Vintage Cab project for JBL D140F's ?

[escholl]

[quote name='Nostromo' post='1276584' date='Jun 21 2011, 01:03 AM']One of my best bass mates just sent me a text saying . . . . sell the D140's . . . .[/quote]
Nooo don't sell them! Don't worry about computer design or any of that other stuff. If you want a cab that sounds like that era, build a copy of one from that era. No need to over-complicate it. Knowing you built it yourself is about 10000x more satisfying and rewarding, too

The links that Mr. Foxen gave you should get you the information that you need, those Sunn cabs are really great, even though admittedly their design is utterly nonsensical in some ways, who cares lol -- good luck and be sure to post the results in the build diary section!

[Mr. Foxen]

Other option is to hunt out an unloaded 2x15. If you can get hands on it, should cost you very little, shipping is the pain. PM Thornybank, I know he has various things to suit, and probably the inclination to unload them if they are loaded. Spendier method is to have Matamp make you an unloaded 2x15.

Dubster is totally far from what you want.

[skankdelvar]

[quote name='Nostromo' post='1276573' date='Jun 21 2011, 12:44 AM']I just want it to sound like a good old vintage Seventies 2 x 15 ? ... What should I do next? [/quote]
Keep it simple. You want a cab that sounds like a 70's 2x15? Buy an old one or make a new one from a relevant design. Load it. Gig it. S'logical.

If you follow the super-wizzo-computerised-modern-lightweight-approximation-reinvented wheel approach, you'll always be wondering if you did the right thing. Nothing worse than that. Makes your head hurt and not in a good way.

Edited June 21, 2011 by skankdelvar

[martin8708]

[quote name='Dad3353' post='1276818' date='Jun 21 2011, 11:06 AM']Good afternoon, Martin...

I see you're on the Isle of Wight. Have you got electricity yet..?

(No, just kidding; I do things the empirical way too. Not always so proud of the results, though..!)[/quote]

Hey , we have had electricity for at least 10 years now , but we just got this new fangled thing called ceefax .
I have nothing but respect for guys like Alex , whose cabinets probably sound 100 times better than mine , but the OP is interested in building his own cabinet , and most people seem to be trying to put him off or confuse the guy with computor talk . Basic woodwork skills are a must , and a well build , sealed , cabinet will look /sound alot better than something which looks as if its going to collapse .
A lot of people will follow computors blindly , ie , motorists driving straight into rivers because their SatNav tells them to keep driving straight on , so use of Brain + Hands is neccessary .
A sheet of 8' by 4' 13 ply Marine Ply will cost approx £55 and any decent builders yard /timber merchant will give you as many accurate cuts to make the basic shape of the cab , if your corners are 90 degrees , most things fall into place .
Most cab depths seem to be approx 15 inches , I suspect this has more to do with Tolex coming in 36 inch width to allow economical use of this expensive material .
Sea Sick Steve built a guitar out of a hubcap given to him by Jack White , If my approach is a bit unorthodox , I make no apologies .
Martin.

[Monckyman]

Martin, I`m with you.
You learn about this stuff by sawing wood, not entering numbers into software.
Half the time its completely wrong, but sounds fine.
Sounds like fun to me.
To the OP, agreed on the finding a sun or similar or even peavey 2x15 box and having a listen before you decide to build your own, you may just decide you found that sound.

[Mr. Foxen]

What amp are you planning on using this with? Might suit older amps with less power/lows, and the 'deficiencies' might be more significant with modern amps.

[Bill Fitzmaurice]

[quote name='Monckyman' post='1277822' date='Jun 21 2011, 05:11 PM']Martin, I`m with you.
You learn about this stuff by sawing wood, not entering numbers into software.[/quote][i]Any sufficiently advanced technology is indistinguishable from magic.[/i]
There's nothing the least bit magical about loudspeaker design, and all you need to learn how to design them is the ability to read and desire to advance your knowledge. Learning how to do this 'stuff' by sawing wood is how it was done when better means did not exist; that era ended with Thiele and Small circa 1965. The only thing that software has done is to remove the need to wade through mountains of equations. If your personal preference is to remain technologically in the dark that's your prerogative. Advising others that they should do so as well, not so much.

[Mr. Foxen]

If you do want to learn to use WinISD, much better off using it to model cabs that you already have, or have heard, because that way you learn what sounds look like on a graph.

[Monckyman]

[quote name='Bill Fitzmaurice' post='1278012' date='Jun 22 2011, 12:50 AM'][i]Any sufficiently advanced technology is indistinguishable from magic.[/i]
There's nothing the least bit magical about loudspeaker design, and all you need to learn how to design them is the ability to read and desire to advance your knowledge. Learning how to do this 'stuff' by sawing wood is how it was done when better means did not exist; that era ended with Thiele and Small circa 1965. The only thing that software has done is to remove the need to wade through mountains of equations. If your personal preference is to remain technologically in the dark that's your prerogative. Advising others that they should do so as well, not so much.[/quote]

That`s me told!
I might remind you though, that this is supposed to be fun, otherwise we`d all be accountants.

[Bill Fitzmaurice]

[quote name='Monckyman' post='1279540' date='Jun 23 2011, 07:27 AM']
That`s me told!
I might remind you though, that this is supposed to be fun, otherwise we`d all be accountants.[/quote]
Knowing what you're doing doesn't make designing and building speakers any less fun. It does save more than a fair share of time and trees.

[martin8708]

[quote name='Monckyman' post='1279540' date='Jun 23 2011, 12:27 PM']
That`s me told!
I might remind you though, that this is supposed to be fun, otherwise we`d all be accountants.[/quote]

Great to hear a kindred spirit out there in the wilderness , again I have nothing but respect for the audio engineers who probably know squillions more about cabs + speaker design . But please give us mavericks in our woodsheds a chance .
I am constantly tinkering with my cabs , stripping them down , adding bits + bobs and seeing how it effects the sound .
I will never go into production , but just enjoy ''punking '' around in the woodshed .
After all, you Americans did put a man on the moon using slide-rules and one of the best Harley Davidson flat track racing bikes was designed by a dentist !!
I may never change lead into gold , but who knows what may happen along the way .

[Balcro]

[quote name='martin8708' post='1280243' date='Jun 23 2011, 10:02 PM']Great to hear a kindred spirit out there in the wilderness , again I have nothing but respect for the audio engineers who probably know squillions more about cabs + speaker design . But please give us mavericks in our woodsheds a chance .
I am constantly tinkering with my cabs , stripping them down , adding bits + bobs and seeing how it effects the sound .
I will never go into production , but just enjoy ''punking '' around in the woodshed .
After all, you Americans did put a man on the moon using slide-rules and one of the best Harley Davidson flat track racing bikes was designed by a dentist !!
I may never change lead into gold , but who knows what may happen along the way .[/quote]

Maybe you do tinker with the wood, but using some good software will help no end, because it doesn't just give you
the modern optimum, whatever that is/may be!

The software is basically clever enough for you to even deliberately design your speakers so that they're technically Wrong and take your choice of a thousand points in-between optimum & wrong. It doesn't just show the size of the box but it can also show you how easily you might blow it up! That bit does come as a surprise.

It's all good fun. Try a little science and you will save yourself a lot of wood and splinters. Enjoy.

Balcro.


PS. By the way it will also tell you how loud it will go. Yee Ha. After a lot of surfing I put the best figures I could find on the
D140 into winISD. Put two units in that old Sun cabinet and came up with 127dBa in the " mids" (460Hz) upwards. All from 120watts input. Welcome to the deaf club.

Edited June 23, 2011 by Balcro

[Nostromo]

[quote name='Mr. Foxen' post='1277848' date='Jun 21 2011, 10:29 PM']What amp are you planning on using this with? Might suit older amps with less power/lows, and the 'deficiencies' might be more significant with modern amps.[/quote]

Hi,

Good question . . . .

Well . . . I sort of assume my big valve amps (as listed in my sig block) would be risky to use to drive a vintage cab as one wrong turn of a Volume knob and I'd probably blow the D140F's ? ? ?

I guess I'm quietly thinking that once I've got the vintage cab done, I'll look round for a vintage 50w valve amp to drive it with. Bassman 50 comes to mind (probably tooo expensive ?) . . and maybe some others ? . . It'll probably come down to what I can find / afford . . . . . . . but the amp is all academic until the cab is built ! ! !

As discussed I am still keen to see any plans of vintage cabs. So do get in touch if you have any useful info ?

Cheers,

[Mr. Foxen]

Here is the 406, upon one of which I may have a lead. There are 3 styles of 406 (one is a 1x18") and I dunno which it is yet.

[Rootboy]

Is a JBL D140 a good match for an Ampeg B100R cabinet?

I am trying to atone for all of the horrible speaker cabinets I made as a kid… So I'm trying to determine which model of raw speakers I already own (JBL D140, K140, Carvin [Eminence] PS15, and unknown old CTS) will be the best match for an empty Ampeg B100R Thiele-design ported cabinet I got last week. Total internal volume is 1.732 cubic feet (sans speaker), has 36" x 10" x 1" "felt" damping material, and two 2.875" x 6" (with cardboard tubes) ports.

I tried using the Eminence Designer software I got for Christmas and I'm not having much luck, as it seems that software is more about telling you what cab to make for your existing speaker rather than what speaker to put in your existing cab.

I'd like to use the D140 although the B100R is a front mount design and I will have to enlarge the hole for either of the JBLs as their frames are slightly too large. I don't mind doing that if it's a good match, but it would be nice to save the effort if they are not the best match.

I noted Bill Fitzmaurice's comment about JBL's working nicely in small ported cabinets. And I am all for his idea of using software rather than trial and error, especially when enlarging the baffle hole does require a fair amount of set up to do nicely. The B100R *is* a small ported cabinet - too small for D140, or just right??

[VTypeV4]

I haven't crunched the numbers but I too am aware that a D140 works well in a small box and have briefly loaded one into an ancient Peavey TNT130 for evaluation.. Significant improvement over the OE Scorpion: More lows, more highs, same volume and no complaint..

[Subthumper]

Why not use the software to design the internals of the cab to obtain an optimum performance but design the outside around the looks of the vintage cabs? Best if both worlds. Used a pair of D140f's many years ago and they always had a very sweet sound. However the modern 15s I replaced them with blew them away, louder, more lows and with the same amp. If I had some now I'd probably keep them for recording.