Choosing cabs and other bits

[stevie]

[quote name='alexclaber' post='505368' date='Jun 4 2009, 11:44 AM']In my experience the shallower the cab, the easier it is to move! I'd much rather have a tall, wide-ish, shallow cab than an equal volume cube. Stick a handle on the side of the cab and you can carry it like a suitcase.[/quote]
That's fair enough if you're talking about a lightweight cab with a neo driver, but a 30kg cab is not a comfortable one-handed lift for most people - certainly not for me!

[alexclaber]

[quote name='stevie' post='505371' date='Jun 4 2009, 11:52 AM']That's fair enough if you're talking about a lightweight cab with a neo driver, but a 30kg cab is not a comfortable one-handed lift for most people - certainly not for me![/quote]

That's true. Tall and narrower and deeper is better for a two hand lift. I think 30kg would be too much for a one hand lift for me too; <25kg is fine but not if your back is at all dodgy! I don't think any traditional 1x15"s are a sensible shape - all too squat. Height is such a good thing in a bass cab.

Alex

[Happy Jack]

As Hawkwind put it: [i]Use your wheels. It is what they are for.[/i]

Edited June 4, 2009 by Happy Jack

[fatgoogle]

So it would be fine to copy the trace cab, i really like it, im not a fan of ashdown cabs, but i love their amps. Does any one know were i could get internal sizes of the trace cab and its ports, I checked the discontinues pages of the trace elliot website, and didn't have any specs. Also i hear alot about bracing being important, i dare say mine wasn't the best, so whats the standard way of bracing. I did a square brace sort of thing.

[fatgoogle]

[url="http://archives.telex.com/archives/EV/Builders%20Plans/TL606%20Builders%20Plans.pdf"]http://archives.telex.com/archives/EV/Buil...ers%20Plans.pdf[/url]

Is this the electro voice cab you were talking about steve, it looks grand, will it handle a low b.

Thanks
Sam H

[stevie]

[quote name='fatgoogle' post='505663' date='Jun 4 2009, 06:09 PM'][url="http://archives.telex.com/archives/EV/Builders%20Plans/TL606%20Builders%20Plans.pdf"]http://archives.telex.com/archives/EV/Buil...ers%20Plans.pdf[/url]

Is this the electro voice cab you were talking about steve, it looks grand, will it handle a low b.[/quote]
Yes, that's the one. It's a 90-litre cab, exactly the same volume as the small Trace 1153. The porting is a bit complicated because of the dual tuning frequency option. You could simplify it by using a full baffle with the two ports you already have. I can work out the port lengths if you like. If I were building it, I'd use two 4" ports at the bottom, move the driver a bit higher, put a 3" wide brace between the front and back panel just under the driver and a horizontal brace 3" deep two thirds up the cab on the back wall.

[fatgoogle]

So i could make the same size box as in the diagram, and then just use two ports, sound ok,

If you have time to work them out that would be great and i can decide which one to go with. Is the Electro voice one already tuned the way it is, so you make it and plonk the speaker in, or does some self calculations have to be done after building.

[stevie]

[quote name='fatgoogle' post='505706' date='Jun 4 2009, 06:51 PM']So i could make the same size box as in the diagram, and then just use two ports, sound ok,

If you have time to work them out that would be great and i can decide which one to go with. Is the Electro voice one already tuned the way it is, so you make it and plonk the speaker in, or does some self calculations have to be done after building.[/quote]
Your 100mm ports should be 180mm in that cab. If you want to design the cab specifically for 5-string, you should lengthen the ports - 245mm is optimum, but anything approaching that will help power handling on the low B. The cab will handle low B better than the one you have now.
There are two tunings available on the EV cab. You need to use the lower of the two, which as far as I can figure out, involves blocking up part of the slot port.
Have a look here: [url="http://basschat.co.uk/index.php?showtopic=380"]http://basschat.co.uk/index.php?showtopic=380[/url], where Below has made a very nice job of the EV cab.

[fatgoogle]

Ive been reading over that, reading over the Electro voice sheet and looking in the shed. Just to make sure i have plenty of 1/2" ply in the shed, but on the cab specs, it says to use 3/4" i reckon ill be grand just making sure. Yep and reading it blocking of the middle square port at the bottom will give me 1 1/2 octave extension in the low end i believe. It would easier for me to do the diagrams build with the square ports as my routers not great so the more round ports the more likely it is to go off.

EDIT: its not going to be specifically for a 5 string, im selling my current 5er so ill only have the 4 string tuned eadg, except i hope one day to get a musicman stingray 5er, and that will have a low B, so i would like to have something usable even then.

Edited June 4, 2009 by fatgoogle

[stevie]

[quote name='fatgoogle' post='505779' date='Jun 4 2009, 08:04 PM']Ive been reading over that, reading over the Electro voice sheet and looking in the shed. Just to make sure i have plenty of 1/2" ply in the shed, but on the cab specs, it says to use 3/4" i reckon ill be grand just making sure. Yep and reading it blocking of the middle square port at the bottom will give me 1 1/2 octave extension in the low end i believe. It would easier for me to do the diagrams build with the square ports as my routers not great so the more round ports the more likely it is to go off.[/quote]

I didn't realize you'd originally used 1/2" ply, and that's certainly another reason to go for a smaller cab. An unbraced 150-litre cab in 1/2" ply will resonate like mad at volume.

Anyway, if you're going to use 1/2 ply, you must make sure you've got lots of bracing in there. Dig around on this forum:
[url="http://www.talkbass.com/wiki/index.php/Fearful%E2%84%A2_12/6_%26_15/6#Crossover_designs"]http://www.talkbass.com/wiki/index.php/Fea...ossover_designs[/url]

where there are lots of examples and pictures of some bass cabs made with 1/2" ply. The bracing you see in there is the minimum you should use. I'd also strongly recommend that you double up on the front baffle, i.e. glue two pieces together to give you one inch thickness. It won't be much heavier than a 1/2 inch baffle - because of the big hole in the middle - but it will be a lot stiffer.

And post the results of your efforts in the DIY cabs section for us all to admire!

Edited June 4, 2009 by stevie

[fatgoogle]

Thanks very much for all your help, ill head to the co-op tomorrow and get wood for bracing, and then start cutting out the wood. Should get rid of some summer boredom, , I think i know what i will do for extra bracing but might come back with extra questions.

Thanks Again everyone

Sam H

[fatgoogle]

I started building to day, and 1 problem, after the wood has been planed, it ended up at 3/4" by 1 3/4" instead of 3/4" by 2", so this leads to a problem, the cleats are 2" high, so im 1\4" of, the easiest thing im thinking is trying to plan down some 2 1/2" wood to 2". I took this into consideration when cutting the rest of the frame. But can i use it like this and have it 1/4" inch to short or should i make sure the rest is the right hieght. Are their tuning problems hear.

[fatgoogle]

heres a progress pic id thought id through in here.