Active...what did I get into?

[gijoe 10+ year member]

I just picked up a 4 channel amp that I was originally going to bridge and run my boston s60 comps passive, but I decided that since I have an 880 I'd just give active a shot. The amp is a Denon 4 channel, 50x4, I'm sure it's at least a few years old, but it was never used. I'm having a really difficult time setting my gains and tuning everything. I expected things to sound weird for a while, until I learned a bit more, but I'm getting periodic crackling in my speakers, especially my tweets. I have the gains on the absolute lowest settings and I still get about the same volume levels as I did running my comps off of hu power. I really need help setting the gains, the tuning I'll get the hang of eventually. I have a theory that could be way off, but it may be something to consider. I'm thinking that maybe my hu's preouts are too powerfull and that this amp wasn't originally designed for such a high voltage. Anyway, I'm hoping someone here can help me get these gains set properly so that I don't ruin anything. I know my speakers aren't ideal (especially in terms of a good active set up) but I'm sure that If I do things right I can make them sound better than they did passive. Someone please chime in!

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[Trey803 5,000+ posts]

hmm I had crackling in my tweets but turning the gain down solved that

 

[gijoe 10+ year member]

I just realized that I have LOUD on, turning this off may help...then again maybe it wont. Can I use test tones to set the gains like I did with my sub? By that I mean, what freq tones can i use to set my gains and protect my equipment? I'm afraid that with my preouts being so powerful I wont be able to turn my volume up high enought without clipping, even with the gains set to a minimum. More help please!

 

[gijoe 10+ year member]

After a little more experimenting, I noticed that I hear the sound in my tweets when I turn the volume down from a relativly high volume while there is no sound (in between songs or after switching from the tuner) I can here a slight crackle (kind of a dull pop) with every level the volume decreases. I really hope someone can help, because I can hear a big improvement in certain areas from my previous setup. I notice a much cleaner and more defined stereo seperation and a much more pleasent midbass. I'd hate to give these up by putting my passive crossovers back.

 

[silvercookie 5,000+ posts]

well to start if your headunit has more than 1 rca out use thaton the second amp

maybe you need to turn the bass down a little on your headunit

maybe that amp isnt good quality?? cause that sounds like it might be clipping (if that can happen on tweeters)

 

[gijoe 10+ year member]

My rca's are run properly, I have all the appropriate channels going to the appropriate amps. I'm just running a mono amp and a 4 channel, it's pretty simple. I can't really comment on the "quality" of the amp because I haven't been able to set it up properly yet, but it's Denon and they make some other great products so I would assume that their amps are at least decent.

I think my problem is the power of the preouts is too high. Can anyone comment on this? Is there anyway to lower the preout power or mod the amp to accept higher volts?

 

[nismos14 5,000+ posts]

It wouldn't crackle if the pre-outs were too powerful. I highly doubt that is the issue.

Are you absolutely certain you don't have the high and mid outputs crossed?

 

[James Bang 5,000+ posts]

what are your crossover points?

 

[gijoe 10+ year member]

I'm about 95% sure that the mids and highs aren't crossed. I will recheck, but I'm pretty confident that everything is correct. As far as my crossover points, I haven't really set them yet. I thought that I needed to get my gains set properly before setting my crossovers. Another thing that happened that's never happened before that has me wondering is that I was listening to music with the car off and when I started it I got a loud thump from my sub. I don't know if this is related or not, but it might help. I think it's strange that I would have my gains all the way down and still get almost the same volume as I did before.

 

[gijoe 10+ year member]

Could a simple grounding problem be the cause? HELP PLEASE!

 

[mlstrass 5,000+ posts]

You need to set your xovers first!!!! I'm "guessing" you're playing too low of frequencies through the tweeters which will make them distort/crackle, even at low volumes as they're not designed to be playing 80Hz or whatever you're sending to them...

 

[gijoe 10+ year member]

Ok, I understand the crossover piont. I'm running them at what my 880 was defaulted to or close to, so it should be somewhere within it's limits.

New and important development! I can hear the noise through the tweets with the volume at 0 but with the hu on. Ground problem? Was my ranting all just a random theory that I wanted to be true?

 

[casper97ta 10+ year member]

This could be a ground issue that some of the Pioneer units had. Try grounding the headunit to a different spot behind the dash instead of using the ground through the harness. Does that make sense?//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[gijoe 10+ year member]

Yeah I understand and I'll try that and report back. It's typical of me to overlook the simple problems.

 

[mlstrass 5,000+ posts]

These HU's do seem to be pretty sensitive when it comes to ground.

If you have the HU in Network mode then I'm 99% sure the xovers aren't even close as mine weren't out of the box...