X-overs and voice coils

[Cassix]

Car Audio Question: So I am running 2 Sundown Audio SA12 D2 750rms DVC subwoofers in a box I built myself. 5 cu^ft ported and tuned to 28hz. They are getting pushed by a Sundown Audio SAE-1500 watt amp. I have them wired down to .5 ohms. Its been running like that with no problems until recently I installed a 4 channel amp for my mids and highs. When I put that in I couldnt figure out what x-over to use, the one one my HU, amp or component system? Also, I have an Alpine ute-52bt HU and cant figure out what (width (Q)) setting is? It can adj on each frequency from 3-5. If anything id guess itd be my slope but isnt making a difference in sound from what I can tell. How do I use that setting? Oh, back to my original question, I have my gain set to about 45 out of 100, my subsonic filter is at 20hz and my low pass is at about 120hz. My max volume on my HU is 35 and I dont go past 22, I dont need to. But when I run them hard I'm starting to get a voice coil smell coming from them and I don't want to bring them up I'm just trying to figure out why I'm getting that smell I run at 14 volts until my bass hits then it drops down to about 12 and a half. Anybody have any ideas because it didn't do that before it just has done it since I put that other amp in which it should have nothing to do with it

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[THATpurpleKUSH 5,000+ posts]

Adding the second amp has increased the current draw on your electrical system causing the voltage to drop. If you are smelling the coils and the dust caps are hot to the touch then you need to upgrade your electrical system and turn the gain down because you are beginning to overheat the subs from a clipped signal. those subs should barely break a sweat on a 1500w amp.

 

[Boomin_tahoe 5,000+ posts]

Big 3 is a must.

 

[Papermaker85 5,000+ posts]

First off. Use the headunit crossover. Typically they are better than any internal crossovers on amps.

2nd the Q is the bandwidth of the frequencies you boost and the frequency is the center frequency you are boosting.

Simply put the higher the Q the less frequencies you boost around the center frequency. Without a mic and rta you are pretty much pissing in the wind..

 

[Papermaker85 5,000+ posts]

3rd. Like purp said. Now you are drawing enough current to get a noticeable voltage drop. Now it's clipping the signal. First thing I would do is upgrade my wiring to 2/0 welding wire. Then get your alternator rebuilt for high output or buy a high output alternator..

 

[Jeffdachef 5,000+ posts]

Car Audio Question: So I am running 2 Sundown Audio SA12 D2 750rms DVC subwoofers in a box I built myself. 5 cu^ft ported and tuned to 28hz. They are getting pushed by a Sundown Audio SAE-1500 watt amp. I have them wired down to .5 ohms. Its been running like that with no problems until recently I installed a 4 channel amp for my mids and highs. When I put that in I couldnt figure out what x-over to use, the one one my HU, amp or component system? Also, I have an Alpine ute-52bt HU and cant figure out what (width (Q)) setting is? It can adj on each frequency from 3-5. If anything id guess itd be my slope but isnt making a difference in sound from what I can tell. How do I use that setting? Oh, back to my original question, I have my gain set to about 45 out of 100, my subsonic filter is at 20hz and my low pass is at about 120hz. My max volume on my HU is 35 and I dont go past 22, I dont need to. But when I run them hard I'm starting to get a voice coil smell coming from them and I don't want to bring them up I'm just trying to figure out why I'm getting that smell I run at 14 volts until my bass hits then it drops down to about 12 and a half. Anybody have any ideas because it didn't do that before it just has done it since I put that other amp in which it should have nothing to do with it

also you might want to redo your gains, set it at 30-32 out of 35 head unit volume with your gains on the amp lower. Tuned at 28hz you dont really need to have a subsonic filter on at all. no crossovers should be used at the amp. For now lower your sub level until your voltages are above 13 until you upgrade your electrical more.

 

[Cassix]

I do have all 0 gauge wire ran and I do have a second aux. battery hooked up. No lights dim at all when my music is up either. I do have the big 3 upgrade done also. If any of that info helps

CBB

 

[shizzzon 10+ year member]

You claim it starts to stink at 22 of 35.. That right there is clear indicator your gains are set WAY too high.

 

[Papermaker85 5,000+ posts]

Your amp should clip at the same time your h/U clips. I generally do 3/4 on the h/u..

40 would be in the 30 to 32 area..