Holly crap!... I may need to look at bridged-mono for the JRX125s as well!... It's a good thing these amps only cost $278.00!... I know, I know,...you get what you pay for..
Here's a possible dilema: In the bridged-mono mode...the EP2500 jumps from 1300 watts @ 8 ohms to 2400 watts @ 4 ohms... Is this to much available power for the JRX115s and 125s?.. Can one create problems by under working the amp?.. And yet...another twist: I can get the EP2500 at the same price or even cheaper than the EP1500... The EP1500 is rated at 1400 watts @ 4 ohms in the bridged mode; which better matches Crown's formula for the loads,...and the EP2500's bridged output power available to the 8 ohm subs...
Gadget, Is this a legitimate concern in the first place?...and if so, can I \"over power\" the speakers or \"under work\" the amp...or both?.. If I need to go bridged-mono for the 115s and 125s (based on the 800 watts to 1250 watts that Crown's formula calls for) does it matter if 2400 watts vs 1400 watts are available?...
Thanks!
Kevin
PS. I will have my DR260 tomorrow evening!... Yaahooo!!!...
Good to hear from you. I hope your project is going well.
Yes, the amps are multiplying like rabbits. : )
Here are my calculations. All amps are bridged 2500s:
Amp 1 - Left channel 2 X 115i's (4 ohm load)
Amp 2 - Right channel 2 X 115i's
Amp 3 - Left channel 125 (4 ohm load)
Amp 4 - Right channel 125
Amp 5 - Left VRS18 (8 ohm load)
Amp 6 - Right VRS18
I don't know what the 4 ohm load power rating is for these amps in bridged mode, but you will have plenty of headroom on the 115i's.
I'm wondering what the 125's will be like because they have that second 15 set to a lower band.
How are you fixed for AC power circuits at the amp rack?
I'm just doing some calculations and find that if you ran this system at RMS power ratings of the cabinets, you would draw about 27 amps total.
Given that I'd say you may want to divide your amps across three separate twenty amp AC circuits if possible.
When you power up amplifiers, there is a fair amount of in-rush current so you don't want to power them on all at the same time. You want to sequence them on with a short delay in between each power up.
How are you fixed for AC power circuits at the amp rack?
I'm just doing some calculations and find that if you ran this system at RMS power ratings of the cabinets, you would draw about 27 amps total.
Given that I'd say you may want to divide your amps across three separate twenty amp AC circuits if possible.
Wolfgong,
Gotcha covered... Fortunate for me I told the electrician that I wanted three dedicated quad-plex 20 amp circuits for the sound booth...and that's where the amp rack will be located along with the DriveRack, mixer, etc., etc...
You probably know this already, too, but when you install the amps leave space between each set of amps for ventilation and heat dissipation.
Wolfgong,
The back and the sides of the amp rack are totally open and there is about 2" of free space between each amp... I hope this will do the trick?..
I'm interested I what Gadget's thoughts are in regards to Crown's calculation and wether or not the EP2500 is to big (2400 watts) in bridged-mono mode for the JRX's... David with Crown mentioned this in his post:
It's better to have an amplifier that is larger rather than smaller-but then again not to big.
Wolfgong,
The amp power-up sequence you wrote makes very good sence!... I have also read that your amps should be the last thing to power-up (5 sec. after DR and mixer) and the first thing to power down... I have also read some hear-say about the DRPA giving amps nasty spikes because the DR's were shutdown pre-maturely or by accident... I recently noticed a DRPA for sale on eBay and the seller had hardwired the power cord directly to inside the unit...so the power plug couldn't be accidently pulled-out...
Loaned my Driverack to my buddy since he was interested in buying one. During his band's gig a drunk accidentally stepped on their PA main power cord and yanked it out of the wall socket. Goodbye power and goodbye speakers. Nice BIG power spike from the Driverack killed his speakers.
Burned my speakers during power down. Be careful since it causes big spikes when turning off the unit. Caused my tweeters to blow up. Big design problem.
Setup is easy, though I would recommend buying a power conditioner to protect your amps and speakers as the Driverack creates power surges. You will love the Driverack for your system!
Wolfgong,
Once again,... I thank you so very much for your advice and help!...
Regarding the amps, it does seem that given the calculated power needed you might be better suited with the EP1500's for the 115i's and 125s.
With the ep1500 bridged at 4 ohms you would get about 1500w, but with the ep 2500 you end up with about 2500w, which I think would be less forgiving if someone dropped a mic or something like that. I think you could also cook your coils pretty 'well done' if you drove your system pretty hard for a while.
The ep2500 work well with the EAW's because they are rated 500w at 8 ohms and the power rating comes out about right at 1500.
Not sure where I read it but...
It is actually better to have the amps (assuming that they all have the same air flow path, front to back, etc) directly on top of each other and any empty rack spaces covered. Air flow thru the amp is the key. Any amps with a different path should be in a different rack as to not draw in hot exhaust.
Although definately not good, a quality speaker will survive the turn off spike (usually). A low rated (wattage) speaker on a high wattage amp would be toast. Get a $30-$40 UPS at a computer store. It is the ONLY thing that will protect againt an electrical failure. Some people open the case and bypass the power switch to prevent an assistant sound tech from helping you power down in the wrong order.
Get a $30-$40 UPS at a computer store. It is the ONLY thing that will protect againt an electrical failure.
Hello Dra,
Could you please be more specific?.. Just making sure here: are you refering to a "uninterruptible power supply" or a decent "surge protector"?.. Most UPS incorporate both battery back-up and surge protection... Do you recommend putting the DriveRack on a UPS,...each amp on a UPS,...or both? I'm assuming it would be OK to put two amps that work together (like two bridged amps of a left and right channel) on the same UPS...if it's sized properly?
Also,...did I get the following sequence correct? I have been bouncing around the web so much lately I can't remember where I got this information (it's a seventies thing)...and if I got it right:
It is actually better to have the amps (assuming that they all have the same air flow path, front to back, etc) directly on top of each other and any empty rack spaces covered. Air flow thru the amp is the key. Any amps with a different path should be in a different rack as to not draw in hot exhaust.
Yes, just the DRPA on a UPS. You could put all your proccessing gear on it if you wish. If you have a electrical power failure, the amp's massive capacitors will be able to provide power to the outputs for several seconds (including the pop / transient spike from the DRPA or other equipment). The UPS will give you quite a few minutes to get to your amps and power them down. UPS's for amps is not practical. Large capacity UPS = large capacity bank account.
Yes, in a turn on / turn off time line, amps meet in the middle.
ON - Once proccessing is on, amps can be powered up (no additional wait is needed).
OFF - Once amps are off I like to wait at least 10 secs or more to be extra safe. Then proccessing.
Yes, just the DRPA on a UPS. You could put all your proccessing gear on it if you wish. If you have a electrical power failure, the amp's massive capacitors will be able to provide power to the outputs for several seconds (including the pop / transient spike from the DRPA or other equipment). The UPS will give you quite a few minutes to get to your amps and power them down. UPS's for amps is not practical. Large capacity UPS = large capacity bank account.
Hello Dra,
Thank you for your advice!... One thing I don't have is...large capacity bank account!... However,...I do have a couple decent UPSs left over from a "company project"... I own a control systems integration company...we do robotics, networking, PLC and PC based industrial control systems... Needless to say...this is a whole new learning experience, and a very challenging project for me!... I've been trying my best to absorb every little bit of info and advice,...and to process it, and apply it to this project...
Hi fellas... looks like you've been busy in my absence...
Ok first off he is getting a 260, not a DRPA.. Yes, I have recommended hard wiring if the DR's cord is accessible, I have bypassed the power switch internally, and again yes get a cheap universal power supply and the thump is NOT an issue...but still not germain to this issue at hand.
Second... \"TOO much power is NEVER enough!\" chuckle...Kinda like your joking about the eardrum vs speaker thing but true none the less. Crown actually say 2 to 4 times the rated power of the speakers... Yes I know it sounds like a lot of power but power isn't what blows speakers... it's LACK of power that does. You can blow a 2000 watt speaker with a 100 watt amp easily...Yes you can over drive the speakers but just because you have 245 horsepower in your lexas and it will do 140 MPH doesn't mean your going to do it all the time does it? The speakers will emit a popping sound if overdriven and just so you have a visual, the sound is made when the voice coil bottoms out on the back plate of the speaker magnet structure. The gain structure/balance set should determine the amp input attenuator settings...those controls will allow you to limit those horses...so to speak. I recommend since this is the youth side that once the system is set that the 260 be locked against prying fingers..(it has varying levels of security.. just don't forget your passwords...) and that the amps be marked for attenuator position and locked up as well.
As for the amps a good MOV (lightning arrestor, available at most hardware stores..)installed on the amp feeder is all I use...the UPS is not necessary for the amps.
I believe that having airspace on the amps is not critical, but these are heavy amps, if you do space them don't hang them by their front rack mounts alone.
Amps always last thing on first thing off.. this will allow any transients that could cause a pop or thump to dissipate prior to the amps turn on/FOH component turn off.
I have been following this thread, but with it's massive length I forgot where I was. KP brought up the quote about the speaker killing pop and that sent me into another time zone.
Sorry,
DRA
PS - Gadget, I laughed my head off at your response to the guy \"just bristling with information\". You must be in a jovial mood.
The gain structure/balance set should determine the amp input attenuator settings...those controls will allow you to limit those horses...so to speak.
Gadget,
I've been studying-up on gain structure but I'm waiting for later to address it... For right now I'm trying to stay focused on the basics...but please don't kick me down to the basement...
I recommend since this is the youth side that once the system is set that the 260 be locked against prying fingers..(it has varying levels of security.. just don't forget your passwords...) and that the amps be marked for attenuator position and locked up as well.
I believe that having airspace on the amps is not critical, but these are heavy amps, if you do space them don't hang them by their front rack mounts alone.
Gadget,
Eventually I was going to ask for the best way to apply one over-all password that locks-out all of the DR features?.. I am using an old decent networking rack... I have installed clear lexan doors with pad locks on the front,..and I placed shelves in every position to support the weight... The back side of the lexan is about 4" from the face of the amps and the shelves created about a 2" space between each position... This rack is fully opened on the back and again about half way back on the sides...
As for the amps a good MOV (lightning arrestor, available at most hardware stores..)installed on the amp feeder is all I use...the UPS is not necessary for the amps.
Ahhh...metal oxide varisiter...a good AC inductive load filter and line spike component... We use those on motor starter coils and solenoid valves...
Amps always last thing on first thing off.. this will allow any transients that could cause a pop or thump to dissipate prior to the amps turn on/FOH component turn off.
When I rehang the 115s should I face the mating joint between the speakers straight outward?... I'm thinking that when these slighltly wedged shape cabs are attached together side by side...they will want to toe-out from each other...
Ahhh so...
you listen well my young padawan...hows that for mixing metafores...
Long axis 94 hz and 140 hz are the primary concerns
width 56, 84,113, 140 hz
note that 140 makes both lists and will become a primary mode of concern
254 and and 423 are also typical problematic frequencies.
The higher the frequency the less likely it is to become a problem, and you have finite resources to deal with these. When the house is rockin put a narrow width bell PEQ on, cut about 6 db and sweep around the area of the primary frequencies and see if the negative energies diminish and you get a cleaner sound... those modes will manifest themselves as a kind of DIN or howl or growl sort of effect.
As for the aiming its more critical to keep the sound off the side walls than it is to worry about making sure the seam is strait. You will be making a huge difference just by getting them together. As you said join them together tightly and use back cables to aim them. A few screws in the front and a couple cheap plates will bind them just fine. The interaction from left and right will be there in the center but will be far less than the effect of the interaction the speakers would have on the walls. There will be some interaction no matter what but get the at as far back as possible and perhaps have the kids do a project and make some hangings that depict bible scenes or something and hang them on the walls to minimize reflection.
\"A picture's worth a thousand words\"... So here's a few pics!... The speakers will be re-hung tomorrow as you suggested... They are covered and not pulled back right now due to other work-in-progress... I will post some more later this evening that shows more things we have discussed,...but I gotta go for now... My wife is calling herself a \"Church Widow\"...
Note: Images have been removed to make room for pics of the final installation...
Shoot me if you have already discussed or are already doing this or something better, why not have one main center cluster with all cabs fanned above front /center of stage? And while you're at it, fly the subs.
Post somes pics when you're done along with your great sound results.
That would be fine too.. I like to run my effects in stereo and if possible guitars and keys as stereo sources panned so as to not have to do too much stuff sitting on top of itself. helps things jump out of the mix and not get lost.
I like to run my effects in stereo and if possible guitars and keys as stereo sources panned so as to not have to do too much stuff sitting on top of itself. helps things jump out of the mix and not get lost.
Gadget, you said that a lot better than I could of...but what you said is exactly what I'm trying to achieve... I'm hoping to pan some of the vocals and instruments in relationship to the musician's location on the stage... I'm hoping this will provide some realisim... If the musician is on the left side of the stage then I was going to pan their voice and instrument slightly to the left...or vise versa...
Here are some more pictures:
Note: Images have been removed to make room for pics of the final installation...
Well,...there you have it!
Summary: I wanted to keep the installation clean and simple so I decided to use no more than three different types of cables... I bought six channel 22AWG microphone snake cable, 10AWG oxygen free speaker cable, and 13AWG rubber jacket speaker cable (all came from Gepco)... All of the external speaker cables have a male speakon connector on one end and a male 1/4 mono on the other... This keeps the youth from using instrument cables as speaker cables or for stringing monitors... The JRX112M monitors have one female speakon and one female 1/4 jack in parallel... Each floor box will have five microphone inputs, one female speakon (for monitors), and one 120VAC duplex outlet... The amp rack is an old aluminum network rack that was left in the building from WalMart... We modified the rack and added lexan doors... I will need to add two more shelves for two more amps...
Please give me any comments or suggestions you may have?..
Your cabling and terminations are excellent! I love that everything is tagged and easy to follow.
I was an electrician for several years and I never saw anything that neat and easy to follow. Troubleshooting will be a breeze except I don't think you'll have any trouble with routing like I see here.
Geez Kevin.. you should be telling ME how this shit works! WOW thats a thing of beauty... very well thought out, well executed and professionally done.. some of the installers I have seen would do well to take hints from your work!
You will not be able to hang all that weight in that tall rack without support from a boundary... Why is there so much space in the rack? you could easily run 2 amps per shelf...lower the bottom amp to just atop the fan guards and you could have all amps installed and have a lower center of gravity for the rack. put the 260 in the rack with the amps, and run it over a single mic cable..cut and spliced into the null modem cable that comes with the unit. its RS232 and comm port 1. The signal can easily run 250 feet and still have adequate dependability.
Very nice.. very nice indeed.. your going to have such a great system...enjoy!
Thank you so very much for your positive comments!... What you guys wrote really makes me feel good about how this project is coming along!...
Hey Gadget,...look what we did today!... I thank you!...:)
Note: Images have been removed to make room for pics of the final installation...
Summary: All of my deminsions worked-out to odd numbers off the back wall... I know this sounds stupid but,...we also wrapped the speaker cab eye bolts with rubber insulation tape;...maybe it will isolate speaker cab vibration from resonating the chain... Well...at least it sounds technical...
After seeing all the pictures... \"Holy\" crap! Nice!
My only recommendation would that the fly height is all wrong. Anyone knows that to achieve the correct tonal properties, you must rise the cabs by one link. I'll follow-up when you get this corrected.
Serious note. I'd \"wrap\" the chains in a dull black material to limit light reflections that will draw attention away from the stage area.
You will also get the added benefit of coupling of the speakers when they are close like that.. thats an added 3 db...free! BTW the same is true for the subs, put them together.. get 3db..free.. I love free. Ya Dra your a real funnyman...When is the inauguration?
Oh a further thought from a former thread... When you pan instruments hard when the speakers are that far apart those on the opposite side of the room will not hear what is panned to the other side..
Gary
You will not be able to hang all that weight in that tall rack without support from a boundary... Why is there so much space in the rack? you could easily run 2 amps per shelf...lower the bottom amp to just atop the fan guards and you could have all amps installed and have a lower center of gravity for the rack. put the 260 in the rack with the amps, and run it over a single mic cable..cut and spliced into the null modem cable that comes with the unit. its RS232 and comm port 1. The signal can easily run 250 feet and still have adequate dependability.
Hi Gary,
Some very good points!... We are going to use floor wedge anchors to secure the rack... I'm going to use your suggestions of stacking two amps per shelf and keeping most of the weight below the center of gravity... I really like the idea of using a mic cable for RS232!... I'm assuming the DB9 pin-out then...only requires pins 2 to 3, 3 to 2, and shield for pins 5 to 5...
When you pan instruments hard when the speakers are that far apart those on the opposite side of the room will not hear what is panned to the other side..
Another good point!,...and I hope to realize this pretty soon!...:)
You will also get the added benefit of coupling of the speakers when they are close like that.. thats an added 3 db...free! BTW the same is true for the subs, put them together.. get 3db..free..
Like you say,...in this particular case free is a good thing!...
Believe it or not...we had our first service in the youth area last night!... They used a small portable PA system for sound... The speakers were spread about 20' apart...one on each side of the stage,...and mounted high (far above listening level) on tripods that were slightly toed-out...away from the audience... The speakers had two 10" cones in each cab... Actually,...this setup sounded pretty good!... I know the system I'm installing is entirely different, unique,...and will provide it's own set of challenges,...but my concerns of the room's acoustics have some what deminished...for now... The room was filled with chairs, cold bodies (heat wasn't working), and a couple of couches... We are having the stage carpeted this Tuesday and I hope to install floor pockets immediately there after...
Hey Dra, It just occured to me...as to why it sounded so good;...the colder room temperature shifted the audible deflection by ten degrees!...
Quick Update: I received my DR260,...and tonight will flash the firmware to ver. 1.510 if not already at that level... If I execute the update I guess I should do a hard reset just to make sure it takes OK?.. I also purchased two more EP2500s...since it looks like I should bridge-mono all of the outputs...
I'm not a firmware expect (or even a firmware idiot), but if you hard reset after installing the update, would it take it all the way back to the the original factory firmware? Not that is would matter in the long run, other than re-installing the new version again.
Unless the DriveRack is different than any other microprocessor based equipment a hard reset usually resets the unit back to it's original factory defaults... A lot of times it also good to do a hard reset after a firmware update... When you update firmware your applications may no longer sync-up properly with the new firmware... For example: this would be the most likely cause if the DriveRack goes flakey right after the firmware is updated... I usually reset any computerized equipment right after a change in firmware... I know it's a pain to reload the program but it could save you a lot of grief in the long run...
Anyways,...maybe this will help someone if they encounter such a problem...
Dra,...I forgot to mention...you should always dance around in circles with a beheaded chicken immediately after the update!...:)
Clockwise or counter-clockwise? Because if you go the wrong way, you might have to get Radar a date with a hair dryer. Figure that last one out and you have great recall.
Comments
Here's a possible dilema: In the bridged-mono mode...the EP2500 jumps from 1300 watts @ 8 ohms to 2400 watts @ 4 ohms... Is this to much available power for the JRX115s and 125s?.. Can one create problems by under working the amp?.. And yet...another twist: I can get the EP2500 at the same price or even cheaper than the EP1500... The EP1500 is rated at 1400 watts @ 4 ohms in the bridged mode; which better matches Crown's formula for the loads,...and the EP2500's bridged output power available to the 8 ohm subs...
Gadget, Is this a legitimate concern in the first place?...and if so, can I \"over power\" the speakers or \"under work\" the amp...or both?.. If I need to go bridged-mono for the 115s and 125s (based on the 800 watts to 1250 watts that Crown's formula calls for) does it matter if 2400 watts vs 1400 watts are available?...
Thanks!
Kevin
PS. I will have my DR260 tomorrow evening!... Yaahooo!!!...
Good to hear from you. I hope your project is going well.
Yes, the amps are multiplying like rabbits. : )
Here are my calculations. All amps are bridged 2500s:
Amp 1 - Left channel 2 X 115i's (4 ohm load)
Amp 2 - Right channel 2 X 115i's
Amp 3 - Left channel 125 (4 ohm load)
Amp 4 - Right channel 125
Amp 5 - Left VRS18 (8 ohm load)
Amp 6 - Right VRS18
I don't know what the 4 ohm load power rating is for these amps in bridged mode, but you will have plenty of headroom on the 115i's.
I'm wondering what the 125's will be like because they have that second 15 set to a lower band.
Keep up the good work. [/list]
How are you fixed for AC power circuits at the amp rack?
I'm just doing some calculations and find that if you ran this system at RMS power ratings of the cabinets, you would draw about 27 amps total.
Given that I'd say you may want to divide your amps across three separate twenty amp AC circuits if possible.
When you power up amplifiers, there is a fair amount of in-rush current so you don't want to power them on all at the same time. You want to sequence them on with a short delay in between each power up.
Furman has sequencing devices like the asd 120.
http://www.furmansound.com/product.php? ... id=ASD-120
You probably know this already, too, but when you install the amps leave space between each set of amps for ventilation and heat dissipation.
Take care.
Gotcha covered... Fortunate for me I told the electrician that I wanted three dedicated quad-plex 20 amp circuits for the sound booth...and that's where the amp rack will be located along with the DriveRack, mixer, etc., etc...
Wolfgong,
The back and the sides of the amp rack are totally open and there is about 2" of free space between each amp... I hope this will do the trick?..
I'm interested I what Gadget's thoughts are in regards to Crown's calculation and wether or not the EP2500 is to big (2400 watts) in bridged-mono mode for the JRX's... David with Crown mentioned this in his post:
Wolfgong,
The amp power-up sequence you wrote makes very good sence!... I have also read that your amps should be the last thing to power-up (5 sec. after DR and mixer) and the first thing to power down... I have also read some hear-say about the DRPA giving amps nasty spikes because the DR's were shutdown pre-maturely or by accident... I recently noticed a DRPA for sale on eBay and the seller had hardwired the power cord directly to inside the unit...so the power plug couldn't be accidently pulled-out...
Wolfgong,
Once again,... I thank you so very much for your advice and help!...
Kevin
Regarding the amps, it does seem that given the calculated power needed you might be better suited with the EP1500's for the 115i's and 125s.
With the ep1500 bridged at 4 ohms you would get about 1500w, but with the ep 2500 you end up with about 2500w, which I think would be less forgiving if someone dropped a mic or something like that. I think you could also cook your coils pretty 'well done' if you drove your system pretty hard for a while.
The ep2500 work well with the EAW's because they are rated 500w at 8 ohms and the power rating comes out about right at 1500.
Take care.
It is actually better to have the amps (assuming that they all have the same air flow path, front to back, etc) directly on top of each other and any empty rack spaces covered. Air flow thru the amp is the key. Any amps with a different path should be in a different rack as to not draw in hot exhaust.
Although definately not good, a quality speaker will survive the turn off spike (usually). A low rated (wattage) speaker on a high wattage amp would be toast. Get a $30-$40 UPS at a computer store. It is the ONLY thing that will protect againt an electrical failure. Some people open the case and bypass the power switch to prevent an assistant sound tech from helping you power down in the wrong order.
DRA
Could you please be more specific?.. Just making sure here: are you refering to a "uninterruptible power supply" or a decent "surge protector"?.. Most UPS incorporate both battery back-up and surge protection... Do you recommend putting the DriveRack on a UPS,...each amp on a UPS,...or both? I'm assuming it would be OK to put two amps that work together (like two bridged amps of a left and right channel) on the same UPS...if it's sized properly?
Also,...did I get the following sequence correct? I have been bouncing around the web so much lately I can't remember where I got this information (it's a seventies thing)...and if I got it right:
Dra,
Thanks!...This makes good sence:
Thank you so much for the info!
Kevin
Yes, in a turn on / turn off time line, amps meet in the middle.
ON - Once proccessing is on, amps can be powered up (no additional wait is needed).
OFF - Once amps are off I like to wait at least 10 secs or more to be extra safe. Then proccessing.
DRA
Thank you for your advice!... One thing I don't have is...large capacity bank account!... However,...I do have a couple decent UPSs left over from a "company project"... I own a control systems integration company...we do robotics, networking, PLC and PC based industrial control systems... Needless to say...this is a whole new learning experience, and a very challenging project for me!... I've been trying my best to absorb every little bit of info and advice,...and to process it, and apply it to this project...
Thanks!
Kevin
Ok first off he is getting a 260, not a DRPA.. Yes, I have recommended hard wiring if the DR's cord is accessible, I have bypassed the power switch internally, and again yes get a cheap universal power supply and the thump is NOT an issue...but still not germain to this issue at hand.
Second... \"TOO much power is NEVER enough!\" chuckle...Kinda like your joking about the eardrum vs speaker thing but true none the less. Crown actually say 2 to 4 times the rated power of the speakers... Yes I know it sounds like a lot of power but power isn't what blows speakers... it's LACK of power that does. You can blow a 2000 watt speaker with a 100 watt amp easily...Yes you can over drive the speakers but just because you have 245 horsepower in your lexas and it will do 140 MPH doesn't mean your going to do it all the time does it? The speakers will emit a popping sound if overdriven and just so you have a visual, the sound is made when the voice coil bottoms out on the back plate of the speaker magnet structure. The gain structure/balance set should determine the amp input attenuator settings...those controls will allow you to limit those horses...so to speak. I recommend since this is the youth side that once the system is set that the 260 be locked against prying fingers..(it has varying levels of security.. just don't forget your passwords...) and that the amps be marked for attenuator position and locked up as well.
As for the amps a good MOV (lightning arrestor, available at most hardware stores..)installed on the amp feeder is all I use...the UPS is not necessary for the amps.
I believe that having airspace on the amps is not critical, but these are heavy amps, if you do space them don't hang them by their front rack mounts alone.
Amps always last thing on first thing off.. this will allow any transients that could cause a pop or thump to dissipate prior to the amps turn on/FOH component turn off.
Good work Dra and wolfie...
Gadget
Sorry,
DRA
PS - Gadget, I laughed my head off at your response to the guy \"just bristling with information\". You must be in a jovial mood.
This is a good thing!... I already have six of the EP2500s for both the PA and wedges... I'll just get a couple more...
Gadget,
I've been studying-up on gain structure but I'm waiting for later to address it... For right now I'm trying to stay focused on the basics...but please don't kick me down to the basement...
Gadget,
Eventually I was going to ask for the best way to apply one over-all password that locks-out all of the DR features?.. I am using an old decent networking rack... I have installed clear lexan doors with pad locks on the front,..and I placed shelves in every position to support the weight... The back side of the lexan is about 4" from the face of the amps and the shelves created about a 2" space between each position... This rack is fully opened on the back and again about half way back on the sides...
Ahhh...metal oxide varisiter...a good AC inductive load filter and line spike component... We use those on motor starter coils and solenoid valves...
Gadget, As always...I thank you for the info!!!
Kevin
When I rehang the 115s should I face the mating joint between the speakers straight outward?... I'm thinking that when these slighltly wedged shape cabs are attached together side by side...they will want to toe-out from each other...
How can I apply the following?...
http://www.teamaai.net/kevin/Youth/Youth_Room_Mode.doc
I'm going to get this done tomorrow...and I just want to get it right...
Thanks again!
Grasshopper
you listen well my young padawan...hows that for mixing metafores...
Long axis 94 hz and 140 hz are the primary concerns
width 56, 84,113, 140 hz
note that 140 makes both lists and will become a primary mode of concern
254 and and 423 are also typical problematic frequencies.
The higher the frequency the less likely it is to become a problem, and you have finite resources to deal with these. When the house is rockin put a narrow width bell PEQ on, cut about 6 db and sweep around the area of the primary frequencies and see if the negative energies diminish and you get a cleaner sound... those modes will manifest themselves as a kind of DIN or howl or growl sort of effect.
As for the aiming its more critical to keep the sound off the side walls than it is to worry about making sure the seam is strait. You will be making a huge difference just by getting them together. As you said join them together tightly and use back cables to aim them. A few screws in the front and a couple cheap plates will bind them just fine. The interaction from left and right will be there in the center but will be far less than the effect of the interaction the speakers would have on the walls. There will be some interaction no matter what but get the at as far back as possible and perhaps have the kids do a project and make some hangings that depict bible scenes or something and hang them on the walls to minimize reflection.
Be well..
Gadget
\"A picture's worth a thousand words\"... So here's a few pics!... The speakers will be re-hung tomorrow as you suggested... They are covered and not pulled back right now due to other work-in-progress... I will post some more later this evening that shows more things we have discussed,...but I gotta go for now... My wife is calling herself a \"Church Widow\"...
Note: Images have been removed to make room for pics of the final installation...
See ya,
Kevin
Post somes pics when you're done along with your great sound results.
DRA
The kids are so lucky.. you DA man!
G
Gadget, you said that a lot better than I could of...but what you said is exactly what I'm trying to achieve... I'm hoping to pan some of the vocals and instruments in relationship to the musician's location on the stage... I'm hoping this will provide some realisim... If the musician is on the left side of the stage then I was going to pan their voice and instrument slightly to the left...or vise versa...
Here are some more pictures:
Note: Images have been removed to make room for pics of the final installation...
Well,...there you have it!
Summary: I wanted to keep the installation clean and simple so I decided to use no more than three different types of cables... I bought six channel 22AWG microphone snake cable, 10AWG oxygen free speaker cable, and 13AWG rubber jacket speaker cable (all came from Gepco)... All of the external speaker cables have a male speakon connector on one end and a male 1/4 mono on the other... This keeps the youth from using instrument cables as speaker cables or for stringing monitors... The JRX112M monitors have one female speakon and one female 1/4 jack in parallel... Each floor box will have five microphone inputs, one female speakon (for monitors), and one 120VAC duplex outlet... The amp rack is an old aluminum network rack that was left in the building from WalMart... We modified the rack and added lexan doors... I will need to add two more shelves for two more amps...
Please give me any comments or suggestions you may have?..
Kevin
PS. Gadget...thank you!
Your cabling and terminations are excellent! I love that everything is tagged and easy to follow.
I was an electrician for several years and I never saw anything that neat and easy to follow. Troubleshooting will be a breeze except I don't think you'll have any trouble with routing like I see here.
Nice job!
You will not be able to hang all that weight in that tall rack without support from a boundary... Why is there so much space in the rack? you could easily run 2 amps per shelf...lower the bottom amp to just atop the fan guards and you could have all amps installed and have a lower center of gravity for the rack. put the 260 in the rack with the amps, and run it over a single mic cable..cut and spliced into the null modem cable that comes with the unit. its RS232 and comm port 1. The signal can easily run 250 feet and still have adequate dependability.
Very nice.. very nice indeed.. your going to have such a great system...enjoy!
G
Thank you so very much for your positive comments!... What you guys wrote really makes me feel good about how this project is coming along!...
Hey Gadget,...look what we did today!... I thank you!...:)
Note: Images have been removed to make room for pics of the final installation...
Summary: All of my deminsions worked-out to odd numbers off the back wall... I know this sounds stupid but,...we also wrapped the speaker cab eye bolts with rubber insulation tape;...maybe it will isolate speaker cab vibration from resonating the chain... Well...at least it sounds technical...
Please let me know what you think?...
Kevin
My only recommendation would that the fly height is all wrong. Anyone knows that to achieve the correct tonal properties, you must rise the cabs by one link. I'll follow-up when you get this corrected.
Serious note. I'd \"wrap\" the chains in a dull black material to limit light reflections that will draw attention away from the stage area.
DRA
Your killing me!...I'm laughing my butt off here!!!
Very good point about the chains!.. Thanks!...:)
Kevin
You will also get the added benefit of coupling of the speakers when they are close like that.. thats an added 3 db...free! BTW the same is true for the subs, put them together.. get 3db..free.. I love free. Ya Dra your a real funnyman...When is the inauguration?
Oh a further thought from a former thread... When you pan instruments hard when the speakers are that far apart those on the opposite side of the room will not hear what is panned to the other side..
Gary
Some very good points!... We are going to use floor wedge anchors to secure the rack... I'm going to use your suggestions of stacking two amps per shelf and keeping most of the weight below the center of gravity... I really like the idea of using a mic cable for RS232!... I'm assuming the DB9 pin-out then...only requires pins 2 to 3, 3 to 2, and shield for pins 5 to 5...
Another good point!,...and I hope to realize this pretty soon!...:)
Like you say,...in this particular case free is a good thing!...
Believe it or not...we had our first service in the youth area last night!... They used a small portable PA system for sound... The speakers were spread about 20' apart...one on each side of the stage,...and mounted high (far above listening level) on tripods that were slightly toed-out...away from the audience... The speakers had two 10" cones in each cab... Actually,...this setup sounded pretty good!... I know the system I'm installing is entirely different, unique,...and will provide it's own set of challenges,...but my concerns of the room's acoustics have some what deminished...for now... The room was filled with chairs, cold bodies (heat wasn't working), and a couple of couches... We are having the stage carpeted this Tuesday and I hope to install floor pockets immediately there after...
Hey Dra, It just occured to me...as to why it sounded so good;...the colder room temperature shifted the audible deflection by ten degrees!...
Thank you!...
Kevin
Kevin
Gadget, knowledge input?
DRA
Unless the DriveRack is different than any other microprocessor based equipment a hard reset usually resets the unit back to it's original factory defaults... A lot of times it also good to do a hard reset after a firmware update... When you update firmware your applications may no longer sync-up properly with the new firmware... For example: this would be the most likely cause if the DriveRack goes flakey right after the firmware is updated... I usually reset any computerized equipment right after a change in firmware... I know it's a pain to reload the program but it could save you a lot of grief in the long run...
Anyways,...maybe this will help someone if they encounter such a problem...
Dra,...I forgot to mention...you should always dance around in circles with a beheaded chicken immediately after the update!...:)
DRA
Did I mention I had "over exposure" in the 70s... Even though I've seen every episode...like umpteen million times and I can't recall...