Another D.I.Y. cab project- quest for light gear

SBrown · #1 09-16-2011, 05:19 PM

I know there have been a few threads like this, but I thought I would post my project in case any of you were considering this. I hurt my back pretty bad at work this year, so I needed a light weight rig that didn't sacrifice tone or power, but at the same time wasn't expensive. I have played Ampegs for years, and really like that tone, but I was also ready to try out some other options. So I sold my beloved V4BH (thanks Bassology) and my heavy cabs and set out to build myself something light. I borrowed ideas from several camps; shelf ports from TL606, bigger port cross section from passinwind, bracing from fEARFUL, size and light construction from Barefaced. I built them out of 1/2" 5 ply plywood, joints glued with PL and brads. I did 2.8 cu. ft. volume, 6"port shelf, and according to my vague math, about 48hz tuning. I still may play with the port shelves after the drivers are broken in. I found 2 3015's (non-lf) on ebay for $200 each. I got all the hardware except grills from speakerhardware .com. With my new SVT 7pro, they sound wonderful. Much louder than I expected, I will probably only use both at outdoor gigs. They are tight, grindy, and punchy with tons of mids. I know there are a lot of good reasons to go with one 3-way, but I figured this setup would give me the tone I was looking for, with expandability, for under $600. The simplicity was a factor as well. The SVT 7pro (rev. C) is blowing my mind as well. I can go from vintage Ampeg, to someting similar to a GK Flea kind of sound very easily. Cabs are 35 lbs. each, head is 15lbs.

Below are some pics.

SBrown · #2 09-16-2011, 05:22 PM

Here they are after rolling on the Duratex.

SBrown · #3 09-16-2011, 05:26 PM

Here they are with the SVT 7pro and drivers installed. Still waiting for feet, handles, and grills. I just couldn't wait to play them.

They sound like KJung's soundclip of the LDS 3015ho. Very happy.

cableguy · #4 09-16-2011, 05:28 PM

Nice work. I have a fEARful 12/6 and love it. I went from a 410 at 90lbs to the 12/6 at 39lbs. Never going back. The SVT7pro looks like a killer head. You will have yourself a nice rig. Be ready for the who makes your cab questions.

rpsands · #5 09-16-2011, 05:49 PM

You could do without a lot of that extra weight in the pieces that the baffle rests on. They're pretty unnecessary. The front edge of girdle braces is enough as long as you get the fit of the baffle tight enough.

* in the place those pieces are they don't add much to the rigidity. The baffle is already there so doubling up doesn't help as much as girdle braces on the side walls would.

1n3 · #6 09-16-2011, 11:55 PM

I have a 3015, and have been weighing my options for a lightweight DIY cab. Reading your post, I had to smile; it was obvious that you and I have been reading many of the same things.

Congratulations on your build. I'm sure it's a killer rig, especially for the weight. Hope you will update this thread after your hardware is added.

I would be interested in further reports on your cab tuning. I'd like to know how actual tuning compares to calculated, and, if you change the shelf length, will be interested in how that goes.

anarkink · #7 09-17-2011, 12:12 AM

That is a sweet rig, regardless of weight. 35 lbs each? Damn.

Lowbrow · #8 09-17-2011, 12:15 AM

That is one lovely rig - nice job!

The Diaper Geni · #9 09-17-2011, 09:57 AM

Sa-WEEEET!!

John D · #10 09-17-2011, 01:56 PM

SBrown,

You have created an outstanding visual design using a good blend of vintage and modern features. If they sound half as good as they look, you have a real winner. It's a shame you have to hide the drivers behind a grill. Would you care to share more construction details, including a full set of dimensions? I, for one, would love to hear clips of your Pbass through this rig.

Cheers,
JD

JGR · #11 09-17-2011, 02:39 PM

Cool! How's the overall response without mids/tweets? I'm not a tweet guy, but I am wondering if these are on the darker end of things without a midrange driver.

Blues Bass 2 · #12 09-17-2011, 04:03 PM

That looks pretty killer ! As an ex owner of a cab with one 3015 that could do about any medium club gig I'm sure two of them will push some serious air . The 3015 has a nice burpy mid sound to it to go with the great low end . Very nice !

SBrown · #13 09-17-2011, 11:25 PM

Yes, the baffle braces are pretty large, but they are actually very light pine that I had around, and they provided a good amount of wood to brad and pl the baffle to and brad/pl to the cab walls, if that makes sense. a big PL footprint if you will. They really added very little weight. I played a bar gig with the dance band last night, and 1 cab at 8ohms was plenty. In fact it was easy to play too loud if I wasn't careful. I might not have to tune it any lower, as I was getting the best lows I've ever played live, especially in the 3rd set after the driver started breaking in. I still might add 2 inches on one of the shelf ports just to compare and tinker. That should drop it down to about 45-46 hz, but again the math is somewhat fuzzy. I will report back on that. I am not a real tweeter lover, so the highs from the 3015 are fine with me. In fact, the mids/highs are a lot more present than I am used to hearing, but I really liked it live because I was getting a grindy, almost picked SVT tone with fingers that was cool on some rockin songs, and it really cut. The inside dimensions are 23" tall, 18" wide, and 12.5" deep. I set back the baffle 1" from the front, which was a mistake because the 3015's flanges are about .75"+ thick. So I dont really have room for the grill I wanted without sticking out past the front edge, so I just ordered some round ones instead. Not a big deal for me, but leave yourself 1.5" setback for a large flat grill. The ports are 3" x 5 5/8", and in my tuning calcs I figured 1 large slot port minus the thickness of the dividers. I don't know if thats the proper way to figure it, but the beauty of the slot port is that its so easy to change, so I will add a bit and see if I like it better. I play next week in a much larger room with a 20' ceiling, so I will play both cabs just to hear how they do.

Etchbass · #14 09-17-2011, 11:27 PM

I thought this said "The quest for light beer" ...so I clicked it. To my pleasant surprise, I've stumbled into a D.I.Y. cab thread. Even Better.

Those are coming out beautifully, btw. You should be proud. Let me know when you take them into mass production. :-)

4Mal · #15 09-17-2011, 11:35 PM

What is the shelf length at this point ? I ask as I have 2 3015's myself. I did. Cab in 2.6 cu ft that I like. I tjink goig up in size a bit, might add some efficiency - which would be beneficial for a low watt tube amp I'm thinking about.

SBrown · #16 09-17-2011, 11:37 PM

Thanks for the compliments! I don't know if I have the technology to get a sound clip up, but I will look into it. During the gig the drummer yelled at me "you're gonna make me s#$%t my pants with the bass!"

SBrown · #17 09-17-2011, 11:50 PM

My port shelves are 6" from the front of the ports, 4.5" from the inside of the baffle. I don't know which dimension is more important, hence the "fuzziness" of the math. In the end I decided that 6" is the actual length of the port, so thats what I based my figures on. From the research I have done, it looks like a larger cab volume lowers the watts limit of these drivers. I think 2.5 to 2.9 is the sweet spot. I don't know what happens with the efficiency, maybe someone with more cab design experience will chime in. I do know that when played with my V4BH (100w tube) my DIY was louder than an SVT115e I compared it to.