Review on 🔊 Fender Rumble 40 v3 Bass Combo Amplifier: Unleash Powerful Bass Tones by Abhinav Drury

In this January 28, 2013 New Yorker article "Music for your ears”. Daniel Levitin (https://en.wikipedia.org/wiki/Daniel_Levitin) "pointed out that most of the lowest notes on most pianos are actually perceived and not heard. The soundboard on most pianos isn't long enough to play the lower octave, but the brain hears the correct overtones for the piano to play, and the neurons in the brain start firing at the frequency of the missing bass note at a time (1950s-1960s) this psychoacoustic feature was used in hi-fi console designs to give the appearance of deep bass without actually having an extended low frequency response. Same goes for Rumble 25. I measured the reaction of this combo as shown in the chart. The red curve shows that all controls are set to 12 o'clock. The blue curve shows that there can indeed be a reasonably flat response from 90Hz to 2.5kHz, +/-3dB with the following knob settings: Bass @ 12 o'clock, Mid @ 9 o'clock, High @ fully counterclockwise. This means that it can only reproduce the 2nd harmonic of the lower bass octave (40Hz to 80Hz). Due to the normal 18dB per octave roll-off for a vented enclosure, the 10dB roll-off point is around 70Hz. At the 2.5kHz frequency, notice that the 12th harmonic of the high A (220Hz) in the bass is 2nd is .64kHz. The driver has low matching and the box is set at around 100Hz, which matches the measurements. These curves are smoothed using a 1/3 octave cepstral algorithm to remove minor inaudible changes in the measurements. There is a large resonant peak just above 3kHz = 1/2 the driver diameter. This is tamed fairly well with the High knob, fully counterclockwise, but still almost 7dB above average. Considering that the paper cone is quite stiff and its design doesn't attempt to dampen the sound waves passing through the cone material, this resonance peak is not at all surprising. This peak corresponds to the 16th harmonic high at 220 Hz in the bass. This peak is probably a good feature for slap bass attacks (which I don't do). Otherwise it doesn't really matter. Other than that, the Rumble 25 works well for me. It was cheap, small, light and while it didn't have a usable output well below 100Hz, it still "sounded" like a decent woofer. With the controls set for the flattest response, it works well for both my electric and acoustic basses, which sound best through a flat response system. The first is a completely original '63 Fender Jazz, and the second uses an NS Design "Copperhead" pickup, a prototype Ned kindly gave me to teach one of his sons to play the bass. Even for those using a speaker system for rooms of around 75-100 people, the Rumble 25 satisfies in terms of sound quality and volume. For larger venues and louder gigs, I have a "big" setup. This is a custom setting with a flat bar response of 40Hz to 2.5kHz. However, it consists of separate EQ, amplifier and speakers = much more adjustment possibilities, is 5 times heavier and costs more than 20 times more than the Rumble 25. This led me to try the Rumble 25 for small gigs. . Anyway, I play almost all genres of music, from classical to rock. One feature I like is Fender's built-in non-adjustable "Delta-Comp" limiter. This seems to work very well and controls when the amp is clipping a bit. Click on the boundary point and some high frequency artifacts will appear. When the amp is pushed to its limit, however, it's almost invisible except for a subtle volume limiter. Despite the measured performance, I give the Rumble 25 five stars because it does exactly what I need it to.