Hi Folks,
I've been lurking here for a couple of months now and I guess it's time to start my first post. I have a dedicated theater room which is 14'x21'x8.5' that I built back in November 2003 and currently I have a pair of Definitive Technology BP-2002s behind my perforated 10.5' wide 2.35:1 screen. The BP's have a 12" sub built into them powered by a 125 or 150 watt plate amp. During most movies, the bass seems adequate but during some movies, presumably movies with notable LFE, I can hear the subs distort. I was watching Alien 3 the other day and at the very beginning of the movie, a spaceship pans across the screen and it was the first time I actually tried to lower the volume of the movie. Naturally, my wife or friends don't even notice the problem, but I have been noticing it more and more. I don't have REW setup yet and haven't used my newly aquired SPL meter from Sonnie to check FR and SPLs but I do intend to do that before switching over to the new subs. I'm sure the BP's don't go down as far as I thought they did when I first got them.:hissyfit:
I was considering a dual RL-p15 project but I have been waiting for the RL-p18's and I snagged two at Mike's introductory offer. I figured if one was good, two had to be better. :bigsmile: I received the drivers Thursday and I must say, they are absolutely huge! You can measure 18" with a ruler and try to estimate their size but until you have them sitting in front of you, you just can't imagine how big these things are! Getting the drivers and picking up the 6 pieces of MDF today made me realize that maybe one RL-p18 would have been enough but I am going to press on.:coocoo:
I would have went with an IB, but I don't like the idea of attaching the drivers directly to the structure of the house. I have 1400lbs of sand in my stage area and thought a LLT would be better in my situation. I think the bass traveling through my attic and into the rest of the house would freak my wife out even more than the two large boxes.:scared: At least she will only see the boxes during construction...
I don't have any pix yet but I will try to get some uploaded here as I make a little more progress. I am making two MDF boxes that will each have an internal area of 64.5"x37.5"x16". Each box will have one driver and one port. When I built the theater, I had never heard of LLT subs so I didn't leave gobs of space behind the screen so that is why I only have 16" or so of internal depth for these boxes. If I calculated correctly after bracing and the 8" port I should come in around 550L. I really wanted to go with 650L per box but that would have forced me to move my speakers up too high. Maybe I won't loose as much volume as I calculated...
If anyone can tell me how much volume the RL-p18 is going to take away from my internal volume, I would appreciate it. I will not be countersinking the drivers as I don't care what these boxes look like as they will be totally hidden behind the screen. Also, I am going to use 5/8" closed cell foam to line the inside of the box. Do I subtract the foam volume when calculating effective area? Lastly, should I line the port as well?
-Tom A.
I've been lurking here for a couple of months now and I guess it's time to start my first post. I have a dedicated theater room which is 14'x21'x8.5' that I built back in November 2003 and currently I have a pair of Definitive Technology BP-2002s behind my perforated 10.5' wide 2.35:1 screen. The BP's have a 12" sub built into them powered by a 125 or 150 watt plate amp. During most movies, the bass seems adequate but during some movies, presumably movies with notable LFE, I can hear the subs distort. I was watching Alien 3 the other day and at the very beginning of the movie, a spaceship pans across the screen and it was the first time I actually tried to lower the volume of the movie. Naturally, my wife or friends don't even notice the problem, but I have been noticing it more and more. I don't have REW setup yet and haven't used my newly aquired SPL meter from Sonnie to check FR and SPLs but I do intend to do that before switching over to the new subs. I'm sure the BP's don't go down as far as I thought they did when I first got them.:hissyfit:
I was considering a dual RL-p15 project but I have been waiting for the RL-p18's and I snagged two at Mike's introductory offer. I figured if one was good, two had to be better. :bigsmile: I received the drivers Thursday and I must say, they are absolutely huge! You can measure 18" with a ruler and try to estimate their size but until you have them sitting in front of you, you just can't imagine how big these things are! Getting the drivers and picking up the 6 pieces of MDF today made me realize that maybe one RL-p18 would have been enough but I am going to press on.:coocoo:
I would have went with an IB, but I don't like the idea of attaching the drivers directly to the structure of the house. I have 1400lbs of sand in my stage area and thought a LLT would be better in my situation. I think the bass traveling through my attic and into the rest of the house would freak my wife out even more than the two large boxes.:scared: At least she will only see the boxes during construction...
I don't have any pix yet but I will try to get some uploaded here as I make a little more progress. I am making two MDF boxes that will each have an internal area of 64.5"x37.5"x16". Each box will have one driver and one port. When I built the theater, I had never heard of LLT subs so I didn't leave gobs of space behind the screen so that is why I only have 16" or so of internal depth for these boxes. If I calculated correctly after bracing and the 8" port I should come in around 550L. I really wanted to go with 650L per box but that would have forced me to move my speakers up too high. Maybe I won't loose as much volume as I calculated...
If anyone can tell me how much volume the RL-p18 is going to take away from my internal volume, I would appreciate it. I will not be countersinking the drivers as I don't care what these boxes look like as they will be totally hidden behind the screen. Also, I am going to use 5/8" closed cell foam to line the inside of the box. Do I subtract the foam volume when calculating effective area? Lastly, should I line the port as well?
-Tom A.