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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 => LAB Subwoofer Forum => Topic started by: Bruce Johnson on August 03, 2017, 03:36:51 PM
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Sorry if this I am putting this in the wrong forum.
Question: Does anyone know if it is okay to daisy chain the JBL SRX828SP to itself.
The sub has 2 XLR inputs for channel 1 & 2 each. They both have direct XLR outs. Can I daisy chain channel 1's direct out to channel 2's input?
I am guessing it would be fine for instances where I am not running a stereo signal.
Thanks,
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Bruce, you could do this, but there is no reason to. There are two input channels so a single sub can be used with stereo full range top speakers by using the "thru" outputs. Plugging in stereo and on thru gets both left and right signals into the sub where they are summed to mono. These are only input channels for the sub and are not connected to two separate amps in the sub. The sub itself is always mono.
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Got it.
I thought with only 1 input I was using half of the sub.
thanks for the explanation.
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Got it.
I thought with only 1 input I was using half of the sub.
thanks for the explanation.
We do this with a Y cord, but chaining the two channels does the same thing. It offers a 6db measured increase in SPL. I'm sure you could get the same increase by adjusting the attenuation, but it's easy enough to do and it makes me feel like we're getting everything they're worth.
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When I use a 'Y' cord I always feel like I am splitting/cutting the signal in half.
Whenever possible I stray away from adapters. Empahsis on 'whenever possible'
Bruce
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When I use a 'Y' cord I always feel like I am splitting/cutting the signal in half.
Whenever possible I stray away from adapters. Empahsis on 'whenever possible'
Bruce
You are not losing any signal when you Y, UNTIL you start to Y a lot.
A good rule of thumb is that as long as the total load impedance is 10x the source impedance, you will not have signal loss.
Of course if you were to plug into both of the inputs of the OP speaker, then the impedance load that the source "sees" would be half of a single channel.
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+1 for Ivan . . . again!
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We do this with a Y cord, but chaining the two channels does the same thing. It offers a 6db measured increase in SPL.
It DOES NOT get you 6dB in overall SPL, ONLY a 6dB gain in sensitivity, at the expense of more setup time.
So it just takes less drive voltage to get to a specific SPL.
The max SPL WILL NOT increase any amount.
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It DOES NOT get you 6dB in overall SPL, ONLY a 6dB gain in sensitivity, at the expense of more setup time.
So it just takes less drive voltage to get to a specific SPL.
The max SPL WILL NOT increase any amount.
When I did this I measured an increase in volume of 3db. That was with the output volume all the way up.
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When I did this I measured an increase in volume of 3db. That was with the output volume all the way up.
The volume control has nothing to do with the actual output capability.
You could turn it almost all the way down, and the cabinet would still be able to deliver full SPL performance.
The volume control is NOT a wattage control, but simply a sensitivity control.
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The volume control has nothing to do with the actual output capability.
You could turn it almost all the way down, and the cabinet would still be able to deliver full SPL performance.
The volume control is NOT a wattage control, but simply a sensitivity control.
You're both saying the same thing.
Connect both inputs together (with a Y-split or using the loopthrough), and the signal going into the sub has increased by 6dB. So long as you're not touching the limiters, there will be a 6dB gain in output.
The box will still limit at the same time, and with this method you're 6dB closer to the limiters.
I've read about users struggling to get enough level out of these boxes, though, and having to go into the DSP to increase input gains.
For the sake of a patch cable, this gets you +6dB sensitivity without doing anything scary. I'd be hesitant to go into the DSP, and I'm pretty confident with these things.
Chris
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You're both saying the same thing.
Connect both inputs together (with a Y-split or using the loopthrough), and the signal going into the sub has increased by 6dB. So long as you're not touching the limiters, there will be a 6dB gain in output.
The box will still limit at the same time, and with this method you're 6dB closer to the limiters.
I've read about users struggling to get enough level out of these boxes, though, and having to go into the DSP to increase input gains.
For the sake of a patch cable, this gets you +6dB sensitivity without doing anything scary. I'd be hesitant to go into the DSP, and I'm pretty confident with these things.
Chris
This is a recurrent theme. What's up will all these messages spooking new users?
There are several places you can add make up gain but surely it's not more complicated that the input strip on an x32
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When I first got my SRX828p I noticed I had to push the gain up on the speaker input to get the same volume as my other comparable subs just like everyone else.
However, although I considered using some of the creative 'fixes' posted here, I chose not to do anything other than leave the DSP settings as they are on the sub, make some subtle changes to my gain structure overall and I can honestly say I have had fantastic results with levels that are quite impressive from this sub. Same with my SRX818p's also.
I am probably too conservative but I worry that using these 'compression make up gain' and 'Y cable ' methods will push the cabs beyond what they were designed to do so I stay safe myself. If I didn't have enough SPL keeping things the way I do, I'd just buy something that met my needs without any weird and wonderful tricks.
I am not in any way passing judgement on anyone here who is running their system using these methods - I just feel safer avoiding them myself.
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I am probably too conservative but I worry that using these 'compression make up gain' and 'Y cable ' methods will push the cabs beyond what they were designed to do so I stay safe myself.
It doesn't matter where the extra gain comes from (simply turning up a level someplace in the system or Ying the inputs), the cabinet WILL NOT get any louder (max SPL) or you will not be pushing it anyway vs another.
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It doesn't matter where the extra gain comes from (simply turning up a level someplace in the system or Ying the inputs), the cabinet WILL NOT get any louder (max SPL) or you will not be pushing it anyway vs another.
So no need to do anything else than plug in and set gain structure - just like I am doing.
However, others have said they get more SPL by using these other methods.
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So no need to do anything else than plug in and set gain structure - just like I am doing.
However, others have said they get more SPL by using these other methods.
Yeah, they THINK that because they hear the sub is now louder than it was, with the same input signal. What they don't realize is they've essentially just turned it up and have removed that 6dB for the inventory of available output.
Your approach is the correct one, Debbie, so don't let the pseud-physics folks sway your ways.
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Yeah, they THINK that because they hear the sub is now louder than it was, with the same input signal. What they don't realize is they've essentially just turned it up and have removed that 6dB for the inventory of available output.
Your approach is the correct one, Debbie, so don't let the pseud-physics folks sway your ways.
:D
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Yeah, they THINK that because they hear the sub is now louder than it was, with the same input signal. What they don't realize is they've essentially just turned it up and have removed that 6dB for the inventory of available output.
Your approach is the correct one, Debbie, so don't let the pseud-physics folks sway your ways.
I moved away from the Y cable and finally found what I think is a good balance between my tops & sub's. My point was that I measured 3db of added output with the Y cable - not 6 db. I too stayed out of the dsp, and get great results with these portable speakers.
What if you are to the point where you're clipping the output of your mixer? I run my channel inputs pretty hot, and have has the main output in the red on several occasions.
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What if you are to the point where you're clipping the output of your mixer? I run my channel inputs pretty hot, and have has the main output in the red on several occasions.
I believe that is called "not enough rig for the gig" ™. No reason to be clipping any gain stage...
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I believe that is called "not enough rig for the gig" ™. No reason to be clipping any gain stage...
The question was aimed at the Y cord option to get added gain out of the system. Tim's post suggested to simply turn up the main output on the mixer. If there's no room to do so, then why not use a Y cord for an extra 3 db?
I'm not saying I need this, but just trying to get a clear answer.
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The question was aimed at the Y cord option to get added gain out of the system. Tim's post suggested to simply turn up the main output on the mixer. If there's no room to do so, then why not use a Y cord for an extra 3 db?
I'm not saying I need this, but just trying to get a clear answer.
Hi Steve, what Ivan was saying is that the Y cable increases input sensitivity, not gain. The max output the speaker is capable of doesn't change. If you get 3 db by using a Y cable, you could also achieve this with a stronger input signal.
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Hi Steve, what Ivan was saying is that the Y cable increases input sensitivity, not gain. The max output the speaker is capable of doesn't change. If you get 3 db by using a Y cable, you could also achieve this with a stronger input signal.
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Still don't understand. Where would you get that stronger input signal?
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Still don't understand. Where would you get that stronger input signal?
Turn up the source (mixer main out or inputs)?
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Still don't understand. Where would you get that stronger input signal?
Anywhere in the signal chain before the actual amplifier technically classifies as "input signal" and that includes the DSP built into these SRX powered boxes. So the moral of this story about a very beaten dead horse is.. get the app already and crank up some gains until the box behaves like others in your inventory. There is NO danger in doing this.. the limiters will still protect the same as before.
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Still don't understand. Where would you get that stronger input signal?
Because the input to the sub has sufficiently high impedance, it acts as a bridge rather than a load (so it does not reduce in the voltage); doubling the number of inputs with the same voltage increases the voltage "seen" by the amplifier input.
Or you could turn up the subwoofer drive level at the console or turn down your top boxes by -3dB (or more, to taste) if you loop through the subs (or tops) for inputs and turn up the console output.
This ain't rocket surgery and I'm alternately amused and frustrated that this simple concept has generated so much unnecessary work, much of it based on legacy drive level expectations that are older than many of the participants here.
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Because the input to the sub has sufficiently high impedance, it acts as a bridge rather than a load (so it does not reduce in the voltage); doubling the number of inputs with the same voltage increases the voltage "seen" by the amplifier input.
Or you could turn up the subwoofer drive level at the console or turn down your top boxes by -3dB (or more, to taste) if you loop through the subs (or tops) for inputs and turn up the console output.
This ain't rocket surgery and I'm alternately amused and frustrated that this simple concept has generated so much unnecessary work, much of it based on legacy drive level expectations that are older than many of the participants here.
I've already stated that there is no headroom left at the mixer. The sub is turned up all the way, and the tops are already set at a reduced level.
The Y cord will get you an added 3 db of volume if you are out of gas everywhere else. I've decided that I don't need it, nor do I need to go into the dsp to add makeup gain via the compressor.
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Turn up the source (mixer main out or inputs)?
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The source (input gains and master output) is all the way up. There is no headroom left.
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Are you using the proper low filters on each channel strip
that do not need low end ?
it sounds like that could be where your head room is being maxxed.
Worth visiting
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The source (input gains and master output) is all the way up. There is no headroom left.
Do the output meters of the mixer reflect this? Or are the faders physically maxed?
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Are you using the proper low filters on each channel strip
that do not need low end ?
it sounds like that could be where your head room is being maxxed.
Worth visiting
Yes, I'm using the high-pass on most channels. Mind you, I have the headroom I need. The discussion is about Y-ing the inputs to get more gain from the sub. JBL used a rather low input setting on these subs, so you have to drive them a little harder.
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Do the output meters of the mixer reflect this? Or are the faders physically maxed?
Yes, the meters are hitting the red, and no, the fader is not fully up.
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Yes, the meters are hitting the red, and no, the fader is not fully up.
You have something else reducing level between the mixer and powered speakers. I took an old Mackie analog 1604 and I can clip the 828sp before any audible distortion from the mixer.
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Yes, the meters are hitting the red, and no, the fader is not fully up.
Steve, what mixer are you using?
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Now we are getting somewhere. The mixer is NOT the problem.
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You have something else reducing level between the mixer and powered speakers. I took an old Mackie analog 1604 and I can clip the 828sp before any audible distortion from the mixer.
Again, I don't have a problem with my system. I am only trying to find out why posters are saying that using both inputs is not seeing a volume increase on any of these boxes. When I first got my sub's, I measured (using a test tone) and saw a 3 db increase in the volume at 60 Hz by using a Y cable to the inputs. At one time I felt I needed more output from the sub in order to get the volume I wanted, but I have since found a nice balance between the sub and top, without using the Y cable. I ran the system last night with the board meters staying in the green, and it worked flawlessly for a crowd of 1000 (not concert level). The only thing between the board (Mackie DL1608) and the speakers is an xlr cable.
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Again, I don't have a problem with my system. I am only trying to find out why posters are saying that using both inputs is not seeing a volume increase on any of these boxes. When I first got my sub's, I measured (using a test tone) and saw a 3 db increase in the volume at 60 Hz by using a Y cable to the inputs. At one time I felt I needed more output from the sub in order to get the volume I wanted, but I have since found a nice balance between the sub and top, without using the Y cable. I ran the system last night with the board meters staying in the green, and it worked flawlessly for a crowd of 1000 (not concert level). The only thing between the board (Mackie DL1608) and the speakers is an xlr cable.
Yes, you get a raise in audible level when you double up the inputs to the powered speaker. What you don't get, and what you are being told, is that you do not get a raise in maximum output of the speakers. You have raised the input level to the speaker, but it still has the same maximum output level.
You can accomplish the same thing by increasing the send level to the speakers that same amount at the console output. The console will be able to drive the speakers into clipping at about the same time as the console goes into clipping.
Mac
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Whenever I'm not getting enough sub, I bring more subs. ;)
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Yes, you get a raise in audible level when you double up the inputs to the powered speaker. What you don't get, and what you are being told, is that you do not get a raise in maximum output of the speakers. You have raised the input level to the speaker, but it still has the same maximum output level.
You can accomplish the same thing by increasing the send level to the speakers that same amount at the console output. The console will be able to drive the speakers into clipping at about the same time as the console goes into clipping.
Mac
Thanks Mac. That last sentence is making it clear to me what's being said.
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Whenever I'm not getting enough sub, I bring more subs. ;)
That would help if the sub is out of output. His is not.
Steve, how are the meter segments layed out? How many yellow and red SEGMENTS? It there an actual clip indicator for the mixer?
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Am I missing something here? This seems like basic gain staging. Run noise or music through the system. Set the main outs where you want to run them. Set the dsp in the speakers accordingly to get the SPL you desire and balance the system.
I'm asking as I am missing the apparent complexity of the issue.
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Am I missing something here? This seems like basic gain staging. Run noise or music through the system. Set the main outs where you want to run them. Set the dsp in the speakers accordingly to get the SPL you desire and balance the system.
I'm asking as I am missing the apparent complexity of the issue.
It is simply that JBL made the dubious choice of having the speaker amp gain be less than all their others and the rest of the competition. Therefore when substituting the new for an old, it is quieter with same drive.
This has confused most who bought them expecting more rather than less.
Another reason I don't shop at the Harmon store. 🙄
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It is simply that JBL made the dubious choice of having the speaker amp gain be less than all their others and the rest of the competition. Therefore when substituting the new for an old, it is quieter with same drive.
There is another advantage to having a lower sensitivity.
It can reduce the system noise, much like putting a pad between a processor and amplifier.
So when you want the most dynamic range in a system, a powered speaker with less gain is a start.
Some call it a disadvantage-others call it advantage.
So-once again-it depends on what somebody is looking for and what is most important for a particular situation.
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It is simply that JBL made the dubious choice of having the speaker amp gain be less than all their others and the rest of the competition. Therefore when substituting the new for an old, it is quieter with same drive.
This has confused most who bought them expecting more rather than less.
Another reason I don't shop at the Harmon store. 🙄
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I guess I understand the frustration when looking at it from this point of view. Thanks Rob.
I guess I'm used to dealing with mismatched gear and consider it par for the course to set gain structure according to what's in the rig. I wouldn't mess around with wye adapters. I would just change the gain setting to +6 in the DSP and be done with it.
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I guess I understand the frustration when looking at it from this point of view. Thanks Rob.
I guess I'm used to dealing with mismatched gear and consider it par for the course to set gain structure according to what's in the rig. I wouldn't mess around with wye adapters. I would just change the gain setting to +6 in the DSP and be done with it.
I might take some flack for this, so I'll preface anything I say with the disclaimer that I am a consumer, not a sound professional, purchasing product the way a significant number of end users do. Meaning, I'm running a small rig that can be used locally for a small band, DJ, etc. I have personally spoken with two people using the SRX 800 series who run live sound for what I'd consider medium sized outdoor events, both used 4 SRX tops, and 8 SRX828's in that scenario, both had bigger line array systems for anything requiring more. Both had very positive things to say about the SRX 800 series, so I'm confident in the right hands they are highly capable
That being said, to me, they seem mismatched from the factory, in this regard. First off, the input sensitivity options between the subs and the tops don't have identical options. From what I've read, this can become an issue for some, and I was one of them. I run a decent quality, but older technology analog mixer, I did have an issue getting a strong input signal to the amp, not an issue getting output from the box.
Many simply suggested cranking the output of the box, and I suppose that's doable, but to my simply complex thinking, that's raising the noise floor unnecessarily. Yes, there's an ability to use make up gain once the internal dsp is accessed, but many consumers don't do that.
As previously stated here and elsewhere, JBL did include a consumer setting on the top boxes. This bumps the input sensitivity 12db, and for me was the simplest and easiest way to get good input levels without driving my board to the waaay upper levels. I ended up dialing back about-5 on the input sensitivity once it was set to consumer, netting about a 7db hotter input signal than what is factory set at the line level setting. That got me a great balance for both input and output levels, and the 835's sounded freaking awesome.
Problem is, that's not available on the subs, only the line level input sensitivity setting is available. Here's the thing, and I'm definitely not 100% sure, but I don't recall seeing anything other than line or mic level input sensitivity settings on any other powered boxes. So, why did JBL do this? My guess is because some want the lower input sensitivity, and some don't, no problem. But, if you're designing a matched system, why wouldn't you have that availability between the entire series.
For that reason, I say they are "mismatched" amongst themselves..
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The level of complexity you are adding to this continues to baffle me. If this was an analog speaker it would be analagous to saying I have to turn the input level up to 6 o'clock to get the same output. Would you still buy the speakers?
Input sensitivity is a bad criteria to jusge them by,
Instead of cranking up the input gain on the tops why dont you turn it down to match the subs?.
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The level of complexity you are adding to this continues to baffle me. If this was an analog speaker it would be analagous to saying I have to turn the input level up to 6 o'clock to get the same output. Would you still buy the speakers?
Input sensitivity is a bad criteria to jusge them by,
Instead of cranking up the input gain on the tops why dont you turn it down to match the subs?.
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I think I said several positive things about the 835's. Whether it's been made complex or not I don't know, but the settings on the speakers themselves are different, that much is true.
I also had to push my board way higher than ever before without altering the input sensitivity to get decent output from them. Once I changed the input sensitivity to consumer I was able to run the mixer in the same operating ranges as before. Coincidentally, that operating range was also Allen and Heaths' recommended levels per their manual, and yes I pulled it out and reread it to be sure. I'm not the only one who had a similar experience.
Obviously it's no big deal to crank the output on one and rollback on another, but when people are going -3 to -5 on the tops, +6 or more on the subs to get them balanced, I'd say that's a bit of a gap for a matched system, but that's just my opinion. Furthermore, rolling back the mains that much and leaving them on the line setting, so they could be matched with the subs didn't provide enough output for MY satisfaction, and I'd clip the mixer, yes without the driverack, before I'd reach limit on the mains.
Once again, I was definitely able to get them to sound Really Good, but these are the real world experiences I've had. The two guys I spoke with run their subs towards max, and the mains rolled back. Just like you said, so no big deal.
My reply was to the post about running mix matched setups, and in some ways, I think these are somewhat themselves. Just my opinion, ok if you don't agree. I can't explain why some don't have issues and some do, but I've dug enough into this to know I'm not the only one who's had some struggles here.
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Scott G, the struggle is in your head. That you have external company is not validation.
Your MixWiz has the same output voltage capability as many (most?) other mixers. The output voltage swing is determined by the console PSU and output circuit capability at that max voltage. A-H (and Yamaha and others) suggest the level you're operating at to preserve about 20dB of headroom for transient peaks (the kind that don't show up on the meter, they're so fast). It's not because there is a majik sweet spot or that the mixer will sound bad/explode/morph into a Model T if you run it 6dB hotter.
Your desire to have everything match up right out of the box is not a bad thing in and of itself, but realize that JBL has more than 1 model of top box and more than 1 subwoofer model in the line. The "consumer" input level selection exists because JBL thought that those models were most likely to be used by less experienced operators, driving them with consumer type mixers (which your MixWiz is not).
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I might take some flack for this, so I'll preface anything I say with the disclaimer that I am a consumer, not a sound professional, purchasing product the way a significant number of end users do. Meaning, I'm running a small rig that can be used locally for a small band, DJ, etc. I have personally spoken with two people using the SRX 800 series who run live sound for what I'd consider medium sized outdoor events, both used 4 SRX tops, and 8 SRX828's in that scenario, both had bigger line array systems for anything requiring more. Both had very positive things to say about the SRX 800 series, so I'm confident in the right hands they are highly capable
That being said, to me, they seem mismatched from the factory, in this regard. First off, the input sensitivity options between the subs and the tops don't have identical options. From what I've read, this can become an issue for some, and I was one of them. I run a decent quality, but older technology analog mixer, I did have an issue getting a strong input signal to the amp, not an issue getting output from the box.
Many simply suggested cranking the output of the box, and I suppose that's doable, but to my simply complex thinking, that's raising the noise floor unnecessarily. Yes, there's an ability to use make up gain once the internal dsp is accessed, but many consumers don't do that.
As previously stated here and elsewhere, JBL did include a consumer setting on the top boxes. This bumps the input sensitivity 12db, and for me was the simplest and easiest way to get good input levels without driving my board to the waaay upper levels. I ended up dialing back about-5 on the input sensitivity once it was set to consumer, netting about a 7db hotter input signal than what is factory set at the line level setting. That got me a great balance for both input and output levels, and the 835's sounded freaking awesome.
Problem is, that's not available on the subs, only the line level input sensitivity setting is available. Here's the thing, and I'm definitely not 100% sure, but I don't recall seeing anything other than line or mic level input sensitivity settings on any other powered boxes. So, why did JBL do this? My guess is because some want the lower input sensitivity, and some don't, no problem. But, if you're designing a matched system, why wouldn't you have that availability between the entire series.
For that reason, I say they are "mismatched" amongst themselves..
Agree 100%. I was hoping for a firmware update for this but it's probably not likely.
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Agree 100%. I was hoping for a firmware update for this but it's probably not likely.
Thank you, I think some skipped over the disclaimer part.
I've been very cautious with my wording because I do feel the SRX 800's are a great product and sound really good once I got them tuned to my liking. Furthermore, they have a level of dsp available that's far beyond just about everything else in its price range. For you more experienced guys that's a plus. For me, it added a level of complexity that I wasn't expecting, or looking for. Perhaps I should have done more research, so that's really my fault.