New Sub Power Issue

[NuttyBenz]

I recently moved a 12 inch ported sub set up out of my commuter in favor of a smaller 10. Upon installation I am am experiencing a problem. When volume is turned to 3/4 I get clipping and horrible cutting of sound along with interior lights flashing on and off. I back off one click on the volume and everything is fine. Older 12in sub had no issues so I did not expect any from the newer RF 10 inch.

Setup is as follows:

Stock HU 2014 Jetta SE to Line out converter

Sound Ordnance (SO) M4050 50W X 4.

Sound Ordnance P-65 6.5 x 4, 50W rms

Sound Ordnance M1500 500W X 1 at 2 ohms

Rockford Fosgate P3D4 10 Punch 500Wrms 1000Wpeak 4 ohm DVC wired to 2 ohm.

8 ga amp wire kit, 4 ga ground, 60W inline fuse.

Any guidance is appreciated.

Thanks

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[Boomin_tahoe 5,000+ posts]

Don't think I've ever heard the brand Sound ordnance...

That said, where is the gain set on your amp? Might be turned up too much.

 

[Jeffdachef 5,000+ posts]

more than likely you arent satisfied with the output and are clipping the amp. The box design and sub completely change the load your amp sees on music aka box rise. That along with clipping is the cause of your issues.

Don't think I've ever heard the brand Sound ordnance...
That said, where is the gain set on your amp? Might be turned up too much.

crutchfield's el cheapo inhouse line. in every way inferior to sonic's NVX line lol.

 

[Boomin_tahoe 5,000+ posts]

more than likely you arent satisfied with the output and are clipping the amp. The box design and sub completely change the load your amp sees on music aka box rise. That along with clipping is the cause of your issues.


crutchfield's el cheapo inhouse line. in every way inferior to sonic's NVX line lol.

Ah gotcha....

 

[NuttyBenz]

Yep it is Crutchfields cheap stuff. I had a coupon when the line first came out and paid almost nothing for all of the equipment. That said, with what I paid I've been pretty happy over the last couple years as it's in an extra vehicle. I have expensive things in other vehicles. I moved the 12 into my boat as I got a good deal on the RF punch. Gain is set about mid way. Just curious as to why the ten would be so drastically different considering the 12 was the same wattage.

 

[audioholic 5,000+ posts]

Gain is set about mid way.

Gain is not a volume knob. Saying the gain is set "half way" implies you dont understand what a gain does (no offense). The gain matches the input sensitivity of the amp to the output signal of your h/u (or processor). It is entirely possible that setting the gain at half way, which common sense would suggest is conservative, is actually setting it far too high.

 

[Boomin_tahoe 5,000+ posts]

[quote name='audioholic']Gain is not a volume knob. Saying the gain is set "half way" implies you dont understand what a gain does (no offense). The gain matches the input sensitivity of the amp to the output signal of your h/u (or processor). It is entirely possible that setting the gain at half way, which common sense would suggest is conservative, is actually setting it far too high.[/QUOTE]


Typically gains are set approx 1/3-1/4 way, depending upon on the HU RCA voltage.....but since your using a line driver.. @Jeffdachef loves line drivers lol

Sorry audioholic, that was for OP.

 

[NuttyBenz]

I do realize the set up is far from ideal. I have other toys and interests so just trying to get this running decently. I am far, far from an expert. That's why I am inquiring here. Upon messing with it further the sub seems to be clipping at ALL levels of gain adjustment with the head unit at half volume. What might this indicate?

 

[Jeffdachef 5,000+ posts]

I do realize the set up is far from ideal. I have other toys and interests so just trying to get this running decently. I am far, far from an expert. That's why I am inquiring here. Upon messing with it further the sub seems to be clipping at ALL levels of gain adjustment with the head unit at half volume. What might this indicate?

take a video and let us hear this so called "clipping" sound you think you are hearing. you really dont hear clipping unless its really bad and its not a mechanical noise either its when your sub changes tone with a dirty signal so still sounds like bass, no crackling or snapping or anything of that sort. If you hear some other type of noise its either coil rub, your box falling apart, air leaks in your box, or a bad ground causing the sub making wierd mechanical noises. Or the sub's tinsel leads are failing or torn spider or damaged surround or loose cone. Could be a LARGE variety of reasons why you are hearing strange noises when your sub is playing.

 

[Kam311]

What coil configuration is your new sub, and what coil configuration was the old one? How are they wired?

 

[NuttyBenz]

Weird mechanical noises sounds about right. It sounds like a bunch of crickets. I have a Sony head unit in the garage that has pre-outs, would it help my cause to install it and get rid of the LOC and see where things are at then? When I had the 12 in there everything was pretty ok for my untrained ears. I would plug it back in but it's in the boat at the lake working well there as well. Tried to upload a video but it says invalid.

Sub is a DVc 4 ohm. On the sub I have the coils wired positive to positive and negative to negative, then to the amp creating a 2 ohm load correct?

 

[Kam311]

The ohm load is right. I would take the sub out and check the resistance of the coils with a dmm

 

[audioholic 5,000+ posts]

Weird mechanical noises sounds about right. It sounds like a bunch of crickets. I have a Sony head unit in the garage that has pre-outs, would it help my cause to install it and get rid of the LOC and see where things are at then? When I had the 12 in there everything was pretty ok for my untrained ears. I would plug it back in but it's in the boat at the lake working well there as well. Tried to upload a video but it says invalid.
Sub is a DVc 4 ohm. On the sub I have the coils wired positive to positive and negative to negative, then to the amp creating a 2 ohm load correct?

What's the specs on your loc? IIRC, they tend to have a hot output signal, it may simply be too much for your amp's input sensitivity at anything over half volume. If that is the case, you can simply call half volume your full volume setting, and readjust gains on other speakers to account for this. You can try installing your h/u that has preouts, temporarily, and see if the problem goes away. You could also have a supply voltage problem to the amplifier. Also, do not use any bass boosts your system has.

Consider investing in a multimeter. You can get them as cheap as like 10 bucks (for a cheapy from harbor freight) and are good to have around the house for various reasons.

 

[Jeffdachef 5,000+ posts]

Lets narrow it down further. Take the sub out of the box and play it free air and see if it makes the same noises. Then we can see if its the box or sub thats the issue.

 

[NuttyBenz]

Thanks for the help. Last night I figured out part of the problem I think. I pulled the RCA cables out of the rear section of the 4-channel amp. The cutting out and power loss / protection mode is resolved when the rear door speakers are eliminated from the system. So that resolves one complaint. I assume this would mean one or both of the rear speakers are bad?

That said I can run on the fronts and the mono amp with sub. However, when I run this way, the sub is muted to almost nothing with both left and right RCA's plugged into the amp. If I remove one of the RCAs to the mono amp the sub starts bumping away as it should, despite the cricket sound which is still there. The RCAs that run to the Mono amp are split off the rear portion of the LOC. So from the LOC there is an RCA splitter which runs a left right pair to the rear of the four channel amp and a left right pair to the mono amp. Even with the rear RCAs disconnected from the 4 channel amp, is the mono amp still somehow "seeing" the bad door speakers? It did not occur to me to disconnect the rear speaker wires from the four channel last night which I am thinking might help my cause.

As you say, the LOC does seem to run "hot." The model is RF-HLC4. If I start with my HU at 3/4 volume and move the gain on the 4 channel amp away from the lowest setting at all the door speakers get far too loud. I will adjust based on half the HU volume being my max as you suggested.