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As I outlined here, I have been working on a large GRS based 3-way using the 12" poly cone woofer and the sealed back mid.
Keep in mind this project was intended for a specific application, that being a couple holes built into the basement wall of a friends new home. They were adamant on using this location, so I was constrained off the bat by size. The openings are ~26.5"h x 15.5"w x 13.5"d. Consequently, the LSS are sized along those lines. Assuming 3/4" construction with bracing and driver displacement, I am left with approximately 1.9 cubic feet or so.
On the shelf, I had a pair of the GRS 12" woofers, the GRS mids and a pair of Dayton 3/4" front mount neo tweeters. They are all priced at or near the bottom of their respective categories.
The cabinets are really too small for the woofers, but on the other hand - the bump that gives them will be pretty satisfying for their teenaged son and his gaming systems.
On five of the six sides, I used 3/4" plywood. Nothing fancy at all. Butjoints all around, glued and screwed. I did countersink the screw holes though. The baffle is 3/4" MDF with 1/2" roundover on the left and right sides. I have not decided what finish the baffles will have - I still have a roll of the Beech buyout vinyl, I may give that a go again.
Drivers are offset 3/4" to one side, the baffles are mirrored. Stuffed with 2 pounds of poly-fill (yes, this project needs four bags of Wal Mart polyfill!!!).
If this project is to be built for other than it's original intended install (in a wall), keep in mind it is only a couple db of baffle step correction built in. They would be fine corner loaded in a garage (I'll be honest, I was gunning after the Golden Boys with this project;)), as well as in a smaller room like, say a college dorm.
If you have the space, I would build them at least six inches taller and a few inches deeper. It won't hurt nothing, and in fact the bass would be ever so much better.
I tried keeping the crossover as simple as possible, and I feel I have hit a reasonable compromise by using only eight components in the entire network. This yielded a decent on axis response, and it varies very little out to 30 degrees off axis. The compromise was less than stellar vertical off axis response, although closer driver spacing would address some of that. Just aim the tweeters anywhere as long as they stay at or about ear height and you will be fine, if that is your thing. Note the reverse phase on the midrange. You can try it in either polarity, the wife and I both prefer the reverse polarity quite a bit. YMMV. Crossover points are ~600 and ~4000.
The impedance should not present any problems to most amplifiers.
(Le Singe Sarcophage is French for "Monkey Coffins" if you were wondering)
Frequency Response:
Impedance:
Crossover:
I would provide build prints for this, but I fully expect people to take some liberties with the dimensions. Just don't change the baffle width much, and keep the driver orientation as-is and it can be made taller or deeper all day.
Upgrades: none really. The drivers cost about as much as the crossover components, so I don't see too much upgrading at this point.
I'll add more information later, but right now I am kind of tired and Metallica is even drifting me off to sleep.
Keep in mind this project was intended for a specific application, that being a couple holes built into the basement wall of a friends new home. They were adamant on using this location, so I was constrained off the bat by size. The openings are ~26.5"h x 15.5"w x 13.5"d. Consequently, the LSS are sized along those lines. Assuming 3/4" construction with bracing and driver displacement, I am left with approximately 1.9 cubic feet or so.
On the shelf, I had a pair of the GRS 12" woofers, the GRS mids and a pair of Dayton 3/4" front mount neo tweeters. They are all priced at or near the bottom of their respective categories.
The cabinets are really too small for the woofers, but on the other hand - the bump that gives them will be pretty satisfying for their teenaged son and his gaming systems.
On five of the six sides, I used 3/4" plywood. Nothing fancy at all. Butjoints all around, glued and screwed. I did countersink the screw holes though. The baffle is 3/4" MDF with 1/2" roundover on the left and right sides. I have not decided what finish the baffles will have - I still have a roll of the Beech buyout vinyl, I may give that a go again.
Drivers are offset 3/4" to one side, the baffles are mirrored. Stuffed with 2 pounds of poly-fill (yes, this project needs four bags of Wal Mart polyfill!!!).
If this project is to be built for other than it's original intended install (in a wall), keep in mind it is only a couple db of baffle step correction built in. They would be fine corner loaded in a garage (I'll be honest, I was gunning after the Golden Boys with this project;)), as well as in a smaller room like, say a college dorm.
If you have the space, I would build them at least six inches taller and a few inches deeper. It won't hurt nothing, and in fact the bass would be ever so much better.
I tried keeping the crossover as simple as possible, and I feel I have hit a reasonable compromise by using only eight components in the entire network. This yielded a decent on axis response, and it varies very little out to 30 degrees off axis. The compromise was less than stellar vertical off axis response, although closer driver spacing would address some of that. Just aim the tweeters anywhere as long as they stay at or about ear height and you will be fine, if that is your thing. Note the reverse phase on the midrange. You can try it in either polarity, the wife and I both prefer the reverse polarity quite a bit. YMMV. Crossover points are ~600 and ~4000.
The impedance should not present any problems to most amplifiers.
(Le Singe Sarcophage is French for "Monkey Coffins" if you were wondering)
Frequency Response:
Impedance:
Crossover:
I would provide build prints for this, but I fully expect people to take some liberties with the dimensions. Just don't change the baffle width much, and keep the driver orientation as-is and it can be made taller or deeper all day.
Upgrades: none really. The drivers cost about as much as the crossover components, so I don't see too much upgrading at this point.
I'll add more information later, but right now I am kind of tired and Metallica is even drifting me off to sleep.
) project.
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