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Author Topic: Help needed - using spacers on a baffle to fit replacement drivers  (Read 392 times)

Matt Ripley

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Here's the story:

I bought 12 18'' folded horns from a respected factory-direct manufacturer who is often mentioned on these forums.  I love them, amazing product.  Sadly six of them were blown during a gig in May.  I shipped them back for re-coning and was sent back six different drivers but supposedly same model drivers to replace them to increase the turn around on shipping for my next gig.  When installing them I found they did not fit because these drivers actually had slightly different dimensions in height (not driver diameter) because of the shape of the magnet which prevented them from sitting flat onto the baffle.

When I contacted the manufacturer (now having to break contract on my gig because these drivers didn't fit) they said the solution was to send me "spacers".  I've built many DIY rigs so some speaker construction didn't bother me too much but i bought this rig specifically to move into a more professional realm and away from DIY.  I expressed some major concerns in this regard but was waved off and silly.  When the "spacers" arrived, essentially they were just wood rings that filled in the recessed portion of the baffle, and pushing them to be sitting in line with the first interior panel and much closer to the front access panel (approx. 1/2'').   

While installing them and seeing this it just didn't make any sense that this was a reasonable solution after paying thousands of dollars for high end gear.  I was instructed to air seal the spacers with foam tape which only made the spacing issue worse and was very difficult to compress properly behind the driver, let alone reliable in the long term.

My questions are this -
1) When the manufacturer promised no changes in subwoofer performance, was that truthful statement?  It seems obvious that changing the position of the driver would change the output considerably.

2) By pushing the driver outside the recessed baffle it is now only held in place by the screws with no side support on the outer edges of the driver normally provided by the wood cut out.  Is it reasonable to assume this puts the drivers at risk of becoming loose or damaged due to increased stress on the screws which now have an excessively long distance between the driver and baffle? approx .75'' of distance between where the screw head connects to the driver and the threads in the baffle?

3) Do you consider this kind of solution an acceptable business practice for a high end sound company?  My guess is the manufacturer was trying to save money on shipping as it is approx. $80 one way, per driver... seems to be putting my whole rig's performance at risk for some minimal savings on their end.

Thanks for any help.
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Mac Kerr

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« Reply #1 on: December 04, 2018, 05:28:49 pm »

Here's the story:

Please go to your profile and change the "Name" field to your real first and last name as required by the posting rules displayed in the header at the top of the section, and in the Site Rules and Suggestions in the Forum Announcements section, and on the registration page when you registered.

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Tim McCulloch

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Re: Help needed - using spacers on a baffle to fit replacement drivers
« Reply #2 on: December 04, 2018, 08:24:33 pm »

Here's the story:

I bought 12 18'' folded horns from a respected factory-direct manufacturer who is often mentioned on these forums.  I love them, amazing product.  Sadly six of them were blown during a gig in May.  I shipped them back for re-coning and was sent back six different drivers but supposedly same model drivers to replace them to increase the turn around on shipping for my next gig.  When installing them I found they did not fit because these drivers actually had slightly different dimensions in height (not driver diameter) because of the shape of the magnet which prevented them from sitting flat onto the baffle.

When I contacted the manufacturer (now having to break contract on my gig because these drivers didn't fit) they said the solution was to send me "spacers".  I've built many DIY rigs so some speaker construction didn't bother me too much but i bought this rig specifically to move into a more professional realm and away from DIY.  I expressed some major concerns in this regard but was waved off and silly.  When the "spacers" arrived, essentially they were just wood rings that filled in the recessed portion of the baffle, and pushing them to be sitting in line with the first interior panel and much closer to the front access panel (approx. 1/2'').   

While installing them and seeing this it just didn't make any sense that this was a reasonable solution after paying thousands of dollars for high end gear.  I was instructed to air seal the spacers with foam tape which only made the spacing issue worse and was very difficult to compress properly behind the driver, let alone reliable in the long term.

My questions are this -
1) When the manufacturer promised no changes in subwoofer performance, was that truthful statement?  It seems obvious that changing the position of the driver would change the output considerably.

2) By pushing the driver outside the recessed baffle it is now only held in place by the screws with no side support on the outer edges of the driver normally provided by the wood cut out.  Is it reasonable to assume this puts the drivers at risk of becoming loose or damaged due to increased stress on the screws which now have an excessively long distance between the driver and baffle? approx .75'' of distance between where the screw head connects to the driver and the threads in the baffle?

3) Do you consider this kind of solution an acceptable business practice for a high end sound company?  My guess is the manufacturer was trying to save money on shipping as it is approx. $80 one way, per driver... seems to be putting my whole rig's performance at risk for some minimal savings on their end.

Thanks for any help.

1)  You need measurement chops (Smaart, Systune, SIMM) to see if the replacements fail to meet "average" performance specs.
2)  No.  It should be okay.  Use blue LocTite on the threads if you're concerned.
3)  You blew them up and pretty much voided your warranty.  That the manufacturer doesn't want to pay additional shipping is hardly a reason to bash them on a public forum.  I'd say you've been treated well, under the circumstances.
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Luke Geis

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Re: Help needed - using spacers on a baffle to fit replacement drivers
« Reply #3 on: December 04, 2018, 09:47:01 pm »

The thing is that you expressed that you needed a quick turn around. The company responded by sending you comparable ( I would read as updated ) units to meet your deadline. Unfortunately, they need a band-aid to work due to the update in driver tech. You got them in time and a solution could have been implemented by you in time enough to fulfill your other gig.

The vendor didn't cause you to lose the other gig, you did. You blew the speakers up; six of them!!!!!! You also had time to get a rental option to fulfill your other gig if need be. You let the other gig go because you didn't want to expend that cost, which is all on you, not the speaker vendor.

You wanted a fast turnaround and you got it. It came with the need to implement a solution, unfortunately. This is not the vendor's fault. You can't have your cake and eat it too. At some point, you have to accept that you f-d up and you stacked yourself against the odds. If you were patient and just rented the needed gear for the next gig, you would have made the money from that gig ( minus the rental ) and then got your re-coned speakers back. When you play stupid games you win stupid prizes, right? Don't blow shit up when you know you need it in short order. It is your fault you blew the speakers, it is your fault you pressed the vendor to come up with a quick turnaround and it is your fault you passed up your other gig.

Perhaps an example. I did a gig where I got to the venue to find out that my monitor's CD was blown. I made a call and a suitable replacement speaker was delivered in time for me to do the show! It cost me the replacement driver and the rental plus delivery. That blown speaker cost me double what I rent it for because of my laziness. That is the cost of doing business and the price I paid for not checking the monitor out earlier in the week as I should have. I could have gotten it fixed in time for less than the money I rent the unit out for. My mistake cost me double what I rent the speaker out for. Stupid games, stupid prizes....... I played and I won.......

To answer your direct questions though:

1. No, it wouldn't change performance. A small difference in placement is not going to diminish the performance. It will perform just as you would expect it too, granted it does have a band-aid to do so.

2. The recessed lip isn't so much to keep the driver in line as much as it is there to simply center the speaker. Many cabinets simply have the driver sitting on top of the baffle with no recess. The screws will clamp with enough force to hold a house up. I doubt the speaker will move if tightened down fully. Blue Locktight will prevent the screws from backing out. The screws are just as likely to back out in this case as before.

3. What savings on their end? They sent you a replacement. You paid for the replacement. If they shipped them free of charge to you, then you are ahead. If you want your drivers back then ship them the ones you have and get your re-coned ones back. Shipping must be able to be done cheaper than $80 if you can package them up in pairs or quads and not individually. 
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I don't understand how you can't hear your self

Jerome Malsack

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Re: Help needed - using spacers on a baffle to fit replacement drivers
« Reply #4 on: December 05, 2018, 08:57:24 am »

One other consideration, is the driver now spaced closer to a front screen and is there a chance the cone will hit the front screen?  May have to add space there now also. 
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Scott Helmke

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Re: Help needed - using spacers on a baffle to fit replacement drivers
« Reply #5 on: December 05, 2018, 10:05:39 am »

To some extent a cabinet manufacturer is at the mercy of what the driver manufacturers sell, and if a very particular driver stops being made then they have to find a workaround.

A couple-three years ago I found that some of the 18" drivers in our Danley Jericho cabinets had literally torn their cones apart without actually failing completely. We went back and forth with Danley on this, and ultimately went with their recommendation to switch to the driver they'd moved to (we had very early production cabinets).  I had to redrill the mounting holes to accommodate the new drivers and add a spacer, and even route away a little wood, but this is what you sometimes get with the audio equivalent of a Mack truck.

There was simply no other speaker where you could roll two of them in and get proper coverage and plenty of output for a Big Ten football game.
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Matt Ripley

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Re: Help needed - using spacers on a baffle to fit replacement drivers
« Reply #6 on: December 06, 2018, 01:05:53 pm »

To some extent a cabinet manufacturer is at the mercy of what the driver manufacturers sell, and if a very particular driver stops being made then they have to find a workaround.

I certainly understand that factor but considering these drivers are proprietary drivers made by the vendor I would have thought they would consider existing cabinet sizes before changing the dimensions of a driver to an unworkable size. 

Oh well, they performed very well over the weekend after installing the spacers.  I'll just keep a close eye on re-tightening the screws and possibly adding locktight.
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Jeremy Young

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Re: Help needed - using spacers on a baffle to fit replacement drivers
« Reply #7 on: December 06, 2018, 03:45:54 pm »

Without naming names, I suspect I know which vendor you're referring to.  If I'm right, the person who designed the speakers and cabinet is the person who was providing the solution.  This alone should be enough for you to feel confident that they will perform as intended.  If it were a larger company (pick any name you might see in a guitar store) you would be talking to someone in customer service with little to no knowledge of the inner workings of the product and I would be hesitant to take their advice on different drivers unless I heard it from their engineering team. 

How old are your cabinets?  The product I believe you're talking about has been under continued improvements over the years with minor changes every few years to improve performance.  These changes may have led to a new driver design and perhaps the old ones are no longer being manufactured in volume for them.  You mentioned that they are proprietary drivers made by the vendor, but my understanding is that they are designed by the vendor and made by a well-known speaker manufacturer to their specs.  So they are not in fact made in-house.  Since you needed 6, perhaps the manufacturer only had a few left of the old style drivers readily available by your required deadline?  It may not have been a case of them requesting rush-freight from the speaker manufacturer, there may have been manufacturing timelines that could not be shortened on such short notice.  Just speculating over here. 

What you've described as a spacer is indeed what a spacer is, what were you expecting?
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Brown Bear Sound
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