Suggestions for setting up 2 amps

[xguntherc 10+ year member]

Hey guys.. I recently added an amp to my 4 doors for the first time. I now have an amped JL 12w6 ( I know, I Know, its only JL, but it was FREEE.) Running off a Polk 600.1 Monoblock 1200w Amp. the 12 is V1 so the 600 rms is enough power. I then have a JL 300/4 amp pushing all 4 doors with Alpine Type-S like sig says. Its not the best but it sure sounds great SQ wise as its my first amping everything. I still have some tweaking to do though.

I've never set up 2 amps before or tweaked settings for the 4 doors amp. Does anyone have some suggestions for a good setup, or settings that work well together when the speakers are all amped as well as sub? My friend suggested setting the 4 chan hpf on front and rear both to 130 so thats as low as it goes, but that was just a guess. I also have the filter slope set to 12db, it has 12 or 24. the 4 channel also has a frequency range setting. x1, or x10. Its on x1. I'll have to look most this up and research some more, but if anyone has some general suggestions that would be really great..

Thanks guys!

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[eharri3 10+ year member]

If you're looking or SQ Id start experimenting with x over points between 80 and 100 HZ with steeper slopes. In my applications if Im not crossing over between 70 and 80 HZ my sub gets into the midbass range and I loose my impression of up-front bass.

What I like to do is set both using some sort sort of establismed method, whether it be by ear, DMM, or o-scope. I usually use a DMM cause they're plentify, cheap, and easy to use. Then, what you'll have to do is level match between the two amps. To make the final tweak listen to something you're familiar with, moving the volume from very low to very high then back down again, listening to see if everything is increasing in volume at a similar enough rate than you can hear the frequencies from both the sub and the door speakers in the right proportions at your normal listening levels. Either dial the gain back slightly on whichever gets loud faster than the other, introduce some slight 'overlap' on whatever is lacking, or some mixture of the two.

 

[xguntherc 10+ year member]

Thanks eharri, I appreciate the informational response.. I dont understand how I could use a DMM to tweak it though.. Ill have to look into that. I should probably buy a DMM for having in general right.. as I dont have one..

So you think I should use higher slopes. I have 12db or 24. So should I just try 24 n see how it sounds. Also your explanation of it feeling like you loose the up front bass is exactly how Id explain my current sound. its lacking the midrange and the feeling and sound of upfront bass... So try working with 80-100. that sounds good. the 85hz range.

What about for the sub??

Also my alpines handle about 50rms, my amp pushes 75 x 4 rms. so I have 4 channel amp gain at about 50% so I dont overdue it on the speakers...

Anything else anyone can recommend? what about the frequency range setting of x1 and x10?

Thanks for all the info, I really appreciate it

 

[gunz4me2 10+ year member]

The X1 or X10 setting is just a multiplier on the crossover. Let's assume you are tuning your crossover for 80 Hz at X1, if you engage the X10, that frequency would be 800 Hz.

I ran a set of the Alpine Type S coaxials and didn't find them to be all that great. They have almost NO output from 80 to 120 Hz and I found the midrange to be quite dirty on them. I switched them out for a set of Type R woofers, which sounded much better on the midrange, but still lack output in the 90 to 120 Hz range. Unfortunately, I am limited in that particular vehicle by door depth, so I am going to have to do some custom work to accommodate anything deeper than an Alpine Type R woofer.

When it comes to setting one's gains with a DMM... a DMM should only be used to get one in the ball park and should NEVER be relied on as a means to an end. In other words, sure it is nice and what not to set your gains via DMM BUT your amplifier is going to respond differently once you load it down with drivers. Learn to trust your ear! Also, DO NOT make the mistake of leaving your speakers connected when setting the gains via DMM.... Unless you have the desire to replace those drivers. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

The proper way to set gains would involve the use of the appropriate test tones, an oscilloscope, and resistive loads, but that starts to get expensive. Another downside is that my oscilloscope is the size of a suitcase so it isn't exactly portable.

 

[xguntherc 10+ year member]

Well Ive never added anything other than stock to my doors, or amped them, so to me the Alpines sound great. But then I do agree the midrange is a little lacking, but that is cuz they are set to 130 still. I'll try 85-100 tomorrow like others suggested.

I also am limited by depth with my truck doors, the type S are pretty close to hitting the window. So I dont have to much more room, but I can see an upgrade coming soon to fill my amps 75w rating better instead of the alpine 50w RMS max.. they probably struggle to hit 50.

They also seem a little airy, if that makes sense. maybe they will also loose that airy sound when lowering them to 85 hz range like I said. fill in the midrange and hopefully loose the airy sound and get a better overall crisp and more accurate sound. But so far im for sure enjoying my system. but it thumps more than before and I have some serious rattles I need to map out and fix. was having a hard time figuring it out..

Thanks, ill try the crossover and the slope changes tomorrow

 

[xguntherc 10+ year member]

So can anyone explain the filter slope setting. 12db or 24db. The otherguy said to use steeper slopes. Does that mean try 24 instead of 12. Hats my only option.

Also if I run my 4 doors around 80-100 h then what's a good starting point for the other amp running the sub. It is around 60 I'd guess right now