[coltcannon]

Hello


This is my first venture into the audio side at AVS.


I am trying to setup a sound system at a bar with four JBL Control 5 monitors, a Crown LPS-800 amp using the amps speakon output. The amp is running in Stereo mode. Can we wire two of the speakers to one of the speakon plugs to get 2xright and 2xleft? If so how? Wiring two speakers to the plugs we have only gotten one channel (the left) to work. All and any help is appreciated.

 

[arnyk]



Quote:
Originally Posted by coltcannon /forum/post/16939254


Hello


This is my first venture into the audio side at AVS.


I am trying to setup a sound system at a bar with four JBL Control 5 monitors, a Crown LPS-800 amp using the amps speakon output. The amp is running in Stereo mode. Can we wire two of the speakers to one of the speakon plugs to get 2xright and 2xleft? If so how? Wiring two speakers to the plugs we have only gotten one channel (the left) to work. All and any help is appreciated.

The fact that there are 2 Speakon connectors on the back of the Crown amp tells me that they are mono. At most one channel is hooked to each connector. The questions in my mind are whether the connectors are NL2 or NL4, and if they are NL4 with just two active terminals.


From the outside of a Speakon connector, you can't tell the difference between a Speakon NL2 (1 channel, 1 pair of active connections) and a NL4 (2 channel, 2 pair of active connections).


It is not unusual to see NL4 connectors with only one pair of connections in use. It seems that is what you have.


What does the manual that came with the amp say?

 

[whoaru99]



Quote:
Originally Posted by coltcannon /forum/post/16939254


Hello


This is my first venture into the audio side at AVS.


I am trying to setup a sound system at a bar with four JBL Control 5 monitors, a Crown LPS-800 amp using the amps speakon output. The amp is running in Stereo mode. Can we wire two of the speakers to one of the speakon plugs to get 2xright and 2xleft? If so how? Wiring two speakers to the plugs we have only gotten one channel (the left) to work. All and any help is appreciated.

Can't find much info on the LPS-800 since it seems to be a non-USA model.


Many, but not all, pro amps have the CH 1 Speakon jack wired so that using a NL4 plug can get you both channels. It's usually set up CH 1 on the terminals +1/-1 and CH 2 on the terminals + 2/-2.


So, if this is the case for the LPS-800, then two of your speakers would connect to +1/-1 and two would connect to +2/-2 of a NL4 plug.


If this doesn't seem to work, then the LPS-800 may not be set up with both channels available through one Speakon (although silk screen on the back panel of the image I found seems to indicate they are).


Or, it might just be easier to spend a few bucks on another Speakon, or just use the binding posts (if it has them).

 

[kouack]

 http://www.audiomaster.cz/download/k...crown/c034.pdf
http://www.jblpro.com/catalog/genera...?PId=196&MId=2


First problem is the JBL are 4 ohms and your amp is not rated 2 ohms.


Second problem the amp is rated 300 watts per side at 4 ohms and speakers are 175 watts max, your best bet would be to connect them in series if you want to hook 4 speakers to that amp.

 

[coltcannon]

Thanks for the responses. We are trying to use the speakon NL4 plug.

What has work but not as hoped was two speakers to one plug, in channel one with the amp in stereo. This provided just the left channel to those two speakers but nothing from channel 2.

Quote:
Originally Posted by kouack /forum/post/16939930

http://www.audiomaster.cz/download/k...crown/c034.pdf
http://www.jblpro.com/catalog/genera...?PId=196&MId=2


First problem is the JBL are 4 ohms and your amp is not rated 2 ohms.


Second problem the amp is rated 300 watts per side at 4 ohms and speakers are 175 watts max, your best bet would be to connect them in series if you want to hook 4 speakers to that amp.

I dont know much of anything about ohm ratings. Could you explain shortly?


What would connecting them in series entail?

 

[ENiGmA1987]

ohms are the resistance. if you connect two, 4 ohm speakers (in parallel?) then the speakers would give a 2ohm load. Which your amp is not rated for and will cause it turn burn out given enough time. If wired in series I think it does the opposite, where connecting two, 4ohm speakers would raise the load to 8ohms. Which I think all professional amps are rated for. The difference between parallel and series is just how the wires go.


Although even still, I don't think your amp could provide enough power to a pair of speakers with an 8ohm load.




One thing I am wondering, if if you cant get sound from the second channel maybe you have the amp set to bridged and not stereo mode?

 

[coltcannon]



Quote:
Originally Posted by ENiGmA1987 /forum/post/16941595


ohms are the resistance. if you connect two, 4 ohm speakers (in parallel?) then the speakers would give a 2ohm load. Which your amp is not rated for and will cause it turn burn out given enough time. If wired in series I think it does the opposite, where connecting two, 4ohm speakers would raise the load to 8ohms. Which I think all professional amps are rated for. The difference between parallel and series is just how the wires go.


Although even still, I don't think your amp could provide enough power to a pair of speakers with an 8ohm load.




One thing I am wondering, if if you cant get sound from the second channel maybe you have the amp set to bridged and not stereo mode?

Can some one explain or diagram the difference between wiring the speakers in parallel or series?


The amp is set to stereo. I am still unsure about exactly what the bridged or parallel output settings mean for the amp.


We achieved the desired result from using the standard terminals on the amp. Two left speakers in channel 1 and two right speakers in channel 2. There is no discernible audible issues. Does someone see a problem with this setup?


Some specs


Crown LPS-800

4-ohm Stereo (per channel) 300W

8-ohm Stereo (per channel) 150W

8-ohm Bridge-Mono 600W


JBL Control 5

175W Capacity

4 ohms

 

[Easyaspie]

I'm not a pro amp guru, but since the back of your amp says that a 4ohm load is the minimum, I would probably stick with it.


edit: This is only if you're using the binding posts on the amp. Those speakon connections are nothing I can help with.

 

[ENiGmA1987]

yes there is a problem with your setup, the way you probably connected it will run the amp at 2ohms per channel which will burn the amp out. Wire the speakers like you see in that "series" diagram to provide the right load to the amplifier.


However, the amplifier does not have enough power to run all the speakers at high volume. So once you get them hooked up in series, turn up the speakers until you get as loud as you will ever want and listen for signs of distortion or clipping as you turn the speakers up. If you hear some, you should probably get a more powerful amp.

 

[whoaru99]



Quote:
Originally Posted by ENiGmA1987 /forum/post/16943272


yes there is a problem with your setup, the way you probably connected it will run the amp at 2ohms per channel which will burn the amp out. Wire the speakers like you see in that "series" diagram to provide the right load to the amplifier.

MAY burn out the amp. Some amps are rated only down to 4 ohms to get around some regulatory stuff, even though they may operate just fine with lower impedances. Don't know specifically about this amp, but I believe that was the case for the Crown XLS series.

Quote:
Originally Posted by ENiGmA1987 /forum/post/16943272


However, the amplifier does not have enough power to run all the speakers at high volume.

The amp may or may not have enough power to drive the speakers to maximum output, I don't know.


The wattage of the amp operating at 2 ohms is unknown, and I don't know if the speaker power ratings listed are continuous, program, or peak rating. Do you?


I do know it will produce quite a lot of volume...if it's enough is another matter that will be determined when the system is used with a bar full of people.

 

[coltcannon]

Thanks for all the help everyone.


I have now wired the speakers in series with two per left/right. That should be 8ohms per channel, with the amp in stereo mode that is 300w per channel. The speakers together are 350W, 175W a piece. They are under powered little but the volume for the room is more than fine, as the walls are all cement and not very large.


I have seen no problems from clipping or anything out of the ordinary.

Again thanks for the help.


Peace

 

[arnyk]



ohms are the resistance. if you connect two, 4 ohm speakers (in parallel?) then the speakers would give a 2ohm load.

So far so good.

Quote:
Which your amp is not rated for and will cause it turn burn out given enough time.

Highly unlikely. For one thing we're talking Crown here, and more generally a pro audio amp from a highly reputable, exeprienced source. More generally yet, we are talking about a modern power amp - one designed and built to the general standards of this millenium, not 4 decades ago.


The power amp's manfacturer's major goals in life are to have a good reputation for reliability and compatibilty and minimize warranty costs. No way will they field a product that they haven't checked out thoroughly from the perspective of damage (long or short term) from a likely operational situation like too many speakers of the wrong kind in parallel.


If there is was only manufacturer in the business that knows how to do this it would be Crown. But there are many, with QSC quickly coming to mind.


There are a host of safeguards, documented and undocumented, built into this and any mainstream power amp that will keep it from being burned out by something as common as a 2 ohm load.


So what will happen if you load an modern amplifier with a load with too low of an impedance? In some cases, it will simply refuse to fully power up. If it powers up, it may simply put out less power than is optimal. If it runs too hot it will shut itself off, probably during the loudest passages.

Quote:
One thing I am wondering, if if you cant get sound from the second channel maybe you have the amp set to bridged and not stereo mode?

That's not how bridging is usually implemented. There are two steps to bridging a power amp - reversing the polarity of the signal to one channel, and the other is connecting the speaker across the plus terminals instead of from plus to minus. Both amps get the same amplitude signal, neither goes silent. Usually the speaker connection change is implemented by extenal connections, not some hidden internal switch.


IOW with bridging there is always a signal from the second channel, and that signal is present whether you connect the speakers from plus to minus, or plus to plus.

 

[kouack]

Here the guts of the LPS1500 amp from crown my feeling are mixed not sure about this one

look like the old board of the XLS B serie with a better heat sink but not too many output devices.

 

[ENiGmA1987]



Quote:
Originally Posted by arnyk /forum/post/16946326


The power amp's manfacturer's major goals in life are to have a good reputation for reliability and compatibilty and minimize warranty costs. No way will they field a product that they haven't checked out thoroughly from the perspective of damage (long or short term) from a likely operational situation like too many speakers of the wrong kind in parallel.


If there is was only manufacturer in the business that knows how to do this it would be Crown. But there are many, with QSC quickly coming to mind.

Thats fine and I am sure the majority of people have great experiences with Crown and QSC. My experience however is that Crown and QSC amps die quite often, especially when run at 2ohm loads. I have seen two Crown XLS 602 amps, an QSC PLX3002, and a QSC USA900 amp die from just a few uses in stereo mode with 2 ohm loads.


But it doesnt really matter cause Colt hooked everything up correctly now and has all his speakers working without any clipping or distortion at the volumes he wants. Which means that his amp will do fine.

 

[Easyaspie]



Quote:
Originally Posted by coltcannon /forum/post/16944696


Thanks for all the help everyone.


I have now wired the speakers in series with two per left/right. That should be 8ohms per channel, with the amp in stereo mode that is 300w per channel. The speakers together are 350W, 175W a piece. They are under powered little but the volume for the room is more than fine, as the walls are all cement and not very large.


I have seen no problems from clipping or anything out of the ordinary.

Again thanks for the help.


Peace

Actually doesn't your amp output 150wpc at 8ohms? That would mean that each speaker has 75 watts available when they are wired in series.


I think that is enough anyway.

 

[whoaru99]



Quote:
Originally Posted by ENiGmA1987 /forum/post/16947536


Thats fine and I am sure the majority of people have great experiences with Crown and QSC. My experience however is that Crown and QSC amps die quite often, especially when run at 2ohm loads. I have seen two Crown XLS 302 amps, an QSC PLX3002, and a QSC USA900 amp die from just a few uses in stereo mode with 2 ohm loads.

And your experience is?


I've run a couple PLX amps at 4 ohms bridged (equivalent to 2 ohms stereo) and have not had any failures.


Hard to imagine Crown or QSC would rate their amps for 2 ohm operation if it was causing them lots of trouble.

 

[kouack]



Quote:
Originally Posted by ENiGmA1987 /forum/post/16947536


Thats fine and I am sure the majority of people have great experiences with Crown and QSC. My experience however is that Crown and QSC amps die quite often, especially when run at 2ohm loads. I have seen two Crown XLS 302 amps, an QSC PLX3002, and a QSC USA900 amp die from just a few uses in stereo mode with 2 ohm loads.

You mean 202,402 or 602 i guess

. you killed all those amps with all the same speakers set up? could be more the speakers the problem

 

[arnyk]



Quote:
Originally Posted by kouack /forum/post/16950319


You mean 202,402 or 602 i guess

. you killed all those amps with all the same speakers set up? could be more the speakers the problem

I'm just shaking my head. I know of dozens of Crown and QSC amps that have worked wonderfully into all sorts of loads for decades. OK, it is probable that nobody tried to gut them out into 2 ohm loads. I would guess that anybody who fries good amps at this fantastic rate is doing other things wrong.