Markbass head won't work with certain high end loudspeaker

[MCMagoo]

So I just had a professional install some faital pro 10HP1020 loudspeakers in my 2x10 Eden cab (Google the specs of you can)

From my knowledge and what my installer says, the speakers should play like a dream and initially he had it wired for 4 ohms but the markbass protection circuit kept activating any time I dug in on the higher notes. so I took the cab in and had him wire it in series so the impedance read about 12 ohms, when I talked to markbass they said anything over 4 there should be no problems. I use a momark 500 watt with the tube gain.

When I tried the cab Again with the new wiring, same issue. This doesn't happen with any of my other cabinets including my 4x10 Warwick cab and my awful 100 watt ashdown cab.

Anyone have any idea what's going on? I spent almost a grand putting this cab together and I'm bummed out. Also sorry if anything is unclearninwrotenthisnpost in a hurry on my phone, I'll edit it later if necessary.

 

[CL400Peavey]

I suspect your "professional" is not what he appears.

 

[Arjank]

Does that cab have a tweeter? maybe something is wrong with that or the "crossover"

 

[MCMagoo]

It does have a tweeter but I'm not sure he even wired it in with the loudspeakers

 

[Arjank]

It does have a tweeter but I'm not sure he even wired it in with the loudspeakers

let the guy check that part.
If the protection circuit kicks in there's a short or a low impedance in a certain frequency range that's giving the amp a hard day.

 

[MCMagoo]

Ok I'll mention that. Is it possible that the tweeter prevents those harsh notes from dropping the impedance?

 

[KramerDon]

I'm curious how he "read"impedance which is not the same as resistance

 

[MCMagoo]

He used an impedance tester. Kind of looks like a guitar pedal, and he also checked the speaker jack with a voltmeter tool. I'm not experienced with these things but that's what I saw when I was in watching him do it. It read something like 12.6 ohms which would make it a 16 ohm cab I guess

 

[S-Bigbottom]

Is it a 210T, XLT, or XST? Each is a very different cab inside.
How do you have your L-pad set? if you turn it all the way down it can burn it up. Check it. Always have the Tweeter a little on to prevent this.
If you do not want the tweeter pull out the bulb.

 

[BassmanPaul]

I suspect the tweeter / crossover. If the woofers are running full range in parallel you'll get 4Ω. In series 16Ω. The crossover will be in circuit unaltered in either case. I'd have the crossover disconnected and the woofers wired in parallel. See what happens now.

 

[okcrum]

Have you tried just the Faitals without the crossover or tweeter?

If it's not the crossover, it sounds like the cab total impedance takes a nosedive somewhere in the low mids. Speaker impedance changes with frequency. Class D amp, right?

agedhorse pointed this out in another thread.

 

[MCMagoo]

It's the 210T, I'm looking right now and the tweeter is not connected I'll add a pic in case anyone wants to see how it's wired. note the 2 wires that aren't connected and are tied to the other wired are the ones that were making it parallel. It's wired in series now.
It's the 210T, I'm looking right now and the tweeter is not connected I'll add a pic in case anyone wants to see how it's wired. note the 2 wires that aren't connected and are tied to the other wired are the ones that were making it parallel. It's wired in series now.

 

[MCMagoo]

Sorry I am doing all this on my phone and it double posted there somehow.

 

[/\/\3phist0]

these?:Faital Pro 10HP1020 10" Mid-Bass Speakers - Faital Pro 10HP1020
mid-bass speaker . This 10" speaker that has a lightweight neodymium magnet -
Faital Pro 10HP1020 1,400 watt 10" has an efficiency of 96dB SPL woofer for all high
power mid-bass applications. Faital Pro 10HP1020
by bet is that the crossover is wired incorrectly, and or the Low pass/high pass is out of phase....
diagram:

checking impedance:
Speaker Impedance

 

[Coolhandjjl]

.....agedhorse pointed this out in another thread.

He has frequently mentioned that some x-overs may be acting like a resonant tank circuit, which some Class D heads are not designed to deal with.

 

[/\/\3phist0]

It's the 210T, I'm looking right now and the tweeter is not connected I'll add a pic in case anyone wants to see how it's wired. note the 2 wires that aren't connected and are tied to the other wired are the ones that were making it parallel. It's wired in series now.
It's the 210T, I'm looking right now and the tweeter is not connected I'll add a pic in case anyone wants to see how it's wired. note the 2 wires that aren't connected and are tied to the other wired are the ones that were making it parallel. It's wired in series now.

you did notice the missing fuse right? the L-pad is not included in the circuit, but cannot tell for certain whether the X-Over is actually bypassed it LOOKS to be in the circuit.

 

[aproud1]

Looks like the fuse is bypassed anyway.

 

[MCMagoo]

It Looks like the crossover is wired to the old school speaker jacks and the 1/4 inch jacks. I'll look again when I get home.

 

[punchdrunk]

I suspect your "professional" is not what he appears.

This

 

[okcrum]

He has frequently mentioned that some x-overs may be acting like a resonant tank circuit, which some Class D heads are not designed to deal with.

Yeah, it depends on the crossover, drivers, cab tuning...I think we assume a series resonance and an overcurrent amp trip. Drivers are themselves a resonant circuit too.

In this case, I'd test with the fuse in and at least a resistor in place of the tweeter.