MJK’s Jordan JX92S OB with a Goldwood GW-1858 Woofer in an H Frame

[tnc]

Originally posted by Godzilla
>>> and 2 Lil Buddy...

tnc, that's what i have rolling around in my brain to build too. Please keep me posted on your progress. Especially what you think of the Lil Buddies on OB. I think you will end up with an absolutely amazing sounding system!

Godzilla,

Just to let you know that the lil buddy and 18" goldwood had arrived (and i haven't forgotten about you) but i have yet able to find anyone locally to build the H frame for me yet therefore i have not done much to this project yet. Out of my curiosity, i hooked up the lil buddy and let them sit on the floor and had a quick listen, they have a nice tone and a quick sound though they roll off pretty bad at around 1600hz or so. they are also very efficient, much more so than my altec 414z - perfect match for my 2 watts single ended 45 amp.

[badman]

Originally posted by tnc


Godzilla,

Just to let you know that the lil buddy and 18" goldwood had arrived (and i haven't forgotten about you) but i have yet able to find anyone locally to build the H frame for me yet therefore i have not done much to this project yet. Out of my curiosity, i hooked up the lil buddy and let them sit on the floor and had a quick listen, they have a nice tone and a quick sound though they roll off pretty bad at around 1600hz or so. they are also very efficient, much more so than my altec 414z - perfect match for my 2 watts single ended 45 amp.

On the floor without a baffle, you get no support, so it's no surprise you're getting only top end, unless I read you wrong.

[tnc]

Originally posted by badman



On the floor without a baffle, you get no support, so it's no surprise you're getting only top end, unless I read you wrong.

You've read me right - it's no really test for them to sit on the floor. I am just to eager to hear what kind of sound these lil buddy would provide...

I could not believe it's so hard to find someone in houston, tx to build a pair of simple H frame... man oh man... I may just go to a a lumber store and have them cut me 8 pieces of 21"x15" and glue them together myself. Problem is i dont know how to glue/clam them together.....

[ecir38]

You need to join this Yahoo group site.

http://launch.groups.yahoo.com/group/houstonaudio/

Brad

[tnc]

Someone at my local area just quoted me $350 to build 2 21" x 16" H frame boxes (with top baffle insert) in nice red mahogany. Is this a fair deal. He said the wood alone are $140 and his labor are $210.

Pictures of his works included.

Aengus, i copied your design, hope that's OK.

[Aengus]

Originally posted by tnc

Aengus, i copied your design, hope that's OK.

tnc, I'm delighted. Just recognize that my "design" was a quick sketch, and comes with no guarantees - you might want to at least check it out using Tolvan's edge; and, in any case, let us know how it works out.

As to your quote for the H-frame, I've no idea how to value this stuff. If the guy is doing it for a living, and it takes him (say) half a day, including set-up time and shop clutter time while the glue dries, that seems pretty OK to me; but it's a function of how much per hour you are willing to grant other people's labour is worth.

You could do it yourself: you don't need mahogany, just a decent grade of plywood. Your local lumberyard will cut it for you for a nominal price (or you could DIY it with a circular saw and cutting guide). Buy a couple of 24" clamps and some glue, and you're there. Really, it depends on whether you think you want to go down the DIY path on this stuff - the decision is always whether to spend the money on the tools and amortize them over the next 10 projects, or whether to avoid the hassle (if it is hassle to you) and just have it done.

There isn't - or shouldn't be - any value judgement attached; the question is where you want to spend your time and energy. My own view is biased in favour of buying the tools and trying it for yourself, because when you learn to do stuff, it expands your abilities in unforeseen areas; but there's always a tradeoff. Given a universe in which entropy exists, you have to decide where to spend your energy.

Good luck with the build, and let us know how it sounds.

Regards.

Aengus

[tnc]

Thank you Aengus. That's very nice of you. Your design should work very well for me.

With 2 little young ones, it would be very hard for me to find time to put the baffle together so I may just bite the wallet and have the cabinets made; the cabinets would look nice and will be acceptable by the lady in the house...

Now on to the crossover parts for the lil buddy and b&c de 10 horn drivers (w/ me10 horns.) I want to try out 1st order crossover at 1500hz; the formula called for a .85MH inductor and a 13uf wired in series - do i need to calculate any baffle loss, roll off, etc...(which i have no idea how to do.) I am new with this so perhaps someone can help me with the correct parts value for this setup. I will then order the parts per your recommendation.

By the way, i understand this is a "full range" forum and the original posting was for the Jordan JX92S so please excuse me if i hijacked the post and/or the question in the wrong forum. Mod, please feel free to move or delete my post if this is not appropriate here.

Thanks.

[dzzmiller]

The wood part of the Orion kit seems to be a good deal for a high-end H frame. It says $695, but adding additional hardware pieces and delivery probably makes it closer to $1000. I'm interested in this kit but building my own digital active xover.

I'm not directing this comment to tnc, justi adding it as an option.

An option for tnc would be to attach plywood (cabinet grade or whatever fit the finish) to a pre-made subwoofer box.

I find many OB designs to be very ugly. So bad that it has not only a low WAF, but could even have a negative effect on the girlfriend. . The Orion to me is acceptable.

[3dit0r]

I'm very interested in trying to build a variant of these OB H-frame design.

A quick question: what would be the minimum power amp requirement to drive these (either 15" or 18") properly?

I currently use a highly upgraded Quad 303, but my speakers are higher efficiency. Is this going to even look at OB designs, or do I need to factor in the cost of a higher powered amp into the equation?

Cheers
James

[seanzozo]

I use a ~15W tube amp right now, I have also used a 45W SS amp. Both work fine for me.

10W at ~40hz exceeds the x-max of the Alpha 15 IIRC.

Sean