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Bryan G

Rear speaker problem, no separation.

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Acoustic wave. There is one that comes from the front of the speaker and the same out of phase completely from the rear speaker. In a perfect world when you combine a wave that is 180deg out of phase (or out of phase completely) together with a normal wave they cancel out to zero completely. This is why you need to isolate the interior of the door from what you visually see on the speaker. Until you do that you will not have midbass.

Cone area & new speakers come later, you need to fix your install first otherwise it is a waste of money.

To block acoustic waves you need mass. Exactly why styrofoam sucks.

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Acoustic wave. There is one that comes from the front of the speaker and the same out of phase completely from the rear speaker. In a perfect world when you combine a wave that is 180deg out of phase (or out of phase completely) together with a normal wave they cancel out to zero completely. This is why you need to isolate the interior of the door from what you visually see on the speaker. Until you do that you will not have midbass.

Cone area & new speakers come later, you need to fix your install first otherwise it is a waste of money.

To block acoustic waves you need mass. Exactly why styrofoam sucks.

Sorry for sounding dumb, but  I'm not sure on this. I thought I heard this years ago, that you need not only the right size box for a speaker, but the right shape.

So, let me see if I'm getting this.

The box will only fix my problem if it is the right size & shape. Because I can't do this properly, I need to have some material to absorb the back wave so it doesn't reflect??

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Acoustic wave. There is one that comes from the front of the speaker and the same out of phase completely from the rear speaker. In a perfect world when you combine a wave that is 180deg out of phase (or out of phase completely) together with a normal wave they cancel out to zero completely. This is why you need to isolate the interior of the door from what you visually see on the speaker. Until you do that you will not have midbass.

Cone area & new speakers come later, you need to fix your install first otherwise it is a waste of money.

To block acoustic waves you need mass. Exactly why styrofoam sucks.

Sorry for sounding dumb, but  I'm not sure on this. I thought I heard this years ago, that you need not only the right size box for a speaker, but the right shape.

So, let me see if I'm getting this.

The box will only fix my problem if it is the right size & shape. Because I can't do this properly, I need to have some material to absorb the back wave so it doesn't reflect??

Shape doesn't matter all that much. Only concern in shape is not having things too uniform, but that is overkill in a car...

You don't need to absorb the back wave, but block it from mixing with the front wave. Any mixing is interference, some constructive, some destructive but neither desirable.

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Back when I was removing the rear speakers I went over all the setting on my amps and noticed I had it all screwed up, don't know how I did it. First, the subs were crossed over at around 200hz. I thought I had the subs at 50hz and the fronts at the same. This might explain why the bass on the fronts got louder when I would turn the subs off, I'm assuming the matching freqs between 50hz and 200hz were canceling each other out.

 

Then I looked at the front amp, it was set at 50hz like I wanted, but I noticed the LPF-OFF-HPF was set to off, so the crossover wasn't even on.

 

So I turned the front crossover on (set to 50hz), turned the sub crossover back down to 50 hz, then things changed. I'm now able to turn the fronts way up, well, the whole system way up without over driving the fronts.

 

I'm now happy with my system. I still need to deaden the door, but it's not such a priority. I was playing some Aerosmith last night is it was almost perfect, certain CD's have  powerful mid punch but the overall quality is, well, perfect. I would like more volume, but to me, precision is more important than loudness.

 

I wish I would have found this forum before I bought my system, then I could have use the money I wasted on the rear speakers and bought better fronts but all and all, at least I did find you guys and was able to get things right.

 

And yes, I can tell just having fronts is better. For the last few weeks before I sold the rears, I would play around with having all 4 on, then back to just fronts, and I did notice the dead spots. The fact that some music would come from the rear and some from the front wasn't a good thing like I thought, the sounds moving around were dead spots and drop outs (I think that's how to put it), unwanted behavior. Once I knew what was happening I could not argue, the rears were messing up the fronts.

Thanks for being here and helping.

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if you're chasing a bit more output you could move the xover point from 50 up to something like 80hz. you would lose some of that upfront bass however. 

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May not even lose up front bass. Takes a heck of an install to get mids to play that low...

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I can't move the xover up, the subs just have a dial that is 50hz on one end and 500 on the other, so I would never find where 60hz is. But it's all good, I had Rush YYZ on today and the mid drums (toms?) almost made me blink every time they hit.

Before I get some different crossovers or adjust anything, I need to get the SDS and seal & deaden the doors. If that makes any improvement I'll be satisfied for a while.

 

I would like to know where I'm lacking though, I'm so close to the level I want, just can't tell if it's the front amp of the speakers that max out. My guess is the speakers, so eventually I'll want to upgrade.

 

I just wish there was someone that lived around here I could have listen to my system and give me an evaluation.

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I can't move the xover up, the subs just have a dial that is 50hz on one end and 500 on the other, so I would never find where 60hz is. But it's all good, I had Rush YYZ on today and the mid drums (toms?) almost made me blink every time they hit.

Before I get some different crossovers or adjust anything, I need to get the SDS and seal & deaden the doors. If that makes any improvement I'll be satisfied for a while.

 

I would like to know where I'm lacking though, I'm so close to the level I want, just can't tell if it's the front amp of the speakers that max out. My guess is the speakers, so eventually I'll want to upgrade.

 

I just wish there was someone that lived around here I could have listen to my system and give me an evaluation.

 

you shouldn't trust the dial at all. pick a test tone, say 60 hz and play that through the sub. now start with the dial at 50 and slowly move up until the test tone starts to decrease in loudness. that will roughly be the -3db point. 

 

its not so much that you should pick the xover frequency ahead of time. that doesn't make sense. This is more so for comparing different xover points (ie. 50 vs 60 vs 80 and so forth). lets say you find that 60 is good but 80 isn't. next you would try something in between. repeat until you find the magic number. 

 

you can do this for the hpf on your mids as well. in this case you pick 80hz for example, start with your dial ABOVE (instead of below), and listen for the -3db point. 

Edited by lithium

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I was just typing out the same method, is it me or is there something backwards here? If you are using LP on the sub, would you not start above the target freq and move down? For mids with HP, start below and work up?

Edited by hdrox88

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Doesn't really matter. Easy to measure with a DMM and a test tone if you want to know where you truly are. Whatever point is 3dB down as lithium said is your crossover frequency

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I can't move the xover up, the subs just have a dial that is 50hz on one end and 500 on the other, so I would never find where 60hz is. But it's all good, I had Rush YYZ on today and the mid drums (toms?) almost made me blink every time they hit.

Before I get some different crossovers or adjust anything, I need to get the SDS and seal & deaden the doors. If that makes any improvement I'll be satisfied for a while.

 

I would like to know where I'm lacking though, I'm so close to the level I want, just can't tell if it's the front amp of the speakers that max out. My guess is the speakers, so eventually I'll want to upgrade.

 

I just wish there was someone that lived around here I could have listen to my system and give me an evaluation.

 

you shouldn't trust the dial at all. pick a test tone, say 60 hz and play that through the sub. now start with the dial at 50 and slowly move up until the test tone starts to decrease in loudness. that will roughly be the -3db point. 

 

its not so much that you should pick the xover frequency ahead of time. that doesn't make sense. This is more so for comparing different xover points (ie. 50 vs 60 vs 80 and so forth). lets say you find that 60 is good but 80 isn't. next you would try something in between. repeat until you find the magic number. 

 

you can do this for the hpf on your mids as well. in this case you pick 80hz for example, start with your dial ABOVE (instead of below), and listen for the -3db point. 

 

Common sense, sometimes I just over look it. I have a CD with all the test tones, don't know why I didn't think of this. I do like the sound I have with it set at 50hz, but 55, 60 or higher might give me a little more punch on the fronts.

It's worth the time to check it out.

Thanks.

Edited by Bryan G

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On 7/18/2014 at 2:57 AM, lithium said:

 

you shouldn't trust the dial at all. pick a test tone, say 60 hz and play that through the sub. now start with the dial at 50 and slowly move up until the test tone starts to decrease in loudness. that will roughly be the -3db point. 

 

its not so much that you should pick the xover frequency ahead of time. that doesn't make sense. This is more so for comparing different xover points (ie. 50 vs 60 vs 80 and so forth). lets say you find that 60 is good but 80 isn't. next you would try something in between. repeat until you find the magic number. 

 

you can do this for the hpf on your mids as well. in this case you pick 80hz for example, start with your dial ABOVE (instead of below), and listen for the -3db point. 

Well, it's been a while but I thought I'd give a final update.
I decided to just make the fronts sound as best they can. Using tones, I set the crossover to as low as I could go before they started losing sound. That turned out to be around 60, when I went lower, they just didn't play it. Then I adjusted the sub amp to the same point tones.
I wonder if time has anything to do with this, do speakers wear in? It sounds better now than ever. Drums from the front punch, loud, the bass is perfect and the high end is crisp and clear. My system does not have much power, but the sound quality is what I wanted, and have.

My head unit blew up, I think that cheap Dual amp for the subs did it. It was making popping noises for the last year. Now I'm just using the KAC-8405 for the fronts and subs, and I swear it sounds better. I replaced the KDC-X397 with a KDC-X302, this one plays .flac so no more .mp3's, no more lossy music.

I really want to thank everyone here, all the advice helped me to achieve my goal, quality sound.

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Glad you are liking the results.  Hope you stick around the forums.

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:woot:

glad you got it all figured out.

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So I just read over all of this and I have to say that it was an awesome close to a thread I've seen a thousand times finally. I have a similar situation as that I've got a car with it's own affliction(s) and I feel like I'm fighting a losing battle. I've got a new toy which I'm enjoying because of the active elements regarding the crossovers but the time alignment is channel specific as in one pair of speakers is simultaneously adjusted. This is great for getting the front seat (in general) sounding good but I'd really like to have a little more separation. 

This thing I got only set me back a little over a bill and it's already proven to be worth the money spent. So much so that I've thought about just buying a second one by and splitting up the channels left and right. Oh yeah it's made in Brazil by Stetsom. It's a "digital audio processor" it's much cheaper than the options made by Zapco or Audison or any of the other companies but it's obviously not as nice. But certainly not worth 1/6 to 1/8th the price. This is helping in setting my Evil6.5's to a desirable frequency that I'm particularly or was particularly lacking in previously. I've still not gotten the sound I am totally happy with but I'm much closer. I think it's time to upgrade my cheap Infinity components.

I will say this though. I have the Evil's mounted in the back doors which happen to fire about 6 inches behind my shoulders. I really have no place else to mount these and I know I could be happier with them in a new spot but for now I'm just trying to figure out MY next move.

Anyway, I was really happy to see this thread pan out and have such a great ending.

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