Seeking opinions or better knowledge

[SilverSquared 10+ year member]

A guy I work with has a BMW 645CI with a single 12" sub in the trunk. He had an alpine type r for over 4 years he said on a JL JX1000 amp. This was in a probox vented box. Its 2.0 cu.ft. tuned to 35hz. Weekend of the 4th he was at a beach thing and said he had the music playing. He claimed he left for 3 hours and when he came back his 12 was toasted. It was. Last weekend (7/11) I brought him to a local place in Houston to help him get some new gear. His type r 12 was bad, you could see the cone was melting around the coil area.

He bought a db drive euphoria ew9 12" sub, d4 coils. Upon installing it it went straight to distorting, so I told him to lower his bass level. You could hear it scratching and popping but not moving to its full xmax. He instantly started complaining that his amp was too strong and was over powering the sub. Said the alpine had much more authority and more punch with far tighter bass.

I told him to go easy on it for a few hours and let it break in a bit before going ham. He texted me about 20 minutes after we left saying he smells the resin burning.

This past friday (7-17) he tells me that he blew the sub again.

Today at work Im trying to tell him he was clipping the amp but he swears up and down that the sub was only good for 750wrms and he was putting 1k to it, so thats why it blew.

He used to be a salesman at a stereo shop in baton rouge that sells alpine, kicker, pioneer, jl, and focal.

Was what I said incorrect?

What does HE need to do or think to rectify this issue?

(Im gonna print this and give it to him)

Click to read more...

 

[Boomin_tahoe 5,000+ posts]

lol amp is too powerful.

Tell him to quit buying mainstream brands and throw a online brand sub in there. Then he won't complain.

Clipping yes.....you said the bass level was turned up....but on what exactly? HU? Amp itself?

 

[SilverSquared 10+ year member]

He doesnt have an aftermarket HU. Its stock with JL amp integrated. The bass adjustment knob he has was at 100% when he first turned it on.

Like I mentioned, the sub was moving less than half its travel, but sounded like it was at its limits. Once he lowered the bass it was moving much

more, and sounded very clean.

IMO, it sounded very good for a single 12 in a box almost 1 cu ft too small. He wants the sound of a good 15, out of a big box brand 12. I cannot

emphasize to him that its NOT gonna happen. I ruffled his feathers when I told him this...you were a salesman, I am an installer. What you know

is on paper from manufacturer. What I know is from actual events and DMMs. His response "I sold because I knew. Those installers dont know what

they are working with, they just know how to put it into a vehicle"

This was my sign to walk away, lol. A JL fanboy for life. And he's close to 40 years old.

 

[hispls 5,000+ posts]

Provided you have verified that the amp is not faulty and delivering DC to the woofer, the ONLY thing that burns up speakers is to put power into them faster than they can dissipate the heat. Time to turn it down or buy a sub with a bigger coil.

 

[Massive spl]

Sounds like clipping to me.

 

[SilverSquared 10+ year member]

Guy claims that he put a cap in and it's solving the problem. But he said without the cap, at full tilt, he had a constant 14.1v at the amp. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[mylows10 5,000+ posts]

He needs a better sub and all the gains on the amp set correctly

 

[SilverSquared 10+ year member]

Thats what I told him. He tells me "he set the gains with a meter". I tell him he's full of it.

Older, blown type r, he said was dual 2, and was running at 4 ohm, got louder than new type r thats dual 4 and running at 2ohm.

 

[los33 10+ year member]

Offtopic post.. You live in montgomery?? Mind helping me out with customizing my truck, i live on 1488 & 1774 passing the woodlands

Sent from my draconis using Tapatalk

 

[SilverSquared 10+ year member]

Yea, live in Montgomery close to 105 and 149, work on Gosling in The Woodlands, So Im on 1488 all the time.

 

[wew lad 5,000+ posts]

Put on oscope on the amp with the gains set the same way he had them set, and run a -10db test tone through it. If the waveform is clipped then you've got all the proof you need plus some. I would tell you a little clipping is okay, but considering you'd be using a -10db tone, the likelihood that any music he would play that's soft clipped on -10db would be extremely hard clipped on 0db.

 

[n2audio 5,000+ posts]

Ooh, a cap. He's getting somewhere now.

He needs a $100 set of signal cables, then he's good to go.