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The cabinet finishing guys on here can tell you what you have to do to finish the edges where they are bigger (longer than the sides top and bottom of the box. You can use your router with a flush trim bit to match top and/or bottom to the sides back and front.
` Rounding over the front plywood baffle will expose the layers in the plywood which then have to filled stained and varnished or whatever. Each layer of the plywood has a different color. Some guys like that layered look, others do not. I'm neutral.
` Mounting and dismounting an 80lb driver into a hole with virtually no clearance IS one of the hard parts of LMS ULTRA ownership. There are many LMS ULTRA owners who have those characteristic LMS ULTRA finger tip scars that are so common. I have my LMS driver mounted outside of the baffle hole with no inset. I can get my fingers under the frame rim with the help of plastic shims. I don't know what you do when you have the driver inset with little or no clearance around the outside of the driver rim. LOL I've often thought you could tilt the box to one side until some of the weight was unloaded to the point where you could lift it up out AND before the driver slid out and crushed your instep. It's best to have the driver and the inside of the box COMPLETELY FINISHED, STUFFED, AND WIRED, so it never has to be removed.
`The LMS ULTRA will work "well" in small boxes but it works "BEST" in a box size of about 6 cu ft when using equalization. There are tests done by several DIYers which show that. ALSO the WinISD program shows the effects of box size using the LMS ULTRA really well and the larger box size has more response down in the 10-20Hz area when using equalization. WinISD simulates equalization when you choose Linkwitz Transform as a "filter type".
Check out the LMS tests completed by Ilkka Rissanen under 'Subwoofer Tests - Archived' on the Home page of Home Theater Shack. Those are THE definitive tests of the LMS 5400 in a sealed enclosure.
 

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Discussion Starter #42
The the wood was too long that would be fairly easy to fix with a router like you suggested. Howver mine is to short. I guess i could put a bit of wood putty down that edge and lightly sand it smooth.... or just try and sand it smooth. Maybe if i went and got a 3/4" roundover that would be enough to hide that booboo because the wood isn't actually 3/4 its more like 11/16

I guess i am just going to have to finish the box completely and then drop in the sub and screw it in place. Kinda wanted to predrill the holes but i think that could be tricky. I don't want to mess up that rubber edge.

This brings me to another question. Is it really nesessary to use a gasket if the lms already has that rubber piece that goes all arount the diamater?

I am also going to have to look into the box filler material. something i have overlooked completely thus far.

And going to need to figure out the feet for the box. I liked the look of the spikes but if i read it right, you have to drill all the way through the box and instert the nuts from the inside????

Ohh, and had a moment to run outside and silicone the interior, lol
 

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Got a question, How did you guys do your holes for the speaker? did you just drop it in and screw it down?
I figured the only way this sub can go in and out of this box is to drop it and and tilt it over and let it kinda slide out. Cant see and way to pick it up out of the box.

Just noticed a thread called "LOUDEST AT SEALED DUTIES"
In it was this quote and below the quote was a graph illustrating the point.




My box is going to be quite a bit bigger than 2.4 cu ft. So is it still going to do as good? all of the boxes i have been looking at around 4-6 cu ft
Just pre-drill the holes and screw the driver in. When your dropping the woofer in you can use twist ties around 2 mounting holes to hold the woofer.

The LMS Ultra will work in 2.4 cuft but the problem is getting this huge driver to fit in such a small enclosure. 3.5 to 4cuft is a more manageable size and still sounds just as good as 2.4cuft.
 

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Excellent work sealing the box!
Yeah . . . . the edges don't quite fit. That sucks. You CAN try to add material but it'll never look quite right. I've made the same mistake and tried all sorts of stuff. No matter how I sanded and whittled and filled, I could always tell where I messed up. This is where we learn to appreciate CNC cutting and machining on factory made boxes that fit together + - 1/32 of an inch!
`
The rubber gasket. Some use it some don't. My front baffle of MDF made an airtight fit without the gasket.
That made it pretty simple for trial fits and removal. I used bolts for mounting with (T) nuts glued to the inside. Some guys use heavy wood screws. I haven't heard that either failed. I HAVE had some of the (T) nuts come loose and consequently it was tricky removing the bolt without the (T) nut being firmly attached to the inside of the speaker baffle. You won't know how tightly the driver mates with the baffle until you play loud subsonic audio material. If it leaks you'll hear it whiiiiishing or you'll feel that the driver frame edge is cooler at the spot of the leak. If you decide to use the factory gasket you do NOT need an additional gasket.
` Box damping material has become simple and cheap. Go to Walmart, buy some cheap polyfil bed pillows (3 few 6 a lot) and stuff em in the box. figure out a way to keep em from touching the moving cone. That's it. Or you can carefully, artfully, and beautifully line the entire box with exotic damping material and then close the box and no one sees it.
` Feet on the box. My house has carpet all around. I didn't put feet on the box for the LMS. To move the box, I slide it on the carpet. It's heavy but it moves. I have feet and wheels on my latest creation cause it's a bigger box with two larger drivers, even larger than the 18" LMS.
I drilled right through the box to mount the feet. I used 1/4 inch bolt with a large washer and nut on the inside. Other guys have glued wooden feet to the box. Feet can be simple blocks or you can go as fancy as you want.
 

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Discussion Starter #45
Just pre-drill the holes and screw the driver in. When your dropping the woofer in you can use twist ties around 2 mounting holes to hold the woofer.

The LMS Ultra will work in 2.4 cuft but the problem is getting this huge driver to fit in such a small enclosure. 3.5 to 4cuft is a more manageable size and still sounds just as good as 2.4cuft.
I will definately be trying the zip tie idea for holders.

You used the factory screws didnt you? Those seem to work ok?
 

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Discussion Starter #46
Excellent work sealing the box!
Yeah . . . . the edges don't quite fit. That sucks. You CAN try to add material but it'll never look quite right. I've made the same mistake and tried all sorts of stuff. No matter how I sanded and whittled and filled, I could always tell where I messed up. This is where we learn to appreciate CNC cutting and machining on factory made boxes that fit together + - 1/32 of an inch!
`
The rubber gasket. Some use it some don't. My front baffle of MDF made an airtight fit without the gasket.
That made it pretty simple for trial fits and removal. I used bolts for mounting with (T) nuts glued to the inside. Some guys use heavy wood screws. I haven't heard that either failed. I HAVE had some of the (T) nuts come loose and consequently it was tricky removing the bolt without the (T) nut being firmly attached to the inside of the speaker baffle. You won't know how tightly the driver mates with the baffle until you play loud subsonic audio material. If it leaks you'll hear it whiiiiishing or you'll feel that the driver frame edge is cooler at the spot of the leak. If you decide to use the factory gasket you do NOT need an additional gasket.
` Box damping material has become simple and cheap. Go to Walmart, buy some cheap polyfil bed pillows (3 few 6 a lot) and stuff em in the box. figure out a way to keep em from touching the moving cone. That's it. Or you can carefully, artfully, and beautifully line the entire box with exotic damping material and then close the box and no one sees it.
` Feet on the box. My house has carpet all around. I didn't put feet on the box for the LMS. To move the box, I slide it on the carpet. It's heavy but it moves. I have feet and wheels on my latest creation cause it's a bigger box with two larger drivers, even larger than the 18" LMS.
I drilled right through the box to mount the feet. I used 1/4 inch bolt with a large washer and nut on the inside. Other guys have glued wooden feet to the box. Feet can be simple blocks or you can go as fancy as you want.
thanks, and i think i found a solution to my problem. instead of trying to add material, i believe i will take away. I went and borrowed a big power sander. I am going to attempt to take 1/16-3/32 off that one side. that way my board will fit closer. Probably going to be very time consuming, but hopefully worth it in the long run

You know how gun cases and instrument boxes are lined with that grey or black thick foam? would that work like the fancy stuff or is it two different things? If not, the pillow is fine.

I think i will find some premade wooden stubs for feet then. I am wanting to try and make this look as good as possible. I don't think the layers will bug me much, ecspecially if i end up just painting it, then you wont even know there is pretty wood underneath.
 

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The box lining can be just about anything including old underwear. Grey foam lining or rubber lining might not be as sound absorbent as even the cheaper lighter weight white 1" foam used for hobby projects or blankets or furniture padding. Another material is home insulation. Get the non "itch" type. Many have used that successfully including me. You can get that in a variety of thicknesses. It's cheap and does a good job of reducing internal reflections, cone pass through, and driver motor noises from the rear.
If your final box finish is going to be paint then sanding the edges to meet the sides may be the way to go.
 

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Discussion Starter #49
After work i wanted to try and get a little bit more done, so i decided to try the bracing. I got a piece of 2x4x 1/2 mdf for this task. I sketched out 2 panels that are 21.5 x 21.5 inches. each has 16.5 inch hole dead center. I measured out 4 inches from each corner and conected those points and cut them off. I also added 4 2" holes in each panel. Probably confusing reading this. I am in a bit of a hurry, the pics should explain it.

On the very bottom of the box i decided to recycle my earlier screw up (when i made hole to big). My new panels i just made are 2 1/2 inches on the outside edge. So on the old panel i measured along the hole till i found where it was 2 1/2 wide. That way it would be flush with my new panels when they are resting on it.

Pictures will explain the rest.

Unfortunately i messed up and put a hole where there was not wood behind it. OOOPS!!! So i took a screw and drenched it with glue and screwed it in. Only solution i could think of.

I still have to put in the other brace that i cut out. That will have to wait. Getting late and got to make diner and get cleaned up.
 

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Discussion Starter #52
ISLAND1000 said:
There ya go! I like that.
What was that one screw in the middle of nothing for?
That was the mess up I had mentioned. . I had predrilled a hole where tgere was no wood behind it. So I put glue on a screw and screwed it on. The only way I could think of to fix it
 

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Wow! Seriously, that's some of the best bracing I've seen. And for some reason I like that the corners of the braces are cut away from the box.
 

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bracing is finished. Everything is glued and screwed in. I think i over did it on the glue. Well, what do yall think? Is it good enough?
That's excellent, are you going to continue the braces to the baffle, not like it would hurt if you have the extra material lying around?

You really have the chops for DIY and cutting away the corner's is what I always do as well, it's the strongest part of the box so no need for bracing there.
 

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Discussion Starter #57
Got a problem. Went to test the sub. I have it in Bridge mode. with the amp all the way up the sub barely moves. I noticed the louder i turned the volume up on the receiver, the more it moved. So got to looking at the signal indicator and it would not be lit at low volume and then as i turned the receiver volume wayy up the light would get strong. but at that point its way to loud on the other speakers. I wasn't sure how to solve this problem. so made sure the bass on the EQ was all the way to +10. Then set the distance of the subwoofer at as far as it would go. All speakers are set to small. made a little difference but not anything to get excited over.

The sub is connected directly from the reciever sub output with a 1/4 rca adapter to chanel one on the Crown amp. Then the wiring is for 4 ohm.

The amp is a sony str-dg820
 

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Discussion Starter #58
Wow! Seriously, that's some of the best bracing I've seen. And for some reason I like that the corners of the braces are cut away from the box.
Thank u! Like sub_crazy said below, i figured the corners to be strong and i wanted the bracing that i had in mind to take up as little space as possible. So i cut the corners out and put 2" holes.

If you would, take a look at my amp problem. I know you have a different model, but maybe you know what to do.

Looks great; now get the front baffle completed and the driver installed you're missing out on some quality movie time!
Yes sir, looking forward to it

That's excellent, are you going to continue the braces to the baffle, not like it would hurt if you have the extra material lying around?

You really have the chops for DIY and cutting away the corner's is what I always do as well, it's the strongest part of the box so no need for bracing there.
I have always enjoyed building stuff, just never tried my hand at this type of wood working. Done a few privacy fences but thats about it.

I have thought about extending it like you mentioned and probably will do so. Right now this amp problem has me side tracked. Thought it was going to be a simple plug and test. wrong. It has noise coming out but nothing amazing
 

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Sounds like your not getting enough output from your receiver, you probably need a signal booster. Pro gear normally has a higher output than standard home gear so you need something to boost the signal coming out of your receiver. It's been a long time since I have read anything about this but I think people were using the Samson S-Convert or Art cleanbox to boost the signal. Not sure what people are using today though and the 2 I just mentioned are probably discontinued.

I have actually never had this problem with the various receivers/pre-amp and pro amps I have used over the years as I have always had the SMS-1 which has variable volume control to boost the signal if needed.
 

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Discussion Starter #60
Sounds like your not getting enough output from your receiver, you probably need a signal booster. Pro gear normally has a higher output than standard home gear so you need something to boost the signal coming out of your receiver. It's been a long time since I have read anything about this but I think people were using the Samson S-Convert or Art cleanbox to boost the signal. Not sure what people are using today though and the 2 I just mentioned are probably discontinued.

I have actually never had this problem with the various receivers/pre-amp and pro amps I have used over the years as I have always had the SMS-1 which has variable volume control to boost the signal if needed.
Ok, i turned on some subwoofer music on pandora. found a subwoofer setting under "hdmi" that i never knew existed. turned that from 0 to 10. that made a little difference. Then i started flipping switches in the back of the amp. i turned the sensitivity from 3.46 to .77 and that made a big difference. for some reason i thought the higher number would make it louder. guess not. that cone can really move. i noticed some heat comming off of it pretty quick so i shut it down. i didn't want to melt the thing. Did it get so hot because it was free air movement?
 
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