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15/6 phase issue?

crusie

crusie

Oct 19, 2009
316
10
43
Djursland, Denmark
#1
Hey.
I got a bass cab with a 15 / 6 configuration.... It seems overly bright. Could this be because of a phase issue between the 15 and the 6? My amp has highs rolled completely off, and my active bass too. This is just so the highs are tolerable. I like a hifi sound but this is just crazy. Amp is a lmII markbass and bass cab is from a well respected builder. Bass is an ibby 1205
 
#2
crusie said:
Hey.
I got a bass cab with a 15 / 6 configuration.... It seems overly bright. Could this be because of a phase issue between the 15 and the 6? My amp has highs rolled completely off, and my active bass too. This is just so the highs are tolerable. I like a hifi sound but this is just crazy. Amp is a lmII markbass and bass cab is from a well respected builder. Bass is an ibby 1205
Click to expand...

Hard to say with out more specifics.

What drivers are used?
What cross over is used?
Who was the builder?

Cabs with mid range drivers can be shocking when first used if you are used to "traditional" cabs with heavy upper mid range roll off.
 
#4
CL400Peavey said:
Hard to say with out more specifics.

What drivers are used?
What cross over is used?
Who was the builder?

Cabs with mid range drivers can be shocking when first used if you are used to "traditional" cabs with heavy upper mid range roll off.
Click to expand...

+1.. Depending on the components used, if the crossover was not designed correctly, the mid will overpower things
 
#8
4Mal said:
Yeah, it is entirely possible. The original spec for the cross over was not corret in that regard. Just flip the leads on the mid driver and test away.
Click to expand...

Hmm dont know if youre being sarcastic or you've researched my gear. I havent included included the brand because I dont want people to search forums for this brand and find this post if what I'm saying is off. I'm sure this uk builder, however "clean shaven" his brand sounds, got his act together. It could be a slipup though. Damn how creative can you be when not making a brand-name searchable? :)
Vle and the vintage filter is both completely off
 
#9
crusie said:
Hmm dont know if youre being sarcastic or you've researched my gear. I havent included included the brand because I dont want people to search forums for this brand and find this post if what I'm saying is off. I'm sure this uk builder, however "clean shaven" his brand sounds, got his act together. It could be a slipup though. Damn how creative can you be when not making a brand-name searchable? :)
Vle and the vintage filter is both completely off
Click to expand...

I guess your best bet is to contact this UK builder...for the sake or argument, let's just call him 'Alex' :)

It could be a slip up, though it could just as easily be the idea that it's a sound you're not used to?

I'm sure it'll become very clear after a couple short conversations with your builder...Best of luck getting great tone!
 
#10
dukeorock said:
I guess your best bet is to contact this UK builder...for the sake or argument, let's just call him 'Alex' :)

It could be a slip up, though it could just as easily be the idea that it's a sound you're not used to?

I'm sure it'll become very clear after a couple short conversations with your builder...Best of luck getting great tone!
Click to expand...

You got the builder right :) I've had this cab for quite some time... Around 2 years so I'm guessing it'd not a "getting used to" issue. I've always had the highs completly off. Eveything on noon hurts ears alot
 
#11
crusie said:
You got the builder right :) I've had this cab for quite some time... Around 2 years so I'm guessing it'd not a "getting used to" issue. I've always had the highs completly off. Eveything on noon hurts ears alot
Click to expand...

Oh! Didn't realize you'd had it for so long...I would still contact Alex and look for suggestions...he's a very sharp guy and I have no doubt will be most helpful.

In the meantime have you tried flipping the phase on your mid driver?
 
#14
Set all frequency bands on the the amp flat at noon. Set VLE and VPF (I think the latter was what Bmorefoozler meant) to zero (fully anti-clockwise). Set your bass flat with no active boost or cut. How does it sound? Start from there.

I would expect phase issues with a 15/6 config to make things bass heavy rather tham bass light as the frequencies being cancelled out would be the high midrange rather than the lows? But it could still be a crossover issue of another sort.

Can you try the head (and bass) with a different cab?
 
#15
It is indeed possible that reversing the polarity of the midrange driver will result in enough cancellation in the crossover region to help out significantly, so try that first because it's relatively easy and cheap to do. But if the excess energy is well north of the crossover region, the solution is probably more complicated, and you may have to consult the clean-shaven one. Perhaps a bit of series resistance in the right place might do the trick, just make sure you don't skimp on power handling.
 
#16
There is a thread on the greenvoy forums about this. The program used to calculate the crossover had an issue in the math which caused a phase issue in the final results of the crossover. Usually with a 2nd order crossover like in the fFearfuls you wire the mid out of phase. With the math issue it was found that you wire the leads normally. Also, check the resister values in the Lpad. If there is not an Lpad or the values are incorrect, that couuld be your problem.
 
#17
winegamd said:
There is a thread on the greenvoy forums about this. The program used to calculate the crossover had an issue in the math which caused a phase issue in the final results of the crossover. Usually with a 2nd order crossover like in the fFearfuls you wire the mid out of phase. With the math issue it was found that you wire the leads normally. Also, check the resister values in the Lpad. If there is not an Lpad or the values are incorrect, that couuld be your problem.
Click to expand...

The cab in question isn't a greenboy cab.

As for the rest, we always goof around with swapping the phase for the mid driver on new designs...software modeling doesn't really tell you what's gonna be the best way.
 
#18
Ah, ... Saw 15/6 and assumed fEarful. Didn' t scope the location... If it was a fEarful inspired build then they could easily have transferred the same issue. Lot's of early fEarfuls had that issue. I actually padded my mid driver back as it was unbearably bright...
 

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