Attention all members!
Have a cool ride? Then show it off on our website! All vehicles welcome!

MTX smoke?

Post all your general car audio questions here.
Ryan from Ohio
Posts: 13308
Joined: Fri Mar 17, 2000 12:00 pm
Contact:

MTX smoke?

Post by Ryan from Ohio »

-Ryan
www.caraudiocentral.net - Your #1 Car Audio Resource on the Net!
geolemon
Senior Member
Posts: 585
Joined: Sun Apr 10, 2005 6:46 pm
Location: Buffalo, NY
Contact:

Post by geolemon »

There's some flake on CAF who's been posting idiotic things about MTX lately...
Saying off-base things like "This MTX sub is better in an SPL competition than a JL W7" (like the W7 exists for SPL duty :rolleyes: ).

There's a thread, something about "for the JL lovers"... he posted the same link.

I wish I had a better connection so I could see it - but what I understand from the comments in THAT thread, is that this is a video showing an MTX competitor beating other competitors?

Or is it a really silly video, so you linked it here?
Justin from Detroit1
Junior Member
Posts: 0
Joined: Wed Dec 31, 1969 6:00 pm
Location: Detroit

Post by Justin from Detroit1 »

great, so the MTX 9500 can take 140 volts, thats awesome. I'll keep that in mind if I ever want to send that much voltage to a subwoofer. What a stupid video.

Again, I can't like a brand that will directly bash another brand.
Ryan from Ohio
Posts: 13308
Joined: Fri Mar 17, 2000 12:00 pm
Contact:

Post by Ryan from Ohio »

Geo- The video shows the L7, W7 and the 9500 being powered by some big amp.

The JL Blows with 106.1 Volts, the L7 a little more and the 9500 was taking 140 Volts...

Now we all knows that our amps send an ac sine wave... So they are taking some volts...

Now what does this test prove?

From what I can tell the 9500 can handle more thermal power...

BTW I got the link from that idiot. Thought it was interesting of MTX to post this. Last breathe of a dying company IMO...
-Ryan
www.caraudiocentral.net - Your #1 Car Audio Resource on the Net!
User avatar
GlassWolf
Master of My Domain
Posts: 6725
Joined: Thu Oct 07, 2004 4:00 am
Location: Columbia, SC
Contact:

Post by GlassWolf »

Justin from Detroit wrote:great, so the MTX 9500 can take 140 volts, thats awesome. I'll keep that in mind if I ever want to send that much voltage to a subwoofer. What a stupid video.
a lot of amps send 120VAC or more to speakers actually.. The Zapco C2K series amps have a warning right in the manual pointing out that the amp's speaker outputs produce more AC voltage and equal current to a typical 120VAC wall outlet, and warn not to touch the speaker leads when the amp is powered.
That aside though, if they blew the subs, the amp was clipping most likely, which tells me the test is pretty much invalid to begin with.
Image
GlassWolf (aka KikiTheCat)
moderator-administrator
geolemon
Senior Member
Posts: 585
Joined: Sun Apr 10, 2005 6:46 pm
Location: Buffalo, NY
Contact:

Post by geolemon »

Hmm...
Seems I've plugged some subs into the wall in my day:
http://www.betteraudio.com/geolemon/dscf0010.avi
(OK, I might have "modified" it slightly before I plugged it in :D )


If that's what they are showing, they sure better show how they WIRED those subs, don't you think?

It's not the VOLTAGE that causes heat (and thermal failure) - it's CURRENT.
The W7 in particular - it's a 3 ohm sub. Or if it's the bigger one, they could have wired it to 1.5 ohms.

IF the L7 was the dual-2 ohm version, they could have wired it to 1 ohm.
Or they could have wired it to 4 ohms, and only 1/4 the amount of current would have flowed through it.

Simple Ohms law. V=IR, where V is voltage, I is current, and R is resistance.

Let's play out a scenario:
Let's assume they wired the JL sub to 1.5 ohms, and let's give them credit... Let's say they used a Kicker sub that was a dual 4 ohm, wired to 2 ohms.
And let's say the MTX sub was a dual 4 ohm... that they wired to 8 ohms.

...unless the MTX sub reached more than 4 TIMES the voltage of the Kicker sub, the test would prove the MTX sub to actually be inferior, if that was the impedence - because that would have been the "break even" point on how much current was flowing.
(and - those impedences may also explain why the JL sub failed just before the Kicker sub - if it had a lower impedence, slightly more current flows ;) )


Even without ANY of this - the impedence CURVE of the sub plays a role... the impedence to begin with is different at any frequency - with ANY sub... the impedence being highest at the resonant frequency of the sub (as high as 40 ohms, for a 4 ohm sub even!!!).

AND, when you stick the sub in a box - the impedence curve changes, actually! Box volume, box tuning all plays a role... but you can control where the resonant peaks in the impedence curve are.

...so the frequency of the voltage (AC voltage we're talking about here... home AC is 60hz - what's their equipment at? ;) ) is CRITICAL!

Hey, all I need to do is measure the impedence curve (LMS would tell me that), and then send THAT frequency through my MTX sub... and I'd be ensured I'd be sending as little current through my sub as possible...
...and I could likewise target LOW impedence points in the other two subs, and show just how much more MY sub could take. :rolleyes:

I hope you guys all understand what I wrote...

Absolutely ridiculous test!
High Society
Master of My Domain
Posts: 2473
Joined: Sun Jan 23, 2005 11:59 am
Location: Philippines
Contact:

Post by High Society »

wow, I can't wait for all the cool kids to start tellin me how the 9500 is the best sub in the world. This is a joke, JL's response to all this. Keep coming out with non b.s. subs :) Oh, that are only sold in shops!!
♠ Mateo ♠

80 pounds of Titanium
Proud Member of Team Wolfpack Audio
User avatar
GlassWolf
Master of My Domain
Posts: 6725
Joined: Thu Oct 07, 2004 4:00 am
Location: Columbia, SC
Contact:

Post by GlassWolf »

trolls.
Image
GlassWolf (aka KikiTheCat)
moderator-administrator
Darthness
Master of My Domain
Posts: 3706
Joined: Thu Feb 03, 2005 6:54 pm

Post by Darthness »

Ryan from Ohio wrote:Last breathe of a dying company IMO...
thats what im thinking here.
Image
- Keith
Post Reply