ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Chris Poynter on July 21, 2016, 11:52:33 AM

Title: JBL SRX815P Power Draw Question
Post by: Chris Poynter on July 21, 2016, 11:52:33 AM
First of all, I am a new member and I hope I am posting this in the correct place!

I am considering purchasing a couple JBL SRX815P speakers to replace my two Yorkville PS15P speakers. I DJ mostly weddings and corporate events, and I do not use separate subwoofers due to storage room and vehicle size.

I am wondering if anyone can help me out with a power draw question:

The only info I can find online is from the specs on the JBL website, and it says they each draw 2.2A (1/8th Power) and 5.6A (1/3rd Power).

In real world use, if I was going to use the JBLs as mains with no sub, how much am I going to draw on average using a pair of them? I want to be able to crank them up, but if they're as loud as the Yorkvilles, I can't see myself really pushing them to their absolute limit.

Currently I am "usually" able to plug my speakers and light show into one circuit (the draw is 14.1 amps when all is said and done.) and my fog machine into a second circuit (it draws about 6 amps).

Thanks so much for your insight!  :)
Title: Re: JBL SRX815P Power Draw Question
Post by: veditor78 on July 21, 2016, 12:29:36 PM
I have the following system:

2 SRX812P
1 SRX818SP
1 SRX828SP

With the entire system playing bass heavy modern music at 105dB I was drawing an average of 12 amps.
Title: Re: JBL SRX815P Power Draw Question
Post by: TJ (Tom) Cornish on July 21, 2016, 12:36:02 PM
First of all, I am a new member and I hope I am posting this in the correct place!

I am considering purchasing a couple JBL SRX815P speakers to replace my two Yorkville PS15P speakers. I DJ mostly weddings and corporate events, and I do not use separate subwoofers due to storage room and vehicle size.

I am wondering if anyone can help me out with a power draw question:

The only info I can find online is from the specs on the JBL website, and it says they each draw 2.2A (1/8th Power) and 5.6A (1/3rd Power).

In real world use, if I was going to use the JBLs as mains with no sub, how much am I going to draw on average using a pair of them? I want to be able to crank them up, but if they're as loud as the Yorkvilles, I can't see myself really pushing them to their absolute limit.

Currently I am "usually" able to plug my speakers and light show into one circuit (the draw is 14.1 amps when all is said and done.) and my fog machine into a second circuit (it draws about 6 amps).

Thanks so much for your insight!  :)
If you keep your speakers out of clipping, the 1/8 power number should be pretty accurate.
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on July 25, 2016, 04:15:11 PM
Great, that really helps! Thanks for your replies you guys!  :D
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on July 29, 2016, 03:25:53 PM
Okay... so... around the same time I posted this I emailed JBL and a "technical support specialist" gave me this answer:

"Each NEW SRX815p is actually going to now draw  5.2 'Normal' and 6.25 amps 'MAX'".

...what?
Title: Re: JBL SRX815P Power Draw Question
Post by: Tim McCulloch on July 29, 2016, 04:08:28 PM
Okay... so... around the same time I posted this I emailed JBL and a "technical support specialist" gave me this answer:

"Each NEW SRX815p is actually going to now draw  5.2 'Normal' and 6.25 amps 'MAX'".

...what?

Looks like they adjusted the AC current draw based on measurements in 1/3 power situations.  The MAX draw is probably based on draw with the system in hardest limiting.

Note that 1/3 power is defined as "severe or sustained clipping."
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on July 29, 2016, 06:47:10 PM
So...... (and sorry to be a bit ignorant in this area) ......if I'm using these speakers "normally" (i.e. barely into the limiting) should I be expecting to draw 5.2 amps from each one?
Title: Re: JBL SRX815P Power Draw Question
Post by: Andrew Zannetos on July 29, 2016, 07:01:17 PM
Okay... so... around the same time I posted this I emailed JBL and a "technical support specialist" gave me this answer:

"Each NEW SRX815p is actually going to now draw  5.2 'Normal' and 6.25 amps 'MAX'".

...what?

What does being new have anything to do with power draw?
Are these just new specs or did they actually change something?
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on July 29, 2016, 07:14:53 PM
What does being new have anything to do with power draw?
Are these just new specs or did they actually change something?

That's what I'm hoping to figure out!
Title: Re: JBL SRX815P Power Draw Question
Post by: TJ (Tom) Cornish on July 31, 2016, 07:39:35 AM
So...... (and sorry to be a bit ignorant in this area) ......if I'm using these speakers "normally" (i.e. barely into the limiting) should I be expecting to draw 5.2 amps from each one?
Presumably CYA. The spec sheet still says 2.2A 1/8 power.
Title: Re: JBL SRX815P Power Draw Question
Post by: Ivan Beaver on July 31, 2016, 09:06:51 AM
So...... (and sorry to be a bit ignorant in this area) ......if I'm using these speakers "normally" (i.e. barely into the limiting) should I be expecting to draw 5.2 amps from each one?
It is not the peak power, but rather the AVERAGE power.

It is entirely possible to have them pull 5A each and never hit a clip light.

It depends on the PROGRAM material AND any other processing you are doing.

If you are running compressed MP3s and running into a limiter or compressor of some sort, then YES, you could easily pull 5A or more each.

But with wide dynamic range material, and just tickling the clip lights, the current draw will be much less.

There is NO easy answer and the TRUE simple answer is that it will change for each song.

Audio is a dynamic changing situation.

What you are asking is like if I asked you "How fast do you drive"  And I only want ONE answer!

If you say 55mph, then I would say you have a lot of guts to drive through your neighborhood or down your driveway that fast-------

If you say 35, then I CERTAINLY don't want you anywhere near the highways I drive on.

You see, there IS NO simple 1 answer for a dynamic situation.

Sure you can speculate and average and all of that, but what you end up with are WRONG answers for a particular situation.

By the way, you fog machine does not draw 6 amps.  It will when it is heating up, but not when it is already heated and waiting for use.

There are some things that pull a constant current-a light bulb in your house, your DJ mixer (but actually it does vary a tad bit depending on how many LEDs you light up at one particular time---

Simple answers result in wrong answers.
Title: Re: JBL SRX815P Power Draw Question
Post by: Rob Spence on July 31, 2016, 12:53:11 PM
So...... (and sorry to be a bit ignorant in this area) ......if I'm using these speakers "normally" (i.e. barely into the limiting) should I be expecting to draw 5.2 amps from each one?

Ah, normal use is not ever in the limiters. If you are, you don't have enough "rig for the gig"™


Sent from my iPad using Tapatalk HD
Title: Re: JBL SRX815P Power Draw Question
Post by: Bob Leonard on July 31, 2016, 02:38:37 PM
What does being new have anything to do with power draw?
Are these just new specs or did they actually change something?

Because the speakers are new to him.

OP, Just use the max figure given by JBL when considering current draw and live life to it's fullest.
Title: Re: JBL SRX815P Power Draw Question
Post by: Lyle Williams on August 01, 2016, 02:58:47 AM
Lots of people operate pairs of powered speakers from one circuit, so in general what the OP wants to do is OK.

He should spend $20 on a green power meter so he can measure the draw when playing his chosen material.  That way he will know how far he is from the edge.
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on August 01, 2016, 10:07:46 PM
Presumably CYA. The spec sheet still says 2.2A 1/8 power.

By "CYA" do you mean cover my ass? :P

...or is there some audio-geek term with CYA as an acronym?  ;)
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on August 01, 2016, 10:11:45 PM
It is not the peak power, but rather the AVERAGE power.

It is entirely possible to have them pull 5A each and never hit a clip light.

It depends on the PROGRAM material AND any other processing you are doing.

If you are running compressed MP3s and running into a limiter or compressor of some sort, then YES, you could easily pull 5A or more each.

But with wide dynamic range material, and just tickling the clip lights, the current draw will be much less.

There is NO easy answer and the TRUE simple answer is that it will change for each song.

Audio is a dynamic changing situation.

What you are asking is like if I asked you "How fast do you drive"  And I only want ONE answer!

If you say 55mph, then I would say you have a lot of guts to drive through your neighborhood or down your driveway that fast-------

If you say 35, then I CERTAINLY don't want you anywhere near the highways I drive on.

You see, there IS NO simple 1 answer for a dynamic situation.

Sure you can speculate and average and all of that, but what you end up with are WRONG answers for a particular situation.

By the way, you fog machine does not draw 6 amps.  It will when it is heating up, but not when it is already heated and waiting for use.

There are some things that pull a constant current-a light bulb in your house, your DJ mixer (but actually it does vary a tad bit depending on how many LEDs you light up at one particular time---

Simple answers result in wrong answers.

Thanks for your reply.  :) Yes, I know that about my fog machine; however, the heater constantly turns on and off to keep it at operating temperature, so I've always found it to be best practice to put it on a different circuit.
Title: Re: JBL SRX815P Power Draw Question
Post by: Ray Aberle on August 01, 2016, 10:11:53 PM
Okay... so... around the same time I posted this I emailed JBL and a "technical support specialist" gave me this answer:

"Each NEW SRX815p is actually going to now draw  5.2 'Normal' and 6.25 amps 'MAX'".

...what?

So they upgraded the speakers. So "new" means "from this point on." I suspect that based on the "is actually going to now draw..." verbiage.

-Ray
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on August 01, 2016, 10:14:03 PM
Ah, normal use is not ever in the limiters. If you are, you don't have enough "rig for the gig"™


Sent from my iPad using Tapatalk HD

I am a mobile DJ and I will occasionally push my speakers to where they are limiting a little bit towards the end of some nights, when the crowd is super rowdy. And I think that's okay to do  :)
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on August 01, 2016, 10:23:42 PM
Lots of people operate pairs of powered speakers from one circuit, so in general what the OP wants to do is OK.

He should spend $20 on a green power meter so he can measure the draw when playing his chosen material.  That way he will know how far he is from the edge.

I actually bought a power meter last week and plugged my current Yorkville speakers into it!  :D The specs for them are listed as 2.4 A "normal" and 3.0 A "max" each. I put on some of the pop music at the volume I would normally be sitting at during peak hours, and I was only pulling 3.2 amps total, for both speakers.

So...

Correct me if I'm wrong... those JBLs are going to draw anywhere from next to nothing all the way up to 5.2 amps, depending on how hard I'm pushing them? However, going by what I discovered with the power meter, they're "probably" going to not draw too much more than the Yorkvilles do under "MY" normal usage?
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on August 01, 2016, 10:26:08 PM
So they upgraded the speakers. So "new" means "from this point on." I suspect that based on the "is actually going to now draw..." verbiage.

-Ray

That's what I understood it to mean as well. But it seemed a bit high to me...? I emailed back to clarify and never got a reply.  :(
Title: Re: JBL SRX815P Power Draw Question
Post by: Andrew Zannetos on August 01, 2016, 11:03:17 PM
That's what I understood it to mean as well. But it seemed a bit high to me...? I emailed back to clarify and never got a reply.  :(

Call them if you want a response. I've never had luck with emailing JBL.
Title: Re: JBL SRX815P Power Draw Question
Post by: Tim McCulloch on August 01, 2016, 11:46:10 PM

Correct me if I'm wrong... those JBLs are going to draw anywhere from next to nothing all the way up to 5.2 amps, depending on how hard I'm pushing them? However, going by what I discovered with the power meter, they're "probably" going to not draw too much more than the Yorkvilles do under "MY" normal usage?

Expansion more than correction:  it depends.  Yeah.  Mostly it depends on any difference between the Yorkies and JBLs in how much electricity it takes to make equal SPL.  The reality is that about 5.6 Amperes is "Full Tilt Boogie" and it looks like that's a brick wall of some kind.

Use #12 AWG extension cords.  Use the shortest length you can for each run.  Don't put more than 12 Amperes of load on a 15 amp circuit; 17 Amperes loading on a 20 amp circuit.  At that point you've done all you can do and you're at the mercy of the facility wiring.
Title: Re: JBL SRX815P Power Draw Question
Post by: Chris Poynter on August 02, 2016, 10:19:21 PM
Well, I heard back from JBL:

I think it was all just a type error.
The product is still the same.

Your probably never going to have them above 3 amps.
At 3 amps these speakers are extremely loud!
 
Most DJ’s never have enough volume and push the hell out of everything they have.
 
It’s all variable.
Depending on how loud you need it.
 
Basically Normal is an opinion….


I ordered a pair today.  ;)