Thread: My recent ventures into DIY audio...

A few months ago a friend of mine asked about replacing his aging PA. He was on a limited budget, and the idea of building some custom speakers came to mind. He had a wood shop, and was ready to make some saw dust. After a good amount of time designing things on paper and making minor tweaks, it was time to go. The attached image is what we came up with. Aside from foam backing the grills, they are done. The tops are a dual 12" and 2", and the subs are a single 18". The original top design called for the horn to be in the middle of the 12's, but he feared that he couldn't get the horns up high enough, so we settled for this.

So far, I'm very happy with my designs! The subs roll off nicely at 34hz, and the tops are solid from 76hz-16k. The rig's been out on a few gigs already, and it just sings. I keep forgetting to save SMAART traces, but hopefully I can get them posted soon. I was so happy with everything that I'm building 4 more subs currently!


Oh, and the whole system cost far less than what a system from a name brand would cost!



Evan

What components did you use?

Evan Rat II? <grin>

Looks great. The only thing I see is you should go for the smaller diameter grills. Any a$$hole with a pencil could really ruin your day...

It would be nice if you could break down exactly how much time went into this: design, construction, tuning? Also, how much were components, materials, expendables, paint, etc?

How about amplifiers and DSP? Did he already have them, or did he need to buy something? How much did all that cost?

I'm nearly 100% positive that if you paid yourself a decent rate and calculated all this out, it's not cheaper.

But if you had fun and the client is happy, that's what counts, if you don't have to pay bills...

Originally Posted by Silas Pradetto

It would be nice if you could break down exactly how much time went into this: design, construction, tuning? Also, how much were components, materials, expendables, paint, etc?

How about amplifiers and DSP? Did he already have them, or did he need to buy something? How much did all that cost?

I'm nearly 100% positive that if you paid yourself a decent rate and calculated all this out, it's not cheaper.

But if you had fun and the client is happy, that's what counts, if you don't have to pay bills...

Hey Silas,
I think you'd be surprised... Most of the design work happened when I was bored on tour. The fine tuning was done when I got home. I couldn't put a solid number down, but it wasn't enough to consume all of my days. Total build costs on all 4 speakers was just under $1700. That includes drivers, wood, paint, handles, grills, ect. He already had most of the amps and DSP- just had to buy one new amp, which cost him $100 after he sold another amp. So, that puts the total cost up to $1800. Figure, what, $500 or so for design and labor and I'm still under $2500. This rig could easily compete with a JBL SRX/EV QRX rig, which would cost you well over $4,000 new. I think we saved quite a bit.



Evan

Making saw dust is part of the learning process, but it usually teaches us to stop doing it...

Enjoy it while it is still fun...

What do you predict the resale value is for those boxes?

JR

Hey, it would make sense to move this thread to the DIY section.....

Very nice. So how good is good? I have some similar cabs and I wonder if mine are yet as good as I can get them. What limits / compromises must one simply accept with two 12s + 2 over single 18? Care to share info on how yours are processed?

Originally Posted by john lutz

Very nice. So how good is good? I have some similar cabs and I wonder if mine are yet as good as I can get them. What limits / compromises must one simply accept with two 12s + 2 over single 18? Care to share info on how yours are processed?

The tops out run the subs by a good bit. It takes 2-3 18's to keep up with the tops. Construction wise, they're built more solid than the comparable MI grade cabs you can buy- 13ply 3/4" birch, and braced very well. The components are better then some manufacturers use, and again, I am very happy with how they sound.

Processing right now is pretty budget minded- A Behringer DCX2496 for DSP, and QSC RMX amps for power. It gets the job done, but hopefully we can upgrade to a lake and crown MA amps soon.

As soon as I get the construction pics uploaded, I'll post those too.



Evan

Originally Posted by Evan Kirkendall

Hey Silas,
I think you'd be surprised... Most of the design work happened when I was bored on tour. The fine tuning was done when I got home. I couldn't put a solid number down, but it wasn't enough to consume all of my days. Total build costs on all 4 speakers was just under $1700. That includes drivers, wood, paint, handles, grills, ect. He already had most of the amps and DSP- just had to buy one new amp, which cost him $100 after he sold another amp. So, that puts the total cost up to $1800. Figure, what, $500 or so for design and labor and I'm still under $2500. This rig could easily compete with a JBL SRX/EV QRX rig, which would cost you well over $4,000 new. I think we saved quite a bit.



Evan

I think Silas was referring to something like this. You say $500 for design and labor. Let's say you get $20/hr. Then that would be 25hrs total for everybodies labor-design time-testing time (that is usually billed at quite a higher rate).

You must have whipped them together pretty quick.

And the word "compete" means different things to different people.

Glad it is working well for you-but just saying there are often other things to consider.

Agreed, maybe this should be in the DIY section so Ivan doesn't need to explain all the differences between this and a professional, commercial design.

If it sounds good it is good, enough..

If Evan can crank out new speaker designs for a few hundred dollars, he can probably find a good gig after he tires of the circus life.

What's next?

JR

JR,

It is in the DIY section.

good job...

Maybe I should lighten up then... :-(

I used to run a kit business and remember when DIY actually saved you money... My old test bench was populated with heathkit test equipment. But then was then and now is now.

Making saw dust is good training (been there done that)... and I suspect many here have done their share... It used to be pretty common for regional sound companies to roll their own cabinets. Some box companies started that way, but not recently.

JR

They look loud.

Need better grilles though. They currently are channeling "DJ" pretty strongly.

I'd love to hear them or at least hear what other have to say about them.

Building a "point source" box using off the shelf components is a fun and challenging learning experience. A little experimenting, tweaking and patience can yield reasonable results in situations that are not critical. Here's a little test for any of us homebrew builders. Take your best sounding effort. Put two of them next to each other with the backs touching. Now start spreading the fronts apart with the backs still touching until you find the angle where they are transparent in their coverage patterns and the frequency response sounds smooth and consistent everywhere within the combined horizontal coverage pattern. The search for the holy grail. This is what separates the big boys from the rest of us.

Originally Posted by Steve Payne

Building a "point source" box using off the shelf components is a fun and challenging learning experience. A little experimenting, tweaking and patience can yield reasonable results in situations that are not critical. Here's a little test for any of us homebrew builders. Take your best sounding effort. Put two of them next to each other with the backs touching. Now start spreading the fronts apart with the backs still touching until you find the angle where they are transparent in their coverage patterns and the frequency response sounds smooth and consistent everywhere within the combined horizontal coverage pattern. The search for the holy grail. This is what separates the big boys from the rest of us.

I have been in this business quite a while, and can remember specifically a bunch of times "when the light bulb came on"-or at least started flickering.

We have a local 2500 seat venue that I used to do concerts in all the time. I knew it well and always took out the same system-4 stacks per side (all with 90°) horns There was a bit of "splay" in the cabinets to get a little bit wider coverage.

Now before you start jumping on me-this was back in the 90's-and there was not the information base/availability of basic audio/acoustic/interactions etc. Yes it was known and studied-but not redily available to the "common folks" like myself-out in the trenches.

Anyway-I did a wedding in the same room-same stage-but only used 1 stack per side because it did not need to be concert level and they didn't have the budget for a larger system.

Both myself and my righthand tech both said "WOW it is not as loud as the full system-but it sure does sound a lot better-clearer etc".

I was not sure exactly why-but it was the interaction between the boxes that was causing the sound to not be as clear as it could be. The regular "full system" sounded just fine-UNTIL I heard a clearer system in the same room.

When I had combfiltering explained decently to me (THANKS PAT BROWN AND SYNAUDCON), it started coming together and making sense.

When your frame of reference is better-THAT is when you start to realize all the "little things" that make a difference. All the little things DO add up.

Nobody will argue that a single box sounds better than multiple boxes. Of course the problem is getting a single box loud enough to do a large crowd. THIS is where the real design work begins. You either need to use multiple boxes that work well together without interaction-or you need a really loud single box.

This is accomplished by just piling a bunch of drivers in a box. Not so bad for the lows and mids-but once you start to get to the high freq-THAT is the problem area. The size of the wavelength and the physical size of the drivers really fight each other.

Once you start to think of audio in terms of the size of the wavelength-everything starts to change (in the way you look at things).

I'll stop now before I start to ramble on.

Well, I loved the single 18's so much, I built 4 more. These things really kick ass for being a single 18. Grills get foam backed on Friday, and I'll have some SMAART traces then too.




Evan

I would add a some shollow hole cups for when you stack sub on sub.

Looking good now! Just what the doctor ordered for that rig. Subs! Lots of subs! Ground pounding, gut wrenching, earth shaking subs. Good old big ones and Big old good ones!