Well, if you look in my playlist ”tech” I try to explain the complexity of eq for older records. The eq network of my preamplifier is a custom built result of many years of work. Simply putting it, for acoustic recording a +25db in low end, starting a little later, because there are nothing really recorded at frequencies below 50-100hz. The crossover point varies from 250-800. No hi frequency attenuation, means flat after crossover point. Some commercial preamplifier has presettings that will not allow to separately chose low amplification, crossover point and high frequency attenuation. Fortunately some can be compensated software after recording. Hope this explains.