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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Installed Sound/Contracting => Topic started by: Travis Benavides on April 12, 2011, 10:54:49 PM

Title: Adding Speakers to system.
Post by: Travis Benavides on April 12, 2011, 10:54:49 PM
I just happened to get a job in a small college town at a Bar as a live sound engineer. The Bar is a decent size (299 occupancy limit). The sound system is pretty bar bones, but I have seen worse. The system comprises of a Behringer Eurodesk sk2442fx, Behringer Multicom pro-lx, a dbx Driverack PX, Behringer ep2500 and QSC plx 3602 power amps, with 2 older model Peavy SP 218 subs and 2 Peavy HDH 224T's for mids and highs. To me this system seems a little bottom heavy I was wondering if I should add more speakers to the system to even it up or pull out a sub or does nothing needs to be done at all. I feel like I have a good ear for this but am still pretty new to the whole setting up and buying equipment. If you need anymore info let me know. Thanks!
Title: Re: Adding Speakers to system.
Post by: Tom Young on April 13, 2011, 06:17:25 AM
I just happened to get a job in a small college town at a Bar as a live sound engineer. The Bar is a decent size (299 occupancy limit). The sound system is pretty bar bones, but I have seen worse. The system comprises of a Behringer Eurodesk sk2442fx, Behringer Multicom pro-lx, a dbx Driverack PX, Behringer ep2500 and QSC plx 3602 power amps, with 2 older model Peavy SP 218 subs and 2 Peavy HDH 224T's for mids and highs. To me this system seems a little bottom heavy I was wondering if I should add more speakers to the system to even it up or pull out a sub or does nothing needs to be done at all. I feel like I have a good ear for this but am still pretty new to the whole setting up and buying equipment. If you need anymore info let me know. Thanks!

Do you mean that the fullrange speakers run out of steam ?  How is the coverage from the fullrange speakers ?
Title: Re: Adding Speakers to system.
Post by: Ivan Beaver on April 13, 2011, 07:27:58 AM
I just happened to get a job in a small college town at a Bar as a live sound engineer. The Bar is a decent size (299 occupancy limit). The sound system is pretty bar bones, but I have seen worse. The system comprises of a Behringer Eurodesk sk2442fx, Behringer Multicom pro-lx, a dbx Driverack PX, Behringer ep2500 and QSC plx 3602 power amps, with 2 older model Peavy SP 218 subs and 2 Peavy HDH 224T's for mids and highs. To me this system seems a little bottom heavy I was wondering if I should add more speakers to the system to even it up or pull out a sub or does nothing needs to be done at all. I feel like I have a good ear for this but am still pretty new to the whole setting up and buying equipment. If you need anymore info let me know. Thanks!
Have you tried simply turning down the sub amplifier?

Usually adding more speakers is the worse thing you can do.  It may get louder-but will most often times sound worse.
Title: Re: Adding Speakers to system.
Post by: Brad Weber on April 13, 2011, 07:30:13 AM
I just happened to get a job in a small college town at a Bar as a live sound engineer. The Bar is a decent size (299 occupancy limit). The sound system is pretty bar bones, but I have seen worse. The system comprises of a Behringer Eurodesk sk2442fx, Behringer Multicom pro-lx, a dbx Driverack PX, Behringer ep2500 and QSC plx 3602 power amps, with 2 older model Peavy SP 218 subs and 2 Peavy HDH 224T's for mids and highs. To me this system seems a little bottom heavy I was wondering if I should add more speakers to the system to even it up or pull out a sub or does nothing needs to be done at all. I feel like I have a good ear for this but am still pretty new to the whole setting up and buying equipment. If you need anymore info let me know. Thanks!
Probably one of the first things you should have verified or done either before or after taking the job was to go through the whole system making sure everything was working correctly and properly adjusted (signal flow, gain structure, EQ and crossover settings, etc.).  In general, really getting to know the system and how it works, including getting into the DSP to learn how it is programmed.  Have you done that?
 
Tom asked about coverage but other questions I'd have would include whether the overall level is acceptable?  What type of music is involved?  Does the problem exist everywhere or is it limited to specific areas?  Any chance the console EQ has the low end turned up on some sources?  Any chance what you're hearing is at least partially a result of the levels from the kick drum and bass amps on stage or from the contribution of the stage monitors?
 
Assuming one HDH 224T on each channel of the EP2500 and one SP218 on each channel of the PLX 3602 you'd be looking at the SP218 probably having somewhere around 5dB greater output, however the specifics of the situation could make that a larger or smaller difference.  So could the specific model of the SP218, over the years there have been different versions with different performance.
 
All that being said, as Ivan suggested, if you're thinking that pulling out a sub is a potential solution then have you thought about simply turning down the levels on the sub amp?  I would still go through the system and make sure everything is working and set properly, but that seems a pretty simple first option.
Title: Re: Adding Speakers to system.
Post by: Chris Carpenter on April 19, 2011, 04:16:35 AM
I just happened to get a job in a small college town at a Bar as a live sound engineer. The Bar is a decent size (299 occupancy limit). The sound system is pretty bar bones, but I have seen worse. The system comprises of a Behringer Eurodesk sk2442fx, Behringer Multicom pro-lx, a dbx Driverack PX, Behringer ep2500 and QSC plx 3602 power amps, with 2 older model Peavy SP 218 subs and 2 Peavy HDH 224T's for mids and highs. To me this system seems a little bottom heavy I was wondering if I should add more speakers to the system to even it up or pull out a sub or does nothing needs to be done at all. I feel like I have a good ear for this but am still pretty new to the whole setting up and buying equipment. If you need anymore info let me know. Thanks!
I'm drawing a target on my back for making a generalization on this board, but to me, Peaveys always sound a little warmer than other brands. Especially if you are dealing with well amped, SP dual 18s. I would be pretty happy to have that kind of bass headroom with a system like that.

Secondly, you said a driverack PX? I understood the PX was for powered speakers, not passive ones?

I agree with the general consensus that, if you have achieved the level you are looking for, and simply need to tone down the bass, turn down the subs. Your processor should be plenty powerful enough to allow you to make this correction.
Title: Re: Adding Speakers to system.
Post by: Travis Benavides on April 23, 2011, 12:07:10 AM
Hey guys thanks for all of the suggestions.

Yes, Ivan I have tried simply turn down the lows through the board and just turning down the amp. Which is what I had been doing for the time being.

Brad, I did as you suggested and checked out the who system top to bottom and found the problem. As it turned out the Crossover had never been properly adjusted to the acoustics of the room. It had just been installed and set to one of the manufacturers presets. After adjusting it to the room it sounds so much better now! 

Chris, I did some research and yes the PX was made for powered speaker. Upon further research I found out that using it for amps wont damage the system, but I was only able to find one source that addressed that kind of problem. If I find anything else about it I'll make sure to post the info.

Thanks again everyone for all the help!
Title: Re: Adding Speakers to system.
Post by: David Sturzenbecher on April 23, 2011, 12:38:45 PM
It had just been installed and set to one of the manufacturers presets.

If you don't trust the manufacturers presets, why would you trust the manufacturer?
Title: Re: Adding Speakers to system.
Post by: Brad Weber on April 23, 2011, 01:25:06 PM
It had just been installed and set to one of the manufacturers presets.

If you don't trust the manufacturers presets, why would you trust the manufacturer?
Because the DSP manufacturers may be able to create presets for certain components, but not for every possible combination.  And speaker manufacturers may be able to create recommended settings for their speakers, but not necessarly for every processor.  And neither can create presets that account for the specific conditions of each individual application.
 
This particular situation also seems to have a significant additional factor as it is apparently a DriveRack PX being used with amps and non-powered speakers. Since the DriveRack PX was intended to be used with powered speakers, I believe the presets available and the models in the Wizard are all related to powered boxes and those may have little relevance to a system with Behringer and QSC amps and Peavey speakers.  They may have simply selected the generic "stereo mains with stereo subs" preset that includes no model specific settings.
Title: Re: Adding Speakers to system.
Post by: Ivan Beaver on April 23, 2011, 08:22:39 PM
Brad, I did as you suggested and checked out the who system top to bottom and found the problem. As it turned out the Crossover had never been properly adjusted to the acoustics of the room. It had just been installed and set to one of the manufacturers presets. After adjusting it to the room it sounds so much better now! 

Chris, I did some research and yes the PX was made for powered speaker. Upon further research I found out that using it for amps wont damage the system, but I was only able to find one source that addressed that kind of problem. If I find anything else about it I'll make sure to post the info.

Thanks again everyone for all the help!

Just curious how you "adjust a crossover for the acoustics of the room".  What exactly did you change that compensated for the acoustics?

Crossovers are used to adjust pass bands between different drivers/cabinets to operate within the intended range and to blend them together as seamlessly as possible.

The acoustics of the room are a different issue.  The acoustics will not change the signal delay needed-nor the level needed or the freq used or the slope or type of crossover filter.

Just wondering what "preset" was used that included the various components in the system-since they were from different manufacturers.  That must be quite the preset to dial up that includes that amount of variables.
Title: Re: Adding Speakers to system.
Post by: Richard Turner on April 24, 2011, 12:11:18 PM
I just happened to get a job in a small college town at a Bar as a live sound engineer. The Bar is a decent size (299 occupancy limit). The sound system is pretty bar bones, but I have seen worse. The system comprises of a Behringer Eurodesk sk2442fx, Behringer Multicom pro-lx, a dbx Driverack PX, Behringer ep2500 and QSC plx 3602 power amps, with 2 older model Peavy SP 218 subs and 2 Peavy HDH 224T's for mids and highs. To me this system seems a little bottom heavy I was wondering if I should add more speakers to the system to even it up or pull out a sub or does nothing needs to be done at all. I feel like I have a good ear for this but am still pretty new to the whole setting up and buying equipment. If you need anymore info let me know. Thanks!

I had a pair of HDH244t a long time ago, The passive crossovers really suck alot of power, If I remember correctly there's 4 20 watt ceramic resistors in there. Unfortunately the Drive rack PX is a 2 in 4 out signal processor. if you could tri amp the rig you might be more pleased with the output, If you could pick up another larger amp for the bottom end , use the driverack px for subwoofer crossover and limiter then add another crossover to biamp the tops it might make a bit more from what you have,

Also the 44t 2" exit driver in those boxes starts dropping off at 12k, I think the cut sheer had the speaker rated at 400w  55-17k but dont quote me on that
Title: Re: Adding Speakers to system.
Post by: Ivan Beaver on April 24, 2011, 01:15:20 PM
I had a pair of HDH244t a long time ago, The passive crossovers really suck alot of power, If I remember correctly there's 4 20 watt ceramic resistors in there.

It all depends on what you mean by "sucking a lot of power".

Yes there maybe some resistors that get hot-but that does not mean you are losing any output.

Look at the typical horn/driver response.  Look around 1-3Khz as compared to say 10Khz

Typically you will see a nice large "mound" or "hump" in the response.  If you want the response to be flat-you have to get rid of the mound.  You can do it electronically via an eq filter, or passively via a crossover filter.

Either way that "hump" needs to be brought down.  You don't lose any "usable" power in the process.

Yes you can argue that the passive is "wasting" energy, and the electronic filter simlply does not allow the amp to reproduce those freq as loud.

BUt you still will not be able to get the horn any louder-because the limiting factor will the point at which the horn has the least amount of energy being radiated.

So it may be "wasting" energy-but you don't get anything extra (in terms of SPL) by not wasting it.