[The Dude]

Hey people, I seem to have an ongoing issue in my install that I thought was strictly an issue with the first Big Belle I had installed (16-ST1300D), but after swapping it out for the newer 16-MCH1300 the other day I am not sure. I am not sure why Memphis designed these amps with the single rca input for the sub channel, which means that you need to use one of their crossovers with the mono sub output, or as in my case, use the 16-BRIDGE bridging module. I am using it, running a short RCA cable out of it, and plugging in the L side only, as that is what is recommended in the manual. I have heard nothing but good things about the Big Belle amp, and when it is working correctly it is incredible. Running the front outputs to my RE XXX6.5C component set (2 ohm set). Using the passive crossovers for now. Sub is a RE SE12D2 (running at a 4 ohm load). At higher volumes the sub stops playing, and then starts again randomly. Also at higher volumes the front components cut in and out. This was happening with my last Belle, so prior to installing this one I rewired my front doors using 2 pair/14awg cable, as I was worried that a wire was being pinched somewhere along the way (causing the components to cut in and out). I used true 4awg for power and ground in the truck. I am thinking of eliminating the passive crossovers and running it active to see if that helps the component issue. Any ideas on the sub issue? I also have a Memphis 16-X03 three way crossover sitting here that I could throw in the mix, to eliminate the bridging module. Thanks in advance.

 

[minbari]

do you have a DMM? when bass hit and the sub channel cuts out, what voltage is at the power wire coming in to the amp? 4ga seems a little lite to me. that amp will put out like 1500watts.

 

[Mark the Bold]

I have lots of experience with the baby belle. I don't think its the power gauge wire not being sufficient, because when running the subs at 4 ohms you should only be peaking at 1000w which with true 4awg COPPER wire should be enough. As for the mono input, I always just connected a single RCA from the L of my headunit to the sub input of the Belle. Most quality headunits put out a mono signal on the sub, and if yours doesn't I'm sure it can be adjusted in the settings.

Now bare with me, I had a similar problem to yours on an install where at relatively high power use the amp would cut in and out on random channels. It turns out the fuses were loose in the distroblock and when buzzing from bass occured it opened the circuit enough to reset the amp. Try that.

Otherwise I suspect its your ground point. Two amps from (IMHO) a very respectable audio manufacturer having the same problem means its 99% percent an install issue. Check you ground wire with a DIMM and see if there is any voltage readings along your ground wire. If you're picking up noticeable voltage, you must have a bad ground.

 

[timaishu]

I run the same amp.

I dont know what your issue is. But I highly doubt that your power wire or the bridge modual are at fault.

I currently run mine on 4 guage wire. I run copper 4guage for the power and have a 4g CCA groud wire. So I doubt its a power issue.

Im running a mach 5 mli-65/blaupunkt vc100 combo at 4ohms and two 12'' PG RSDC's sealed.

When I had my older kenwood HU installed, it had two(left/right) subwoofer outputs. I used a y-splitter with no issues even though the manual said not to.

Wish I knew more to help you.

 

[The Dude]

Thanks all for the responses. The amp I am running is the Big Belle, not the Baby one. 4awg is recommended in the manual, and is as big as I can cram into the terminals. Not sure why Memphis did not provide larger input terminals. My truck is an old Landcruiser, I had a steel plate welded into the back right corner of my truck, I have grounded to this plate. Ground it down to bare metal. Only about 5 feet away from the amp. I know about doing a resistance check to ground, but have not checked to see if there is any large voltage kicking back to ground, good to check. I do have a DMM, have to check to see what is happening on the big bass drops. I do not have any distro boxes in line, straight 4awg off the battery (fuse holder within a foot of the battery also) to the amp. I do have the power/ground for the bridge module crammed into the amp terminals, I should do separate runs for those. Thanks for the info on the y-splitter also. My deck is the Kenwood KIV-BT900, it has tons of features, but I have not found a way to select mono/stereo sub out on it yet.

 

[The Dude]

I have lots of experience with the baby belle. I don't think its the power gauge wire not being sufficient, because when running the subs at 4 ohms you should only be peaking at 1000w which with true 4awg COPPER wire should be enough. As for the mono input, I always just connected a single RCA from the L of my headunit to the sub input of the Belle. Most quality headunits put out a mono signal on the sub, and if yours doesn't I'm sure it can be adjusted in the settings.

Now bare with me, I had a similar problem to yours on an install where at relatively high power use the amp would cut in and out on random channels. It turns out the fuses were loose in the distroblock and when buzzing from bass occured it opened the circuit enough to reset the amp. Try that.

Otherwise I suspect its your ground point. Two amps from (IMHO) a very respectable audio manufacturer having the same problem means its 99% percent an install issue. Check you ground wire with a DIMM and see if there is any voltage readings along your ground wire. If you're picking up noticeable voltage, you must have a bad ground.

Dumb question, should I check the d.c. voltage using the amp ground terminal, and the actual ground point in my truck as a reference? In other words, measure d.c. voltage between the ground terminal on the amp, and the spot that it grounds to in the truck?

 

[Mark the Bold]

Dumb question, should I check the d.c. voltage using the amp ground terminal, and the actual ground point in my truck as a reference? In other words, measure d.c. voltage between the ground terminal on the amp, and the spot that it grounds to in the truck?

Yes. Between the ground terminal on the amp and the ground point. Should be near zero with a good ground. If anything close to a 0.5 v it might be a bad ground. I'm just speculating on the 0.5v here - some dude on this forum probably knows a precise value of ranges).

Also, I was thinking, with your speakers at 2ohm are you running the front 4 channels bridged for those speakers? If so, that could cause the instability because that amp would be highly unstable if bridging the front speakers to 2ohms.....

 

[The Dude]

Thanks Mark. I am running the components off of the front 2 channels only, not bridged off of the amp. Will have to take some measurements, and see if the Protection is kicking in on the amp.

 

[sirvent_95]

Definitely monitor voltage during the failure first. If you have sagging voltage you should inspect your fuseholder. Make certain you don't have a defective fuse minimizing your current draw.

 

[The Dude]

Definitely monitor voltage during the failure first. If you have sagging voltage you should inspect your fuseholder. Make certain you don't have a defective fuse minimizing your current draw.

Good point, thanks. I am only running a 60 amp fuse, also, as I have not swapped in an ANL fuse holder yet. I better get on that.

 

[The Dude]

Amp is definitely going in and out of protection, watched the LED while I had it turned up. Unplugged the sub, in case it had a short in it today. Still going into protection. I suspect the passive crossovers that came with the component set. Going to carry on some troubleshooting, maybe go active now, take the passives out completely.