8" Kick Drum 'Sub'woofer? - Heresy!

LarryJ

Active Member
WARNING - Long Winded Post 😴😴😴

I have been on this forum and DFO for many years and know all of the reasons this won't work. I can probably write all of the replies I will get explaining why it doesn't. But let me tell a story anyway.

Blues/rock trio, tending towards ZZ Top and Jimi Hendrix. In larger venues we run a 2 channel PA - vocals, guitar, snare and drum overhead through one channel - bass guitar and kick drum through the other to an ElectroVoice 15" passive subwoofer.

In smaller venues the bass and guitar use their amps (both have small cabinets), drums are not miced and only vocals are run through the PA. We are experienced enough to mix this well by ear, but the kick gets lost in the bottom end noise.

The obvious solution is to mic the kick, but the bandleader/guitar player is afraid his worn out speakers won't handle that and I am not about to haul my 55 lb subwoofer and set it on a microscopic stage for what we get paid. So begins the search for a small, lightweight, and cheap, subwoofer to handle the kick drum only.

I found that a 12" didn't offer a significant enough size and weight reduction to be worth the cost. A good single 10" probably wouldn't be enough for the job and certainly isn't cheap. Then one day I was rummaging around in my attic and found an old Kustom 10" passive monitor of such high quality that today it costs $99 new. Of course it wouldn't work, but it was free. What the heck ...

At sound check it sounded like pooh - all kinds of distortion with a midrange resonance for a half second or so. We decided to try it for part of the show anyway. Maybe the bass guitar would drown out the ugliness. A drummer friend, who had come along to evaluate the experiment, said that when I was heel down he could "feel" the kick. When I was heel up he could hear it and it sounded OK to his ears. Not great, but better than nothing.

Enter a friend of mine who has a side business designing and building speaker cabinets. He measured my cabinet and modeled it in his design software. He found that, in a cabinet that small, an 8" woofer with sufficient Xmax and power rating should work much better than the 10" el cheapo midrange speaker that had proven to be adequate(?). Better yet, he had a discontinued Celestion neodymium he felt would fill our needs and that he would give to me, complete with grill, free of charge. Well within my budget!

So I gutted the cabinet, bought some plywood, built a new baffle, installed the woofer and just gigged it for the first time.

Will it fill the Superdome? No

Rattle your teeth with bottom end? No

Faithfully reproduce the sound of your painstakingly tuned Stradivarius kick drum? Not exactly.

Add enough bump to the kick to make its presence known in a small venue? Absolutely.

And at only 21 lbs and $6. 🥳🥳🥳



Which one would you rather load in and out?

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That’s about the size of it, pardon the pun. Big enough cab for a sub speaker with lots of xmax to operate freely and you can put out some low end. The trade off is efficiency, but if the 8 works, then it should work exactly as you said.
 
Cool! I have an old Yamaha powered sub with its own crossover built in, I'm going to try it too. It does give a nice little bump here at the practice room, and it's only about the size of a rack tom
 
Man, if it works for you and you're happy with it, who cares what we say! You never know what will work until you try it. Good on you for doing so!
 
From my experience, anything less than a 15" speaker trying to reproduce the thump you hear on a recording pales in comparison. You gotta move some air to make a kick happen. The industry standard being what it is, that's just the way the cookie crumbles. You can move more air with a 22" or 24" kick drum than an 8-inch speaker will do. I used to have a 24" Rogers kick with only a batter head, an Evans hydraulic, and a small blanket inside. That thing was 'nuclear', it didn't even need miking, but that was in the 70's before miking was routine.
 
From my experience, anything less than a 15" speaker trying to reproduce the thump you hear on a recording pales in comparison. You gotta move some air to make a kick happen. The industry standard being what it is, that's just the way the cookie crumbles. You can move more air with a 22" or 24" kick drum than an 8-inch speaker will do. I used to have a 24" Rogers kick with only a batter head, an Evans hydraulic, and a small blanket inside. That thing was 'nuclear', it didn't even need miking, but that was in the 70's before miking was routine.
Having built PA speakers for some time, I cant disagree with this. I've built "subs" with woofers as small as 12", and the bigger ones always out perform the small ones.

Now having said that, I've seen some tiny subs in cars (8s & 10s) that will peel your skin off.
 
Having built PA speakers for some time, I cant disagree with this. I've built "subs" with woofers as small as 12", and the bigger ones always out perform the small ones.

Now having said that, I've seen some tiny subs in cars (8s & 10s) that will peel your skin off.
Even my electronic kit when amplified needs a 15" to reproduce the kick properly. Anything smaller 'farts' when pushed to the point where the kick is as loud as the rest of the kit.
 
Even my electronic kit when amplified needs a 15" to reproduce the kick properly. Anything smaller 'farts' when pushed to the point where the kick is as loud as the rest of the kit.
I guess compression is the key, because most stereos can reproduce a kick quite well with smaller speakers, but that's a recording technique. Live, I've always found that anything more than a 1.5 to 1 or a 2 to1 max compression ratio really sinks a kick, even with multiple 18's..
 
Couldn't one just get a small practice bass amp? I've done this before in small venues where you needed a small boost to your low end and didn't have the extra channels in the pa (or crappy pa speakers that can't handle extra low end). I had a little 20 or so watt practice bass amp that I set next to my bass drum and plugged a mic into it. Certainly not super loud not earth rattling low end but it really helped give a boost to the low end from the back of the room.
 
Couldn't one just get a small practice bass amp? I've done this before in small venues where you needed a small boost to your low end and didn't have the extra channels in the pa (or crappy pa speakers that can't handle extra low end). I had a little 20 or so watt practice bass amp that I set next to my bass drum and plugged a mic into it. Certainly not super loud not earth rattling low end but it really helped give a boost to the low end from the back of the room.
Yeah, sure. There are a ton of ways to skin this cat, some better than others.

There is a lot of nuance to cabinet building. By and large, I’m going to take a purpose built 8” sub (self powered, for the sake of the argument) vs a combo bass amp with a 10” driver. They’re just meant for different things. The key phrase from the OP was “measured my cabinet and modeled it in his design software.”
 
Yeah, sure. There are a ton of ways to skin this cat, some better than others.

There is a lot of nuance to cabinet building. By and large, I’m going to take a purpose built 8” sub (self powered, for the sake of the argument) vs a combo bass amp with a 10” driver. They’re just meant for different things. The key phrase from the OP was “measured my cabinet and modeled it in his design software.”
Totally, that makes sense and there is always something cool about DIY. I'm just getting old and lazy these days haha. If I have a problem I immediately try to see the cheapest way Amazon prime can fix it lol.
 
Couldn't one just get a small practice bass amp?

Certainly could. In my case I already had a powered feed from the PA so didn't need the amp, and weight was a major reason for doing this in the first place.

Since my original posting, I have heard a Zoom recording of a gig from out front in the audience. It worked better than I expected. The kick sounded quite good and was actually too hot in the mix.
 
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