass Filters (LPF) in live and studio settings. You’re already aware of the Fletcher-Munson curve, which is essential for understanding how our perception of frequencies changes at different volumes. At louder volumes, like in a live setting, we are more sensitive to mid and high frequencies.
For live use, using an LPF around 6-7kHz, as you are doing, is a very common and sensible approach. Guitar speakers themselves naturally roll off higher frequencies, and cutting above this range in a live mix can help reduce harshness and prevent your guitar tone from becoming too shrill or fatiguing, especially at high volumes through a PA. It also helps to create space in the mix for other instruments and vocals which often occupy higher frequency ranges.
In the studio, or for quieter listening, you have more flexibility. Cutting frequencies around 10.5kHz, or even higher, is also perfectly acceptable. The “best” setting really depends on the specific profile you are using, the overall mix, and your personal taste. Some profiles might sound great with a more extended high-frequency range, adding air and sparkle, while others might benefit from a gentle roll-off to sit better in a mix.
Here are some guidelines for setting HPF and LPF:
- Start Flat: Begin with your Kemper’s output EQ relatively flat.
- Live LPF: Experiment with an LPF between 6kHz and 8kHz as a starting point for live gigs. Adjust by ear based on the room and PA system.
- Studio LPF: In the studio, you can often extend the LPF higher, perhaps to 10kHz or even bypass it entirely, depending on the profile and mix context.
- HPF: A High Pass Filter (HPF) is also useful, particularly in live settings. Rolling off unnecessary low frequencies below 80-100Hz can clean up the low end, prevent muddiness, and free up headroom in the mix.
- Listen Critically: Always use your ears as the ultimate guide. Adjust the HPF and LPF until your guitar tone sits well in the mix and sounds balanced and pleasing.
Reaching for “Real” Tone: It’s About the System
You mentioned wanting to get your tones “as close to the real thing” frequency-wise. Understanding that “real thing” isn’t just about the guitar speaker’s frequency range is key. It’s about the entire signal chain, including the amplifier’s preamp and power amp stages, the speaker cabinet’s resonance, the speaker’s response, the microphone capturing it all, and even the room.
The beauty of the Kemper is that it captures this entire system. Don’t be afraid to explore the full frequency spectrum that your Kemper profiles offer. Experiment with EQ, but trust your ears. You’re already on the right track by understanding the frequency limitations of guitar speakers and how microphones extend that range. By carefully using HPF and LPF, you can tailor those rich, full-spectrum Kemper profiles to sound fantastic in any situation, whether live on stage or in the studio. Keep experimenting, and enjoy the journey of refining your tone!
