Phase, Pin Outs, Sources, Amps, Speakers—What’s important?

[AudioHTIT]

I’m starting this thread because I feel a bit guilty about the number of posts I’ve made in the RMC-1 owners thread about this subject. It is obviously important, and there is a lot to consider on he topic, but some aspects are more theoretical than practical, and we probably need a place to discuss the many places phase can affect your system, and when you need to be concerned.

I’d like to make a strong opening statement, but so much has been said that I’ll probably copy material from the other thread to have here as reference. Let’s try to let the RMC owners use their thread to discuss that processor, and move the general Phase topic here. I’ll expand this post and the next soon.

I’ll start with one of my last statements from the other thread...

All of your speakers need to be in phase with each other, and that’s all that’s important.

New: 8/19/2020 — This post contains the latest summary of Emotiva amp, preamp, and processor pin configurations.
emotivalounge.proboards.com/post/1046160/thread

In summary:
The BALANCED INPUTS on Emotiva XPA and XPA‐DR amplifiers INVERT ABSOLUTE PHASE.
(They are wired as: Pin1=SHIELD, Pin3=HOT/POSITIVE, Pin2=COLD/NEGATIVE.)

The BALANCED INPUTS on Emotiva PA‐1 Class D monoblocks DO NOT INVERT ABSOLUTE PHASE.
(They are wired as: Pin1=SHIELD, Pin2=HOT/POSITIVE, Pin3=COLD/NEGATIVE.)

The BALANCED OUTPUTS on Emotiva Preamps and Processors DO NOT INVERT ABSOLUTE PHASE.
(They are wired as: Pin1=SHIELD, Pin2=HOT/POSITIVE, Pin3=COLD/NEGATIVE.)

The BALANCED INPUTS on Emotiva Preamps and Processors DO NOT INVERT ABSOLUTE PHASE.
(They are wired as: Pin1=SHIELD, Pin2=HOT/POSITIVE, Pin3=COLD/NEGATIVE.)

Update 5/22/2023
It has not been mentioned previously, but the Emotiva UPA-1 also has balanced inputs, a user has stated that the XLR inputs on the UPA-1 are also inverted (pin 3 hot). This has not been confirmed by Emotiva, but I have no reason to doubt it.

[AudioHTIT]

What has caused all the phase discussion and should I be concerned? First of all nothing has changed, the conditions prompting all the ‘phase talk’ have been in place for many years; namely that all* Emotiva power amps have their XLR / Balanced inputs wired with pin #3 hot as opposed to the current industry standard of pin #2 being hot. This causes the phase of the signal to be inverted 180 degrees between the XLR input and speaker outputs. To be clear, if you are using all RCA connections with your Emotiva amps, the signal is not inverted; the discussion below will refer mostly to XLR connections, but those using RCA cables may still find it interesting or helpful. For reference here is Lonnie’s statement as to why Emotiva power amps have Pin #3 hot.

“15 years ago the first and second series of amps were wired to the EU standard which is now out of phase to the US standard. On many occasions we discussed changing this but decided not to because anyone who had older gear would run into problems. Better to keep things consistent especially since it doesn't matter as long as all the speakers are wired the same way.”

Let’s look at some common situations some of us might be in, remembering that the goal is to have all of our speakers moving in and out together, or being ‘in phase’ with each other, also known as correct relative phase. While we can remedy phase differences with either the XLR cable or the speaker cable, I will use the speaker cable for these scenarios.

Scenario #1 Any Single Amp System /wo Subwoofers:

No matter who’s amp you’re using, with either RCA or XLR connections, as long as you connect all of your inputs and speaker terminals the same way, your speakers will be in phase with each other.

Scenario #2 Emotiva Amp(s) Only + Subwoofers

Most systems with ‘separates’ have a single multi-channel amp, and many here have a single Emotiva amp, though this scenario also applies to those with multiple Emotiva amps. If you use the XLR inputs AND have a subwoofer, all of your main and surround speakers will be in phase with each other, however your subwoofer may be out of phase. Subwoofer placement and adjustment are an entire topic unto itself, I’ll only mention them when you need to consider their phase adjustment in relation to the main amplifier(s). In my system, with a single Emotiva amp, the subs measure and sound best when they are 180 degrees out of phase in relation to the XPA output. You can either reverse the polarity of all your speaker terminals (my preference), or (if your sub has one) flip the phase switch.

Scenario #3 All Emotiva amps with mixed connection types

If for some reason you choose to use both XLR and RCA connections to the different channels of your Emotiva amps, you will need to compensate for the phase differences. Let’s say you have an XPA-7 G3 and have the L&R channels hooked up via XLR cables, and all the other channels use RCA (most XPA amps have a switch on each channel allowing you to do this). The phase of the L&R channels will be out of phase with the 5 other channels, the easiest (and most logical) remedy would be to switch the polarity on the L&R channels at the amp end of the speaker cable. The same would be true if you had multiple Emotiva amps with mixed connection types, reverse the polarity on the channels using XLR connections.

Scenario # 4 Mixed Amplifier Brands, some Emotiva
This situation is actually similar to #3, you would treat your non-Emotiva amps as if they were hooked up via RCA, that is, compensate for the phase differences by reversing the speaker polarity on the Emotiva XLR channels.

That’s a start, watch this space for more info and please comment or ask questions in this thread.

[Gary Cook]

I have never found that "correct phase" was any different sounding to "same phase". Even in a stadium with hundreds of speakers or at home with just 2.1, aligning the phases of all speakers is important, but having them all "correct phase" made no audible difference. That said, since aligning the phase is important it is easy just to follow the convention and make all the +'s (red) and all the -'s (black). That way a quick check of one or two speakers' phasing is made easier/quicker when the convention is followed.

Cheers
Gary

[405x5]

Phase correct can be unnoticeable, Or impactful, depending on the source material.
Source material that contains a lot in the high frequency range will be more apparent when out of Phase.

Subs out of Phase have reduced relative low frequency output.

Out of phase is utilized by design in some instances with bi-pole surrounds to increase diffuse effects.

Bill

[KeithL]

I need to correct a slight ambiguity.

If a sub is out of phase with your main speakers at the crossover point then there will be a dip in the frequency response where they overlap.

And, if you have two subs, and they are out of phase with each other then together they will produce very little output (again, because of cancellation).

However, in both cases, we are talking about relative phase.

(They are out of phase with each other.)

Absolute phase is something different... and far lass audible.

(And a single speaker or sub, which won't encounter cancellation from the output of some other speaker, will output exactly the same amount of sound, regardless of whether its absolute phase is correct or reversed.)

It's also worth noting that, when we talk about phase, we are talking about the audio signal as measured at the listening position.

At 20 hz, the wavelength of a single cycle of a sine wave is about 50 feet......

This means that, if you have two subs that are perfectly in phase electrically, and you move one 25 feet further away from you, they will now be perfectly OUT of phase.

(When the distance from two sources to the listener are different by one-half wavelength they are out of phase.)

This also means that, if a sub is a few feet too close or too far away, it will not be very far out of phase.

However, at 12 kHz, the wavelength of a single cycle of a sine wave is about 1/2 INCH......

(So, if you slowly move one speaker of a pair further away from you, for every inch you move it, it will go from "in phase" to "out of phase" and back to "in phase" once.)

However, at higher frequencies, most of what we hear is a jumble of direct and reflected sound, and we aren't especially sensitive to this at those higher frequencies, so we tend not to notice it.

At MIDRANGE frequencies, like 1200 Hz, where we are quite sensitive to phase, the wavelength of a single cycle is about a foot.

(That's why things like phase alignment between speaker drivers in this frequency range is so important.)

If you want to do the math at other frequencies.... sound, in air, at sea level, travels about 1100 feet-per-second.

Note that relative phase changes with distance - but absolute phase does not.

Jul 29, 2019 7:49:27 GMT -5 405x5 said:

Phase correct can be unnoticeable, Or impactful, depending on the source material.
Source material that contains a lot in the high frequency range will be more apparent when out of Phase.

Subs out of Phase have reduced relative low frequency output.

Out of phase is utilized by design in some instances with bi-pole surrounds to increase diffuse effects.

Bill

[mgbpuff]

Equipment electrical phase is one thing and listening phase determination is another. The phase of input vs output of a component depends on the number of amplification stages in that component. An odd number of amplifying stages results in the output being inverse to the input. An even amount of amplification stages results in output phase inline with input phase. XLR cabling is just another possibility for a phase inversion to be added or not depending whether pin 2 or 3 is treated as the 'hot' pin. Speakers are phased such that a positive going signal on the + (red) terminal vs the - (black) terminal results in the cone pushing air into the room. Listening phase sensing is more involved. It depends upon the MLP position and perhaps room size and reflections. A simple stereo system is rather straight forward to setting up to get a pinpoint center sound from a mono signal sent to both channels(given a centered MLP position of course). But an immersive sound system with many speaker locations and differing amplifier schemes is another matter altogether. Here, the Immersive sound prepro (or the prepro section of an immersive receiver) must be capable of calibrating the MLP position to the correct phases such that 3 dimensional sound can be accurately pin pointed for that specific listener. The phase of all these immersive direction speakers must be relatively (not absolutely) in phase with the original location of sound recording. Summarizing - stereo phasing at the listening position is important and easy to accomplish but immersive phasing is best left to the complicated equalization software built into the prepro. Bi pole or dipole speakers can result in pleasing but not necessarily accurate-to-source effects. Don't complicate the already complicated process of immersive set ups by using bi pole or di pole speakers. In addition to in phase vs inverse phase problems, there can be propagation delay differences in different equipment including speakers; the best solution here, besides depending on the equalization software, is to insure that all the equipment is the same for each channel - same amps, same speakers, maybe even the same wire lengths.

[DYohn]

The electrical phase is important, but more important is the time-phase alignment at your listening location. It's about what you hear, and that's all that matters, and it really doesn't matter what it takes to get it.

[KeithL]

Let me throw a little more information at you.

First off, when we're talking about full range speakers, including surrounds and heights, if some are out of (relative) phase with others, it's going to affect imaging.
If your front left and right speakers are out of phase with each others your left/right sound stage will be very badly affected.
Likewise, for any other pair of speakers (like your two surrounds).
The effect of different pairs being out of phase is generally a lot less important - and, in some situations, deliberately reversing the surrounds relative to the fronts may be a good thing.
(It tends to make sound more "diffuse" - which you may want if your surrounds are too close to the listening position.)
And, as someone else suggested, as long as all your height speakers are in phase with each other, their absolute phase may not matter much.
(However, it never hurts to start out with "right".)

I would also always suggest maintaining "amplifier symmetry" between left and right.
For example, if you have two stereo amplifiers, of different brands...... use one for both fronts and one for both surrounds.
(DO NOT use one for the left front and surround and the other for the right front and surround.)
This will ensure that the speakers in each of those pairs is phase the same - and avoid any other asymmetry due to some other minor difference in how the amps sound.

It's also worth mentioning that "phase" and "delay" and "distance" are all related.
(So, when you run automatic room correction, and it measures and adjusts distance, it will also to some extent adjust the phase.)

Second, when we're talking about the phase of XLR and speaker connections - there are only two options: "normal" and "reversed".
And, in case it wasn't obvious, when you reverse something twice, you end up back where you started from.
So, as long as you don't continually move equipment around, all that matters is the end result, which is the sum of everything in the signal chain.
For example, if your source maintained absolute phase, and your amplifier reversed it, and you flip the speaker leads to reverse it again, the end result is that the absolute phase is correct.
This is EXACTLY equivalent to having every component correct to begin with.
So, for example, if one amplifier flips the absolute phase, you can correct it by flipping the wires on every speaker connected to that amplifier.
(You could also correct it by putting special interconnects that flip it between that amp and the preamp - but don't do both or you're right back where you started.)

Third, subs are a slightly different matter.....
In order to avoid cancellations that cannot be corrected by ordinary EQ, you want all of your subs to be in-phase at the listening position.
And, furthermore, you specifically want your subs to be in phase with your main speakers in the range of frequencies where they overlap (the crossover region).
The best way to ensure this is to play some tones AT OR NEAR THE CROSSOVER FREQUENCY.
Play the tone through your entire system, so it's coming from both the mains and the subs.
Then adjust the phase controls on your subs - if they have them.
The best setting is the point where that test tone, at or near the crossover frequency, is LOUDEST at your listening position.
The tone will be the loudest when both subs are in phase with each other and with your mains (or, if you have one sub, when it is in phase with your mains).
You can THEN use levels and EQ to lower the amount of bass or adjust the amount of bass at the crossover point to be correct.)

One final thing worth knowing is that many full range speakers have a lot of phase shift over the full range of audio frequencies.
(I'm telling you this just to put the issue of "absolute phase" in perspective.....)
A typical amplifier or CD player may have a phase shift of a small fraction of a single degree.
When you "flip the phase" or "put something entirely out of phase" we're talking about a phase shift of 180 degrees.
I've seen speakers with several drivers and complex crossovers that have a shift in phase, over the 20 hz to 20 kHz range, of over 720 degrees....
This phase shift often occurs gradually, over a range of frequencies, and doesn't have much effect on imaging, as long as it happens equally in the left and right speakers.
This is one reason why you ALWAYS want to have matched left and right speakers in any given pair....
And why you want a center that is pretty well matched to the front left and right speakers.

Here's a graph I swiped from an article which cited it as "the excess phase response of a typical loudspeaker".....

Note that (on this speaker)......
- assuming that we choose their "0 degree point" of 300 Hz as a reference
- the absolute phase is correct at 300 Hz
- the absolute phase is REVERSED at 2500 Hz
- the absolute phase is correct again (reversed twice) at around 5 kHz or 6 kHz
- at around 16 kHz, the absolute phase is reversed again (it's been completely flipped, flipped back, and flipped again)
- and at around 21 kHz, it's correct again, after being flipped entirely four times
(remember that 180 degrees is "one complete flip")

Now, obviously, no matter what your amplifier is doing, if you have these speakers, your absolute phase is very badly incorrect over most of the audible range of frequencies.
(Interestingly, however, they probably don't sound bad at all.... as long as the error is the same for the left and right speakers.)

[cwmcobra]

For those of us with legacy Sherbourn equipment, what are their XLR input pinout configurations? Specifically, the PA 7-350 and PA 7-150. Which XLR pin is hot?

Thanks,

Chuck

[AudioHTIT]

Glad to see the phase discussion move over here. I’ve started to add ‘Scenarios’ in he second post above, they’re intended to help readers identify when their system might need phase adjustment or consideration. I will add more scenarios there as time allows, please feel free to make comments, clarifications, and suggestions. I’ll add that when I mention subwoofer phase adjustment above, it is in the general sense, that it may need adjustment due to the scenario. We should cover more specific subwoofer phase adjustments as part of this thread as well, as it is wholly integrated into the topic.

The Scenarios Post

[jim80z]

Hi

I didn't necessarily see the answers to all of these in the other thread so will ask here so we can get a definitive baseline?
- Are all the XPA-? Gen 3 amps wired the same wrt XLR ins ie Pin 3 is hot?
- Which pin is hot on XSP-1 Gen 2 XLR ins and outs? Is it pin 2 or 3?
- Which pin is hot on RMC-1 XLR ins and outs? Is it pin 2 or 3?
- Others?

Thanks

[DYohn]

Jul 28, 2019 23:00:10 GMT -5 AudioHTIT said:

-edit.

"Speakers in phase" is only part of the solution. Having all your electrical connections the same phase is a good start, but depending on room geometry, speakers position and distance to the listener, loudspeaker configuration, and a thousand other acoustic factors, that does not mean it is in phase when you hear it. This is especially true when multiple speakers are playing the exact same signal, such as in a multiple subwoofer setup, as two subwoofers might be in electrical phase but cancel each other out at the listening position. So it is NOT enough to be in electrical phase, you need to measure for acoustic phase as well. This is, by the way, one of the most powerful things most automatic room setup routines does for you.

[KeithL]

Easy answer #1.....   all of the XLR inputs on all the XPA Gen3 amps are wired the same.

(And, incidentally, all of the RCA inputs are in true absolute phase to the output.)

Jul 29, 2019 11:07:43 GMT -5 jim80z said:

Hi

I didn't necessarily see the answers to all of these in the other thread so will ask here so we can get a definitive baseline?
- Are all the XPA-? Gen 3 amps wired the same wrt XLR ins ie Pin 3 is hot?
- Which pin is hot on XSP-1 Gen 2 XLR ins and outs? Is it pin 2 or 3?
- Which pin is hot on RMC-1 XLR ins and outs? Is it pin 2 or 3?
- Others?

Thanks

[AudioHTIT]

Jul 29, 2019 11:07:43 GMT -5 jim80z said:

Hi

I didn't necessarily see the answers to all of these in the other thread so will ask here so we can get a definitive baseline?
- Are all the XPA-? Gen 3 amps wired the same wrt XLR ins ie Pin 3 is hot?
- Which pin is hot on XSP-1 Gen 2 XLR ins and outs? Is it pin 2 or 3?
- Which pin is hot on RMC-1 XLR ins and outs? Is it pin 2 or 3?
- Others?

Thanks

*** Updated 7/30/2019 ***
*** Updated 7/27/2020 ***
*** Updated 8/19/2020 ***

—Confirmed by Emotiva, ALL Emotiva amps of any generation have their XLR inputs wired with Pin #3+ (the signal’s phase will be reversed by the amp)
—Confirmed, Emotiva XPA & DR amps of any generation have their XLR inputs wired with Pin #3+ (the signal’s phase will be reversed by the amp)
—Corrected, Emotiva PA-1 amps have their XLR outputs wired Pin #2+ (the signal’s phase will not be altered)

—Confirmed by Emotiva, ALL Emotiva preamps and processors have their XLR outputs wired Pin #2+ (the signal’s phase will not be altered)
—Confirmed by Emotiva, ALL Emotiva preamps and processor have their XLR inputs wired Pin #2+ (the signal’s phase will not be altered)

— Confirmed by Emotiva, ALL Emotiva products are non-inverting through the RCA connections (the signal’s phase will not be altered)

[AudioHTIT]

As they are pertinent to the phase discussion, I’ve copied these two comments from Keith and Lonnie from the other thread.

Jul 27, 2019 19:26:03 GMT -5 KeithL said:

Let me try and explain.
There are two ways of looking at phase: "absolute phase" and "relative phase" (which is what most people just call "phase").

Realtive phase refers to the fact that all channels are "in phase with each other".
In very simple terms this means that, if you played a monaural recording of a drum being hit, all of your speakers would go in at the same time and out at the same time.
(You wouldn't have some going in while others were going out.)
The reality is a bit more tricky because, if your speakers are different distances from the listener, you must adjust things so that the sound reaching the listener acts this way.
As dominicd said, if you have this wrong with two subwoofers, or between your sub and your regular speaker, then you'll get some odd sort of cancellation at certain frequencies.
However, dominicd is incorrect in saying that it doesn't matter at higher frequencies.. because it does have a major effect on imaging and soundstage.

Let's take the simple case of only two speakers - set to play in stereo.
If there is an instrument, or a vocalist, who sounds as if they're in the center, that sound is coming equally from the left and right speaker, and in phase.
If you were to reverse the phase of one of those speakers, instead of seeming to be in the center, that voice would seem to be coming from somewhere off to the side.
In fact, it will usually sound as if it's coming from some indistinct location that is distinctly NOT in the ceter where it belongs.
The effect would be less dramatic in a system with a center channel - but would still be somewhat odd and annoying.
(You can hear this for yourself easily enough by simply swapping the red and black wires on ONE of your front speakers - and then playing something in stereo.)

However, you can rely on the fact that all of the channels in any particular amplifier are all wired the same way... and that, for example, all of our XPA Gen3 models are wired the same.
And, if you had another amplifier that was wired the opposite way, all you need to do to correct it is to swap the red and black wires on all the speakers connected to one of the amps.
(A passive loudspeaker is essentially a balanced device - you can reverse its phase simply by swapping the red and black wores going to the amp.)

Absolute phase refers to the same idea... but goes beyond "all the speakers going in the same direction at the same time".
When you play a bass drum, the beater hits the back side of the drum head, and the drum head first moves out towards the audience, then bounces back and forth.
If the recording, and all of your equipment, "preserve absolute phase", then your speakers will move the same way - outward first (and not inward first).
Some people insist that they can distinguish when this is incorrect - with certain recordings of certain instruments.
However, some recording engineers don't consider it important, and many modern multi-track recordings fail to maintain absolute phase anyway.
(And there's no way to correct it once individual audio tracks with different absolute phase have been mixed together.)

Assuming this was wrong in some part of your system - and you could hear it on certain recordings - the solution would be to flip the red and black wires on ALL of your speakers.
(In general, at best, this might matter on a very few high quality stereo recordings - but is a total lost cause on multi-track multi-channel recordings.)
(In a system that uses balanced interconnects, rather than flip the speaker connections, you can also invert the phase by reversing the two signal leads in each interconnect...)

Jul 29, 2019 11:03:46 GMT -5 Lonnie said:

Just to clarify something here. Absolute phase means nothing. That is to say, connecting everything in the same phase relationship doesn't mean any of it will be correct at the seated location. Sound is a pressure wave representative to that of a sine wave. The length of the sine wave is dependent on the frequency. So from the point of origination to your seated location you could end up at any point along the wave front. Lets say you measure it at 1Khz and you dial in the phase of each speaker where they are all perfectly matched and in phase. Now test again at 2Khz or 20Khz or 200 hz. The phase of each speaker is all going to be different unless each speaker is exactly the same distance from your seated location.

I personally only care about the transition point of the subs to the main speakers. For that I use the phase control on the sub and play a test tone at the crossover point. Adjust the phase control of the sub to bring them both in alignment for that frequency and the rest doesn't matter as long as they are all wired the same. Oh and by the way, your speakers don't care one way or the other, they pull in just as far as the push out because they are reproducing complex sine waves.

Just a little food for thought.

Lonnie

[mgbpuff]

These threads are getting out of phase!

[donh50]

Jul 28, 2019 22:17:02 GMT -5 AudioHTIT said:

I’ll start with one of my last statements from the other thread...

All of your speakers need to be in phase with each other, and that’s all that’s important.

At the MLP, natch. Due to distance and the (large) phase changes made by the speakers themselve what phase the signal is from the amp into the speakers hardly matters though it should be matched for equidistant identical speakers. For subs, the important frequency is at the crossover point -- above that and the sub is rolling off, below that and the mains are rolling off. Absolute phase, the often hotly-debated "does my amp invert" question, is essentially a non-issue in real life (absolute phase is undetectable -- it takes many cycles for something like a drum strike to build and we hear the attack envelope, not the individual signal cycles). relative phase among speakers is very important... If the L and R speakers are 180 degrees out of phase you'll get a "hole" in the middle and the image will be hosed (bad). If the front pair is out of phase with the front pair again you'll have a fuzzy, indistinct image for sounds playing from all speakers. Etc.

In the real world you'll need to either let a room-correction projection align them all or manually set phase (usually via the distance tweak in the receiver/processor). My subs include a phase control that was invaluable in getting the subs (four of them) and other speakers to play nicely together. Due to the way bass management and Dirac Live works I had to futz with DL's target curve and the phase on the subs to align everything properly. My XMC-1 separates the crossover and DL functions since DL treats all as full-range speakers. As a result the phase shift added by the crossover was not correctly compensated for my subs. I have read and tend to believe that no room correction program really "understands" multiple subs and I do not think that's changed for DL 2.0 -- the new Dirac Live Unison program should, but don't think it is out yet, at least not on any AVR/processor. Supposedly some of the higher-end processors (e.g. Trinnov, SDP using SFM), do handle multiple subs but I have not tried any of those systems.

FWIWFM - Don

[AudioHTIT]

Good points Don, and I think we all agree Relative phase is important, and Absolute phase is not. Also good to point out that room correction (ala Dirac) will identify some of these phase issues, and correct them if they're not too drastic.

I do think the following might be misleading to some.

Jul 29, 2019 13:58:53 GMT -5 donh50 said:

... Absolute phase, the often hotly-debated "does my amp invert" question, is essentially a non-issue in real life

I understand the context in which you're using it, that is, if I have one amp then it doesn't matter if it inverts, because all the channels will still all be in-phase, and we're not concerned about absolute phase. But, in scenario's 3 and 4 above, you definitely want to know if your amp inverts, and it's helpful to know when working with subs. I just want to make sure that the nuance we add to the conversation doesn't get confusing to those trying to learn the details.

You also reminded me I wanted to post this article that I first read and started using some time back, and which agrees with what most are saying about measuring/adjusting the subwoofer phase at the crossover point. This could be useful for those wanting to learn more about adjusting their subs. There are probably other good articles, if anyone has a favorite please post it.

www.soundandvision.com/content/setting-subwoofer-phase-easy-way

[donh50]

Jul 29, 2019 16:04:33 GMT -5 AudioHTIT said:

Good points Don, and I think we all agree Relative phase is important, and Absolute phase is not. Also good to point out that room correction (ala Dirac) will identify some of these phase issues, and correct them if they're not too drastic.

I do think the following might be misleading to some.

Jul 29, 2019 13:58:53 GMT -5 donh50 said:

... Absolute phase, the often hotly-debated "does my amp invert" question, is essentially a non-issue in real life

I understand the context in which you're using it, that is, if I have one amp then it doesn't matter if it inverts, because all the channels will still all be in-phase, and we're not concerned about absolute phase. But, in scenario's 3 and 4 above, you definitely want to know if your amp inverts, and it's helpful to know when working with subs. I just want to make sure that the nuance we add to the conversation doesn't get confusing to those trying to learn the details.

You also reminded me I wanted to post this article that I first read and started using some time back, and which agrees with what most are saying about measuring/adjusting the subwoofer phase at the crossover point. This could be useful for those wanting to learn more about adjusting their subs. There are probably other good articles, if anyone has a favorite please post it.

www.soundandvision.com/content/setting-subwoofer-phase-easy-way

Thanks, and obviously I didn't read the whole thread, sorry... Yes, I was thinking of a single amp or AVR/whatever. If you are mixing amplifiers, Emotiva or not, the relative phase comes into play if some are inverting and some are not. Again, room correction should handle it anyway (may get an "out of phase" warning), but as always if you are aligning them manually you need to be aware of the inversion(s). Again, the inversion matters less than getting all the speakers aligned so the wavefront at the MLP is in phase from all speakers where they overlap in frequency.

Long ago I bi-amped my speakers and the bass amp was non-inverting, treble amp inverting, so I had to learn this stuff early... They were Maggies with an asymmetric crossover so alignment was a little tricky. At one point I built an all-pass circuit into the crossover (my own design) to allow me to time-align the bass and mid/treble panels properly.

[jim80z]

Jul 29, 2019 11:34:22 GMT -5 AudioHTIT said:

Jul 29, 2019 11:07:43 GMT -5 jim80z said:

Hi

I didn't necessarily see the answers to all of these in the other thread so will ask here so we can get a definitive baseline?
....................

—To my knowledge, ALL Emotiva amps of any generation have the XLR inputs wired with Pin #3 hot.
—To my knowledge all Emotiva preamps and processors have their XLR outputs wired Pin #2 hot.
—To my knowledge not stated by Emotiva (hearsay is that) all Emotiva Preamp/Processor inputs are Pin #2 hot.

I here ask KeithL or Lonnie to verify these statements.

Thanks Audio....my gut feel is the same just want certainty.

lonnie , keith

1. Can you please confirm the above from AudioHTIT re which pins are hot on each product category?
2. Keith you have already confirmed the input to output circuitry on the Emotiva amplifiers retain absolute phase ie no flipping internally.  How about the processors and the preamps?


These are not questions to solicit theoretical answers but simple technical question on how the Emotiva gear works (yes, no, confirmed etc). As for the debate around absolute or relative or or or other phasing we can work that out post understanding how the gear works. I don't really care what standard Emotiva used (thats your call and I still bought the gear ) as long as I know how to treat it in the real world when I connect it to other gear and speakers.

Thanks