Did I blow the driver? (1 Viewer)

[Brett Creider]

I dunno why...but it seems after I pushed it for about 5 minutes...it doesn't seem to sound the same...

I have changed a lot of settings messing around on the comp so that might be it....but are there any definite ways to know if I've damaged the voice coil?

I dunno it seems like it is blown when I put my ear up to it and it seems to not have the definition it DID have....


What can I do?

 

[Brett Creider]

BTW It's a Tempest and a PE 250watt amp.

 

[Allen Ross]

what driver and what amp? and does it make a scratching sound when the drive is pushed in? or played? or are you just noticing lower output?

 

[Darren_T]

I think you just toasted your ears. You'll know if you have blown the driver. It will sound horrible.

 

[Brett Creider]

When I reach near the end of the xmax's potential it sounds like it's rubbing something.....


See it sounds fine to me when its playing a continous long low note but when it hits.....I dunno it sounds wierd.....

 

[Brett Creider]

See the thing is when it HITS it sounds like it's blaring up close...from the normal listening position it just sounds weaker....I think....

Maybe I am just now paranoid and I wasn't before or something but when I had it cranked right before I noticed all this the driver didn't look or sound like it was bottoming out.

 

[Darren_T]

You may be sitting in a null. Place the sub in your listening position and walk around the room. The spot where the bass sounds best is where the sub should go optimally. The corner of the room is a generally good spot.

 

[ThomasW]

Unless your box is some how horribly miss-tuned or has an air leak; it's pretty hard if not impossible to toast a Tempest with that amp. Remember that Tempests are rated to handle ~350 watts/vc

You may have just accelerated the burn-in process. That usually results is the driver playing lower in frequency with a little less output at the mid bass frequencies.

If you're comparing nearfield and farfield output levels; note that the SPL will decrease by 6 dB every time the distance from the sound source doubles.

When I reach near the end of the xmax's potential it sounds like it's rubbing something.....

Again it's virtually impossible to reach Xmax with that amp unless you have a HUGE amount of bass boost dialed in. If you hear this when moving the cone by hand stop doing that. You can trash the voice coil cycling the cone in and out by hand.

Might be a good idea for you to pop for a RS SPL meter and take some measurements.

 

[Brett Creider]

Well I took the driver out (and in the process broke that wierd surround stuff around the edge but glued it back) there was some polyfill between the basket and cone...

I took it out and it no longer makes a scraping noise anymore but it still does seem the mid bass lacks compared to high or low frequencies....and it is in the corner...I put it in the other corner and it's the same.

 

[ThomasW]

That 'weird surround stuff' is to the driver, as your shocks and springs are to you car (= suspension). Don't mess it up. There are special adhesives to repair it. You can't simpy use any old 'glue' and have the repair last. Some glues will actually eat/dissolve the surround material, or are to stiff and won't properly flex. As a result it's possible that there will be a new air leak where the surround is damaged. If this happens the surround will have to be replaced for the driver to operate correctly.

Polyfill between the frame and the cabinet created an air leak that's why you where hearing the strange sound.

Although not rocket science; attention to detail and proper assembly techniques are important considerations to get good performance.

The human ear isn't a reliable source for determining output frequency levels. The only way to accurately know the frequency response is to measure it.....

 

[Stephen Hopkins]

ThomasW,

I think you mis-read 2 things in Brett's last post. I beleive the "weird surround stuff" he broke off was the cork-like material outside the surround material that sits in the same circle as the screw holes. Don't worry about this stuff, there was some chipped off my Shiva and it doesn't make a bit of difference in performance.

I also think you misread his polyfill problem. I beleive some pollyfill had worked it's way inside the basked on the back of the driver between the back of the cone and the spider. This would definately cause the sound you were talking about and, unless you did some damage to the tensil leads (which it doesn't seem you have) or the spider it's self (doubtful as well) then you should be fine.

Hope everything else is turning out enjoyable for you and goodluck w/ your sub and the rest of your system

 

[Brett Creider]

Ya it was the cork like stuff, not the suspension. I am not THAT much of a nublet. Also, the polyfill was inside the cabinet, stuck between the basket and BACK of the cone...just like Stephen said...

But still I don't get that lack of mid bass...

 

[Geoff L]

Take a chill pill!

Get a SPL meter and measure if you want accurate output information....

 

[Darren_T]

Brett,

I think you are experiencing the migration from car audio to home audio. You need to adjust your expectations, sit back with a SPL meter and calibrate your system. You aren't going to get chest pounding bass like in a car... I know you are aware of that but it's hard to let go of that expectation.

Since you solved the scratchy sound you should be set.

 

[ThomasW]

But still I don't get that lack of mid bass...

As was previously stated probably a room null. Only way to know is use the procedure Darren described in post #7 of this thread, and or measure the output with an SPL meter.

 

[Hank Frankenberg]

Yep, just do it.