phase cancellation ?

phase coherency is necessary for maximum enjoyment .

[QUOTE]It destroys impact and obliterates low end. It makes musical tracks sound thin and lifeless . [/QUOTE]

[QUOTE]Phase cancellation is a an audio phenomenon where the waves of multiple tracks work against each other to eliminate certain frequencies. The resultant sound is often flat or dull.[/QUOTE]

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Integrating a subwoofer into your system is challenging because the subwoofer is optimized for putting out lots of low bass, not for reproducing detail. The main speakers’ upper bass is quick, clean, and articulate. The subwoofer’s bass is often slow and heavy. The word “slow” in this application is not technically correct, but vividly describes how such a subwoofer sounds. More precisely, a “slow” subwoofer is one that has excessive overhang: the cone keeps moving long after the drive signal has stopped, which conveys the impression that the bass is “slow.”

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Phase cancellation occurs when two signals of the same frequency are out of phase with each other resulting in a net reduction in the overall level of the combined signal. If two identical signals are 100% or 180 degrees out of phase they will completely cancel one another if combined.

Is there a question here or just some statements?

No question, please add something if you have something on "cancel

This looks like a copy/paste of different conversations with just enough incorrect claims to spawn a few pages of roaring debate about nothing.

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Originally Posted by Justin Zazzi

This looks like a copy/paste of different conversations with just enough incorrect claims to spawn a few pages of roaring debate about nothing.

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That is what I was thinking......I was actually trying to figure out how to say that when I saw the email that you posted and you nailed it for me.

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Originally Posted by Queef

No question, please add something if you have something on "cancel

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Can you please be more specific? Are you trying to learn something?

If you set your time delay correctly and use the correct crossovers than phase cancellation between midbass and subwoofer won’t be an issue. It will also show up on an RTA as a dip between the two if they are out of phase with each other. If you want a quick accurate subwoofer than get one with a strong motor, low inductance, and light cone and put it in a well built enclosure and tune it to a house curve with DSP and take out cabin gain if it is excessive. Also choose a subwoofer with Thiele small parameters that work best with the type of enclosure you want and model it before you buy it.

If sound qaulity matters than you need to consider all of this.

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Originally Posted by Queef

phase coherency is necessary for maximum enjoyment .

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So is writing coherency

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Originally Posted by Justin Zazzi

This looks like a copy/paste of different conversations with just enough incorrect claims to spawn a few pages of roaring debate about nothing.

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You'll have to excuse him. When he was younger, his head caught on fire and they tried to put it out with a hammer

:tss:

If main speakers upper bass is fast, can I use a lot of fast main speakers and build a fast subwoofer out of them?

nah, use longer speaker wires to slow them down

Tweeters with short wires are the fastest right?

So if I used one hundred tweeters in a ported box, how long should I make the port?

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Originally Posted by Justin Zazzi

Tweeters with short wires are the fastest right?

So if I used one hundred tweeters in a ported box, how long should I make the port?

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What tuning frequency? ;)

See you have it wrong there....you need 42 tweeters with a 42” port.....or is it a 42 cm port.....either way always 42!

I have not personally had phase issues to speak of, but hopefully this will help those who have.
I totally agree with JCsAudio and I have a 12" NOS Nguyen Dang, the cone is made like a butterfly wing with a detroit diesel powering it.

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Originally Posted by Queef

I have not personally had phase issues to speak of, but hopefully this will help those who have.
I totally agree with JCsAudio and I have a 12" NOS Nguyen Dang, the cone is made like a butterfly wing with a detroit diesel powering it.

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Cool story bro... if you’ve played in a car you’ve had phase issues!

Could never figure out "suck-out" , phase issue, EQ, etc..,

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Originally Posted by Queef

Could never figure out "suck-out" , phase issue, EQ, etc..,

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So you can’t figure them out not you’ve never had them, slight difference, why post a troll post instead of asking an intelligent question?

As near as I've ever seen was - SPEAKER BOUNDARY INTERFERENCE

speakers wave hit obstacle and bounces back causing cancellations , carpeting ,padding ,dash mats ,help.

[QUOTE]Speaker boundary interference response (SBIR for short) is a little known and poorly understood issue that is responsible for deep dips or “suckouts” in bass response below the transition frequency. SBIR is caused by the destructive interaction of the direct sound wave from the speaker and the reflected, indirect sound wave from a nearby boundary.[/QUOTE]

I.E.

Direct Path Length, ft	Indirect Path Length, ft	Difference, ft	Cancellation frequency, Hz
11	18	7	81
9	15	6	94

DumDum who is your father ? [intelligent question ?],<<<like this

Come on guys! Don’t turn this into another caraudioforum where you get attacked if you don’t word the question right or ask the right question. This place will die out if that happens.

Queef, I’ve experience what you call SBIR, also referred to many times as a null on DIYMA that in my case causes a big dip in the response around 500 Hz that no amount of EQ can fix. Where did you come up with that graph?

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Originally Posted by JCsAudio

Come on guys! Don’t turn this into another caraudioforum where you get attacked if you don’t word the question right or ask the right question. This place will die out if that happens.

Queef, I’ve experience what you call SBIR, also referred to many times as a null on DIYMA that in my case causes a big dip in the response around 500 Hz that no amount of EQ can fix. Where did you come up with that graph?

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But there wasn't a question asked, that was the issue...Just some statements posted with just enough good information to get someone to believe it, but also a lot of mis-information. That is why I asked in post #2 what question he had on phase so we could answer it.

Also if you look at post #3, Justin called this happening. We are having a "roaring" debate about nothing :)

Jdunk54nl, I hear you man and hopefully what Justin said doesn’t happen and I agree it should be phrased more as a question. Just trying to steer this away from going negative. This place has become more active since the DIYMA debacle with Nick so I don’t want to see it go in the wrong direction.

My Bad ! I apologize for not explaining , spelling out exactly why I was addressing this issue :(

So. Let's try this again. What questions do you have about phase?

Also, carpeting, padding, dash mats in vehicles isn't going to do a whole lot for subwoofer frequencies, which seems to be your focus. Mainly due to the amount needed to make a difference would make the vehicle unsafe for road travel.

Then your example of path length differences, look at those distances, 11 feet and 18 feet. How big is your car cabin? Go out to your vehicle and measure and figure out the path the sub frequencies would have to travel to get to 11 feet and 18 feet. I highly doubt you will get an 11ft direct path length...

A lot of people will get this in the ~400hz area if they have a center console and door mounted mids. Center consoles are about 18-24" away from the door. An 18" path length difference would be a 400hz cancellation. A 24" path length difference would be about a 280hz cancellation.

Also, sound follows the inverse square law, so every time we double the distance, the sound gets cut by about 6db. My wife's SUV has the sub at 4'8" away from the listening position. It is about 2' from the back hatch. So to go to the back hatch and back, the sound gets cut by ~6db. This 4' path length difference gives a cancellation frequency of 140hz. So, at 140hz, which is already cut by 24db since her crossover is at ~70hz, has the reflected sound cut by an additional 6db.

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Originally Posted by JCsAudio

Come on guys! Don’t turn this into another caraudioforum where you get attacked if you don’t word the question right or ask the right question. This place will die out if that happens.

Queef, I’ve experience what you call SBIR, also referred to many times as a null on DIYMA that in my case causes a big dip in the response around 500 Hz that no amount of EQ can fix. Where did you come up with that graph?

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That graph is here
http://www.acousticfrontiers.com/wha...-interference/

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Originally Posted by Queef

My Bad ! I apologize for not explaining , spelling out exactly why I was addressing this issue :(

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So, what is your question? What do you want to learn? [intelligent question] <<<like this

I was not asking a question. I cut and pasted what apparently to some is BS. I was attempting to post a little insight into a problem another member seemed to think might have been "cancellation".

If I do require help, I will pm you on it.
Thank you, Justin.
P. S. Please feel free to search the internet and explain to the people I have used "what you know" ?

Justin Zazzi
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Re: phase cancellation ?

This looks like a copy/paste of different conversations with just enough incorrect claims to spawn a few pages of roaring debate about nothing.

[QUOTE=Queef;47561]phase coherency is necessary for maximum enjoyment . [/QUOTE]< I posted this, my thoughts

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It destroys impact and obliterates low end. It makes musical tracks sound thin and lifeless . [/QUOTE]< not me = truth or fiction ?

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Phase cancellation is a an audio phenomenon where the waves of multiple tracks work against each other to eliminate certain frequencies. The resultant sound is often flat or dull.[/QUOTE]<not me = truth or fiction ?


Phase cancellation occurs when two signals of the same frequency are out of phase with each other resulting in a net reduction in the overall level of the combined signal. If two identical signals are 100% or 180 degrees out of phase they will completely cancel one another if combined.

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not me = truth or fiction ?

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Please call out what you saw as incorrect ?

If either of you would care to add more to this thread or start a new one on ways you sort out phase (pink noise, white noise, reversing polarity, etc.., ) . I for one , am looking forward to your responses, Justin and Justin?

Best way to sort out phase is to
1) Make sure levels between speakers are consistent.

2) Make sure T/A is set properly using one of the various methods (tape measure is fine)

3) Make sure there are no obvious phase issues with pairs of speakers (Measure both speakers individually, then together. Any spot where the together speaker responses dips compared to the individual speakers is a phase issue, If they speakers are playing the same level, it should ideally be IIRC 3db louder when combined.)

4) Use measurement techniques that can show you the phase of the speakers (REW with using sweeps can do this or paid programs like smaart or systune can do it with any audio playing)

5) Fix as much as you can, not all can be.

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Originally Posted by BigAl205

nah, use longer speaker wires to slow them down

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Oh jeez, gerald is leaking into this place

Sent from my SM-G975U using Tapatalk

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Originally Posted by Queef

I was not asking a question. I cut and pasted what apparently to some is BS. I was attempting to post a little insight into a problem another member seemed to think might have been "cancellation".

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Then why not reply to that member on their thread that way you know they will see it?

I did , explained that his IB for the IDMAX had his sub in the zone !
No cancellation , just pure sweetness!

Here may be a reason as to why I said that: I designed my first box on WINISD when I was on Elite Car Audio.
A carpenter built it out of 1" HDF (ported and sealed with a removeable top). One of My son`s has it now .

I golf because I know my ass from a hole in the ground.

When I play riders on the storm with my 100 watt amp in that enclosure with a 12" MB Quart , you will check the sky.

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Originally Posted by Jdunk54nl

So. Let's try this again. What questions do you have about phase?

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https://www.caraudiojunkies.com/show...t=Midbass+null

This thread adresses an issue I am wondering how "you" solve ?

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Originally Posted by Queef

When I play riders on the storm with my 100 watt amp in that enclosure with a 12" MB Quart , you will check the sky.

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Which amp?
Does it have the same rain sound when no music is playing?
;)

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Originally Posted by Holmz

Which amp?

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Zuki 100 watt mono https://www.caraudiojunkies.com/atta...2&d=1464576446

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Does it have the same rain sound when no music is playing?
;)

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Not on a beautiful sunshine filled day.

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Originally Posted by Queef

Zuki 100 watt mono https://www.caraudiojunkies.com/atta...2&d=1464576446



Not on a beautiful sunshine filled day.

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I should have put another couple of smily faces in there.
i have heard some "rain sounding" amps in the past. ;)