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View Full Version : Mb Quart: 6 ohm Tweeters???? Help!



Ebbsnflows
05-27-2006, 10:00 PM
Hi all-
I have a question that is busting my brain. I recently ordered a set of MB Quart DUA 216's (6.5" component system) from OnlineCarStereo.com for my 00' 4Runner. As I was installing them, I realized that the driver is a 4 ohm speaker (as it should be), however the 1" Tweeter is rated at 6 ohms (as stamped on the back of it). I thought that was odd...but figured MBQ knew what they were doing? However, When I finished wiring everything up thru the crossover (supplied w/ the speakers)...the driver works just fine, but I get nothing out of the tweeter. Zero, zilch, nothing.

Is this due to the odd 6 ohm load? Or did I just miswire something (although I'm not sure how I could have screwed that up...I've already checked my terminal connections). Why would MB Quart make the tweeters 6 ohm?

I have a basic understanding of electronics/car audio...but this one is beyond me. Can someone please 'splain it to me?

FoxPro5
05-27-2006, 10:31 PM
www.bcae1.com (http://www.bcae1.com) <---- your best place to start my friend :)

Ebbsnflows
05-27-2006, 11:02 PM
Thanks for the link ;)
But I'm still confused as to why MBQ would use a 6 ohm tweeter? Why not stick w/ 4 ohms for both the driver and the tweeter?

PESteele
05-28-2006, 12:20 AM
read squeaks speaker faq. I think its so that when playing the tweeters frequencies it doesnt recieve as much power

helotaxi
05-28-2006, 01:12 AM
In a lot of cases, that's just what it comes out to. Also once the zobel filter is wired in the imp will normalize in the range of 4 ohms anyway.

jluv
05-29-2006, 11:46 AM
You should definitely still be getting output from those tweeters. Something else is the problem. Triple check your wiring.

Ebbsnflows
05-29-2006, 08:47 PM
You should definitely still be getting output from those tweeters. Something else is the problem. Triple check your wiring.

Ok, I messed around with them again this afternoon. I changed the crossover setting from -6 db to 0 db (for the tweeter). After that, I cranked the volume up to about 30 (with the factory component speakers I never went beyond 20 because it became painfully loud)....anyway, with deck at 30, and my ear literally pressed against the tweeter I could hear faint music. So they are producing sound...its just really, really, really faint. Meanwhile, the mid-driver is pounding right along.

To check that the MBQ tweeters weren't defective I wired the factory tweeter (4Runners have components from the factory) to the crossover and got the same results.

The speakers are rated at 50-120 watts rms. I have them hooked up to a Fosgate 75x4 amp with the gain at about 85%.

Based on this info...anyone else want to take a guess? I realize that the 6 ohm design will diminish the power running to them...but THat MUCH? To the point where I can just barely hear sound coming from them with my ear touching them?

PESteele
05-29-2006, 08:55 PM
is it both sides thats messed up cause it sounds like something with the crossover

FoxPro5
05-29-2006, 09:31 PM
What kind of resistance do you read across the tweeter terminals on the crossover??

Ebbsnflows
05-30-2006, 09:55 AM
is it both sides thats messed up cause it sounds like something with the crossover

Yes, both sides behave identically (I initially thought the crossover was bad too). So while its entirely possible that both are bad...it's not likely.

Fox-
I don't have a multi-meter, so I'm not able to say. I'll see if I can borrow one from my buddy.

I have a new amp arriving today by mail. It's an AudioBahn A1504DP. It's rated at 150x4 rms...I'm going to hook the MBq's up to that and see what happens. Perhaps the speakers simply need more power than the 75w Fosgate can push?? At this point, I'm grasping for straws and becoming extremely frustrated. I was really excited about finally having a decent audio setup and it's turned into a huge non-functioning PITA.

Gary S
05-30-2006, 01:35 PM
is the crossover in biwire/biamp mode?

Ebbsnflows
05-30-2006, 06:58 PM
is the crossover in biwire/biamp mode?

The supplied MBq x-overs are passive...there are no external switches/adjustments. Based on that, I have no idea what "mode" they're in.

Ebbsnflows
05-31-2006, 07:46 PM
DOH! I figured out my problem. I was chasing the wrong path.

My deck has 3 outputs (Front, Rear, seperate Subwoofer). Up until recently I had been using the Fosgate amp to power my Sub.

When I installed the components up front, I just unhooked the Sub wires, and ran the components to it in order to test them out. Obviously the sub-output on the Deck wasn't allowing any hi-level freqs to pass, thus silencing the tweeter but allowing low freqs to reach the mid-driver.

I'm so stupid sometimes.

So now that I've got it all squared away and a new amp installed (the one I mentioned above), Am I happy? No. As far as the MBq's are concerned, I'm very disappointed in them. The mid-range is washed out and the Highs are dull. I really expected more crisp highs and solid mids. At this point, I'm tired of screwing with it. I think I'm just gonna pick up a set of 2 ways for the door (power them w/ the Amp) and re-install my stock 1" tweets (and power them w/ the Deck).

Thanks to all that offered advice and input!