ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2 3  All   Go Down

Author Topic: Help installing bulbs inside my MRX515 to better protect my HF drivers?  (Read 18774 times)

Yosi Melamed

  • Full Member
  • ***
  • Offline Offline
  • Posts: 228

I've had a bad experience with a friends MRX system in a live event. Fried the HF driver twice, each one in a different gig. The MRXs were working with subs, there was absolutely no clipping. I am interested in putting light bulbs in my MRX internal crossover, and I could really use some help, so has any of you guys done such a project?
Logged
Don't bring up facts that can ruin our good argument.

Crown i-Tech 8000
Allen & Heath ZED60-14FX
4 X Cerwin Vega ProStax PS-12 II
1 X Cerwin Vega Sub 15
1 X Rolls RS-80 Tuner
1 X MaxxBass 101
1 X Weekend warrior

Charlie Zureki

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1244
  • South Eastern Michigan (near Windsor)

I've had a bad experience with a friends MRX system in a live event. Fried the HF driver twice, each one in a different gig. The MRXs were working with subs, there was absolutely no clipping. I am interested in putting light bulbs in my MRX internal crossover, and I could really use some help, so has any of you guys done such a project?

  Hello,

   My advice is to do some reading here in the archives, before you attempt this project.  Read anything and everything on setting limiter/compressors. I'm guessing that you've got too big of gigs for the rig.

  But, if you insist on persuing this, you may try contacting Curtis List (Too Tall) here on these Forums.  He may be able to help you with the calculations in redesigning your crossover.
 
   Cheers,
   Hammer
Logged
Do it the right way....don't be a Dino!

Bob Leonard

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 6807
  • Boston, MA USA

No clipping + blown driver = too much power.

Size your amplifiers properly, check for unity gain, and the problem goes away. Redesigning JBLs crossover is not the answer to the problem. If you need a cabinet that will handle more power then buy that cabinet.
Logged
BOSTON STRONG........
Proud Vietnam Veteran

I did a gig for Otis Elevator once. Like every job, it had it's ups and downs.

g'bye, Dick Rees

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 7424
  • Duluth

  Hello,

   My advice is to do some reading here in the archives, before you attempt this project.  Read anything and everything on setting limiter/compressors. I'm guessing that you've got too big of gigs for the rig.

  But, if you insist on persuing this, you may try contacting Curtis List (Too Tall) here on these Forums.  He may be able to help you with the calculations in redesigning your crossover.
 
   Cheers,
   Hammer

Eventually......

Say the light bulb project is completed.  Now when you're doing whatever is frying the drivers, the light bulb does its job and opens the circuit.  What have you gained?

The show still stops

Until you learn the root cause you're just putting on band-aids.
Logged
Pay no attention to the man behind the curtain...

gary makovsky

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 69
  • Delmont (Pittsburgh) PA

Had the same issue when I had an MRX setup. replaced HF drivers constantly, even at moderate levels and the same happened when a PRO user Friend borrowed my system. My ultimate fix was replacing all the HF drivers with a Selenium D220Ti. 2 things happened didn't blow any drivers for the rest of the life of the system and clarity in the highs drastically improved. Just my .02
Logged

Chuck Simon

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1139
  • Pittsburgh, Pa.

Bob is correct.  You are feeding those cabs too much power.  I have been using 2 MPro 412s for over 10 years and have never blown a driver.  I did replace a diaphragm once when a guitar player spilled a beer in one!
« Last Edit: June 14, 2012, 01:22:17 PM by Chuck Simon »
Logged

Garry Wilson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 206
  • Laurel, MD
    • 98.6 Sound

I've had a bad experience with a friends MRX system in a live event. Fried the HF driver twice, each one in a different gig. The MRXs were working with subs, there was absolutely no clipping. I am interested in putting light bulbs in my MRX internal crossover, and I could really use some help, so has any of you guys done such a project?

I've also had problems with my 515s to include at least one or two crossovers, I also have the MPro415. Powered the same and no issues with the MPros. I had (4) MRX515 boxes and sold two, replaced with 715, which is a whole different level. I may have to check into the Selenium driver, I do love the size/weight of the 515, especially when compared to the MPro. I wished that the MRX515 was cut for dual use like the MPro or MRX512. BTW, I still have the Tuki covers for the pair I sold, if anyone is interested.

Garry W
Logged
Garry W.
CTS, SBE-CEV, A+
www.986sound.com

Yosi Melamed

  • Full Member
  • ***
  • Offline Offline
  • Posts: 228

Thank you all for the replies...

Using too much power was my first assumption but the volume wasn't that high and I too had a parallel rig, using the exact same amp/processing/gain structure/source combo but with EV speakers instead of the MRX rated less wattage then the MRX with the same impedance, they still hold up just fine so I'm relieved to see I'm not the only one with MRX HF driver failures.

Further more, if I understand things correctly then the fact that the driver is more sensitive to damage at lower then rated power level, then installing a lamp using the rated power of this driver for the calculations of the lamp specs will not protect it and I will still be blowing drivers.
« Last Edit: June 14, 2012, 01:39:30 PM by Yosi Melamed »
Logged
Don't bring up facts that can ruin our good argument.

Crown i-Tech 8000
Allen & Heath ZED60-14FX
4 X Cerwin Vega ProStax PS-12 II
1 X Cerwin Vega Sub 15
1 X Rolls RS-80 Tuner
1 X MaxxBass 101
1 X Weekend warrior

Rob Spence

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3531
  • Boston Metro North/West
    • Lynx Audio Services

Thank you all for the replies...

Using too much power was my first assumption but the volume wasn't that high and I too had a parallel rig, using the exact same amp/processing/gain structure/source combo but with EV speakers instead of the MRX rated less wattage then the MRX with the same impedance, they still hold up just fine so I'm relieved to see I'm not the only one with MRX HF driver failures.

Further more, if I understand things correctly then the fact that the driver is more sensitive to damage at lower then rated power level, then installing a lamp using the rated power of this driver for the calculations of the lamp specs will not protect it and I will still be blowing drivers.

All you discovered with the EVs is that those particular speakers hold up better to over powering them.

When you say they were not running "all that loud", I suspect they were running harder than they are designed to.

I agree with the others that you likely have too much gig for the rig.
Logged
rob at lynxaudioservices dot com

Dealer for: AKG, Allen & Heath, Ashley, Astatic, Audix, Blue Microphones, CAD, Chauvet, Community, Countryman, Crown, DBX, Electro-Voice, FBT, Furman, Heil, Horizon, Intellistage, JBL, Lab Gruppen, Mid Atlantic, On Stage Stands, Pelican, Peterson Tuners, Presonus, ProCo, QSC, Radial, RCF, Sennheiser, Shure, SKB, Soundcraft, TC Electronics, Telex, Whirlwind and others

Tim Perry

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1251
  • Utica-Rome NY

Yoshi,  as a MRX user discussions for failure mode always peak my interest.

The MRX series HF section takes a JBL 2408H driver with a JBL D8R2408  diaphragm.

The power specs seem a bit difficult to find but I believe they are HF: 40 W (160 W peak), 2 hrs , 8 ohms.

Ok at this point we have a large amp, say 500 to 1000W hooked up to the speakon connector the signal goes to passive crossover lows go the the 15 and highs go to the horn. So far so good. now lets say you have a DJ the puts in a steep smiley face EQ and the program content has a lot of compressed HF content and the DJ pushes it up.

Can you see how large amp + lots of HF = overpower? What's the answer? well it's not use a smaller amp. (unless you rewire to biamp) and I don't do that so im nit pushing that as a solution. 

At over $100 a piece for JBL drivers or diaphragms the light bulb thing starts to look attractive.

Now which one? ... well first off the bulbs use the the JRX series are minimall evvective and hard to obtain.  the typical bulbs used in Yorkvilles elite are more effective however they are europian 24V  50/55W (P45T) headlight bulbs and also hard to find. the older Yorkvilles use a single
1156. 

I'm going to suggest you use 2 1156 in series on each HF driver.  Sure it will slightly lower the output but you can EQ it back. .. (kinda sort of) 

 Personally my solution is more speakers: Here's my buddy helping me unpack yet another pair of 525'5 (Hey Tim lets just turn this upside down and lift the box off!
Logged

ProSoundWeb Community


Pages: [1] 2 3  All   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.025 seconds with 24 queries.