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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 => The Basement => Topic started by: Mark Knapp on July 11, 2019, 09:34:55 PM

Title: Blown srx 728
Post by: Mark Knapp on July 11, 2019, 09:34:55 PM
I recently came into possession of a 4 ea srx725/728, however 1 of the 728 is blown.  Im taking suggestions as far as reloading the subs. Opinions on should I just recone, or are there suggestions to replacing drivers
Title: Re: Blown srx 728
Post by: Tim McCulloch on July 11, 2019, 10:12:05 PM
I recently came into possession of a 4 ea srx725/728, however 1 of the 728 is blown.  Im taking suggestions as far as reloading the subs. Opinions on should I just recone, or are there suggestions to replacing drivers

Exact replacement woofers are available from JBL dealers for surprisingly little over the cost of re-coning once we factored in freight to/from the cone shop.
Title: Re: Blown srx 728
Post by: Scott Holtzman on July 12, 2019, 04:11:02 AM
I recently came into possession of a 4 ea srx725/728, however 1 of the 728 is blown.  Im taking suggestions as far as reloading the subs. Opinions on should I just recone, or are there suggestions to replacing drivers

If you replace with anything but original drivers your sub is worthless.

If you are near Cleveland we can recone them for you. 

Title: Re: Blown srx 728
Post by: Tim McCulloch on July 12, 2019, 02:07:47 PM
If you replace with anything but original drivers your sub is worthless.

If you are near Cleveland we can recone them for you.

Proximity is everything.  It was the 2 way shipping at "rack rate" vs the killer FredEx rate JBL had that tipped that balance to using new replacements rather than reconing.  If I had a local JBL-approved/trained/supplied re-cone tech, we'd have gone that route.
Title: Re: Blown srx 728
Post by: Riley Casey on July 13, 2019, 11:01:40 PM
The US was once paved with JBL certified recone installers but I gather that’s no longer the case. I went the Northridge in the late 70s to sit with the Mexican ladies on the repair line and inhale MEK all day to get my certificate.

Proximity is everything.  It was the 2 way shipping at "rack rate" vs the killer FredEx rate JBL had that tipped that balance to using new replacements rather than reconing.  If I had a local JBL-approved/trained/supplied re-cone tech, we'd have gone that route.
Title: Re: Blown srx 728
Post by: Tim McCulloch on July 14, 2019, 10:31:43 AM
The US was once paved with JBL certified recone installers but I gather that’s no longer the case. I went the Northridge in the late 70s to sit with the Mexican ladies on the repair line and inhale MEK all day to get my certificate.

I wonder if folks are blowing up fewer JBL transducers these days?  In the last 10 years we've probably averaged less than 1 a year in a shop with a couple thousand transducers.  Add that to the much closer pricing for direct OEM replacements vs reconing and there's not a lot that favors the recone.

My local JBL re-cone guy retired after his 2nd open heart surgery and our local non-factory re-cone guy retired after developing nerve damage from solvents and adhesives.  I'm guessing the reason nobody stepped up to replace them is a lack of demand/income for this service, locally.

Title: Re: Blown srx 728
Post by: Helge A Bentsen on July 14, 2019, 10:58:56 AM
I wonder if folks are blowing up fewer JBL transducers these days?  In the last 10 years we've probably averaged less than 1 a year in a shop with a couple thousand transducers.  Add that to the much closer pricing for direct OEM replacements vs reconing and there's not a lot that favors the recone.

My local JBL re-cone guy retired after his 2nd open heart surgery and our local non-factory re-cone guy retired after developing nerve damage from solvents and adhesives.  I'm guessing the reason nobody stepped up to replace them is a lack of demand/income for this service, locally.

This is a common trend with top-level speaker manufacturers these days.

I can't remember the last time I had a «brand-name» rig with a blown driver.
Title: Re: Blown srx 728
Post by: Ivan Beaver on July 14, 2019, 03:26:06 PM
The US was once paved with JBL certified recone installers but I gather that’s no longer the case. I went the Northridge in the late 70s to sit with the Mexican ladies on the repair line and inhale MEK all day to get my certificate.
I am also JBL certified reconer, although I have not reconed a speaker in quite a few years.

After I got my JBL certification, I was certified for everybody except EV.  For some reason they would never even talk to me.  OK so it is aftermarket kits for EVs---

I got into reconing because I was blowing so many of my own speakers at gigs, so it was to save me money and time.

I learned a lot about speakers and failures from seeing so many speakers come through my shop.  I feel it gave me a better understanding of what is really happening out in the field.

Title: Re: Blown srx 728
Post by: Caleb Dueck on July 14, 2019, 05:05:01 PM
This is a common trend with top-level speaker manufacturers these days.

I can't remember the last time I had a «brand-name» rig with a blown driver.

Remember the 'good old days' when manufacturer recommended processing was a spreadsheet with a couple EQ filters, HP, and LP?  Now notice Powersoft amps, L'Acoustics, d&b, et al where the amp output is tracked vs impedance, level vs time vs frequency, and dynamic EQ/HPF.  It seems like half of the secret sauce processing now is some flavor of limiting. 
Title: Re: Blown srx 728
Post by: Dave Pluke on July 15, 2019, 11:43:01 AM
It seems like half of the secret sauce processing now is some flavor of limiting.

Agreed.  Plus steeper crossover slopes, perhaps.  And more robust HPF at several points in the signal path.  More reliable DSPs and power amps that don't clamp to DC out...

Unless physically damaged or exposed to excessive moisture, drivers can last a long time.

Dave
Title: Re: Blown srx 728
Post by: Taylor Hall on July 15, 2019, 12:03:42 PM
I wonder if folks are blowing up fewer JBL transducers these days?  In the last 10 years we've probably averaged less than 1 a year in a shop with a couple thousand transducers.  Add that to the much closer pricing for direct OEM replacements vs reconing and there's not a lot that favors the recone.

My local JBL re-cone guy retired after his 2nd open heart surgery and our local non-factory re-cone guy retired after developing nerve damage from solvents and adhesives.  I'm guessing the reason nobody stepped up to replace them is a lack of demand/income for this service, locally.
A friend of mine has seen a similar trend. The only JBL stuff they see come in is long discontinued cabinets, cabinets that don't have some type of "factory tuning" profile, or cabinets that have used custom profiles because they "sounded better". The most common things he sees these days are 12" two-way SOS cabs run too hard without a sub, usually EV ZLX or Eon DJ types who just plug in and keep turning it up when the output doesn't suit them.