Please, No Laughing, Spitting or Throwing anything at the Noob

[joecarrow]

Holy moley! You're not kidding with "overkill". Thats going to be something like 85 pounds of drivers in each cabinet. Any idea what the final mass of the behemoths is going to be with the wood? I'd guess they're going to weigh more than a full keg. They might even be more fun than one! I'm cheering you on.

[kingpin]

Holy moley! You're not kidding with "overkill". Thats going to be something like 85 pounds of drivers in each cabinet. Any idea what the final mass of the behemoths is going to be with the wood? I'd guess they're going to weigh more than a full keg. They might even be more fun than one! I'm cheering you on.

My guess is somewhere around the 280-330lb mark with the crossovers.
Each cabinet is 2 1/2 sheets of 1"mdf plus a half sheet of 3/4"
I am starting to wonder if they are going to fall forward as it seem a lot of the weight is in the front. 8O 8O

Thanks for the nice words. :T

Mike

[joecarrow]

On a more serious note.. be careful! If anyone has a good estimate of the center of mass for the woofers used, I wouldn't mind doing a little tip analysis at lunch today.

[cjd]

Order looks perfect!

Does Madisound not have the 14ga Perfect Lays any more, or are they just that much less from the other source?

And Joe, the cabinet itself will have a center of mass slightly below center. The subs are significantly bigger than the 10's, BUT... it's going to be up to how the feet are done. I would actually consider "outrigger" feet near the front of the cabinet for this one, try to get the stance out to 16" c to c on the feet...

I won't put things like oil lamps on mine (though I only put 3 feet - should have done 4 I guess).

C

[kingpin]

Good news is there will never be kids around me or any of my equipment for a long, long time.
I saw some outriggers but I think I will be getting some made at out of steel or a cnc'ed from a solid piece of aluminum$$$$$$$$.
Something like this.

Image not available

Image not available

At Madisound a 3.0mH 14 gauge is $ 30.05 each. I save $20.us
At Madisound a 1.2mH 14 gauge is $ 19.15 each. I save $14. us

So for a savings of about $45-$50 cdn with taxes I will order them from B&G Audio(oregondv)

Mike

[joecarrow]

Tipping...

I just put together a quick spreadsheet to see what it would take to tip this thing over.



A link to the excel file is here: http://jzoe.com/files/tipping.xls

It doesn't look too likely to tip sideways with those outriggers, and the mass of the cabinet may be enough to keep the center of mass balanced between the front and back. Seems like a good idea to put the crossovers low and toward the rear.

As noted in the file, the force required to open an ADA standard exterior door is 7 pounds. Think about how hard it is to open the door when you go to the bank or a government building, multiply by several, and that gives you an idea of how hard you have to push or pull to get these things to lift one edge.

[Dennis H]

Interesting, Joe. Those outrigger dimensions are from the center line of the box, right?

[joecarrow]

Yeah, from the center of the box. It's really just box width, so these tables assume you're using identical outriggers at the front and back.

The part that I didn't figure out was how much extra force it would really take to make it tip over. That's where you'd see a lot of benefit from a lower center of mass and a wider base.

[kingpin]

Holy crap man.
Joe that is an awesome thing you just did for me. :T :T
Helped with a little of the paranoia.

It's funny that I had a friend over just now who loves my tv and stereo equipment at the present time. I was telling him about all the awesome people here and how speaker building is as much of a science as it is woodworking skills. When I opened this thread up and I saw your spreadsheet with my info on it I was so shocked and amazed that someone else would take the time to do this for somebody they didn't even know I sat silent for a minute or so. My buddy was just shaking his head as to how much support and help was available to me.

You guys are wild. ;x( ;x( ;x( ;x(
Now I have to add somebody elses name to the honorary plaque that will ne going on the back of these speakers.

Thanks again
Mike

[joecarrow]

Hey, I'm just a bored mechanical engineer! It took me two minutes to whip that thing up, and I spent almost a minute uploading it to my site. I give way more props to the guys who help with crossovers. For that matter, your buddy's going to deserve more of a place on a plaque if he helps you MOVE the things

[kingpin]

I hope one day I'll be able to help you guys.
I read through everybodies threads and wish I could help but mostly all I can say is good job, good work, that looks awesome.

If you ever need to know anythig about custom picture framing(my old business before I shut it down 2 years ago) residential painting(my backround), or Corvettes(my dream) I will be happy to help.

You are a "retired" mechanical engineer and you use words like "props" :P
What, did you retire at a young age or do you have the young generation hanging around you?

Next Thomas will be starting a thread with.

"Yo" Howz my boyz doin' for the dizzle fishnizzle. That earpiece(speaker) is dope dawg." :B :B :B

Mike

[joecarrow]

Not retired, just bored. I work at a startup company that has been keeping me busy with a lot of stuff I don't really find interesting. I'm only 24, and I hope to have much more interesting work by christmas.

This is one of those "epic" projects. You're bankrolling it and building it, and as long as you put up some good pictures you're bringing something good to this forum.

[kingpin]

Not retired, just bored. I work at a startup company that has been keeping me busy with a lot of stuff I don't really find interesting. I'm only 24, and I hope to have much more interesting work by christmas.

This is one of those "epic" projects. You're bankrolling it and building it, and as long as you put up some good pictures you're bringing something good to this forum.

Thanks Joe.
Those are very kind words.
Being 31 myself I am at the other end of the spectrum. I closed my business of 5 years and found myself starting over again at the bottom of a Hardware chain. Oh well, c'est la vie.

Interesting day today.

Borrowed a piece of crap table saw. Shoved it under the table and never turned it on. :roll:
Glued together 2 pieces of 1"mdf for the front baffle. 1 piece is oversized so I can take the roundover bit and make them perfectly flush.
Decided while the glue was drying I would try the 3/4" chamfer bit on a piece of mdf. As I was tightening the bit down the the bracket that holds the collett in place broke into pieces. Looks like there was a defect because you could see bubbles in the metal.
Since I bought it from work I returned it no problem but we are sold out of the same one. So I may get a better one tomorrow for the same price.

Here are some pics of the gluing.
Whoever said you can never have enough clamps is right. :T
I hope things progress quicker though. I have decided to go back to the shop where I had the sides and the braces ripped and cut all the internal braces on their saw. I just don't like how things are going with the circular saw.


Images not available



Mike

[Bent]

lots o clamps, some of them still have the tags on them...

can I buy them at a discount 'cause they are used now? LOL.

[kingpin]

lots o clamps, some of them still have the tags on them...

can I buy them at a discount 'cause they are used now? LOL.

I wish I had more.
They were $5 a piece at princess auto in Whitby. Not of high quality but they will work for now.

Progressing slowly. Have glued together both front baffles and just finished using the flush trim bit to make them exactly the same. I finished cutting all the braces yesterday except for the smaller ones for the mid enclosure. I will be using my circular saw for this as there are no angles to cut.

This weekend I hope to be able to cut out the recesses and the holes for the drivers(really nervous about this). I also hope to have all the rabbits cut in the side panels so I can begin some assembly early next week. I also have a friend coming over this weekend to help cut all the 3" holes in the braces.

I wish I would of bought some of that swiss cheese wood so I didn't have to cut the 70-80 holes that are needed for each speaker. :B :B

Anyways off to work.

Mike

[joecarrow]

You have a holesaw, right?

Also, I had to abandon using my circular saw because I was having trouble doing better than +/- 0.25" on the cuts. Of course, I might have had the world's cheapest circular saw...

[ThomasW]

Also, I had to abandon using my circular saw because I was having trouble doing better than +/- 0.25" on the cuts. Of course, I might have had the world's cheapest circular saw...

Or really bad case of the jitters..... :B

[joecarrow]

Yeah, I was kind of nervous balancing on the balcony so I wouldn't get sawdust in my apartment...

[Bent]

I believe that feature is caled "Auto Dado", LOL

[kingpin]

Just got back in after spending a couple few hours outside in the garage.

You ever been using a router and out of your peripheral vision you see a skunk walk right by you. 8O
There was no way in hell I was going to let Pepe LePew screw me up. I slowly stopped what I was doing and slammed the garage door shut.

Most of my time was spent trying to get my router to only leave a 1/4" of the spiral bit showing. I ended up taking the base of the router and using the circle attachment jig I have spaced with a few washers which works well enough.

Was only able to make the rabbits in one of the side panels. Yes I know, slow as molasses, but I want to keep the screw-ups to a minimal.

Having a bit of a hard time making the rabbit not too tight or not too loose. One of the joints is a bit loose so I will have to do something about that.

Since this is my first time building a set of real speakers I find myself second guessing a lot of things I am doing and this adds in wasted time. Not too mention figuring out ways to clamp straight edges down on an 80" piece of mdf as well as setting up jigs and tool issues. I thought I was ready with a folder full of drawings and measurements. I am now using these as guidelines and am improvising as I go along or else I would never get anything done.

Tomorrow is another day.

Mike

[kingpin]

On another thread somebody was mentioning something about the optimum Qtc for sound quality is 0.50.
For my 2 Dayton's how can I figure this out. I am keeping the cabinet sealed as I am looking for quality of bass from the bottom end not spl or how low it will go.
I will be running the RS 12's actively but would still like to now how I can achieve this Qtc rating of .5

Thanks
Mike

[kingpin]

I think I figured out that in a sealed box for one dayton rs12 you would need somewhere around 22,000 cu inches for a Qtc of .50

That sounds totally unreasonable for me so I take that the active crossover I get will help me out with this issue.

Mike

[cjd]

I already did that math. :P You should be pretty much set on the bass bins with some stuffing. I think.

C

[kingpin]

I already did that math. :P You should be pretty much set on the bass bins with some stuffing. I think.

C

Good Morning Sir.

Winisd is telling me I get a qtc of 0.662 with 2 drivers in a box of 8864 cu inches.

I guess with the active crossover I can lower that. Is that correct.

[cjd]

Sorry, .6 sounds about right. You can lower it with stuffing. .6 is usually my target though.

I think you'll find the bass is nice and snug, regardless. The biggest advantage you'll have is being able to tame room nodes.

C

[ThomasW]

I guess with the active crossover I can lower that. Is that correct.

Nope, takes a Linkwitz-Transform circuit to lower the "Q"

[kingpin]

Sorry I should of been clearer. I am planning on buying the ULTRADRIVE PRO DCX2496 does this not have a LT filter to do so.
I thought I read this somewhere.

[kingpin]

Man, I should of bought a Jasper Jig. :cry:

Couple of things I would like to mention to anybody else who is new to this.

When buying a straight bit for your router make sure it is not too long that when the plunge is all the way up it is sticking out 5/8" and you have to shim out the base. This is concerning the depth of a recess for a driver. :M

I don't know how you guys make your own circle jig, well actually I do and have seen some here and in other places but trying to get perfect results for me has been a big pain in the a$$.

Also the smallest part of the base of my router is 4". So trying to cut out the tweeter and the rs180 means I will have to shim the jig that I made so there is a gap between it and the router. :E

Screwing around with the router and the jigs has pretty much cost me my weekend. All I had to do was spend the $50 to get the jasper jig. ops:

I think I will start drinking now. :boozer:

Mike

[jonathanb3478]

Screwing around with the router and the jigs has pretty much cost me my weekend. All I had to do was spend the $50 to get the jasper jig. ops:

I had premonitions of this, and that justified (in my mind) the $38 that Amazon charged me for the Jasper 200.

Sometimes, even setting that up to work with my plunge router and making sure the plunge routers 3 alternate stops are setup to take just over 3/4" on the last pass is a pain in my butt. If I had to make the jig first, I would probably end up as a danger to myself or others.

[cjd]

I use a 1/4" pin driven through the hole such that ~1/4" sits above. The hole for the pin can be "hidden" by the router in this way - it's how Jasper works. I've done holes as small as 1.5" I think (though for the really small ones I have a base that has no relief around the bit - my "normal" one has a 2" hole around the bit)

C

[kingpin]

Disaster

Well a little bit of a disaster today.

Image not available

Image not available

All my fault. A lot of stupidity. Wish I could have this one back.
Was standing up the side panel on a piece of ply and I guess there was something under the ply whic made it act like a see-saw. Stepped on the edge of it and the side panel fell against the wall snapping it where one of the rabbits were made. 8O

I can honestly say that so far nothing has gone smoothly and am again felling dejected. I keep falling off the horse and getting back on, but I am beginning to feel like there is a greater power keeping me from building these.

Do I have the ability to build these? Damn right.
Will they be of cabinetmakers quality and finish? Probably not.
Am I giving up? Never. It is not part of my character to do so.

Think I need some time to re-think the way I am doing things, maybe acquire a couple more tools(table-saw) and go at this again.

An extremely frustrated
Mike

P.S. This pic was taken shortly after I broke the panel. Gives you an idea of the size. I am 5' 10" 269lbs. The front baffles are standing behind me. The side panels beside me.
A little pi$$ed off.

Image not available

[cjd]

That can be repaired and recovered...

Patience, one step at a time.

So far, your roadblocks are far short of my last one - i.e. bad bad finger injury. So, you know, keep at it.

C

[ThomasW]

Ouch! Oops....do over.......

Don't feel you're alone. I've made some very embarrassing screw ups....But I keep them secret...:wink:

[cjd]

Seriously, once you assemble things, you'll be able to glue that back together and be at no loss whatsoever. It sucks, but.. do-over? you're crazy Thomas :P

C

[kingpin]

Seriously, once you assemble things, you'll be able to glue that back together and be at no loss whatsoever. It sucks, but.. do-over? you're crazy Thomas :P

C

Are you serious man. No disrespect intended. :B
There is no way I will try to glue that back together. For another $20 I will just buy a new piece and cut it out with the guide on the router and my straight bit.

I know glue joint is stronger than the mdf but I couldn''t do that.

Again no disrespect intended. :T :T

Mike

[cjd]

Yup.

When it goes down on the braces and it all gets clamped together, you do a sandwich clamp around that spot, wax paper or whatever you prefer to make sure the sandwich doesn't glue to the rest of the piece. That last brace might have to wait to slide in, but I think you can get the whole mess together at once.

One of the tricks I've learned in my few years is to pick out the spots where you can make yourself proud about a recovery, vs. perfection. You get over the "oh shit" moments faster. It really hit home when I was racing (cars) - bad approach can't be fixed, so you rethink and forge ahead. But I learned it in the metalshop long before. I had one raising that cracked, turned into one of my favorite pieces after I cut away the dead materia and moved on.



Started life as a flat piece of metal. Well, the lid was a second piece. And the hinge started as wax (hand carved of course) and was lost-wax cast in a centrifuge. This was one of my high-school pieces...

C

[ThomasW]

you're crazy Thomas :P

No one will dispute that .... :B

[Martyn]

[QUOTE=kingpin]

I can honestly say that so far nothing has gone smoothly and am again felling dejected. I keep falling off the horse and getting back on, but I am beginning to feel like there is a greater power keeping me from building these.

...I need some time to re-think the way I am doing things, maybe acquire a couple more tools(table-saw) and go at this again.

An extremely frustrated...

A little pi$$ed off.
QUOTE]


Mike, your situation reminds a little of the tongue-in-cheek "six stages of a project" which are:

1 Enthusiasm
2 Disillusionment
3 Panic
4 Search for the guilty
5 Punishment of the innocent
6 Reward of the non-participants

You are presently at 2. The two immediate challenges are: how do we stop things from getting worse; how do we start things going better?

First, slow down! You know the saying: "more haste, less speed". It's true. What's more, as Chris has pointed out, in the world of wood-working it could easily be replaced with: "more haste, fewer fingers". Take a break every hour or so and spend a few minutes tidying your workspace. If it take an extra couple of weekends, does it matter?

Second, adjust your expectations. Not only is this a new endeavour for you, but you're attempting it in spades. If you think it's frustrating now, wait until you've got these things at the glue-up stage! What I'm saying here is that you are going to make mistakes, so get used to the idea and look for ways to minimise their visual impact. Even when you get to the finishing stage, it's going to be difficult to move these things around without dinging the edges or scratching the sides. How much did you say they are going to weigh? As a friend of mine reminded me when I was building myself a new maple workbench recently: "You're not building a @#$%ing piano, you know". Although you start out with a thing of beauty in your mind's eye, be prepared to settle for something that's a little less than perfection (I always have to).

Third, it's only a piece of MDF!

Fourth, I don't think a tablesaw is going to relieve your frustrations (although retail therapy at the tool store might certainly help). The larger the workpiece, the harder it is to manoeuvre and the more space you need.

Fifth, keep your dadoes relatively shallow. A 1/4" dado in 3/4" material will still provide location and plenty of strength without weakening the board as much.

Sixth, if you're frustrated now, just wait until you're at glue-up!

Finally, it's the sound that counts!

[cjd]

If it helps, I went through a number of "oh crap, now what" stages with mine.

After getting my boxes together, I still had to measure, measure, and remeasure. Then whip up some crossover options. Then plunk down a bunch of cash, assemble crossover, test, remeasure, come up with new crossover options, order more parts, assemble, test, test another option... Somewhere in there I also had a foot slip while moving one resulting in a kicked woofer. Another order. And finally, finally, a "ahh, I like this sound - I may be done" stage.

C

[jonathanb3478]

One of my towers fell during early assembly. It fell onto carpet, so it was not dinged. An unsupported glue joint failed with the impact, however. That lead me to "fail" another glue joint manually (read: pound it off) and build the thing upside down to avoid the areas that were affected by the failed glue joints.

I can relate to the disillusionment and panic stages in the list that was posted. :T

I think they lead to a stage where you realize you can handle problems. You can handle them even better once you can skip the disillusionment and panic, for sure.

[Dennis H]

Old carpenters' saying: "If it's made out of wood, we can fix it." No worries mate, it's all part of the game.

[kingpin]

[QUOTE=Martyn]

I can honestly say that so far nothing has gone smoothly and am again felling dejected. I keep falling off the horse and getting back on, but I am beginning to feel like there is a greater power keeping me from building these.

...I need some time to re-think the way I am doing things, maybe acquire a couple more tools(table-saw) and go at this again.

An extremely frustrated...

A little pi$$ed off.
QUOTE]


Mike, your situation reminds a little of the tongue-in-cheek "six stages of a project" which are:

1 Enthusiasm
2 Disillusionment
3 Panic
4 Search for the guilty
5 Punishment of the innocent
6 Reward of the non-participants

You are presently at 2. The two immediate challenges are: how do we stop things from getting worse; how do we start things going better?

First, slow down! You know the saying: "more haste, less speed". It's true. What's more, as Chris has pointed out, in the world of wood-working it could easily be replaced with: "more haste, fewer fingers". Take a break every hour or so and spend a few minutes tidying your workspace. If it take an extra couple of weekends, does it matter?

Second, adjust your expectations. Not only is this a new endeavour for you, but you're attempting it in spades. If you think it's frustrating now, wait until you've got these things at the glue-up stage! What I'm saying here is that you are going to make mistakes, so get used to the idea and look for ways to minimise their visual impact. Even when you get to the finishing stage, it's going to be difficult to move these things around without dinging the edges or scratching the sides. How much did you say they are going to weigh? As a friend of mine reminded me when I was building myself a new maple workbench recently: "You're not building a @#$%ing piano, you know". Although you start out with a thing of beauty in your mind's eye, be prepared to settle for something that's a little less than perfection (I always have to).

Third, it's only a piece of MDF!

Fourth, I don't think a tablesaw is going to relieve your frustrations (although retail therapy at the tool store might certainly help). The larger the workpiece, the harder it is to manoeuvre and the more space you need.

Fifth, keep your dadoes relatively shallow. A 1/4" dado in 3/4" material will still provide location and plenty of strength without weakening the board as much.

Sixth, if you're frustrated now, just wait until you're at glue-up!

Finally, it's the sound that counts!

Thanks for the pep talk. :T

You know it's kind of funny. Last weekend I had planned to have a buddy of mine to come over and help me start cutting out the holes in the braces. Everything was going fine 'till he showed up. My dadoes were going perfect my measurements were bang on. The moment he showed up I started making mistakes and felt like a total ass in front of him. I not only wasted his time for coming over but I got absolutley nothing done.
On Saturday things were going great until another friend of mine came by to see what I was doing and it all went to hell again. So I stopped all together and didn't do a thing for the rest of the night.

What does this all mean. No idea. But, there is something there.

Panic hasn't set in yet, but boy, am I looking forward to it. :B
I am using a 3/8 dado in 1" mdf.
Yes. One day we will have sound.

Mike

[cjd]

People there are a distraction... I've found this to be true many a time. Driving, woodworking... anything.

If it's dangerous, I no longer work with folks there.

If they are, on go my big earmuffs so I can't hear them and I focus and ignore them.

C

[kingpin]

I feel a little rejuvenated today. Actually alot. :T :T

I picked up another piece of mdf last night had it pre cut to the long dimension.This morning I lined it up with an existing panel and used the flush trim bit to make an exact copy and then routed out the rabbits. Man I love that flush trim bit. I will have to pick up another one though that is 2" long so I can flush trim the front baffle which is 2" thick.

Started to do some dry assembly and found that the braces were not square to the front of the box(Heh wasn't that a surprise). So instead of worrying about spilled milk I looked at my piece of crap table saw and decided to make a sleigh board(sliding extension) so that I could cut pieces at least 18" in front of the blade. Worked like a charm. Now I have an abundance of squared up braces to fit my cabinets. Woo-Hoo

Forgot to take some pics but I will when I get a chance to.
Also did a major cleaning job tried to make another template for the router to cut some circles but just decided to order a jasper jig in the following week or so.

Thanks to everybody who helped me out the past couple of days. ;x( ;x(

Back at her tomorrow after work.

Mike

[kingpin]

I thought what I was building was big.
Ever seen these.

http://www.lenardaudio.com/051_opal_const.html

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