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JBL 8330 project thread - Page 2

post #31 of 164
Thread Starter 
kingpin, just curious, why line it with wool? Erich sent the fiber glass that was in the mid chamber JBL used. I am not opposed to trying something different if it is an improvement.

Muzical, I appreciate your input and the link. As I will need a little more flexibility in the aiming department, those won't work for me. I hope someone else finds them as a good fit though.
post #32 of 164
When I built my big speakers it was recommended to use thick wool 3/8"-1/2" thick.
I couldn't find any around me so I used a special type of flooring underlay until I reached the desired thickness.

The masters at Htguide recommended it as a great thing to use. Who am I to disagree. I think wool absorbs very good and is also pretty dense in those thicknesses.


post #33 of 164
Thread Starter 
Wow, very nice! If I am unhappy with the fg I will def try it out.
post #34 of 164
Thread Starter 
I just went through your build thread. Top notch stuff right there. One day I hope to go bigger than I need. I have huge spots on either side of the fireplace just begging for that.
post #35 of 164
I need to clarify it's wool felt. Not just loose wool. LOL!
post #36 of 164
Thread Starter 
kingpin, I knew what you meant.

Here are pics from today. I will cut down the ports tomorrow.



post #37 of 164
Dang those ports look impressive! Much nicer than the PVC I plan to use, but hey, no one will notice when I'm done.

Work is really getting in the way of my build time, so I made very little progress again today. Attached are a couple pics of dry fitting the mid enclosure, and verifying the braces are the proper length. You can also see where the XO will sit with respect to the drivers. It's almost time to glue and screw the first cabinet!

The last pic is what I will use to hang these bad boys. I'll start with 2, and go up to 3 per speaker if needed. You can pick them up at Ace Hardware, or almost any home improvement store. A set of 2 was ~$3.50. These exact hangers have held my Paradigm ADP100s on the wall for many years.

Hopefully I will have more tomorrow...
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post #38 of 164
Quote:
Originally Posted by Ed H View Post

Dang those ports look impressive! Much nicer than the PVC I plan to use, but hey, no one will notice when I'm done.

Work is really getting in the way of my build time, so I made very little progress again today. Attached are a couple pics of dry fitting the mid enclosure, and verifying the braces are the proper length. You can also see where the XO will sit with respect to the drivers. It's almost time to glue and screw the first cabinet!

The last pic is what I will use to hang these bad boys. I'll start with 2, and go up to 3 per speaker if needed. You can pick them up at Ace Hardware, or almost any home improvement store. A set of 2 was ~$3.50. These exact hangers have held my Paradigm ADP100s on the wall for many years.

Hopefully I will have more tomorrow...

Looks great Ed!

Those hangars you are using are going to be fixed so you can't move them around.
Do you not need the abitity to angle or rotate them.
I know of a great HD speaker hangar that I have used.
Let me know if you want the link.
post #39 of 164
Thread Starter 
Nice job Ed. The Precision Ports were on sale. That made my mind up for me.

I would like to see the mounts you are thinking of kingpin, if you would post the link.
post #40 of 164
Here you go.
http://www.htd.com/speaker-cables-ac...-Duty-Brackets


post #41 of 164
Thread Starter 
Those are nice! Going to keep that link handy. TY
post #42 of 164
Those look nice.
Another alternative is tilt/swivel LCD mount from monoprice, rated upto 60lbs.
http://www.monoprice.com/products/product.asp?p_id=4564
post #43 of 164
Well, I measured the mid enclosure volume after dry fit yesterday and I screwed something up. It was only 0.8 liters with the cover on. No biggie, I'll just cut the 3 sides a little taller and I am good. I thought it looked a little small. This is exactly why I dry fit everything first...

Port length 4.5". Erich, I assume this is the length the port extended inside the box, not the total length including cabinet thickness (which would be 5.25"). Can you confirm?

The speaker mounts look awesome, but I need to mount mine dead flat against the wall due to space restrictions (thus the 9.5" height I am building). The drop ceiling is only 7.5" in my basement. I will post pics when I get them finished.
post #44 of 164
Got everything cut for the first two of the the four surrounds today. Still have to route the baffles and the crossover cutout and I'm good to go for testing and finishing. No pics yet because it's just a 19x14x9.5 box and not that interesting. I'll post some pics when the drivers go in and more after finishing.
post #45 of 164
Thread Starter 
Made some progress today in spite of my f'n foot. Went to Home Depot and bought a new blade. The old one was a 60 tooth and had burned up after lending it to a neighbor to finish his hardwood floors. I forgot how awesome a new blade is.

Here are the mid chamber cuts:



Here are the bottom, top, and back:



The sides are cut, less the angles, and I will get pics of them as I progress.. I hope to get that accomplished tonight.
post #46 of 164
Ah, what straight cuts you make. Lookin' good! I hope to finish assembling and give these a listen this weekend. It looks like we are all on pace to do the same...
post #47 of 164
Quote:
Originally Posted by Ed H View Post


Port length 4.5". Erich, I assume this is the length the port extended inside the box, not the total length including cabinet thickness (which would be 5.25"). Can you confirm?



The length is 4.5". That's the entire port length whether you measure cabinet thickness or not.

The port flare I removed from the enclosures was part of the cardboard tube glued inside the cabinet. The flare wasn't glued in, so I could easily remove it.

When you make your port, it should be 1 piece and 4.5" from the bottom to the top of the flange I sent. The thickness of your cabinet shouldn't change that. Hope that helps.
post #48 of 164
1st one built. Now, got to complete the 2nd and get them finished. Numbers 3 and 4 to come later.
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post #49 of 164
Thread Starter 
TY Ed, the new blade made all the difference. Just got home from work and remembered I took an early mock up pic, again less the angles:



The angle is pretty aggressive on purpose. I will move the bottom or top out if it is too much. Listening will be the determining factor there. Hope to get these glued tonight. You know how that goes though.

Eddie, nice job! Do you plan on finishing them or leaving them bare?
post #50 of 164
I plan on finishing them the same way I did my curved SLA center. Dark walnut stain on top of the oak, then high gloss poly.
post #51 of 164
What a day. I found time to finish the first two cabinets!!

These will be the side surrounds. I plan to start the rear surrounds (different cabinet design) very soon.

FWIW, I used a permanently flexible rope caulk to help seal the drivers to the front of the cabinet. It's hard to believe JBL mounted these without a gasket of any kind. I used the same caulk to seal the mid enclosure wire access hole, both inside and out. It worked very well. almost considered using it to seal the rear panel should I want to go back in again. But changed my mind. and sealed it tight as a drum.

I'll post 'rough finished' pics in a bit..
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post #52 of 164
Here we go.

They turned out very well. I was concerned with the 9.5 inch height at first, but after giving them a listen? WOW! I played these as mains for a few tunes and they certainly handle power. They play very loud and crisp. As stated in another post, they would probably benefit from a speaker cover to knock down the highs just a touch, but otherwise they are awesome.

I was very impressed. I hate to say it, but it might be time to upgrade my Paradigm 9seMK3's These sounded very good as mains....

Tomorrow (hopefully) I will get them hung and give them a listen as surrounds. I can only imagine..
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post #53 of 164
lots of us are lurking...thanks for sharing and keep it going.
post #54 of 164
Very nice, Ed!
post #55 of 164
Thread Starter 
Very nice Ed. You are making me wish I just did square boxes, lol.

I got the mid chambers assembled and glued yesterday. I make sure to do a little bit every day.

post #56 of 164
Nice work guys!
Filtor...don't forget a hole in those boxes for your hook-up wires.
post #57 of 164
I feel like a dummy. I just re-checked my (homemade) box volume calculator in Excel, and I only subtracted the thickness of the board ONCE from each dimension (H, W, D). It should be twice.....

As a result, my enclosures are only 0.9ft3. They sound great though! I'll post a couple more pics later. I will not be as space-constrained with the rear surrounds, so they will get the correct enclosure volume.
post #58 of 164
The before (Paradigm ADP100) and the after. These sound really good as surrounds. Heck, they sounded really good as mains!

Audyssey crossed them at 80Hz (and down a few dB), so the somewhat small enclosure isn't going to hurt too bad.

Time to start planning the rears.
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post #59 of 164
Quote:
Originally Posted by Ed H View Post

I feel like a dummy. I just re-checked my (homemade) box volume calculator in Excel, and I only subtracted the thickness of the board ONCE from each dimension (H, W, D). It should be twice.....

As a result, my enclosures are only 0.9ft3. They sound great though! I'll post a couple more pics later. I will not be as space-constrained with the rear surrounds, so they will get the correct enclosure volume.

I wouldn't be too worried about the bit you're off, the chance of you noticing are slim to none. Plus, my method for getting the internal volume wasn't exactly rocket science. I just used those tiny round foam pellets and poured them into a measuring bucket. I could have been off a little myself. Anything around 1 cu ft should be just fine I'd think. Let Mother Nature sort out the rest!

I never went back to get a REALLY accurate measurement using plastic pellets because you guys had already started building right away. I was close initially though.
post #60 of 164
Got the mid chambers cut and glued up and baffle for number 2 routed. Should have pics of the first finished pair soon. I'm using 3/4 oak veneered ply. Since there are some places where edges show, what I'm going to do on these and go back and finish on my SLA center is to put some solid oak pieces around the outside edges of the two sides and the top and bottom to kind of go for a "craftsman" style furniture look. Don't know how it will turn out, but I think it will look pretty good.
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