speakers

[scripted13]

why does the speaker has a positive and negative input? what would happen if i mistakenly reverse the inputs? thanks good guys

 

[MikeMl]

Nothing, unless you have multiple speakers; then they are driven out-of-phase. It is particularly important to drive left and right stereo speakers with the correct phasing.

 

[Ian Rogers]

I have heard it makes a slight difference in speaker quality... But as speakers are normally driven with an AC signal, I can't see how there's a difference...

I'm sure someone here will shoot this down.... IMHO no difference..

 

[canadaelk]

In a stereo setup, if one speaker has it's polarity reversed to the other, a loss of bass is the result.

 

[wizard]

Nothing, unless you have multiple speakers; then they are driven out-of-phase. It is particularly important to drive left and right stereo speakers with the correct phasing.

Correct, I think the polarity is written there on the speakers just for when you have more than one Speaker (in stereo or parallel usages). By knowing the polarity of each SP hence you would be able to avoid out of phasing.

 

[Nigel Goodwin]

Yes, it's only for phasing in multi-speaker systems.

 

[audioguru]

In "the good old days", salesmen in appliance stores always wired the speakers out-of-phase then cranked up the bass control. Still there was no bass.
Whenever I went past I quickly wired the speakers in phase and turned the bass down to normal and it sounded great.

You can easily hear it yourself especially if the speakers are close together or are facing each other and are close together.

 

[crutschow]

It case it isn't obvious, the reason out-of-phase speakers sound weak is because as one speaker is moving out, the other is moving in, thus tending to cancel the sound waveform radiated into the room. This is most noticeable for speakers much less than a wavelength apart so the problem is not so apparent for the higher frequencies unless the two out-of-phase speakers are in the same housing.

Out-of-phase speakers will also cause a hole in the stereo affect between the two speakers. Instead of hearing a continuum of sound you will tend to hear each speaker individually.
Edit: This can be easily heard if you cross-wire a DPDT switch in series with one pair of the speaker leads to reverse the phase when the switch is thrown.

 

[unclejed613]

the polarity marking (i'm surprised nobody else mentioned this) means that if the + terminal is positive (i.e. on the positive half of the waveform), the cone moves out. this is most important with woofers or multi driver cabinets, since the cancellation effect you would get using two stereo speakers out of phase would be most noticeable for bass, or in the case of a speaker cabinet with two woofers, two mids, and two or more tweeters. also with woofers (and especially subwoofers), when you are playing music that has a pronounced kick-drum, the effect of having the woofers moving IN when the kick drum is hit, makes the music sound like it's missing something. you hear the kick drum, but it doesn't sound right. there are people who take the whole "absolute phase" thing and blow it completely out of proportion, but it isn't really that important except at low frequencies.

 

[audioguru]

when you are playing music that has a pronounced kick-drum, the effect of having the woofers moving IN when the kick drum is hit, makes the music sound like it's missing something. you hear the kick drum, but it doesn't sound right.

If the drum "kicks" in or out does not matter since our hearing does not identify the "in or out" phase of a pulse. Our hearing responds only to AC frequencies (not DC pulses) at 20Hz and higher.

 

[jpanhalt]

the polarity marking (i'm surprised nobody else mentioned this) means that if the + terminal is positive (i.e. on the positive half of the waveform), the cone moves out. this is most important with woofers or multi driver cabinets, since the cancellation effect you would get using two stereo speakers out of phase would be most noticeable for bass, or in the case of a speaker cabinet with two woofers, two mids, and two or more tweeters. also with woofers (and especially subwoofers), when you are playing music that has a pronounced kick-drum, the effect of having the woofers moving IN when the kick drum is hit, makes the music sound like it's missing something. you hear the kick drum, but it doesn't sound right. there are people who take the whole "absolute phase" thing and blow it completely out of proportion, but it isn't really that important except at low frequencies.

Monster Cable doesn't agree with that. One cannot predict the direction of the cone from that label.

https://www.electro-tech-online.com/custompdfs/2013/03/A2500_Speaker_Phase.pdf

Most of the time the term phase is mistakenly applied to the direction a speaker moves when driven by an input signal. This is really a description of polarity. The polarity of a speaker may vary from one brand of speaker to another. Some cones move forward and away from the magnet when a positive voltage is applied to their coil terminals. Other speaker cones move backwards and into the magnet when a positive voltage is applied to their terminals. There are even some manufacturers that label tweeters differently than woofers.

I found that whole article interesting. There is also an interesting article by Bose about noise cancellation and phasing that I could not find. It was almost 10 years ago when I was looking at noise cancellation. It covers the reason you cannot have effective noise cancellation in a room, but you can with head phones.

John

 

[unclejed613]

i was referring to the driver itself. manufacturers may do odd things between the rear panel of the cabinet and the driver itself, as well as the phase getting shifted or inverted in the crossover. there are "bipolar" or "dipole" cabinets where the drivers in the front are wired one way, and the rear drivers wired backwards.

 

[Nigel Goodwin]

Monster Cable doesn't agree with that. One cannot predict the direction of the cone from that label.

I wouldn't pay any attention to anything the crooks at Monster Cable say

Speakers are marked +/- so you can connect them correctly easily - and making the +ve terminal positive always moves the cone forwards - there would be no point in marking if it wasn't a firm standard.

Has a nightmare at a gig once - the two sides of the stage were reversed, and individual cabinets on each side were.

Needless to say - no tools or test gear - but managed to borrow a PP3 out of a guitar effects pedal!

 

[jpanhalt]

I wouldn't pay any attention to anything the crooks at Monster Cable say

Speakers are marked +/- so you can connect them correctly easily - and making the +ve terminal positive always moves the cone forwards - there would be no point in marking if it wasn't a firm standard.

Has a nightmare at a gig once - the two sides of the stage were reversed, and individual cabinets on each side were.

Needless to say - no tools or test gear - but managed to borrow a PP3 out of a guitar effects pedal!

Monster Cable is a successful company that has been in business 35 years and has well over 400 employees (http://en.wikipedia.org/wiki/Monster_Cable_Products). Regardless of what you may personally think of its customer service or even its products, I see no point in such name calling here.

The point you make regarding the direction of cone movement is simply not supported by the facts. While that may be the preferred definition, there is inconsistency in the market with respect to labeling. Here are some other links that report that inconsistency:

http://www.bcae1.com/speaker.htm
https://www.electro-tech-online.com/custompdfs/2013/03/SMARTSYSTEM2000.pdf

What can you provide in support of your position that such marking is a "firm standard?"

John

 

[Nigel Goodwin]

Monster Cable is a successful company that has been in business 35 years and has well over 400 employees (http://en.wikipedia.org/wiki/Monster_Cable_Products). Regardless of what you may personally think of its customer service or even its products, I see no point in such name calling here.

A company who rip people off selling vastly over priced cables that work no better than cheap ones but make imaginary claims for them, and sue anyone who attempts to use the name 'monster' in any thing - including Disney for the film Monsters Inc.

The point you make regarding the direction of cone movement is simply not supported by the facts. While that may be the preferred definition, there is inconsistency in the market with respect to labeling. Here are some other links that report that inconsistency:

http://www.bcae1.com/speaker.htm
https://www.electro-tech-online.com/custompdfs/2013/03/SMARTSYSTEM2000.pdf

What can you provide in support of your position that such marking is a "firm standard?"

Every speaker I've seen and used over MANY years.

Have you EVER seen a speaker wired differently? (assuming it wasn't a manufacturing error of course).

 

[audioguru]

Sure Monster Cable company is a bunch of Chinese crooks.
Hee, hee they got caught: "In one experiment conducted by a customer, audiophile listeners could not distinguish between short Monster cables and ordinary coat hangers. Another reviewer concluded that 16-gauge lamp cord and Monster [speaker] cable are indistinguishable from each other with music."

Energizer battery company caught their lies about the Monster batteries.

 

[jpanhalt]

Every speaker I've seen and used over MANY years.

Have you EVER seen a speaker wired differently? (assuming it wasn't a manufacturing error of course).

It's good to know you agree it is not a "firm standard," but rather based on your personal experience. I was hoping you or someone would find the aforementioned standard for all of our benefit.

As I tried to point out before this discussion got diverted, what may be common practice is not necessarily universal. So, when dealing with components from different manufacturers, it is possibly advisable and easy enough to test.

John

 

[audioguru]

I saw a speaker once that was made and shipped without a magnet. I betcha the manufacturer did not test it.

 

[Sangoma]

I saw a speaker once that was made and shipped without a magnet. I betcha the manufacturer did not test it.

They employed Beethoven in QC

 

[Nigel Goodwin]

It's good to know you agree it is not a "firm standard," but rather based on your personal experience. I was hoping you or someone would find the aforementioned standard for all of our benefit.

Presumably, as you avoided the question, you have NEVER seen one wired differently?.

As I tried to point out before this discussion got diverted, what may be common practice is not necessarily universal.

You mean like marking one end of an electrolytic +ve? - exact same thing.