You WILL need Flash Player version 8 or higher for this website.
   
 

Go Back   StudioAuditions.com > The People > Anything Goes
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Anything Goes Silly Stuff, Political, Off Topic, It’s All Good!



Reply
 
Thread Tools Display Modes
Old 05-22-2011, 01:44 PM   #1
crossroads
Registered Member
 
crossroads's Avatar
 
Join Date: Apr 2007
Location: Country of Dracula - ROMANIA
Posts: 77
Send a message via Yahoo to crossroads
JBL MRX - please help

Hi there,
First of all greetings. I don't want to "kiss" myself. but i have been in show-biz for the last 25 years. I am saying this because i want to assure all readers that i know about sound and systems and - I have NEVER EVER burned a speaker or a driver in my entire life, until now.
I usually work with quite few systems ( not all at the same time but depending on the venues we go to) - we use JBL SRX , Mackie systems, Turbosound aspect (100.000 watts RMS) and few other systems like Dynacord and so on. on any of these speakers i have never had a problem in 25+ years.

Please allow me to tell you my problem and than help me with a solution.
I have got myself recently from Germany a system made out of:
- JBL-MRX 500 Series
• 2x JBL MRX525
• 2x JBL MRX528S
• 2x Crown XTI4000
• Allen & Heath ZED 428
I have got my presets from some very nice guys at Crown. And the sound during my gig was ok, no distortions, no peaks, no feedback – I loved the sound.

Now in my opinion i should be able to run this setup with no problem but on my second gig with this brand new system i managed to burn - for the first time in my life - the HF Drivers.

I have that kind of experience on sound to cut NOT boost and therefore I always make 100% sure that i never have red clipping on my boards both in the PFL or on the mains and i always prefer to be on the green area seldom on yellow BUT NEVER RED
1. I don't get it how in only 1 hour and 30 minutes i blew up those drivers… NOW

2. WHY HARMAN company is selling these as a set IF these MRX top cabinets are not properly matched:
a. HF Drivers with 2x15” woofers – 25 HFreq Driver vs. 800 w in the woofers.
b. MRX Cabinet vs. the power of the XTI 4000 amp
c. Someone at Crown told me that the DSP is not that good actually and advised me to get the DBX Drive Rack PA+

… IF I only knew that HF driver is only 25 w I would never bought that system. BUT NOBODY is saying that in any booklet.

3. WHY do they put a HF driver of 25-30 W in a cabinet with a 2 x 15" - 800w woofers?
4. Why the guys the Music Store Germany in Koln tell me I lost warranty - IF i have 1 year warranty - is the warranty valid for the WOOD (as in cabinet) only?
5. I am now actually losing money because I cannot rent my system to our gigs.

and now some technical questions.
Obviously i need to fix the drivers with or without warranty:

1. I need to know IF I can PUT a bigger driver in my MRX tops that would fit the same horn without tempering with the horn or the cabinet – What model form JBL would fit in the HORN flange that would have bigger power? I need something like 150 – 200 w / driver
2. Along with the bigger drivers to add to the whole system a DRIVE RACK PA+ from DBX and turn the system in 3 ways.
3. Add the same original membranes to the driver the D8R2408 in the 2408H HF Driver and ADD on top 2 more separate bigger horns to ease the “tension” on the MRX drivers.
4. FIX the MRX + add the Drive Rack + the new bigger horns + a new XTI smaller amp for the HIGHs.
My point is that I don’t want to ever burn those drivers again.
It is obviously that the current driver IS WAY TO SMALL – I don’t even know why they bothered to use this concept.

I am looking at at least 2 options since I DO NOT have the money NOW to upgrade to all 3 things – new drivers, new controller, new amp.

Best regards to all of you reading this.
__________________
Crossroads Studio - Make Music, Not Noise!
www.vlahopol.com | www.vlahopolguitars.com |
www.starmediaproduction.com | www.thecrossroads.ro
crossroads is offline   Reply With Quote
Old 05-23-2011, 08:03 PM   #2
Dave Alewine
Registered Member
 
Join Date: Apr 2009
Location: Columbia, South Carolina
Posts: 20
Hello Crossroads,
Thanks for posting your questions on Studio Auditions forums, and sorry to hear about the HF drivers in your new JBL cabinets. JBL is well known for making solid and dependable speaker systems and it is uncommon to hear about any of their components failing. I'll do my best to either answer your questions or provide some ideas on how you can take steps to ensure that you don't have a repeat of this unpleasant occurrence.

JBL designed the MRX525 as a full-range speaker system for live music production and speaking applications using what they consider matched components to create an affordable, high-output loudspeaker. When set up properly, matched with the correct power amplifier and using a good quality compressor / limiter for protection, these speakers will perform quite well.
First, you didn't mention whether you were using any outboard gear for signal processing, like an equalizer, compressor/limiter or effects processor. The DSP onboard the Crown XTi ampliers is a very useful tool when you want to keep the setup simple and the gig doesn't warrant extra outboard gear, but it sounds like you could certainly benefit from adding an external processor to your system. The dbx DriveRack PA+ would be an excellent way to provide complete system control and speaker protection. With the on-board DSP and factory presets, it's super-simple to set up, especially for a JBL and Crown system. Using the DriveRack as your active crossover for the system will enhance the overall sound quality and give you more control and flexibility in tuning the sound of your system.

Next, it seems you are under-powering the MRX525's. These are rated at 1600 watts per ch. @ 4-ohms and the XTi 4000 is only delivering 1200 watts per channel. With a power amp providing at least the recommended minimum output level, you are far less likely to experience blown drivers. The Crown XTi 6000 would be the logical choice if you want to stick with the Crown XTi Series amps. Having headroom in the power amp will let you operate the system more efficiently and you should also hear improved overall sound quality.

JBL does not provide any other option, nor recommend replacing the 2408H HF Driver with any other product. However, your idea of using a separate horn enclosure may work well for your system as a 3-way setup. I'm not sure that using the high frequency horn in the cabinet plus another horn would work too well, but you could experiment with that type of configuration and see how it goes. The MRX525 is not capable of being bi-amped using the factory installed input panel, but if you were not concerned with the warranty on the loudspeaker, you could certainly modify the connectors and internal wiring to allow for a 3-way system using separate subwoofer enclosures.

Hope I've been helpful. Be sure to let us know what you think about these ideas and please, send more questions.

Dave Alewine
Live Sound Specialist
Front End Audio
dave@frontendaudio.com*email
www.frontendaudio.com*website
888-228-4530 - Toll Free
803-748-0914 ext. 109
Sign up for the FEA e-newsletter
Dave Alewine is offline   Reply With Quote
Old 05-24-2011, 04:52 AM   #3
crossroads
Registered Member
 
crossroads's Avatar
 
Join Date: Apr 2007
Location: Country of Dracula - ROMANIA
Posts: 77
Send a message via Yahoo to crossroads
Quote:
Originally Posted by Dave Alewine View Post
Hello Crossroads,
Thanks for posting your questions on Studio Auditions forums, and sorry to hear about the HF drivers in your new JBL cabinets. JBL is well known for making solid and dependable speaker systems and it is uncommon to hear about any of their components failing. I'll do my best to either answer your questions or provide some ideas on how you can take steps to ensure that you don't have a repeat of this unpleasant occurrence.
Thank you for your message first of all , much appreciated... Name is Mike ;o)

Quote:
Originally Posted by Dave Alewine View Post
When set up properly, matched with the correct power amplifier and using a good quality compressor / limiter for protection, these speakers will perform quite well.
I have with another 2 partners of mine for a 100.000 RMS Turbosound Aspect, JBL SRX, Mackie with active subs and tops. I think I know how to set up a system. I worked with huge artists with all sorts of equipment. MRX + XTI 4000 - that was the set I got from Germany. I got it because i loved the sound of the SRX knowing that it could be good for smaller venues when the SRX is not available. I know it is not the same power but i wanted similar quality in sound.

Quote:
Originally Posted by Dave Alewine View Post
First, you didn't mention whether you were using any outboard gear for signal processing, like an equalizer, compressor/limiter or effects processor.
No, we did not use any other equipment for processing the sound as both our racks were going to a different gig.
Just :
Allen and Heath Zed 428
MRX system
XTI 4000 - with no clipping, no RED on the PFL or Mains, no overloading. with a crossover on both cabs sent by Crown people + a -3db Limiter on the preset

Quote:
Originally Posted by Dave Alewine View Post
The DSP onboard the Crown XTi ampliers is a very useful tool when you want to keep the setup simple and the gig doesn't warrant extra outboard gear, but it sounds like you could certainly benefit from adding an external processor to your system.
A guy at Crown told me that DSP of the XTI is not that much reliable. i don't know how he gave me that information or why ;o)
I am considering getting the Drive Rack PA +


The dbx DriveRack PA+ would be an excellent way to provide complete system control and speaker protection. With the on-board DSP and factory presets, it's super-simple to set up, especially for a JBL and Crown system.
Using the DriveRack as your active crossover for the system will enhance the overall sound quality and give you more control and flexibility in tuning the sound of your system.


Quote:
Originally Posted by Dave Alewine View Post

Next, it seems you are under-powering the MRX525's. These are rated at 1600 watts per ch. @ 4-ohms and the XTi 4000 is only delivering 1200 watts per channel. With a power amp providing at least the recommended minimum output level, you are far less likely to experience blown drivers. The Crown XTi 6000 would be the logical choice if you want to stick with the Crown XTi Series amps. Having headroom in the power amp will let you operate the system more efficiently and you should also hear improved overall sound quality.
WOW, underpowered? i read what you are saying.. but.. I had no clipping, no red the guys in Germany told me I lost warranty because i burned them while you say they are under powered. -
To be completely honest with you at first when when i got the system i thought the same.. but after i fried the drivers.. and that even if i wanted to push it a little because I got used to the SRX - I DID NOT.

My question now is.. - How all this non cliping, not red, underpowered, -3db limiter and the main volume on both amps being at 3 o'clock burned my diaphragms?


Quote:
Originally Posted by Dave Alewine View Post
JBL does not provide any other option, nor recommend replacing the 2408H HF Driver with any other product. However, your idea of using a separate horn enclosure may work well for your system as a 3-way setup. I'm not sure that using the high frequency horn in the cabinet plus another horn would work too well, but you could experiment with that type of configuration and see how it goes. The MRX525 is not capable of being bi-amped using the factory installed input panel, but if you were not concerned with the warranty on the loudspeaker, you could certainly modify the connectors and internal wiring to allow for a 3-way system using separate subwoofer enclosures.
I saw many post in quite few forums of people frying their drivers. i cannot tell of their sound experience i am only saying about mine.
I still don't know how a 25W driver is pushed to 100W to match the 800w 15" woofers.

I do have 2 subs and 2 tops that is why i am considering to switch it on a 3 way system...
Warranty??? - those MF%$#@ told me I lost warranty - and I am pretty pissed OFF after 8 years of buying form them of more than 300.000 euros they are turning their back on me on my first service attempt.
So with NO warranty - i can modify the system to whatever. i guess.. i am just looking at what the best solution would be.

Quote:
Originally Posted by Dave Alewine View Post
Hope I've been helpful. Be sure to let us know what you think about these ideas and please, send more questions.
one more thing.. what about these aftermarket diaphragms ??? are they any good?

the price of there are pretty high.. i hope I don't have to change those every 2-3 gigs ;o) - other wise i will take a chainsaw and work on the JBL cabinets and make some clothing cabinets out of them


Thank you for your post...

Mike
__________________
Crossroads Studio - Make Music, Not Noise!
www.vlahopol.com | www.vlahopolguitars.com |
www.starmediaproduction.com | www.thecrossroads.ro
crossroads is offline   Reply With Quote
Old 05-26-2011, 06:58 PM   #4
Dave Alewine
Registered Member
 
Join Date: Apr 2009
Location: Columbia, South Carolina
Posts: 20
Quote:
Originally Posted by crossroads View Post
WOW, underpowered? i read what you are saying.. but.. I had no clipping, no red the guys in Germany told me I lost warranty because i burned them while you say they are under powered. -
To be completely honest with you at first when when i got the system i thought the same.. but after i fried the drivers.. and that even if i wanted to push it a little because I got used to the SRX - I DID NOT.

My question now is.. - How all this non cliping, not red, underpowered, -3db limiter and the main volume on both amps being at 3 o'clock burned my diaphragms?
Although you may not have been red-lighting the amps or levels on the mixer, using an amplifier with a lower power rating than the speakers require could possibly be the cause. As a rule, it's best to use amps providing 10 to 20 percent more than the minimum requirement of the speaker. Also, you could try running the gain up all the way on the amps and controlling volume from the mixer. It's usually not the high level of power that destroys drivers, but the distortion from a low-powered amp or, possibly a transient spike that could have been caught by a good compressor/limiter.


Quote:
Originally Posted by crossroads View Post
one more thing.. what about these aftermarket diaphragms ??? are they any good?

the price of there are pretty high.. i hope I don't have to change those every 2-3 gigs ;o) - other wise i will take a chainsaw and work on the JBL cabinets and make some clothing cabinets out of them
I've had no experience with aftermarket diaphragms, but have had some good results replacing entire high-frequency drivers with other brand units. With minor modification (without a chainsaw) I was able to retro-fit the horn lens to the new driver upgrading to a higher powered and better performing horn for the highs.


Dave Alewine
Live Sound Specialist
Front End Audio
dave@frontendaudio.com*email
www.frontendaudio.com*website
888-228-4530 - Toll Free
803-748-0914 ext. 109
Sign up for the FEA e-newsletter
Dave Alewine is offline   Reply With Quote
Old 10-03-2011, 01:29 PM   #5
rburris2
I'm Here, Now What?
 
Join Date: Oct 2011
Location: U.S.
Posts: 1
2408H driver problems

I too have had issues with 2408H drivers in my MRX515 cabs. I use these cabs for small venues and have to take 3 cabs with me to each show because I cannot rely on the 2408H drivers in the MRX cabs (the 3rd cab I keep as a backup). In the last two weeks I have had two 2408 drivers go out. That makes a total of four in the last two years.

I contacted JBL after the first one went out to ensure I was using the proper amplification for the cabs. They confirmed that my configuration should be fine:
I use a bridged QSC PLX1602 to power a pair of MRX515 cabs (serial connection). In bridged mode the PLX1602 produces approximately 1600 watts into the 4 ohm load. The program rating for the MRX515 is 700 - 800 watts per cab. I use a Presonus StudioLive mixer into a Drive260 that feeds the PLX1602. I don't ever clip and I never have errant high frequency feedback that can fry a driver.

I noticed that some of the drivers I have replaced showed signs of being overheated, but the last one appeared to have corrosion problems in the coil assembly.

I know that with the PLX a bridged configuration does produce a much higher level of harmonic distortion that a stereo configuration, but I would be very disappointed if the harmonic distortion inherent in the amplifier is the source of my driver problems. Based on my experience I would have to conclude that the 2408H driver is subject to periodic failure due to faulty materials or assembly.

Note: I also use the JBL SRX700 series with QSC amplification for bigger shows without any problems. That is why I am now considering replacing the MRX515 cabs with SRX715 cabs (bi-amp capable).

Last edited by rburris2; 10-03-2011 at 01:33 PM..
rburris2 is offline   Reply With Quote
Old 10-03-2011, 06:52 PM   #6
Dave Alewine
Registered Member
 
Join Date: Apr 2009
Location: Columbia, South Carolina
Posts: 20
Hello rburris2,

Sounds like you're playing by the rules but still being penalized. With the amplifier matched properly for the cabinet, overload protection provided by the Driverack 260 and limiting engaged through the Fat Channel on the master output of the StudioLive Mixer, you should be worry-free.

Upgrading your MRX to the SRX Series would certainly be a smart move. I've mixed many shows on both of these speakers and really do appreciate the exceptional sound quality offered by the SRX models. With greater power handling and extended frequency response, the SRX speakers deliver a good bit more punch and with a more elevated and clearer top end than the MRX speakers.

Dave Alewine
Live Sound Specialist
Front End Audio
Your Ultimate Pro Audio Dealer!
dave@frontendaudio.com email
www.frontendaudio.com website
888-228-4530 - Toll Free
803-748-0914 ext. 109
Sign up for the FEA e-newsletter
Dave Alewine is offline   Reply With Quote
Old 10-03-2011, 06:59 PM   #7
crossroads
Registered Member
 
crossroads's Avatar
 
Join Date: Apr 2007
Location: Country of Dracula - ROMANIA
Posts: 77
Send a message via Yahoo to crossroads
hi there ya'll ;o)

i had lots of difficulties making the shop understand it wasn't my fault when i burned the diaphragms and after i sent the pictured to JBL they saw that is was a fabrication defect.

Then they told the shop that they should give me new drivers. in the mean tiem i had to work (it took 3 months for the stupid shop to get it straight) i got myself from the US some aftermarket diaphragms.

The after market is what i am still using today. they do not sound the same .. they lack that sparkle around 8 - 10K. its not like the original.
but since i got the Drive Rack PA+ from DBX it seems to be ok..
1. I have fixed the old diaphragms
2. I got the aftermarket
3. i have the new original drivers and diaphragms.

so i am covered for a long time.

I have an incredible guy he fixed my burned diaphragms they sound better than the aftermarket.

so i am all set for a long time ;o)

JBL and Crown both told me the shop was guilty in the first place for selling the wrong amp with the wrong cabinet.

I have the MRX with the XTI 4000 - they should sell it with XTI 6000...

I will try to sell the 4000 put some more money and get the 6000.

all the best...
__________________
Crossroads Studio - Make Music, Not Noise!
www.vlahopol.com | www.vlahopolguitars.com |
www.starmediaproduction.com | www.thecrossroads.ro
crossroads is offline   Reply With Quote
Old 10-03-2011, 07:04 PM   #8
crossroads
Registered Member
 
crossroads's Avatar
 
Join Date: Apr 2007
Location: Country of Dracula - ROMANIA
Posts: 77
Send a message via Yahoo to crossroads
[QUOTE=


I've had no experience with aftermarket diaphragms, but have had some good results replacing entire high-frequency drivers with other brand units. With minor modification (without a chainsaw) I was able to retro-fit the horn lens to the new driver upgrading to a higher powered and better performing horn for the highs.

[/QUOTE]

I am really considering .. getting some more powerful drivers.. for my MRX i have a double 15" woofer and a 1,1/2 driver.. any ideas for that?
__________________
Crossroads Studio - Make Music, Not Noise!
www.vlahopol.com | www.vlahopolguitars.com |
www.starmediaproduction.com | www.thecrossroads.ro
crossroads is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump




 
 Home  |   Industry News   |  Pro Audio Articles  |  Gear Reviews   |  Studio Space   |  Jam Room Sessions  |  Audio Forums
 Manufacturers  |   FAQ   |  Troubleshoot  |  Quick Start   |  Contact Us   |  Advertise Here
© 2006, 2007, 2008, 2009 StudioAuditions.com

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.