Subwoofer keeps blowing

[focusedRS]

Hey folks,

I was hoping to get a second opinion about my setup that I had installed recently by a shop. My initial setup consisted of an Alpine MRV-500 Mono amp paired with a shallow mount Rockford Fosgate R2SD4-12 sub in a 2016 Ford Focus RS. I paid a pretty penny for a custom box to fit in the false floor by where the stock sub goes. When the car was returned to me, it sounded good and the bass was pretty powerful that I had to turn the bass down on the stock head unit and turned off the bass booster EQ on my iPhone as soon as I got the car back to me. About 15 minutes into my drive home, the sub cuts out in the middle of a song. Mind you, I was not blasting the stereo, it was only on Volume 20. When it kicked back on, the sub sounded horrible (blown). I took it back to the shop and explained the situation and the guy who installed everything told me my sub is blown and he has never seen a sub blow like that before? He blamed the manufacturer and advised to get another sub so they can swap it out......

I then purchase a Rockford Fosgate P3SD4-12 which has a higher rated RMS just to be on the safe side so this doesn't happen again. I get it installed by the same shop (Christmas Eve) and proceed to drive to my parent's house for Christmas which is 2 hours away. About an hour into the drive, the sub dies and now sounds blown. This is now 2 brand new subwoofers blown in the span of two weeks. I call the shop to explain the situation and they assure me the install was done correctly and it must have been a faulty subwoofer and implied I should have purchased the subwoofers from them...........

I paid a lot of money for this setup to be done by professionals because I am not too familiar with this stuff but out of the 4 cars and 3 different sound systems I have owned previously this sort of situation has never happened to me. I have never used this shop before but it has been highly recommended by the Focus groups here in Central FL so I am swimming upstream if I go and blast them. I'll post pics of the settings to see if maybe someone can determine what might be the issue as I really do NOT want to buy an additional sub/amp and have this happen again where I'm literally throwing money in the wind.

Small side note, my car spent a full business day at this shop. When the car was returned to me I noticed my dashcam was unplugged. When asked why they explained it was company policy. A part of me says BS and they took the car for a spin, but who knows.

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[Buck 5,000+ posts]

Hey folks,

I was hoping to get a second opinion about my setup that I had installed recently by a shop. My initial setup consisted of an Alpine MRV-500 Mono amp paired with a shallow mount Rockford Fosgate R2SD4-12 sub in a 2016 Ford Focus RS. I paid a pretty penny for a custom box to fit in the false floor by where the stock sub goes. When the car was returned to me, it sounded good and the bass was pretty powerful that I had to turn the bass down on the stock head unit and turned off the bass booster EQ on my iPhone as soon as I got the car back to me. About 15 minutes into my drive home, the sub cuts out in the middle of a song. Mind you, I was not blasting the stereo, it was only on Volume 20. When it kicked back on, the sub sounded horrible (blown). I took it back to the shop and explained the situation and the guy who installed everything told me my sub is blown and he has never seen a sub blow like that before? He blamed the manufacturer and advised to get another sub so they can swap it out......

I then purchase a Rockford Fosgate P3SD4-12 which has a higher rated RMS just to be on the safe side so this doesn't happen again. I get it installed by the same shop (Christmas Eve) and proceed to drive to my parent's house for Christmas which is 2 hours away. About an hour into the drive, the sub dies and now sounds blown. This is now 2 brand new subwoofers blown in the span of two weeks. I call the shop to explain the situation and they assure me the install was done correctly and it must have been a faulty subwoofer and implied I should have purchased the subwoofers from them...........

I paid a lot of money for this setup to be done by professionals because I am not too familiar with this stuff but out of the 4 cars and 3 different sound systems I have owned previously this sort of situation has never happened to me. I have never used this shop before but it has been highly recommended by the Focus groups here in Central FL so I am swimming upstream if I go and blast them. I'll post pics of the settings to see if maybe someone can determine what might be the issue as I really do NOT want to buy an additional sub/amp and have this happen again where I'm literally throwing money in the wind.

Small side note, my car spent a full business day at this shop. When the car was returned to me I noticed my dashcam was unplugged. When asked why they explained it was company policy. A part of me says BS and they took the car for a spin, but who knows.

Hey man, I'm on the west coast of central FL. Hit me up. I won't BS you like shops will lol. I don't have a shop, but after I get my window fixed, maybe we could meet somewhere and I could look it over for you.

A few things come to mind. #1 is voltage drop. #2 is both high pass and low pass filters. #3 is the type of box it's in.

That does sound like a strange explantion on it's face, but I bet there's an overlooked reason why this is happening.

 

[Buck 5,000+ posts]

Ok so is that gain like barely up or is it almost maxed out? It's hard to tell.

 

[Buck 5,000+ posts]

And is that a sealed box or a ported box?

 

[focusedRS]

Ok so is that gain like barely up or is it almost maxed out? It's hard to tell.

The gain is barely up and the box is sealed.

 

[focusedRS]

Hey man, I'm on the west coast of central FL. Hit me up. I won't BS you like shops will lol. I don't have a shop, but after I get my window fixed, maybe we could meet somewhere and I could look it over for you.

A few things come to mind. #1 is voltage drop. #2 is both high pass and low pass filters. #3 is the type of box it's in.

That does sound like a strange explantion on it's face, but I bet there's an overlooked reason why this is happening.

That would be awesome and I would really appreciate it. I had this equipment sitting for over a year because or financial situations and I wanted to save up the money to have a clean setup where I can retain my trunk space and have it looking stock. I never expected it to be this big of a headache.

 

[Buck 5,000+ posts]

That would be awesome and I would really appreciate it. I had this equipment sitting for over a year because or financial situations and I wanted to save up the money to have a clean setup where I can retain my trunk space and have it looking stock. I never expected it to be this big of a headache.

Pm me or email me @ buck.box.designs@gmail.com and we can talk some.

 

[Buck 5,000+ posts]

I may get you to explain some specific stuff to me and see if I can help.

 

[Buck 5,000+ posts]

Like I'm trying to look at your LOC, the pic is kind of fuzzy so I can't see what each setting is. But seriously, I'll help you out. I'm bored right now haha

 

[focusedRS]

Pm me or email me @ buck.box.designs@gmail.com and we can talk some.

Sent you an email with higher res pictures!

 

[Buck 5,000+ posts]

Sent you an email with higher res pictures!

Responded.

 

[Popwarhomie 5,000+ posts]

Do you have resistors added to the factory amp that is now not seeing any resistance on the subwoofer channel?
The Sony system on these cars don't like having no load on all the channels. If the model number of the Sony amp ends with -AA or -AB you don't need the resistors. If its AE you do need to add a resistor to the subwoofer output so it sees a load.

I went with the DSR1 and completely removed the factory amp to avoid that problem

 

[jt4x4]

Reread

 

[jt4x4]

Resistance and power rating of resistor?

 

[Popwarhomie 5,000+ posts]

Yeah what do I know about Focus stereos... JL audio and Audio Control even makes resistor harnesses cause it's a know issue with factory amps.

 

[Buck 5,000+ posts]

Just looking at some of his pics and settings. He has a very powerful LOC, it does like 9.5v pre out's. Even with the amp turned down a bunch, that could still be an issue. They also have the Accubass (seems like bass boost) turned up some on the LOC.

 

[Popwarhomie 5,000+ posts]

That Alpine input sensitivity is 10V-0.4V. LC2i max is 9.5V. Gain looks decently low on the amp but very well could still be clipping it to hell.

 

[hispls 5,000+ posts]

I'm usually not on the "clipping" bandwagon but between using a phone as a source (with bass boost?!?) and LOC you probably are overdriving the hell out of the amp.

Unfortunately the underlying issue here is that this small setup isn't loud enough for OP and he will not be satisfied once someone helps him get this dialed in at an output level that won't blow things up. slim/stealth box and sub is a huge limiting factor particularly with only 500W on tap and in a trunk.

 

[focusedRS]

I'm usually not on the "clipping" bandwagon but between using a phone as a source (with bass boost?!?) and LOC you probably are overdriving the hell out of the amp.

Unfortunately the underlying issue here is that this small setup isn't loud enough for OP and he will not be satisfied once someone helps him get this dialed in at an output level that won't blow things up. slim/stealth box and sub is a huge limiting factor particularly with only 500W on tap and in a trunk.

I turned the EQ on my phone off and turned down the bass on my stock head unit as soon as I got the car back because it was too much for me.

I need to retain trunk space that is why I opted for a shallow mount sub. I told the shop they can utilize the entire spare wheel space if they needed to but they opted with the box size you see pictured. I don't know anything about speaker environment so I assumed they knew what they are doing building the box that they did.

 

[Buck 5,000+ posts]

I turned the EQ on my phone off and turned down the bass on my stock head unit as soon as I got the car back because it was too much for me.

I need to retain trunk space that is why I opted for a shallow mount sub. I told the shop they can utilize the entire spare wheel space if they needed to but they opted with the box size you see pictured. I don't know anything about speaker environment so I assumed they knew what they are doing building the box that they did.

What I'd like to do is bring me fluke with me and run some test tones and test your RCA voltage. I NEVER use bass boost, which I'm pretty sure that's what that Accubass is, just they brand named it, if you will. If you have to use bass boost, IMO, something else isn't right.