ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 ... 3 4 [5] 6 7   Go Down

Author Topic: JBL's New SRX800 Series Subs - How do they compare?  (Read 26199 times)

Tom Bryant

  • Newbie
  • *
  • Offline Offline
  • Posts: 5
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #40 on: October 13, 2015, 03:27:15 pm »

I don't even think it's a terminology thing..................  I never really brought up unity and when I did, it was more for reference, not an operational standard. I only mention that the SRX-800 has a unity gain setting. The metering is in dbfs however and unity for digital technically doesn't exist.

The only point I am trying to make is that the SRX series will likely have most users wanting to find more SPL sooner so it matches their current operational standards. There is nothing wrong with the SRX powered line at all. The way it works is simple:

The max input before clipping is 21dbu, at which point the output of the amp will be clipping as well.



The level metering is different than most all are used to. It is in dbfs ( digital scale ) and has no relation to analog metering levels.

The SPL produced by the speaker is pretty linear to its input. The ratio of input to output makes sense, but is not akin to the way other equipment seems to work. Many are used to having the SPL needed by about the time unity gain is hit on the mixers output buss. These speakers will not start producing that same relative level until you are producing right around 16dbu. This leaves about 5-6dbu of headroom in the speaker. Many lower end mixers will be nearly out of headroom by then. In essence the output of the mixer will be close to clipping right about the time the speaker is.

The +12db available at the speakers master output is the quick and easy way to get you more SPL quicker ( by +12db of course ), but is only giving you exactly what it says. The little cheat dubbed the " make up gain technique " allow you to acquire +14-16db of gain before clipping at the same point as simply turning up the master level to +12. More for less; no more, no less.......

Forget that I ever mentioned unity. I know what it is. It is not relevant to the way these speakers operate other than for reference.
I played outside this weekend and had my 2-818's on on each side about 20ft apart with +15 comp make up gain and the volume on the back at 7.  The level indicators on the the back were only hitting about 80 to 90% during a loud drum solo, with the kick real loud and chest pounding kick.  I think this technique is great to get the most spl out of the subs and I had more to give on the master volume on the mixer!   I had my 812 top at +10 comp and the volume on the back at 0.  The system sounds great, balanced and had lots of compliments on the sound Sunday!  I like the sound of my new SRX800's for FOH better that my old SRX718's with a Itech4000.
 
Thanks for the help on dialing in my new SRX818's.
Logged

Scott Holtzman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4098
  • Ghost AV - Avon Lake, OH
    • Ghost Audio Visual Systems, LLC
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #41 on: October 16, 2015, 03:02:04 am »

Interesting point is since the processing is in the digital domain  no power is added it's just a shift to the right.  The a/d converter is where the power is made.  Being an analog device it will have an output power rating and a signal to noise ratio.  In a powered speaker gain staging past the input is irrelevant to the user. 

Sent from my SM-T800 using Tapatalk
« Last Edit: October 16, 2015, 04:09:00 pm by Scott Holtzman »
Logged
Scott AKA "Skyking" Holtzman
River Delta Audio is now:

Ghost Audio Visual Solutions, LLC
Cleveland OH
www.ghostav.rocks

Marjan Milosevic

  • Full Member
  • ***
  • Offline Offline
  • Posts: 218
    • MM-acoustics
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #42 on: October 16, 2015, 01:04:59 pm »

I wonder how they come up with the 141db peak if the amp is 2000W peak.

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8243
  • Atlanta GA
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #43 on: October 16, 2015, 01:49:21 pm »

I wonder how they come up with the 141db peak if the amp is 2000W peak.
Since 2000 watts is a gain of 33dB, then that would mean the sensitivity HAS to be 108dB with 1 watt applied (at some freq----) for a sub.
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Luke Geis

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1141
    • Owner of Endever Music Production's
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #44 on: October 17, 2015, 04:44:09 am »

I will put it simply...... The SRX line will not produce the stated peak SPL ever....... Period. They will get very close and sound good doing it though. Looking through the deep editing features it almost seems possible to bypass a couple of the safety features, or at least augment even further than what has been done thus far. This may yield the results they spec., but I doubt it?
Logged
I don't understand how you can't hear your self

Jamin Lynch

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1754
  • Corpus Christi, TX.
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #45 on: October 26, 2015, 03:14:00 pm »

I will put it simply...... The SRX line will not produce the stated peak SPL ever....... Period. They will get very close and sound good doing it though. Looking through the deep editing features it almost seems possible to bypass a couple of the safety features, or at least augment even further than what has been done thus far. This may yield the results they spec., but I doubt it?

So is JBL lying, misleading the facts, incorrect, or don't know what they are doing? What are you implying?
« Last Edit: October 26, 2015, 03:25:36 pm by Jamin Lynch »
Logged
Authorized Dealer for: JBL, Crown, Soundcraft, dbx, Lexicon, AKG, BSS, Sennheiser, CBI Cables, Countryman, ProCo Sound, Da-Lite Screens, Dunlop, Digitech, Grundorf, Lumastream Lighting, Hosa, Gator Cases, Perdue Acoustics, Optoma, Cosmic Truss, and others. jlsoundpro@gmail.com

Using: JBL VP tops, subs, and monitors, Si Performer

Luke Geis

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1141
    • Owner of Endever Music Production's
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #46 on: October 26, 2015, 10:21:25 pm »

I don't think they are lying. I think they did the test in a way that gets the number. A pink noise burst with a 3db crest factor perhaps? I don't know. What I am saying is that not You, Me, nor anyone else, will never see that spec come to life in real world use. As far as I can tell the speakers will produce an at best peak of about 3-6db below the stated peak spec. This is a short term allowance though. The true output that is practical for these speakers is closer to 6-9db lower than the stated peak. Still not bad though when you consider that your sitting at about 130db in SPL that can actually be produced! If you get that loud I don't want to be around.

I took some time to play with the panels that Audio Architect has. It offers some deep editing and more metering options. I didn't find any way to alter the output production beyond what is available in the normal editing window, but did find some other interesting things I will note below:

1. You can see the metering for just about everything. Temperature, incoming voltage, output voltage; RMS, peak and channel gains. If you want to see the meter for something, you can probably set it up to monitor it.

2. You can edit the amps output channels independently for gain, EQ, limiting and a couple other options. You can turn off the lows or the highs if you want.

3. There is auxillary EQ, guest EQ and other options for settings that you allow for multiple uses.

4. You can use different EQ's for each input channel and adjust limiting and other features independent of the other channel.

While I was not able to get more from the speaker it was neat to see what it was doing. Some things I noticed. The temperature meter stays pretty stable once up and running. There is a lot of thermal room in these amps as far as I can tell. The limiting of the outputs did not actually show up for me even though I was showing limiting in the UI. It leads me to believe that the limiting you do see is in the digital realm and not necessarily at the amps? Still not confirmed with that though....... I have still yet to see the limit light in the UI change from green to yellow. How can you be clipping at the amps and not have any limiting? I think the UI is designed to scare you a little. There is more in there for sure, otherwise why would they give you the ability to do so? The EQ has the option to use an all pass filter in which you can add gain........ Another option I have not played with yet. So to cap things up, JBL is probably not lying at all, but the product they have provided will require some user tweaks to get close to the stated specs. I stand by my statement that the speaker will not produce the stated peak number though. You would not want or hopefully need to though. They sound real good all the way to the point where they are more than loud enough for their intended use. I can get 116db C at 26' from the speakers at the point when the UI says they are limiting. This is 6db more than I thought I would get and 16db more than the venue wanted to produce. That is also 3 generations away from the speakers! The power is there, they just need a little push is all.
Logged
I don't understand how you can't hear your self

David Sturzenbecher

  • Hero Member
  • *****
  • Online Online
  • Posts: 1243
    • Sturz Audio
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #47 on: October 26, 2015, 11:22:46 pm »

The limiting of the outputs did not actually show up for me even though I was showing limiting in the UI. It leads me to believe that the limiting you do see is in the digital realm and not necessarily at the amps? Still not confirmed with that though....... I have still yet to see the limit light in the UI change from green to yellow. How can you be clipping at the amps and not have any limiting? I think the UI is designed to scare you a little.

Luke,
I do not have one of these speakers so I cannot test the following, maybe you can.    The green limit light on the stock UI is derived from the "common output" object.   This is the first series of devices where I have seen this specific block. It's possible this object is just an aggregate of the individual limiter blocks from the entire amp.    You may try placing the "gain meter" from within the peak limiter, rms limiter, thermal limiter, or processing output objects onto a custom panel meter and check limiting that way?   Those are the usual suspects for limiting on most crown amps I have come across. You could also temporarily adjust the limiter voltage so something very low (10V) and check to see if that trips the LED indicators.
Logged
CTS-D, CTS-I
AES Full Member

Andrew Brubaker

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 64
    • Reliquis Productions
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #48 on: October 19, 2016, 11:31:19 pm »

So my real question from all of this: do I keep my iTech 8000s and SRX728s or sell them and go for the SRX828sp? I am currently debating between buying another pair of 728s or selling it all to go with a powered solution. I currently have 4 SRX728s and 3 iTech 8000s so I could easily add another pair of subs off of the 3rd iTech.

What are peoples' thoughts now that the SRX828 has been out on the market for a while and in use?
Logged

Art Welter

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1174
Re: JBL's New SRX800 Series Subs - How do they compare?
« Reply #49 on: October 20, 2016, 09:54:41 am »

So my real question from all of this: do I keep my iTech 8000s and SRX728s or sell them and go for the SRX828sp? I am currently debating between buying another pair of 728s or selling it all to go with a powered solution. I currently have 4 SRX728s and 3 iTech 8000s so I could easily add another pair of subs off of the 3rd iTech.

What are peoples' thoughts now that the SRX828 has been out on the market for a while and in use?
I have no actual use of the SRX828, but the drivers it uses are not as good as the neodymium magnet structure differential drive drivers in the SRX728, and have no more Xmax, so from a technical standpoint the SRX828 are a step down, not up.

And the SRX peak figures are hogwash, but industry standard hogwash.

Here is an explanation of how the hogwash works:
David Gunness wrote on 4/10/14, post # 18:

https://soundforums.net/threads/9905-Compact-Power-Subs-for-Stick-mains

"OK, here we go. Once more into the breach. The reason I hate this is that in the process of explaining how our industry does specs, it appears that I am justifying practices that I actually don't agree with.

One of the reasons I don't like peak SPL specs is that "SPL", at least in textbooks, is defined as the RMS sound pressure (referenced to 2x10-5 pascals). So theoretically, there is no such thing as "peak SPL". OK, maybe that's too pedantic: we could interpret it as "peak sound pressure, expressed in units of SPL". Let's go with that.

The point is that "Peak SPL" as it is treated in the professional loudspeaker industry, is peak pressure, not "highest reading of an SPL meter" (SPL meters only measure RMS; even if there is a peak hold function, it is the "highest rms reading observed", and that includes the selected averaging time). Anyway, peak pressure is calculated using the peak voltage of the amplifier. With non-powered systems, the assumption is that a user will supply an amplifier with twice the power rating of the loudspeaker, and that the peak voltage of the amplifier is 3 dB higher than that, because amplifiers are rated with sine waves. Hence, the peak pressure should be 6 dB higher than the maximum continuous SPL.

Keep in mind that maximum continuous SPL is a survival rating, not a useability rating. Of course what would be more useful is "maximum useable SPL", but that would be signal dependent and would have to be subjectively determined. So we're stuck with a calculated value that serves only as a point of comparison: "This one's red line is 2 dB higher than this one's red line."



Art
Logged
Pages: 1 ... 3 4 [5] 6 7   Go Up
 


Page created in 0.05 seconds with 19 queries.