Modern musicians are more and more likely to face AMP-LESS, which leads to the use of equipment such as Amp Modeler, Profiler, and IR-Loader to handle this usage scenario.
As for Modeler and Profiler, those who are interested may go to "Modeler vs Profiler?!"
Here we will talk about IR-Loader.
IR= Impulse Response, commonly known as "pulse response".
What is IR (Impulse Response)?
Impulse response is a parameter of the mathematical algorithm called convolution. Those who study electronics or electrical engineering should be familiar with it. (https://goo.gl/MHe5GN Click the link if you want to learn the theory) Use a signal whose time approaches zero and whose signal approaches infinity (commonly known as a pulse, so some people also call it an impulse response) to enter a system to measure its output. By converting this result from the time domain to the frequency domain using Fourier transform, we can get the frequency response of the system. The impulse response intuitively reflects the way our living world expresses sound. Literally speaking, shock response is a response to "shock". It sounds mysterious, but it is not complicated. Let us explain it in a simple way.
Suppose a musician is in a room and wants to know the acoustic characteristics of the room. What is the simplest way to do this?
Clap your hands once and listen to the echo in the room, and you will basically understand. This process is the simplest way to obtain impact response. The clapping time is extremely short and can be regarded as an impulse signal. The subsequent echo is the acoustic characteristics of the room, that is, the impulse response of the room. Performing in this room is equivalent to performing a convolution operation with this impulse response data and the musician's performance.
The above operation is still applicable to the electronic system. The process of a musician using a guitar speaker to amplify the signal and then making the sound through the speaker is the convolution process of the guitar speaker and the guitar.（Note: The convolution operation is only applicable to clean sounds. If the system has distortion, convolution will not be applicable.）
IR length
The reverberation of a concert hall often lasts for tens of seconds. If we want to express the reverberation characteristics of this concert hall, we must obtain an impulse response of at least tens of seconds. Using this impulse response of tens of seconds to perform convolution is a very large amount of calculation (usually requires millions of calculations). Even with the current level of technology, it is difficult to express the acoustic characteristics of a concert hall in real time.
Fortunately, the impulse response data for speaker systems does not need to be that long. It only needs to express the range that the human ear can recognize (20Hz ~ 20KHz). In this way, the 50ms long impulse response data can fully meet the performance of various speakers from bass to guitar.
There are usually two ways to express the length of an impulse response, the time value mentioned above and the point value. The point value and the time value can be converted to each other. For example, if the sampling rate of the effector is 44.1KHz, then a 2048-point impulse response data is equivalent to 2048 x (1/44100) = 46 ms. (Note: Fractal's Normal is 1024 samples, 20ms; HiRes is 2048 samples, 40ms.)
If the impulse response data is too short, it will affect the accuracy of low frequencies. For example, many manufacturers use an impulse response length of less than 512 points to avoid using expensive high-end DSPs. The accuracy of low frequencies will deviate seriously from the correct position below 150Hz, making the low frequencies weak and muddy:
The above picture shows the difference in low frequency when the guitar speaker collects 2048-point and 512-point impulse response lengths. It can be seen that the 2048-point is more than 3 dB higher than the 512-point at 130Hz, and the low frequency decays rapidly after 90Hz, which greatly increases the control over the low frequency and makes the sound clear and powerful.
Solid Studio MKII
Then let’s take a look at today’s protagonist, Solid Studio MKII.
It uses the NUX TSAC-4K algorithm, and the playing feel is indeed very satisfying, and the fullness of the tone is also impeccable, an absolute professional level!
There are two things that I find most interesting:
1. Preamp and Power Amp can be turned on and off independently. (When the lower computer enters the AMP block to adjust parameters, long press the PREAMP or POWER AMP button to BYPASS.)
2. The Power Amp can be freely selected, which means you can freely choose the tone of the power amplifier.
Even though the number of Amp Models seems small, these classic speakers combined with the post-amplifier changes are more than enough to cope with Amp-less usage scenarios.
CYBER IR
Cyber IR, a collaboration between NUX and Choptones, is quite interesting. You can adjust the type, position, and distance of the microphone, and adjust the Low Cut, High Cut, and Level; you can even adjust the Pan.
PEDAL PLATFORM: OVERDRIVE SIGNAL COMPATIBILITY
110dB dynamic range and TSAC-4K algorithm make it very suitable for use with external effects pedals.
Tone Demonstration:
Solid Studio MKII provides BASSMAN and STAGEMAN amp models for bass and acoustic guitar. I used Wu Bai's "Passive" to demonstrate three different tones: "electric guitar with Marshall Super Lead 1959", "bass with Fender Bassman", and "acoustic guitar with NUX Stageman".
For recording, just use the USB Audio of the machine itself, which is very convenient.
