GK MB212 Tweeter

raymondl3 · #1 03-09-2011, 08:55 AM

I been reading over dozens of pages about this amp and done a search. While some have talked about replacing the tweeter, I wonder if any of you have actually done this. If so, what did you replace it with? What are some good tweeter options?

raymondl3 · #2 03-09-2011, 08:14 PM

Marko5657 · #3 03-09-2011, 08:45 PM

I musta missed that. Why are people replacing the tweeter?

Are they trying to make it sound better, or having problems with them?

I’m asking because I have the MB500 head over the 4-ohm 212MBE cab, which I think is the same combination as the combo, and (fortunately last song of a set) I got this horrible buzzing sound from the cab.

Here the tweeter was on, and I guess I blew it. I turned it back off and all is well, but now I’m curious if there's another option.

pbasswil · #4 03-09-2011, 08:49 PM

I'm interested too.

Quote:

Originally Posted by Marko5657

I musta missed that. Why are people replacing the tweeter?

Are they trying to make it sound better, or having problems with them?

They sound pretty awful, wouldn't you say? I think most people leave them off. I can only imagine turning mine on in a horribly raucous bar where I was desperate for every bit of cut I could muster.

raymondl3 · #5 03-09-2011, 08:55 PM

I just got the MB212 and used it on a gig the day I bought it. I noticed something slightly artificial or "plastic" in the highs or maybe the high mids. Anyway, I've read some remarks about the tweeter and wonder if it was the culprit. I'm also new to GK, so maybe I just need to learn how to EQ it better.

craig.p · #6 03-10-2011, 06:34 AM

The block diagram shows it as a "piezo horn" with a series switch to disable it. We're not talking world-class fidelity here, so it's important to set your expectations properly. If the diagram is correct, then doing a proper job of things would involve adding a 5" or 6" midrange to the baffle board and cutting a hole in the cabinet's back to accept a speaker plate to hold a crossover. Is there enough real estate on the baffle board for such a midrange, and if so, would the midrange interfere with any existing internal bracing? You could mount the crossover board internally but you'd still need a cutout somewhere in the cab to mount an L-pad for midrange level adjustment.

And this is all assuming the MB212 head is going to "be okay" with a crossover's complex impedance -- both during power-up load check and during steady state operation. It ought to be, but... famous last words.

Do any of this stuff and you can forget about warranty work if the amp decides to go south on you.

If the tweeter isn't doing it for you, you might want to switch-disable it and EQ up in the treble region; in other words, hand the treble duty to the twelves, even though you'd be asking them to do things they may not have been designed to do. It may still net out positive.

raymondl3 · #7 03-10-2011, 06:42 AM

Quote:

Originally Posted by craig.p

If the tweeter isn't doing it for you, you might want to switch-disable it and EQ up in the treble region; in other words, hand the treble duty to the twelves, even though you'd be asking them to do things they may not have been designed to do. It may still net out positive.

I just wondered if there was a higher quality direct replacement tweeter. I'll probably just keep it turned off as it doesn't seem to add a lot of high end and as you said the 12s already have quite a bit of top. Actually I just turned the treble down a little last night and it seemed to lose some of that brittleness.

Thanks.

craig.p · #8 03-10-2011, 08:14 AM

Hi Ray. Yep, understood. There may be a higher-quality replacement, but my opinion is that the improvement would be incremental at best. You'd still be stuck with a piezo with an ersatz crossover. IMHO, that'd fall squarely into the category of Why Bother. And anyway, sounds like you've pretty much gotten around the problem. Nice combo, though.

To get a little less brittleness/blaring, consider lining the inside of the cab with sound-absorbing material, if it isn't already lined. That could be half your problem. (There are plenty of threads already here on what to use.)

raymondl3 · #9 03-10-2011, 08:29 AM

Quote:

Originally Posted by craig.p

Hi Ray. Yep, understood. There may be a higher-quality replacement, but my opinion is that the improvement would be incremental at best. You'd still be stuck with a piezo with an ersatz crossover. IMHO, that'd fall squarely into the category of Why Bother. And anyway, sounds like you've pretty much gotten around the problem. Nice combo, though.

To get a little less brittleness/blaring, consider lining the inside of the cab with sound-absorbing material, if it isn't already lined. That could be half your problem. (There are plenty of threads already here on what to use.)

Hey thanks for the advice. I will definitely look into that. I don't think I need the tweeter that much and from what I can hear, they must have crossed it over pretty high (?) because I'm not missing much. Probably the biggest issue is not really knowing GK, since I've been mainly an Eden guy for 15 years. I really like the clarity and power of the GK though.

garagebassman · #10 03-10-2011, 11:55 AM

Quote:

Originally Posted by Marko5657

I musta missed that. Why are people replacing the tweeter?

Are they trying to make it sound better, or having problems with them?

I’m asking because I have the MB500 head over the 4-ohm 212MBE cab, which I think is the same combination as the combo, and (fortunately last song of a set) I got this horrible buzzing sound from the cab.

Here the tweeter was on, and I guess I blew it. I turned it back off and all is well, but now I’m curious if there's another option.

I run similar rig (8 ohm 212MBE & MB500), and was just curious if your limiter switch was engaged on the 500 ?
I think the tweeter may lack a little compared to the 212NEO I have, but for the weight and price I can't complain.
I only ask because I have been messing with this switch on/off, usually off @ rehearsals (seems MAYbe a bit more clarity), but been keeping it on @ gigs.
hope it works out.

I do prefer the extra top end "cut" with the tweeter on myself

vince a · #11 03-10-2011, 12:04 PM

I have an MB212 combo, which is not my gigging amp. I bought the MB212 as a light alternative to take to band practice, and to use on Sundays on the Praise & Worship team. The MB212 does quite an adequate job for these situations. I run it fairly flat (somewhat down on the Bass and Lo), and the rest are flat . . . Master at about 1:00, Gain about 11:00, Contour on, and tweeter on . . . and the combo sound terrific . . . though I get some cabinet resonance on certain notes, which I eventually will get rid of.
The tweeter is fine . . . unless it's blown, don't void your warranty - get it fixed with your warranty!

raymondl3 · #12 03-10-2011, 12:48 PM

I did have the limiter on. What was happening was the high mids were almost like that of a modeling amp, where nothing I did with my right hand placement seemed to alter them. Hard to explain.

4-string · #13 03-10-2011, 04:57 PM

I don't really know how different the MB212 and MB115 are, but I assume they have identical tweeters. From my little experience with the MB115 I thought the tweeter sounded fine, the problem is that there's no tweeter control/attenuator, so there's way too much of it. Roll off the treble a bit, and problem more or less solved. I say more or less because a tweeter control would sound much better.

Tweeter off gave utterly useless results to my ear, nothing but honky hi mids.

bassbeard · #14 03-11-2011, 11:49 AM

does anyone else notice alot of "noise" coming from the tweeter even when it is off? the air moving past that thing seems really loud to me and it is really starting to bug me. is that happening on anyone else's amp?

nanookofnj · #15 03-11-2011, 12:22 PM

^ Mine is dead quiet when it's off. When it's on it's horrendous however.

bassbeard · #16 03-11-2011, 01:00 PM

can anyone else weigh in here? i have already had to send this thing back once to get it repaired, and i am wondering if i am going to have to do it again. it just sounds bad right now.

gidbass · #17 03-11-2011, 01:01 PM

Mine is quiet off too, and I never turn it on.

**lowendfriend** · #18 03-11-2011, 01:09 PM

Get the Neo 212-ii

bassist4dalord · #19 03-11-2011, 01:22 PM

I have the GK MB115. I bought it from a TBer, and I've loved it since day 1. The tweeter crackles when it's on, but I don't use tweeters anyway. Never saw the point. To each their own, of course.

I just leave it off 100% of the time.

raymondl3 · #20 03-11-2011, 01:29 PM

When I turn the horn off the noise is greatly reduced, but there is still some noise from the 12s. Is that everyone's experience?