SRM-150-10 Build Project

2013-12-28 23.45.48So I started using the DPA 4099 mic about 3 years ago (2011ish) I can’t remember for sure, and I really like it. For almost all situations it sounds very natural and unless you really push the volume (which I don’t like to do, but that’s another post), it’s very feedback resistant.  The main challenge that this mic has presented me with is amplification. Do I use a standard bass amp somehow, or go toward a more PA system setup. The other challenge is that the mic needs phantom power. Before I got the mic, I used (and still do from time to time) an David Gage Realist Pickup and a Carvin BX500 head into a Schroeder 1X10 cabinet. This was a great combination for me, the Carvin has a plethora of EQ options and I could get a usable sound pretty quickly. My problem with a lot of acoustic bass amplification is that there is no “air” in the sound. That sounds like an old bandleader in Chicago I had who would tell the keyboard player the string patch on his piano needed more “rosin”. What I mean by that is, there’s no space in between the string sound and the amplified sound. If the bass is an acoustic instrument where the strings are amplified by transferring the string energy into the large open cavity of the body, then all pickups are cutting out that much needed acoustic middle man.

Anyway, long story short I was convinced a microphone was the way to go, and for me it definitely is. I’ll get into my feelings on the way I think a bass should sound/feel in an ensemble (mostly playing technique wise) in other posts, but anyway, microphones. They’re sweet. So I got the DPA and was trying to use a little Behringer Tube Mic Pre just for the phantom power and then into my bass amp. This yielded really good results. Again the Carvin head has so many EQ options I could get a good sound with relatively little tweaking, or tweak away and find a sound that would work with a large number of environments.

The inherent flaw in my being is that I’m lazy. I am militantly lazy to an extent where I plan how to be lazy or “efficient” I guess if you want to use a positive word. The setup I was using had so many cables and pieces I was determined to come up with a simpler alternative.

This led me on a quest for a small amp with decent power and phantom power built in. It doesn’t really exist. Sure there are little amps out there, but they are either too big or too small and what I really wanted was say a QSC K10 with phantom power built in. It’s not out there. I came across these little “lunchbox” amps for lack of a better term that were almost perfect.  I bought a Behringer B205D from Guitar Center and tried it out for awhile. I actually liked it for really small gigs. That’s all I’m using in this clip for example:

It sounded good, but if you push it, especially with bass frequencies, it will start to break up. So I returned it and ended up with the Mackie equivalent, the SRM-150. Same deal, would break up at loud volumes, but I countered that with plugging into a larger system when those gigs came up.

Again my militant laziness reared it head and I said “There’s got to be a better way!” I loved the package of the amp, but the speaker was just too darn small. So I set out to take the amp guts and make my own enclosure with a 1×10 speaker in it. I was having a hernia operation at the beginning of 2014 and I needed the amp to be as light as possible, so I used 1/4″ ply for the top bottom and sides and used 3/8″ ply for the front and back baffles.

Here’ s a few picks I took of the build. Sorry there aren’t more.

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2013-12-14 09.40.36So clamps. They’re great.


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Really great.

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I should have taken more pictures, but this one shows pretty well how I combated the problems inherent in too thin of materials. I used braces as you can see inside the cabinet to provide some stiffness for the sides and I applied “Truck Bed Liner” Herculiner in this case to the outside and inside of the cabinet for hardness.

All in all this build came out great. The amp has 150 watts and weighs about 17lbs! A winning combination for my back.

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It sounds great and I can use it with a jazz quartet as long as the drummer isn’t too rowdy. I’ve also used it with larger 5-6 piece bands if there’s a good sound guy that I can give a feed to and they aren’t trying to make the bass louder than it should be in a Jazz context. (But that’s another post!)