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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: The Classic Live Audio Board => Topic started by: Andrew Brubaker on July 11, 2012, 04:06:59 PM
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I currently have 4 JBL MRX528s and am considering switching over to the SRX728s because I have heard really good things about those subs and I need some subs that hit lower frequencies and are just tighter hitting in general. Currently I am running 2 XTi6000s in stereo doing 2100 watts to each of the MRX528s. I would look at doing the SRX728S in bridged mono off of each XTi6000 to make sure that I am getting enough power to each speaker. The question I have is will it be worth it to go from 4 subs to 2? If I had the money up front I would go ahead and but one of the SRX728s to do a side by side comparison of it vs 2 of the MRX528s.
Can anyone help me out with an opinion? Unfortunately my funds are rather limited right now so I would be selling the 4 MRX528s to purchase the 2 SRX728s plus a little extra cash on my part most likely. I just want to make sure that I'm making the right decision on this one!
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You could Rent 2 SRX 728s, and see if you can make your gigs work with them for a while. You should be able to rent a set just about anywhere. If they work fine, get them and save up for the second pair if appropriate.
Questions: Do you always use all 4 MRX? How much "rig for the gig" do they feel like? What are your business competitors bringing? What kind of application (EDM/rock)?
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I currently have 4 JBL MRX528s and am considering switching over to the SRX728s because I have heard really good things about those subs and I need some subs that hit lower frequencies and are just tighter hitting in general. Currently I am running 2 XTi6000s in stereo doing 2100 watts to each of the MRX528s. I would look at doing the SRX728S in bridged mono off of each XTi6000 to make sure that I am getting enough power to each speaker. The question I have is will it be worth it to go from 4 subs to 2? If I had the money up front I would go ahead and but one of the SRX728s to do a side by side comparison of it vs 2 of the MRX528s.
Can anyone help me out with an opinion? Unfortunately my funds are rather limited right now so I would be selling the 4 MRX528s to purchase the 2 SRX728s plus a little extra cash on my part most likely. I just want to make sure that I'm making the right decision on this one!
What's the goal here? Subs that play lower and sound tighter, or do you want louder? Two SRX728's will play lower and have a 'tighter' response than the MRX, but will likely not be louder than four MRX. What type of gigs are you using them for?
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Questions: Do you always use all 4 MRX? How much "rig for the gig" do they feel like? What are your business competitors bringing? What kind of application (EDM/rock)?
I haven't found any places in the immediate vicinity to rent from unfortunately. I found two for $900/ea which I think would be a really good deal.
I don't always use all 4. It depends on the gig but for larger gigs I use all 4. I have 4 MRX525 that I have on top of them. I have a mobile production company and do anything from dance/electronic to rock to hardcore. Basically anything.
What do you mean "rig for the gig"? From looking at SPL levels of the two different speakers and the difference in wattage I would still think that the SRX would be louder even against two MRX subs.
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What's the goal here? Subs that play lower and sound tighter, or do you want louder? Two SRX728's will play lower and have a 'tighter' response than the MRX, but will likely not be louder than four MRX. What type of gigs are you using them for?
The main goal is for overall better sounding bass. Hit tighter and lower. Louder would be nice too. From looking at SPL levels and the power output that will be hitting the SRX (6000 watts) vs the amount hitting the MRX (2100/ea) I would think that the SRX would also be louder as well but I may be wrong.
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The main goal is for overall better sounding bass. Hit tighter and lower. Louder would be nice too. From looking at SPL levels and the power output that will be hitting the SRX (6000 watts) vs the amount hitting the MRX (2100/ea) I would think that the SRX would also be louder as well but I may be wrong.
Part of the problem, especially if you are running longer cables, is that at 2 Ohms the damping factor is killing you. Bridging the amps and running them at 4 ohms will help a little (you can use slightly longer cables), but damping factor issues could have something to do with the sloppy bass you're getting.
Cheers,
Randy Hyde
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Part of the problem, especially if you are running longer cables, is that at 2 Ohms the damping factor is killing you. Bridging the amps and running them at 4 ohms will help a little (you can use slightly longer cables), but damping factor issues could have something to do with the sloppy bass you're getting.
I am running the MRX at 4 ohms each. Running the XTi6000 in stereo doing 2100 watts at 4 ohms to each speaker. I have 2 XTi6000s. Well actually 4. 2 of them for 4 subs and 2 of them for 4 mains. Cable lengths are not more than 100' and 12gauge. Typically 25 or 50' though.
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The main goal is for overall better sounding bass. Hit tighter and lower. Louder would be nice too. From looking at SPL levels and the power output that will be hitting the SRX (6000 watts) vs the amount hitting the MRX (2100/ea) I would think that the SRX would also be louder as well but I may be wrong.
Those are 1kHz ratings and hopefully you don't run 1kHz to your subs, so the actual ratings in your use would be a little less in both cases. But just using those numbers and the published sensitivity gives 130dB per MRX528S and 136dB per SRX728S, so if you compare two MRX528S boxes right next to each other so that they acoustically couple to a single SRX728S it's basically a wash. However, the SRX728S boxes would be running closer to their and the amps' limits meaning the practical output in some usage might turn out to be a bit lower. But that is just the calculated output level and not the preceived loudness.
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What do you mean "rig for the gig"? From looking at SPL levels of the two different speakers and the difference in wattage I would still think that the SRX would be louder even against two MRX subs.
"rig for the gig" comes from something I started saying about gear a long time ago. "Enough Rig for the Gig" means that you have both the coverage and output necessary to meet the demands of the act, audience, promoter and Band Engineer.
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"rig for the gig" comes from something I started saying about gear a long time ago. "Enough Rig for the Gig" means that you have both the coverage and output necessary to meet the demands of the act, audience, promoter and Band Engineer.
+1..
Hammer
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The main goal is for overall better sounding bass........... I would think that the SRX would also be louder as well but I may be wrong.
So louder is better? I think there's more to it than that.......and not just your choice of speakers.
Start with the quality and appropriateness of the initial signal being fed into the system. Proceed step by step through the signal chain. The output end of the chain is probably the wrong end to start "fixing".
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Those are 1kHz ratings and hopefully you don't run 1kHz to your subs, so the actual ratings in your use would be a little less in both cases. But just using those numbers and the published sensitivity gives 130dB per MRX528S and 136dB per SRX728S, so if you compare two MRX528S boxes right next to each other so that they acoustically couple to a single SRX728S it's basically a wash. However, the SRX728S boxes would be running closer to their and the amps' limits meaning the practical output in some usage might turn out to be a bit lower. But that is just the calculated output level and not the preceived loudness.
A wash in which's favor? The MRX would be better or the SRX? I realize that calculated output vs perceived loudness may be different from each other. I would rather have the perceived loudness be higher. For the applications that I use the subs for I need hard hitting and punchy bass that will carry well and that will be felt well. I think that is one of the things that I am not very impressed with the MRX about. You can hear the bass pretty well but they do not hit very low or very tight. They are fine for lower level applications but when I need hard hitting bass for dance music or to really feel the kick drum they leave something to be desired. Plus I think that I will have more versatility with the horizontal shape of the SRX over the vertical of the MRX. I am open to check out other subs as well if people have some opinions as to other subs I should be looking into. :)
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So louder is better? I think there's more to it than that.......and not just your choice of speakers.
Start with the quality and appropriateness of the initial signal being fed into the system. Proceed step by step through the signal chain. The output end of the chain is probably the wrong end to start "fixing".
The signal that I have coming in is at the desired gain level and I don't have any issues with the sound through the mains. When I add in the LF extension of the subs though the low end is a little muddy and leaves some to be desired. I typically run the subs on an aux and only put them on certain instruments that would need that more beefy low end that my mains can't hit very well. I have adjusted my crossover settings several times as well to get a tighter response from the subs and I have seen some improvement but am still not satisfied with the end result.
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The signal that I have coming in is at the desired gain level and I don't have any issues with the sound through the mains. When I add in the LF extension of the subs though the low end is a little muddy and leaves some to be desired. I typically run the subs on an aux and only put them on certain instruments that would need that more beefy low end that my mains can't hit very well. I have adjusted my crossover settings several times as well to get a tighter response from the subs and I have seen some improvement but am still not satisfied with the end result.
I'm still not sure you're taking into account all the various factors involved in reproducing the sound. You say that you have the desired gain level, but what does it sound like coming in? If you're getting mud in LF, it may well be mud coming in from the tone settings on the bass.
Are you taking a DI feed from the bass before it hits the amp? Are you taking a direct feed out of the bass amp? Are you miking the amp? Any or all of the above? You say that it sounds OK in the mains but not when you start adding the subs. The clarity and punch is up in the mains, so it should sound OK. The "fat meat" is down in the subs and switching subs will probably make something of a change, but the balance between the subs and the tops, the ability of the tops to keep up with the change in subs, the crossover point, any compression or other processing and so on must be taken into consideration. Change one thing, you change everything.
The fact is that there's not a lot of "hard center" LF down in the subs range to begin with. The "tightness" of the LF tends to lie above what the subs are doing.....which is to support the sound from below. Simply adding more bottom end will not help the clarity or punch of the bass guitar if the input contains a lot of ill-defined LF to begin with. GIGO.
Your quest may be righteous, but don't focus strictly on the output. You have to sort out and understand what you're being given to put out.........
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I'm still not sure you're taking into account all the various factors involved in reproducing the sound. You say that you have the desired gain level, but what does it sound like coming in? If you're getting mud in LF, it may well be mud coming in from the tone settings on the bass.
Are you taking a DI feed from the bass before it hits the amp? Are you taking a direct feed out of the bass amp? Are you miking the amp? Any or all of the above?
I am mostly speaking in generalities at this point. Since I do some DJing where the input is coming from a set source where the levels are set to nominal and I am not changing the EQ of what is coming in the difference would lie with how it is being reproduced. When doing bass guitar I often mic the cab and may also use a DI to assist the overall sound. I prefer to mic because what is coming out of the bass amp is most likely the tone that the bass player is wanting to be heard anyways. I try to have most of my faders around nominal though obviously slight variances occur. The gain is typically set so that at the loudest input coming in the meters are not clipping.
I hope I am making sense! :o
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I am mostly speaking in generalities at this point. Since I do some DJing where the input is coming from a set source where the levels are set to nominal and I am not changing the EQ of what is coming in the difference would lie with how it is being reproduced. When doing bass guitar I often mic the cab and may also use a DI to assist the overall sound. I prefer to mic because what is coming out of the bass amp is most likely the tone that the bass player is wanting to be heard anyways. I try to have most of my faders around nominal though obviously slight variances occur. The gain is typically set so that at the loudest input coming in the meters are not clipping.
I hope I am making sense! :o
The tone the bass player hears on stage has nothing to do with getting it to sit in the mix out in the "house". You need what you need, not what the bass player hears on stage.
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The tone the bass player hears on stage has nothing to do with getting it to sit in the mix out in the "house". You need what you need, not what the bass player hears on stage.
True. And I make sure to adjust for the difference in tone that I want coming through FOH. My main quest on the subs isn't as much for the actual bass as it is for a sub that is hard hitting and punchy. Something that is really good for kick and dance type music as well.
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True. And I make sure to adjust for the difference in tone that I want coming through FOH. My main quest on the subs isn't as much for the actual bass as it is for a sub that is hard hitting and punchy. Something that is really good for kick and dance type music as well.
Again, what you put into it does make a difference. You may well benefit from Mr Chiaras favorite "Transient Designer" to tailor your low end. I occasionally use the envelope mode on a TCE IIIC or more often just engage the "punch" feature on my Drawmer MX40.
A sub can't give you something you don't put in.
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A wash in which's favor? The MRX would be better or the SRX?
That meant that based on their specs they would have essentially the same output, however with the SRX both the amps and speakers would seem to be operating closer to their limits.
Bass that is "hard hitting", "punchy", "tighter" and "carry well" can also often relate to frequencies at or above a typical sub to main crossover. Just curious, but what have you done to optimize the processing in the XTi for your current system?[/quote]
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Just curious, but what have you done to optimize the processing in the XTi for your current system?
I'll have to look back at my crossover settings. I haven't done anything to the EQ. I believe I have the mains dropping around 60-70 as their frequency response is down to 57 if I remember correctly. I think I have my subs around 120 on the top end and 35-40 on the low end though I don't remember the amount of decibel drop at each frequency. I just know that after this thread I went back through and redid all my crossovers to utilize and be near what the frequency response of the speakers and subs are rated for.
I am still debating about the SRX because I like the lower frequency response that that would give me but I still have yet to see a real world usage unfortunately.
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I have the mains dropping around 60-70 as their frequency response is down to 57 if I remember correctly. I think I have my subs around 120 on the top end and 35-40 on the low end though I don't remember the amount of decibel drop at each frequency.
I believe this to be non-standard practice. I don't want to say "wrong", but having your subs and your tops both operating in the same octave can't be doing your sound much good. Is there a particular reason to have both boxes overlap in their output? Just because your tops are rated down to 57 doesn't mean you have to run them that low. With that kind of reasoning you'd think that you should run your subs up as high as they're rated as well.
I don't think so.
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I believe this to be non-standard practice. I don't want to say "wrong", but having your subs and your tops both operating in the same octave can't be doing your sound much good. Is there a particular reason to have both boxes overlap in their output? Just because your tops are rated down to 57 doesn't mean you have to run them that low. With that kind of reasoning you'd think that you should run your subs up as high as they're rated as well.
I don't think so.
The upper cabinets may well be good down to 47hz, but at how many db down from higher freqencies, say about 1K. Dick is correct in that you are following a non standard practice. The center frequency for the subs you're using is somewhere in the neighborhood of 80-90hz.
Generally that would indicate a high pass filter about 85hz for the subs and a low pass filter for the tops about 5hz higher, or 90hz. This would eliminate overlap at the center frequency eliminating a possible 6db hump at that frequency (depending on filter type and DSP).
The second mistake you're probably making is not setting the low pass filter for the sub at an appropriate frequency. set the low pass too low and your speakers will attempt to handle sounds that are of no benefit to the music being played. Low order harmonics, etc. do not make for good sound. Try setting the filters to 90hz and 45hz and see where that gets you. Also note that you may have to drop the input to the upper cabinets 6db or more in order to balance the transition from top to bottom. Start with the sub and mute the upper cabinets while you work with the crossover and keep in mind that you shouldn't hear the snare in the sub, but you should hear the kick in the upper cabinets AND the sub. ;D
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The SRX728 is a much better sounding sub. By better, I mean articulate, punchy, not woofey.
You can't couple any number of MRX's together and get the sound you will get from an SRX sub.
Volume wise, the SRX series seem to thrive on ample power (properly limited) while the MRX series seems to go into compression much earlier (ie adding more power doesn't give you more output).
What are you using for tops? What amps are you using?
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I believe this to be non-standard practice. I don't want to say "wrong", but having your subs and your tops both operating in the same octave can't be doing your sound much good. Is there a particular reason to have both boxes overlap in their output? Just because your tops are rated down to 57 doesn't mean you have to run them that low. With that kind of reasoning you'd think that you should run your subs up as high as they're rated as well.
I don't think so.
I do not run a bi-amped system. I run my mains full range and use the subs just for the low frequency extension of certain instruments (ie. bass, kick, etc). I typically do a line check with the mains alone and add in the subs after I already have a good sound of the instrument. This way I have more control on what is going through the subs and how much. I have also found that I get a tighter bass response this way because of the help of the mains in some of the lower register.
How would you propose doing things "the standard way"? Running the mains and subs as one system and not running the subs on an aux?
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The SRX728 is a much better sounding sub. By better, I mean articulate, punchy, not woofey.
You can't couple any number of MRX's together and get the sound you will get from an SRX sub.
Volume wise, the SRX series seem to thrive on ample power (properly limited) while the MRX series seems to go into compression much earlier (ie adding more power doesn't give you more output).
What are you using for tops? What amps are you using?
Thanks for the info on the SRX728s!
I am using four MRX525 (two a side) and am using 4 XTi6000s. One amp per pair of mains and one amp per pair of subs. (I have 2 pairs of mains and 2 pairs of subs)
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How would you propose doing things "the standard way"? Running the mains and subs as one system and not running the subs on an aux?
Get a decent cross-over and re-read Bob Leonard's post.
You are apparently satisfied with your setup and convinced that it is giving you what you need, so I'm not going to try and convince you to do otherwise. I'll just say that it's likely not the best way.
Have fun......
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"rig for the gig" comes from something I started saying about gear a long time ago. "Enough Rig for the Gig" means that you have both the coverage and output necessary to meet the demands of the act, audience, promoter and Band Engineer.
Seems to be lost on many in my area.
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Seems to be lost on many in my area.
Not enough "smarts in your parts"?
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Generally that would indicate a high pass filter about 85hz for the subs and a low pass filter for the tops about 5hz higher, or 90hz. This would eliminate overlap at the center frequency eliminating a possible 6db hump at that frequency (depending on filter type and DSP).
Thank you for the input, Bob! I will definitely try these crossover settings the next chance I get. Unfortunately, I do not have my own space to tweak settings regularly anymore but will keep you posted once I have been able to do so!
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Get a decent cross-over and re-read Bob Leonard's post.
You are apparently satisfied with your setup and convinced that it is giving you what you need, so I'm not going to try and convince you to do otherwise. I'll just say that it's likely not the best way.
Re-read.
Any particular crossover that you'd recommend? Also, I am more than willing to try different approaches and learn better ways to do things so if you have a better method please enlighten me! :D
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Re-read.
Any particular crossover that you'd recommend? Also, I am more than willing to try different approaches and learn better ways to do things so if you have a better method please enlighten me! :D
Your choices for a cross-over fall into two general categories: analog or digital (DSP).
The advantages of the newer Digital Signal (or Speaker) Processors is that in addition to the frequency dividing filters in the older analog units, you typically get parametric EQ, driver alignment delay and limiting. All this is good. You just have to put in the time and effort to learn how to properly set up all these features, knowledge which you should have anyhow.
The advantage of these Forums is that this information is available in threads previous to yours. If you search diligently you can find a lot of info already posted. Or you can ask your questions as you come upon the need for specific information.
Again, good luck.
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Andrew,
You don't necessarily need a crossover, you can use the processing in your xti amps, if you use xti for your tops as well. Check the JBL website, I am sure they offer tunings for the MRX series, they may even have presets for the amps.
Doug J.
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Andrew,
You don't necessarily need a crossover, you can use the processing in your xti amps, if you use xti for your tops as well. Check the JBL website, I am sure they offer tunings for the MRX series, they may even have presets for the amps.
Doug J.
Being a certified old fart, I completely forgot that the newer amps incorporate speaker processing. Whatever, the knowledge required to set them up is exactly the same.
So whichever you choose you'll still have to learn what and why.......
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One link is worth a thousand words:
http://www.amazon.com/Sound-Systems-Optimization-Techniques-Alignment/dp/0240521560/ref=dp_ob_title_bk (http://www.amazon.com/Sound-Systems-Optimization-Techniques-Alignment/dp/0240521560/ref=dp_ob_title_bk)
Doug J/
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One link is worth a thousand words
Thanks! I just ordered it!
And Dick, I have been searching and reading up a lot on different processing techniques as I have a lot of area for growth. I do use all XTi amps so I have built in processing, but you are correct that the same knowledge I need would apply. If you have any books or learning resources in addition to what are in these forums please let me know!
One thing I don't understand is why there is not more tuning information available for the MRX series. All I could find on JBL's website are the tunings for the DR4800.
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When you download System Architect, the files will be there under:
Device Files - System Architect 3.20\Portable PA\JRX MRX SRX VRX Crown XTi and XTi 2
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When you download System Architect, the files will be there under:
Device Files - System Architect 3.20\Portable PA\JRX MRX SRX VRX Crown XTi and XTi 2
Thanks Tom, but I have been unable to find any of those in System Architect 3.3. They have the XTi but none of the MRX or SRX. It appears to be just vertec speakers that are preloaded. I have tried adding in the presets I got off of JBL's website but they don't seem to load by opening them with the program or by copying them into the device folder in the programs folder. Any ideas?
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Thanks Tom, but I have been unable to find any of those in System Architect 3.3. They have the XTi but none of the MRX or SRX. It appears to be just vertec speakers that are preloaded. I have tried adding in the presets I got off of JBL's website but they don't seem to load by opening them with the program or by copying them into the device folder in the programs folder. Any ideas?
Nope. I think you're off to tech support land.
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Thanks Tom, but I have been unable to find any of those in System Architect 3.3. They have the XTi but none of the MRX or SRX. It appears to be just vertec speakers that are preloaded. I have tried adding in the presets I got off of JBL's website but they don't seem to load by opening them with the program or by copying them into the device folder in the programs folder. Any ideas?
Huh?
You said earlier that you have XTi amps. There ARE presets for passive MRX boxes with and without subs; there are some fairly extensive presets for SRX models. I'm looking at them in SA 3.3 right now.
Or did I misunderstand something?
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Huh?
You said earlier that you have XTi amps. There ARE presets for passive MRX boxes with and without subs; there are some fairly extensive presets for SRX models. I'm looking at them in SA 3.3 right now.
Or did I misunderstand something?
***Disclaimer*** I do not consider myself a skilled user of SA. In fact I've only recently begun learning it. ***End Disclaimer***
I've got SA3.2 on my desktop. When I open a new venue and drag an XTi amp in, then open it for speaker files there are several MRX configs available but no 528's in any config.
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***Disclaimer*** I do not consider myself a skilled user of SA. In fact I've only recently begun learning it. ***End Disclaimer***
I've got SA3.2 on my desktop. When I open a new venue and drag an XTi amp in, then open it for speaker files there are several MRX configs available but no 528's in any config.
Ahhh... use the 518 preset and lower the pass band output by 3dB.
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Ahhh... use the 518 preset and lower the pass band output by 3dB.
Thanks for the help! I will get that setup right away ;D