Brahma this, Brahma that...

I think this might be because alot of people don't listen to the stereo with the trunk open, and eveyone has said they usually don't notice it when sitting in the cab. Also, alot of people don't have the chance to own a loud SQ driver like the Brahma so we just compare it to our shitty subs and don't realize it is bad or abnormal since we are use to the distortion and popping

I have learned quite a bit in the last year about car audio. A couple years back I had a Cerwin Vega "vega" in a ported box and I always thought my trunk rattled real bad. One day I bought some deading material and turned on the system. When I went to the back to listen to wear the rattles were coming from I realized the sub was blown. I didn't even have rattles

My point is, just because people don't report the problem doesn't mean it isn't happening. Now that the word is getting out, I think a lot of people are starting to realize they all have the lead slap issue. I am not talking down on you dan, nor your product. But the more people that realize this, the faster we will find a solution to fixing it. You will then have one more customer to represent

Don't take this post the wrong way Dan.

dave

 

I have had huge popping noises that were resolved by simply correcting a poor ground. In each case it was when the bass got deeper, the pop got worse. The ground is just as important as the power.

 

I mean, I would go in a heart beat, but I am in so much debt, I barely have enough gas to make it to work each day LOL.

In a week or 2 I would cause I would have money.

PG Cyclone? Is that a sub..? I wouldn't be able to buy it.

 

No I didn't this pop is weird.
I think I should let Dan handle it so I don't void my warranty, and leave it to the professionals.

 

here is a cyclone. It is a rotary sub. I'm dying to hear one.

I think you are right, ryan. Sounds like a problem to me. Send it back, and have them look at it.

 

here is the first set of fix pics. As you can see the fix is quite unobtrusive, yet works quite well. Also, in picture 4 (with my finger holding the tinsels) you can see the wear on the tinsel lead, that helped lead me to the problem. I will post some more soon.

 

Sounds like you are just pushing the sub way too hard. Ease off it and see if it still makes the noise.

-Chris

 

Yep, it is about that far...
I drove to NYC a few years back, I think I passed Albany at about the 6 hour marker...
Not a short drive..

I wish I could help... I would absolutely LOVE to help you troubleshoot this... first thing I would do would be to invert it and try some of what Sandt did, you might start there! (although sending it back certainly sounds like the right move in this case)

Networkguy is driving to my house as we speak, so I will finally get to hear a Brahma in action! He just lives in Niagara Falls, Ontario, so he's not very far from me.

He's got the same setup as you, Sandt... we will put it through it's paces to see if we can intentionally get any lead slap out of it...
He says his doesn't get lead slap though, so it might be like Dan said.. related to the tinsel lead tolerances! From eyeballing the picture that you took, I was wondering about the flat metal that the tinsels were connected to, maybe bending them would offer a solution...


I can't wait to hear this, Brahma 12, sealed, on about 1400 watts...

 

You mean you couldn't buy it because it's discontinued, or because it's too expensive?
Well, it's discontinued, but you CAN find them used if you search for them! And, you can find nice examples for less than half of what they cost new...

As far as "what is it"...

It's a sub that has no voice coil... it's not a linear voice-coil-motor sub, it has a rotary servo-motor that powers it, it churns back and forth like a washing machine... waving two "vanes" that perform the same job as the cone on your subwoofer - they stimulate the air!

A servo motor is wickedly efficient compared to the voice coil motor (voice-coil motor is one of the least efficient - if not THE least efficient - electromagnetic motor out there)... 300 watts to a servo motor sub might not sound like much, but it's comparable to 1000 or more watts to a regular voice coil motor, just because of efficiency...

Did I mention that it has a resonant frequency of 10Hz?

Pretty cool stuff... begs the question of "well then, why aren't there more servo motor subs on the market?"
The answer to THAT is that Tom Danley of ServoDrive owns ALL the patents to them - literally! The Phoenix Gold Cyclone was extremely expensive ($1200-ish in the mid 90's) not just because of the technology, but because they had to license the rights from ServoDrive (who helped engineer the Cyclone!)...

There's some great tech info here, if anyone is curious about servo subs: http://www.mindspring.com/~sdinc/pages/contra.html
Particularly that whitepaper by Tom Danley himself...


And here's some pictures of my Cyclone, and two motors that I have that I will be building a twin motor SPL "super sub" (and no, unfortunately I can't compete with it ):
http://www.geocities.com/geolemon/servoproject.htm

 

The slap is most noticeable at around 47Hz. I suggest trying it there wide open. I did post (I think) that I did bend those mounts up from their 60 degree angle to about 80 degrees.

It is more like 1550 to 1600 you will be hearing it on todat Geo. Oh, let me be the first to welcome you to heaven

 

maybe i'm not being "specific" enough for you...............a bad amplifier ground won't cause the amplifier to heat up on its own............

 

No? It does with every other electrical device I know of. Make a bad ground with your amp and pound it for a while. Feel the power and ground wires and the amp itself. It may not set it into protect, but it will generate heat.

Edit...

I cannot say for sure if it would be enough to send it into protect, I've heard it will, but I have no personal experiance. I would assume a bad ground should shut down an amp that has both thermal and current protections (the JBL has both, right?).

 

Chris -

You probably haven't read my other posts. I have had this problem since the first time I played it even took it to local friends and local shops turned down the gains, and what not, and it still does it even with the bass down and at low volumes.

so...

 

go ahead and visit www.carsound.com and check the bad amplifier grounds post..............

You believe that a shortage of power to the amplifier would result in it heating up on its own?

Heat up the wire...............not the amplifier.........like said before, go check the Carsound thread.......

good day

 

Well, fill us in Geo... What was your first superorgasmic... Uhhh, supersub experiance like? What did Tre do about his box? I know he had it in the MAXs 1.6 sealed box before, I'm just wondering if he corrected it. I haven't talked to him for quite a while.

I know what amp he runs silly.... I sold him that amp for a killer deal.

Let us know, Geo. Tell Tre to get his ass back on here now and again.

 

By the way fellas. I added the pics of the adhesive and what the high pyle felt look like. I also added pics of the felt fix, both near and far away, so you could see what it looks like when repaired...

http://photos.yahoo.com/bc/sandt38/lst?.dir=/Brahma+pics&.view=t

 

Well, here's my impression....

Like I said, I heard this sub sealed (and Tre built a new box for it, a bit smaller than the MAX box actually), with a huge amount of power behind it - although he definitely had his gains set to be reasonably well balanced with the front speakers.

The sub is tight, very tight... I agree with people's statements about how it hits and disappears quickly - it is fast, and detailed in the same way that makes me love my JL XR component set's tweeters - very sharp sound.
And the tonality is wonderful, the notes are very true and realistic, very musical.

In respect to output, bear in mind that this was in a sealed box, although it had a ton of power.

The output was very comparable to my JL's, I think they would meter within a couple dB of each other.
My JL's are in a ported setup, I probably have nearly triple the cone area to boot. Of course, I don't have that much power going to my JL's, but in this case that shouldn't be too much of a penalty - likely not even 3dB.

Very impressive, that a single 12" sealed sub would have more output than a trio of fairly high excursion tens, in a large ported install that was designed in part to maximize output!

And obviously partly the fault of my large, efficient ported enclosure...
The accuracy of my JL's was just shameful compared to the Brahma in it's sealed home...
I would love to compare them, ported compared to ported, or sealed compared to sealed...
But I really think the Brahma would still shame them, it WAS that accurate!

As regards the lead slap, we did get some at not only 40-50Hz, but also when we were really beating on it at about 10hz-15Hz... I mean beating on it, we wanted to see how far we could visually make the Brahma logo move - since 10Hz is obviously inaudible. We did stop when lead slap became audible, fearing that we might acutally bottom the driver, causing more severe damage.. (do NOT try this at home... even in a small sealed box! )

However, I will note that as far as this lead slap goes, it was very mild, a slight ticking sound only audible when we were looking at the sub with the trunklid open.

From inside the car, at this same output level, the noise was inaudible... it IS that mild!

That being said, I would still want to fix it myself...

 

what does it mean
this tear jerking scene
beamed into my home.............

 

It means, I send back my sub and wait for Dan to fix it.

 

To me it sounds like you are over-driving your subwoofer, expecting it to be louder than is possible in this application, or else it is playing very loud but without the distortion you may be used to from other subwoofers--distortion which you perceive as loudness. Maybe you cranked it to hard right off the bat, bottoming and permanently damaging the subwoofer from the get-go. Now it's crapped out and you don't know why.