MXR M81 Bass Preamp part deux, or Further adventures in going direct!

In October of last year I wrote a post about my experiences with the MXR M81 bass preamp pedal, in which I said that it had given me the confidence to leave my bass amp at home for the first time since I started playing bass in 2000. Since then, I’ve had a few more experiences with this amp-less setup and have more specific things to share, both as a bass player and as a sound engineer. Let’s start with a picture:

My amp-less setup with the MXR M81 Bass Preamp, Fender American Standard Precision bass, Android tablet with the SQ MixPad app and Community MX10 floor monitor.

Specific things that I like about this setup after five months of use:

  • No more schlepping my bass amp!!! This is without a doubt the single biggest plus of this way of doing things. As I mentioned in the previous post, my back is pretty worn out from years of moving gear, and I have already had one operation to decompress pinched nerves in 2021. Anything I can do to preserve what I have left is a huge plus in my book.
  • No more worrying about the effect of my bass amp on the FOH sound! No more worrying about being asked to turn down my amp because well, there isn’t one! And yes I know it’s not that simple – read on 😉
  • No more fussing with stands or chairs to get my bass amp pointed at my ears instead of at my knees. Kickback style bass amps go some way towards solving this issue, but monitor wedges are purpose-built for that, and are already in the venue.
  • Being able to hear my bass in context with the other instruments in my monitor mix, rather than having the bass come out of one speaker and everything else out of another.
  • Being able to hear my bass through a fullrange speaker rather than through a frequency-limited bass amp. This not only helps me when adjusting the EQ on the M81, but also hearing how the bass sits in the overall band sound.

My single biggest concern with this setup had been that the Community MX10 does not have much in the way of bass extension: the listed frequency response is 70Hz to 18kHz, and a look at the spec sheet reveals that the bass actually begins to roll off from around 140Hz! This has proven to be completely unfounded, for two reasons: firstly, the subwoofers in this particular PA system are hung above the stage, and serve to bolster the low end of the wedge in a way that is surprisingly seamless: I really can’t tell which part of the bass sound is coming from the wedge and which is coming from the subs. Secondly, a small boost at 400Hz using the M81 helps the midrange of the bass cut through. In other words, the subs help me to feel the bass while the wedge helps me to hear the notes I’m playing. Note that the bass in the picture above is actually strung with flats, which could be argued is the worst-case scenario for intelligibility. But it has really been a non-issue.

Best practices, if you are considering such a setup:

  • You must determine beforehand if your sound system is up to the task: at the very least it must have at least one subwoofer located relatively near the band. “Speech only” systems without a sub are probably not good candidates for this setup.
  • Your really should have your own dedicated monitor mix – not just your own wedge, but one entire mix. In venues where there are only one or two mixes for the entire band, bass and drums typically share a send, even if they have individual wedges which are daisy-chained together. I believe that such a system will NOT work, because bass and drums have quite unique monitoring requirements, especially once the bass amp is removed. The venue I play in has a total of eight monitor mixes, so no shortage there.
  • Ideally, your monitor mix should be pre-EQ and channel processing, especially compression! In my setup above, the EQ on the bass guitar channel is set flat (all EQ is done on the MXR M81) and the channel processing (gate and compressor) are switched off. I have seen amp-less setups derailed by the Front of House (FOH) engineer making sudden changes to the EQ or compression settings on the channel: imagine having 10dB of compression suddenly placed on your signal – you would lose all level in your wedge, and no amount of turning your bass preamp up would solve the problem.
  • You should have control over your monitor mix: as you can see from the picture above I use an Android tablet running the requisite app to control the venue’s A&H SQ7 console. This not only allows me to set the level of the bass in the monitor but also to make small adjustments as necessary throughout the performance. How this is realised is dependent on your particular system, which leads me to the next point.
  • Communication with your FOH engineer is absolutely essential! Even though you are removing the bass amp from the equation, it is equally possible for the monitor wedge to be too loud, at which point you are back to square one. However, what I have found is that the engineers I have worked with in this venue are happy for me to ‘babysit’ my own mix. On my part, I agree to never adjust the FOH mix or the settings on any other channel. This mutual respect is paramount, seeing as you are separate artists working on a shared musical canvas. In situations where the engineer is, understandably, not comfortable with musicians having access to so many mix parameters, Allen and Heath make an app called SQ4You, which is designed specifically for this type of mix-your-own-monitors application.

I hope that these points are helpful to those of you considering such a setup, especially if you have been burned by them in the past. As I said in my last post, I have become a believer! I also think that this setup is a viable and much simpler alternative to in-ear monitors (IEMs) – removing loud amplifiers from the stage but still giving the musician a sense of ownership and control over their sound.

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