If you're looking for an effect that can be used to great effect in a mix, then the Bass Compressor Pedal is what you need. It's perhaps one of those'must haves' for mixing. It's not actually a true distortion device in the sense that it distorts the sound, although you will get some 'pumping' effect from using it. Instead, what it does is it compresses the signal before it ever reaches the ears and creates a more precise and limiting type of signal. So, technically it's a limiting reverb pedal. But this is more about its usability than any particular definition of it's effect on sound.
These bass compressors are generally used along with other low-end effects pedals, such as the bass octave pedal, and/or low-end guitar effects pedals. But they are put further down in the signal path, so as to achieve a more limiting type of sound. This way, they can be used for limiting the perceived depth of a sound, or for creating a more compressed 'wall' of sound for example. The name comes from the physical design of the amplifier that has these pedals attached to; basically, the amplifier has a capacitor that acts as a buffer for the incoming signal, so it's always ready when the pedal is pressed. When you release the pedal, the capacitor returns the amount of power that was used, back to the amplifier.
So the main use of the Bass Compressor Pedal is for making the sound much less'shapey' when the main sound is being compressed. This is achieved by reducing the high frequency response of the sound, and also the low-frequency response. In essence, what this does is to give the sound an unnatural character, as if it's being pushed down into a lower octave. This is done by using the compressor without letting the sound overpower the mix.
Basically, the Bass Compressor Pedal captures the energy from the low-frequency sound, and pushes it up to the high frequency sound. When done correctly, you can end up with a sound that has increased strength in its mid-range and bass response, but without having the perception that you're hearing the background noise from above. One way to achieve this is to turn the volume knob all the way up, which will push the sounds higher, but will keep the background noise in place.
However, while having the best bass compressor pedals is great for live performance, they aren't the best for recording. There is a lot of gain pressure required to get the wah pedals to work at full effect, and when using them on recording tracks the sounds can often appear to freeze. There are solutions to this issue, however. Firstly, as mentioned earlier, it's best to leave the volume knob at its default setting of half-way up, allowing the compressor to kick in and produce its effects. This way, you'll only need to use your sound engineer to boost the levels a little if a particularly heavy or unusual effect is required.
Another negative aspect of some of these compact units is their construction. A majority of them are constructed using a thin veneer of aluminum, with none of the metal parts actually attached to the console. Obviously, the lack of attachment to the console means that the light is not necessary, and the fact that the lights are attached to the pedal instead means that the unit is not too weatherproof. Although, most companies do provide a lifetime warranty on their products, this is not always the case with the bass compressor pedal models. Consequently, although they may be incredibly practical, these types of pedals may not be as durable as you would like. Fortunately, most manufacturers provide a limited lifetime warranty on their constructed units, and in many cases up to 25 years in case of components.
It is important to check out the price and full specs on amazon. The main advantage of shopping on the internet is that you can find and compare many different products without leaving your home. If you do not want to read through the long reviews on a particular model, then it is possible to simply search for "bass compressor pedal" and read through some of the product descriptions. Amazon also has customer ratings, which can help you determine which products have the most positive reviews. If there are plenty of positive reviews, then you will probably want to purchase that particular model.
Finally, one thing that you should definitely look out for when purchasing new compressor pedals is compatibility. Make sure that the amp that you purchase has the same type of input signal that your compressor has. Also, make sure that the amp is compatible with your current sound board. In addition, you should also ensure that it has sufficient outputs for all of your equipment. The last thing that you should do before deciding on the product that you want is to read through all of the instructions in order to make sure that you know everything that you need to about the product.