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Post by AudioHTIT on Aug 1, 2019 10:33:47 GMT -5
... (Remember that this matches with what Dan pointed out that sound travels at approx. 1 foot per second) ... Interesting ideas, not sure I could lie to my system like that, would it talk to me in the morning? Kidding aside I can see the possible advantage, I didn’t check all your math, but do have to mention, donh50 correctly used the speed of sound at about 1125 FPS. |
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Post by donh50 on Aug 1, 2019 11:02:46 GMT -5
Random thoughts: I used 1127 ft/sec for the speed of sound, just a number I remember from my grad acoustics class text ages ago. That was at STP (standard temp and pressure) but it varies with density and temperature (among other things) so is just a ballpark. If you go through a bunch of speaker reviews you'll very often find drivers within the speaker cabinet are actually out of phase with other drivers in the same cabinet. This is to compensate both crossover phase and distance (different drivers may have their effective driving point a little forward or behind other drivers). And a look at most any review will also show that phase changes wildly over the frequency range of most speakers. In the end you hope the designers got it right. In the real world all that matters is if you like their sound, linear-phase or not. My subs (Rythmik) have a continuous phase control. Only way I could get four of them aligned without going the miniDSP or other processing route. My earlier sub was a DIY and I included an all-pass stage to allow me to adjust the delay. I had used a BBD (bucket-brigade device, something probably five people remember) to do a true time delay but it was more trouble than it was worth. Electrical delay varies wildly with the processing and amplifiers used. Some amplifiers delay more than others, analog filters (crossovers or otherwise) introduce their own phase shift and delay, digital filters can add small to very large delays depending on their clock rate and number of taps. Worrying about it (polarity) will drive you nuts (a short drive in my case). In an analog system I'll measure and align things; mostly these days I let the room correction algorithm do its thing then check and tweak later using REW or whatever. I am still slightly vexed but happy that REW and a $100 mic replaced my $10k measurement system and $1k measurement mic. Where was it 10 or 15 years ago?  If you have a mix of amplifiers (EMotiva or not) some may maintain absolute phase and some may not. You could flip the speaker cables or polarity switch (active speakers and subs) on the "wrong" ones but, depending upon where the speakers sit relative to the listening position, you may make things better or worse. FWIWFM - Don |
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Post by hsamwel on Aug 1, 2019 13:04:07 GMT -5
(For example, all of our current Airmotiv models are pretty well matched.) Or a complete 7.x.x set of Focal Utopia Grande EM speakers..  Maybe find a way to put 4 of these on the ceiling as atmos aswell. Massive reinforcement needed  |
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Post by AudioHTIT on Aug 1, 2019 13:20:32 GMT -5
... Worrying about it (polarity) will drive you nuts (a short drive in my case). In an analog system I'll measure and align things; mostly these days I let the room correction algorithm do its thing then check and tweak later using REW or whatever. I am still slightly vexed but happy that REW and a $100 mic replaced my $10k measurement system and $1k measurement mic. Where was it 10 or 15 years ago? If you have a mix of amplifiers (EMotiva or not) some may maintain absolute phase and some may not. You could flip the speaker cables or polarity switch (active speakers and subs) on the "wrong" ones but, depending upon where the speakers sit relative to the listening position, you may make things better or worse. FWIWFM - Don I have to be able to run my system without RC. I’ve actually made several recent changes and right now my speakers are running naked (no RC or EQ), it sounds good. I’m not rallying against RC/EQ and I use them, I just want to make the polarity corrections at the amp or sub, so that my system isn’t dependent on correction to sound good. So I think there’s value in pointing out where amps or speakers make drastic (180) changes in phase, or maybe it’s better to use polarity when it’s a complete reversal. Though it’s good to also add the inner speaker details you and Keith have bought to the table. I think back to the Dahlquist DQ-10, a speaker that besides sounding great, brought phase and frequency alignment into the speaker lexicon (also remember meeting Saul Marantz at a Dahlquist dealer presentation). I’m using a UMIK-1, iPad Pro 11, and AudioTools for most of my measurements these days, but it’s no REW, at least without all the add ins.  |
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Post by markc on Aug 2, 2019 2:01:23 GMT -5
... (Remember that this matches with what Dan pointed out that sound travels at approx. 1 foot per second) ... Interesting ideas, not sure I could lie to my system like that, would it talk to me in the morning? Kidding aside I can see the possible advantage, I didn’t check all your math, but do have to mention, donh50 correctly used the speed of sound at about 1125 FPS. Oops! Thanks. I meant approx. one foot per millisecond! Hence adding 10-25 feet distance to the sub to compensate for it's 10-25 millisecond processing delay I've now edited the post so that the distance/time alignment makes sense |
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zimmo
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Post by zimmo on Aug 2, 2019 7:59:55 GMT -5
I have one question,when you said you have phase problem you collect speaker cable red to cable black or white ,when you switch the color cable is from the processor or direct to the speakers.
thank you
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Post by AudioHTIT on Aug 2, 2019 10:20:27 GMT -5
I have one question,when you said you have phase problem you collect speaker cable red to cable black or white ,when you switch the color cable is from the processor or direct to the speakers. thank you The easiest place to correct for phase is at the output (speaker terminals) of the amplifier, just reverse the red+ with black- . I like it here because it’s simple, and you see all of your connections in one place — as opposed to the back of the speaker where you have to look 7 different places (but that would also work). If you’re correcting for the amplifier, it’s also logical to do it at the amp. If you’d rather do it at the amp inputs that ok too, either build or buy cables or adapters that swap pins 2 and 3 from one end to the other. Certainly more difficult to build or find, but just as effective. The key is to only do one of these solutions, not both. |
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zimmo
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Post by zimmo on Aug 2, 2019 13:28:22 GMT -5
thank you Htit
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Post by donh50 on Aug 2, 2019 13:37:01 GMT -5
And, just because in the primordial past a customer did it, I'll mention that you only want to swap red/black (or whatever) at ONE end of the speaker cable, not both... Switching at the speaker end and the amp end puts you back where you started.
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Post by babadono on Nov 9, 2019 0:25:36 GMT -5
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Post by AudioHTIT on Nov 9, 2019 1:19:15 GMT -5
I new around here and don't know how to quote parts of others posts. So I will just try to comment on those parts and hope it adequate for understanding. # 1 the phase of a signal from input to output of an amplifier is not determined by the number of stages. Some stages invert and some don't. #2 why is pin 3 of XLR input to an amp hot while the output of a preamp pin 2 is hot? Just to keep the input on the RCA input in phase with the output? Read the second post, second paragraph in this thread, Lonnie’s explanation is quoted in italics. The rest of the post explains how to deal with it. >>> Second Post Here <<<Edit: To quote someone, go to that post and hit the “Quote” button in the upper right corner, that will put their post in a reply box for you to complete and save. |
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Post by doc1963 on Feb 9, 2020 9:13:14 GMT -5
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.Question, I have an Onkyo PR-RZ5100 and use mixed outputs XLR for LCR and RCA for subwoofer. The LCR are powered by an Emotiva DR3 and the subwoofer by an active plate in the sub. Are the balanced XLR input pins of the Emotiva amps reversed? Should I throw the subwoofer 180 degrees out of phase [as a baseline]? Pin 2 looks to be positive from the Onkyo 5100 [see attachment]. View AttachmentAll modernized audio electronics manufacturers should follow EIA Standard RS 297-A which was originally adopted in the 1970’s (and strictly used by Japanese and European manufacturers) which designates “pin 2 hot - pin 3 cold”, but Emotiva uses the reverse (which was only used by some US manufacturers who chose to not adhere to the adopted standard). AFAIK, every current manufacturer of home audio amplifiers, except Emotiva, adheres to the adopted XLR pinout. It is also interesting to note that Emotiva does adhere to the adopted EIA standard pinout in all of their preamps and processors. Only their amplifiers are reversed from the adopted standard. The easiest solution when using amplifiers from mixed manufacturers is to reverse the speaker output polarity at the back of the Emotiva amp. If only a subwoofer is affected, reversing polarity at the subwoofer’s amp (if possible) is a viable solution. |
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Deleted
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Post by Deleted on Feb 9, 2020 10:05:30 GMT -5
Question, I have an Onkyo PR-RZ5100 and use mixed outputs XLR for LCR and RCA for subwoofer. The LCR are powered by an Emotiva DR3 and the subwoofer by an active plate in the sub. Are the balanced XLR input pins of the Emotiva amps reversed? Should I throw the subwoofer 180 degrees out of phase [as a baseline]? Pin 2 looks to be positive from the Onkyo 5100 [see attachment]. All modernized audio electronics manufacturers should follow EIA Standard RS 297-A which was originally adopted in the 1970’s (and strictly used by Japanese and European manufacturers) which designates “pin 2 hot - pin 3 cold”, but Emotiva uses the reverse (which was only used by some US manufacturers who chose to not adhere to the adopted standard). The easiest solution when using amplifiers from mixed manufacturers is to reverse the speaker output polarity at the back of the Emotiva amp. If only a subwoofer is affected, reversing polarity at the subwoofer’s amp (if possible) is another viable solution. Thanks, I have a 180 degree phase dial on my subwoofers so easiest solution for me is to just turn the subwoofers 180 degrees out of phase from the LCR. If the subwoofers because of mixed input signals are out of phase this explains what I dealt with this week. I noted at one point the bass was no louder with the subs than not. Since the L and R use 4 12" subs and my dedicated subwoofer channel is 4 10 inch subs it was more difficult for me to detect. I actually thought I had a standing wave and was trying to reposition the speakers by adjusting distance in between and toe as well as reposition the subwoofer. The Onkyo standing wave calibration was picking up a dip at 63hz of a few db. |
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Post by mmcgranahan on Apr 18, 2020 10:01:51 GMT -5
So, if one in using an Emotiva preamp via XLR outputs to amps with only RCA inputs, which RCA wires should be connected to which XLR pins? Will the attached pinout for an XLR to RCA cable work to connect an XLR only preamp to an RCA only amp? (Seems to me it would be bad to short the differential output to the ground pin, wouldn't it? )
Thanks so much.
Attachments:
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Post by megash0n on Apr 18, 2020 11:23:50 GMT -5
So, if one in using an Emotiva preamp via XLR outputs to amps with only RCA inputs, which RCA wires should be connected to which XLR pins? Will the attached pinout for an XLR to RCA cable work to connect an XLR only preamp to an RCA only amp? (Seems to me it would be bad to short the differential output to the ground pin, wouldn't it? )
Thanks so much.
Im now wondering if I need to swap pins on my minidsp connection. I forgot about the whole pin issue. Can anyone remind me? If you are feeding a non emotiva amp from a RMC, using XLR, do you need to reverse the pins or polarity? |
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Post by geebo on Apr 18, 2020 12:29:23 GMT -5
So, if one in using an Emotiva preamp via XLR outputs to amps with only RCA inputs, which RCA wires should be connected to which XLR pins? Will the attached pinout for an XLR to RCA cable work to connect an XLR only preamp to an RCA only amp? (Seems to me it would be bad to short the differential output to the ground pin, wouldn't it? ) Thanks so much. Im now wondering if I need to swap pins on my minidsp connection. I forgot about the whole pin issue. Can anyone remind me? If you are feeding a non emotiva amp from a RMC, using XLR, do you need to reverse the pins or polarity? I think you could just swap the speaker connections at the speaker for any that are connected to an Emo amp via XLR. Leave the rest alone. |
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Post by AudioHTIT on Apr 18, 2020 12:42:28 GMT -5
Im now wondering if I need to swap pins on my minidsp connection. I forgot about the whole pin issue. Can anyone remind me? If you are feeding a non emotiva amp from a RMC, using XLR, do you need to reverse the pins or polarity? Since all the Emotiva processors follow the industry standard pin 2 hot, and assuming the MiniDSP is correct, then you shouldn’t need to do anything ‘special’. It’s only when Emotiva power amps are involved that you need to consider phase. |
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Post by megash0n on Apr 18, 2020 12:45:37 GMT -5
Im now wondering if I need to swap pins on my minidsp connection. I forgot about the whole pin issue. Can anyone remind me? If you are feeding a non emotiva amp from a RMC, using XLR, do you need to reverse the pins or polarity? Since all the Emotiva processors follow the industry standard pin 2 hot, and assuming the MiniDSP is correct, then you shouldn’t need to do anything ‘special’. It’s only when Emotiva power amps are involved that you need to consider phase. Cool. I knew there was something. So, how do they feed their own amps? I have an RMC and 2 XPAs. How do they follow industry standard on the RMC and not the amp? Wouldn't this mean I need to fix something? |
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Post by AudioHTIT on Apr 18, 2020 12:54:39 GMT -5
Since all the Emotiva processors follow the industry standard pin 2 hot, and assuming the MiniDSP is correct, then you shouldn’t need to do anything ‘special’. It’s only when Emotiva power amps are involved that you need to consider phase. Cool. I knew there was something. So, how do they feed their own amps? I have an RMC and 2 XPAs. How do they follow industry standard on the RMC and not the amp? Wouldn't this mean I need to fix something? Yes, start with the first two posts in this thread. |
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Post by AudioHTIT on Apr 18, 2020 16:32:42 GMT -5
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