Next semester I will be building my school a pretty large sound system for our football field and I thought I might as well document it here. I have another thread about this here but that was more for design
Although I will not actually start building until summer is over I've already planned the whole thing and started the ball rolling. I've got a little time so I might as well give a bit of background.
My school tends to go through sound systems, we have destroyed two since I was a freshman, I attribute this to not spending enough for adequate hardware and then putting high schoolers in charge of it who want to play it louder than it was built for.
I have been given a $5500 budget to build a system, and by my initial estimates I will be able to build a system to rival much more expensive systems, in the range of $15000.
The plan is this:
4 Bill Fitz DR250
4 http://www.diyaudio.com/forums/subwoofers/178029-c-e-x-pa-flat-30-ft30-pa-th-awesomeness-69.html Bass horns
A bunch of Crown XLS 1000 DriveCore Series Power Amplifier Flexible for Any Pro Audio Amplification Need 245-500
One of dbx DriveRack PA+ Complete Loudspeaker Management System 246-171 to work everything
A few power conditioners, maybe a limiter, some other small stuff...
Some sort of control board, haven't decided which one yet
I am going with the BFM tops mainly because I am unfamiliar with that sort of design where directionality is a concern etc. I ordered and received the plans today, so I will go through all of that and see whats crackin. I am planning on not building the crossover as that will add unneeded cost when I am already buying the driverack, also it's simpler.
The subs I am more familiar with so I'm okay with doing some more improvising, designing, and using a relatively untested design (I think 2 or so have been made).
I need to go through and see where I can save a bit of money because my original budget came out to almost exactly $5000, and that didn't include the wires or the control board. I think I can handle that though because I got an excellent quote on baltic birch ($67/ 4x8 sheet) which is less than I budgeted, and also I am using the $300 18TBX100, which I might be able to replace with a slightly cheaper model. Also I am hoping to work with parts express to get reduced pricing for the large order considering its for a school, but thats not a guarantee.
I calculate that going pretty much full tilt the system should be able to average between 135 and 140 dB at 1 meter all the way down to 35 or so Hz. That's plenty powerful for my school, and the design is such that half the system will be able to be easily used for smaller venues, such as gym dances. One of my main concerns will be just making sure that the ASB is able to set it up and use the system correctly without wrecking anything.
I will have two periods free (either 4 hours every other day or 2 hours a day) to work on this system, for a semester. Sadly it will not be ready for the end of our football season, which is its primary intended purpose. It's main debut will be at my graduation, which is somewhat poetic
This is going to a pretty awesome thing for me to put on my resume, also it will be helpful for future sales, having such a large system under my belt. People are often skeptical of buying speakers from me because I am 17 but they generally change their minds when they hear the things I've made, so it will be great marketing to the DJ crowd I know.
Over the summer I will be putting the finishing touches on my design and then I will start posting build pictures basically as soon as school starts again.
Questions, comments, concerns welcome
Although I will not actually start building until summer is over I've already planned the whole thing and started the ball rolling. I've got a little time so I might as well give a bit of background.
My school tends to go through sound systems, we have destroyed two since I was a freshman, I attribute this to not spending enough for adequate hardware and then putting high schoolers in charge of it who want to play it louder than it was built for.
I have been given a $5500 budget to build a system, and by my initial estimates I will be able to build a system to rival much more expensive systems, in the range of $15000.
The plan is this:
4 Bill Fitz DR250
4 http://www.diyaudio.com/forums/subwoofers/178029-c-e-x-pa-flat-30-ft30-pa-th-awesomeness-69.html Bass horns
A bunch of Crown XLS 1000 DriveCore Series Power Amplifier Flexible for Any Pro Audio Amplification Need 245-500
One of dbx DriveRack PA+ Complete Loudspeaker Management System 246-171 to work everything
A few power conditioners, maybe a limiter, some other small stuff...
Some sort of control board, haven't decided which one yet
I am going with the BFM tops mainly because I am unfamiliar with that sort of design where directionality is a concern etc. I ordered and received the plans today, so I will go through all of that and see whats crackin. I am planning on not building the crossover as that will add unneeded cost when I am already buying the driverack, also it's simpler.
The subs I am more familiar with so I'm okay with doing some more improvising, designing, and using a relatively untested design (I think 2 or so have been made).
I need to go through and see where I can save a bit of money because my original budget came out to almost exactly $5000, and that didn't include the wires or the control board. I think I can handle that though because I got an excellent quote on baltic birch ($67/ 4x8 sheet) which is less than I budgeted, and also I am using the $300 18TBX100, which I might be able to replace with a slightly cheaper model. Also I am hoping to work with parts express to get reduced pricing for the large order considering its for a school, but thats not a guarantee.
I calculate that going pretty much full tilt the system should be able to average between 135 and 140 dB at 1 meter all the way down to 35 or so Hz. That's plenty powerful for my school, and the design is such that half the system will be able to be easily used for smaller venues, such as gym dances. One of my main concerns will be just making sure that the ASB is able to set it up and use the system correctly without wrecking anything.
I will have two periods free (either 4 hours every other day or 2 hours a day) to work on this system, for a semester. Sadly it will not be ready for the end of our football season, which is its primary intended purpose. It's main debut will be at my graduation, which is somewhat poetic
This is going to a pretty awesome thing for me to put on my resume, also it will be helpful for future sales, having such a large system under my belt. People are often skeptical of buying speakers from me because I am 17 but they generally change their minds when they hear the things I've made, so it will be great marketing to the DJ crowd I know.Over the summer I will be putting the finishing touches on my design and then I will start posting build pictures basically as soon as school starts again.
Questions, comments, concerns welcome
The driverack has a built in compressor/limiter that I can use to limit signal level, that won't prevent people from turning up the amps but they would have to individually turn every one up and then retune the system to match levels. I'm not giving them the ability to turn at least the subs all the way up, the amps will only give them around 300 watts each with a rated RMS of 1000w. That should at least protect the drivers, not so much peoples hearing though as that will still give over 135dB... At least if people hot swap plugs or accidentally turn it on with the volume all the way up the speakers won't go.
I just thought it would be handy to have power distribution consolidated so I don't have power wires everywhere, and it would provide one more line of defense agains surges. Our power mains are generally pretty good though.
I suppose I could use just fused power strips instead, what do you think?
Whats wrong with the crowns? I'm under the impression that those are excellent amplifiers.
In regards to the drivers getting fried by something wrong with the amps I am setting the system up to minimize this. The main thing I could see happening would be the Crown amp for the 10" midranges being plugged into the compression horns and killing them. I am designing the wiring scheme such that that would be basically impossible without going and getting several adapters first.
Another thing that could happen I guess would be the XO point on the drive rack being set way too low, but I can just not do that, and once I'm done setting up that part of the system its going to be locked up pretty tight
Also even if the crowns were for whatever reason to fail fully on the subs at least could handle it
Alright ladies and gentlemen, it's almost that time.
School is back in session, and my purchase orders finally went through. I am expecting 400lbs of gear from Parts Express friday, and about that much lumber from the local hardwood store in about an hour.
I will post pictures of the supplies as they arrive, but for now, a few of my toys.
The table saw I get to use is a StopSaw, so there's little worry about getting killed or anything. One of my favorite things about it is that it has measurements in mm and in for the gate, which will be awesome for my metric cut sheets. It's going to be a dream to use, except that my engineering teacher insists that she be there whenever I am using it. Considering that I have been using a saw since middle school, and its the safest saw in the world, that's pretty annoying.
The other toys I should be able to use on my own. We have a couple of scroll saws, some sanders, drill press, chop saw, and a bunch of handheld tools. There is also a CNC but it's out of commission I will also be bringing in my own pneumatic brad nailer to hold everything together until the glue dries.
I should start making saw dust very soon, hopefully this week. I have my work cut out for me
School is back in session, and my purchase orders finally went through. I am expecting 400lbs of gear from Parts Express friday, and about that much lumber from the local hardwood store in about an hour.
I will post pictures of the supplies as they arrive, but for now, a few of my toys.
The table saw I get to use is a StopSaw, so there's little worry about getting killed or anything. One of my favorite things about it is that it has measurements in mm and in for the gate, which will be awesome for my metric cut sheets. It's going to be a dream to use, except that my engineering teacher insists that she be there whenever I am using it. Considering that I have been using a saw since middle school, and its the safest saw in the world, that's pretty annoying.
The other toys I should be able to use on my own. We have a couple of scroll saws, some sanders, drill press, chop saw, and a bunch of handheld tools. There is also a CNC but it's out of commission
I will also be bringing in my own pneumatic brad nailer to hold everything together until the glue dries. I should start making saw dust very soon, hopefully this week. I have my work cut out for me
Attachments
I have a friend who has a friend...
But seriously, this guy has been hired to do sound for some really big name acts, and he attributes much of his commercial success to his use of power conditioners. Yes, the US grid is less than wonderful. But more importantly, enforcement of noise suppression on equipment is extremely lax. In a football stadium, I can see all sorts of things being plugged in that would create noise, from popcorn machines and drink coolers to computers and radio/video transmitters.
Update
So it's about time for an update...
I've decided to start with the subwoofers because they will be able to go into action during this football season (the system they're using until mine is ready is REALLY inadequate).
I started with just one of the four TH18s, I wanted to make sure there was nothing wrong with the cutlist and figure out all the tricks before going in whole hog. Once this one is making some noise I will cut the other three and build them simultaneously to boost my efficiency a bit.
So far it's going pretty well, I cut two boards wrong but it was not because of a cut sheet issue, and they were pretty small pieces so I'm fine on supplies.
I got all of the stuff over the last week, there were a few things that got back ordered but none of it is mission critical, and one of the rack cases never made it to the fedex truck, they have since reshipped it though.
Hopefully I will be making some bass my next week, all thats left on the one is cabinet hardware, putting the other side on, and painting.
So it's about time for an update...
I've decided to start with the subwoofers because they will be able to go into action during this football season (the system they're using until mine is ready is REALLY inadequate).
I started with just one of the four TH18s, I wanted to make sure there was nothing wrong with the cutlist and figure out all the tricks before going in whole hog. Once this one is making some noise I will cut the other three and build them simultaneously to boost my efficiency a bit.
So far it's going pretty well, I cut two boards wrong but it was not because of a cut sheet issue, and they were pretty small pieces so I'm fine on supplies.
I got all of the stuff over the last week, there were a few things that got back ordered but none of it is mission critical, and one of the rack cases never made it to the fedex truck, they have since reshipped it though.
Hopefully I will be making some bass my next week, all thats left on the one is cabinet hardware, putting the other side on, and painting.
Attachments
Building the BFM DR250. remember to use compression drivers. The version with piezo sounds like crap... unfortunately, since i build that. had to convert it afterwards.
best of luck with the project
There's 8 asd1001s in those boxes
Ive heard piezos before too
Are the dr250s as hard to build as they look?
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A few more pictures...
One sub is done (except for paint), and I cut all the wood for the remaining wood. I started with one so that in case there were cut sheet issues I wouldn't ruin a couple hundred dollars worth of wood. Now that the prototype was a total success its move-ahead time.
Hopefully those three will be done within two weeks, and I can get onto the testing
All the electronics are here now. So far I haven't had any major issues with the products I ordered, I forgot a couple of wires, but nothing mission critical. I am very happy that I received the Pyle power conditioners that were backordered. They have a TERRIBLE backorder history and I thought it could be up to 4 months before I got them.
I did high level testing inside of the room the sub and all the stuff is pictured in. That was GOOD fun. Everything was shaking, the windows were visibly flexing, with the doors open even. That room is pretty large, but the sub is designed for a space even larger If I had to guess (spl meter batteries died) I was hitting 125dB with music, without a high pass filter, and still not pushing the cones to xmax.
The finished sub is going to work next friday at out home coming football game. It is supplementing the rental system we are bring in. Next season when I am all done we won't have to rent
One sub is done (except for paint), and I cut all the wood for the remaining wood. I started with one so that in case there were cut sheet issues I wouldn't ruin a couple hundred dollars worth of wood. Now that the prototype was a total success its move-ahead time.
Hopefully those three will be done within two weeks, and I can get onto the testing
All the electronics are here now. So far I haven't had any major issues with the products I ordered, I forgot a couple of wires, but nothing mission critical. I am very happy that I received the Pyle power conditioners that were backordered. They have a TERRIBLE backorder history and I thought it could be up to 4 months before I got them.
I did high level testing inside of the room the sub and all the stuff is pictured in. That was GOOD fun. Everything was shaking, the windows were visibly flexing, with the doors open even. That room is pretty large, but the sub is designed for a space even larger
If I had to guess (spl meter batteries died) I was hitting 125dB with music, without a high pass filter, and still not pushing the cones to xmax.The finished sub is going to work next friday at out home coming football game. It is supplementing the rental system we are bring in. Next season when I am all done we won't have to rent
Attachments
I also tested it outdoors so I could just hear it not the room, nothing really bad. There's a little bit at certain frequencies but if your more than a few feet away you can't hear it. I have yet to brace the mouth of the horn, I do plan to add that though, along with a grate, both of which will reduce the cabinet "walking."
When I was inside the room was making quite few "cabinet rattles" though
p.s. I plan to paint everything at once near the end, which is why the sub is moved to it's more long term home in the ASB room (I built it in the engineering room, pictured in a previous post)
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