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creyc

bottom mids

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I just got my Pioneer PRS components running active on a Rockford Power 600-4 amp and Pioneer P800-PRS head deck. So far I'm quite pleased with the results but it's not perfect. On some songs I notice distortion/light bottoming which I traced to come from the 6.5" mids in the doors, and only when I'm really rocking out :)

I've got them crossed over fairly low, at 80Hz because I've got my sub-stage crossed at 63Hz. I like the way this sounds, I could cross the mids higher and solve this problem but then it sounds like a large hole.

I don't want to raise the sub crossover point either to fix this, my subs play pretty sloppy IMO near 80Hz plus I don't like what that does to the imaging. I'd prefer to keep them crossed at or below 63Hz.

Overall it sounds amazing at low levels, it's very hard not to grab hold of that volume knob! How can I remedy my situation and stop the distortion? (in case you're wondering, no I'm not getting amplifier clipping. It's the speaker itself)

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You've just reached the mechanical power handling of the mid, plain and simple. There is nothing you can do to any settings if you don't want to raise the crossover. Unless you have an EQ and can cut around 100 hz, that would maybe give you a little extra midrange and treble without the midbass stopping you. But then the midbass wouldn't be as loud relatively, so it may mess up the balance of the system.

Other than that, if you just have the mids free air or IB in the doors, you could build sealed enclosures for them. That'll raise the mechanical handling a little.

Or else just control the volume knob finger and be satisifed with what they can give you.

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Any pics of the install? Curious how your baffle/deadening/sealing is.

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Unfortunately I don't have the most recent pictures of the doors (just cleaning up some of the dynamat and adding some self adhesive foam around the wires) since I put the door panels back on I can't get more pics, but this should give you an idea of what I've done.

DSC00744.jpg

DSC00747.jpg

DSC00746.jpg

DSC00745.jpg

The red flat piece is fiberglass I cut to fit and seal the larger holes.

For lack of a better place to put them, and needing a basline of comparison to start with, the tweeters were mounted in the stock locations with modified brackets, on the dash reflecting off the windshield.

I'm using time alignment on the P800-PRS, and its in 3-way active Network Mode.

Edited by creyc

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Looks like you did a pretty good job on those doors. You've just run out of speaker capability.

Maybe you need to step up to a 3-way active with a dedicated 8" midbass?

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I thought I was currently running a 3-way active system, or does the substage not count?

Including subs, and adding a midbass, wouldn't that be a 4-way? I'm interested in trying a dedicated midbass driver but not sure how I could run 4 channels off my P800-PRS which only has 3 sets of RCAs and active crossovers.

My other thought was to simply double up on drivers, add another set of PRS components to better handle the power. Only non-simple part being I would need to build/buy a custom door panel.

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No, sub stage doesn't count. When we say 2-way, 3-way, what have you, we are only talking about the front stage. The sub is obvious so it isn't counted.

As for the head unit problem, you'd just run one set of preouts to handle two sizes of the speakers, one set to handle the other in the front stage, and the third is for the sub (since it's just a sub preout, correct?) For instance, you could run the front preouts to a 4 channel with a y-splitter to get the signal to all channels. Set the head unit crossover where you want the midrange highpassed at, like 400 hz or whatever. Then on the amplifier, use the highpass on the front outputs to go to the tweeters, then the lowpass on the other two channels going to the midrange. Then you'd have the rear preouts from the head unit going to a 2 channel amp to power the midbass speakers up front. You could set the highpass on the head unit to 70 hz or wherever, then use the lowpass on the amp at 400 hz to bandpass the midbass.

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Hmm.

You aren't completely wrong, the sub can count depending on your definition but generically speaking 2 way means 2 way + sub and so on. On an aside, there is no sub stage just a sub ;)

Have you played with phase yet? Perhaps you have some cancellation that could be addressed that way. I am a bit surprised that they fall off at 80hz. What slopes are you using? A bit more detail on your setup might help us trouble shoot things although you may be out of driver...but I still think there is some more hidden :)

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You need to deaden in inside skin of the actual door panel. That is where most of the noise comes from, not the piece you applied deadening to. Noise comes from vibration, that outer door skin has the least structural support of the door and is going to vibrate the most.

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Oh yeah, why didn't I think of phase. Try reversing the + and - on one mid and see if you get better response.

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Do I want to change the phase of just one mid or both?

The P800-PRS has adjustable phase for each, highs, mids and lows, but I'm assuming this changes the phase of BOTH speakers at the same time. I played with it a bit today, flipping from normal to reversed on all three but couldn't for the life of me hear even a subtle difference. I thought the tweeters sounded a bit wider at one point when switching back and forth but I couldn't be certain. I'm wondering if I should try it first with time alignment off, though I doubt it would make a difference?

I'm surprised I couldn't hear more of a difference, I spend a great deal of time with hi-fi headphones and never have a problem picking out slight nuances, so I think something about my car environment is masking the phase effect.

As for sound deadening, both layers of the door are coated. You can see a little of the outer skin covered (behind the glass) in the first photo with the fiberglass removed. I'm not too concerned about this, as I'm fairly certain I covered every significant part of the door.

M5, thanks for your info. I shall just call it the sub now. :) I'm using 12dB/oct slopes on the tweeter HPF, mid LPF, and sub LPF. I'm using a steeper 18dB/oct slope for the mid HPF, trying to cut it off quick to keep the low bass off of it but I'm not sure I like how this sounds.

My nose noticed today I must also be approaching the thermal limits of the mids. ;) It was surprising because I would estimate the overall loudness to be about on par with a somewhat decent factory radio (sub excluded) albeit thats where the comparison ends. I would just prefer to have a bit of headroom, I'm right at the limits currently.

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Also, M5, regarding your comment of the 80Hz crossover point, could you elaborate more on this? Would this typically be higher or lower? I merely set it this way because it sounds good. :)

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I assume m5 ment they should be getting lower. Pop one of the mids out of phase once if u havent. Also if it comes down to new woofers u could do a deticated mid bass and a small full range. I just did this myself with great results. I used an 8 " peerless Sls with a 3" peerless full range. I'll be updating my build late.... The instal is still kinda rough... But sounds amazing!!!

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Some of the settings on this head deck are a bit wacky.

I noticed for example in the crossover

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Do I want to change the phase of just one mid or both?

The P800-PRS has adjustable phase for each, highs, mids and lows, but I'm assuming this changes the phase of BOTH speakers at the same time. I played with it a bit today, flipping from normal to reversed on all three but couldn't for the life of me hear even a subtle difference. I thought the tweeters sounded a bit wider at one point when switching back and forth but I couldn't be certain. I'm wondering if I should try it first with time alignment off, though I doubt it would make a difference?

M5, thanks for your info. I shall just call it the sub now. :) I'm using 12dB/oct slopes on the tweeter HPF, mid LPF, and sub LPF. I'm using a steeper 18dB/oct slope for the mid HPF, trying to cut it off quick to keep the low bass off of it but I'm not sure I like how this sounds.

My nose noticed today I must also be approaching the thermal limits of the mids.

Just one mid. Shut off the tweeters and the sub and just listen to the mids. Then swap the phase on one of them. *I am assuming you are in "network" mode as I have no ideas the settings on the deck outside of it.

Those mids "should" be able to take more than 80hz at 18dB. I would expect way more. Of course, now I wonder how your gains were set on them....in particular since your noes noticed them starting to get unhappy. That shouldn't happen.

I would also expect them to be worlds louder than a stock setup. Either they are so clean that with the lack of distortion they just don't sound loud to you or something is a bit off.

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Also, M5, regarding your comment of the 80Hz crossover point, could you elaborate more on this? Would this typically be higher or lower? I merely set it this way because it sounds good. :)

Sorry, mine have never been higher than 50hz but I can't say that I am a fan of a localized subwoofer at all. I would expect "most" people to like it crossed higher.

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Some of the settings on this head deck are a bit wacky.

I noticed for example in the crossover

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Eh, most people can locate their subs position because they are bass-happy. I don't think I've ever sat in a vehicle, aside from a competitor who actually had the level blend seamlessly.

I'd venture to say 95% of people are overboard on sub level.

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Agreed, exactly why I used quotes around most. I should have clarified as I meant nearly all.

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I know you know I know you know. . .

Ha Ha.

That was more just a comment for the masses as sub bass is always exaggerated in my experience. Hell, I'm guilty of it myself sometimes, but I tend to be heavy in the mid bass level. Guess I'm a mid-basshead.

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Midbass >>> Sub bass :D

And much more difficult to attain, I'm realizing!

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Figured out if you push and hold the select button you can individually adjust the level and phase of any one particular speaker. So there's no need to reverse the speaker wires at the amp. It can all be done from the deck.

I notice the midrange sounds much wider and each speaker location becomes too obvious.

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