To test wether two tweeters are in phase.
Measuring the lobing effect might be a way.
Set both speakers close side to side, tweeters at the same height, some short distance apart.
Send same level same pitch tone.
With a mike or a young ear at the height of the tweeters, exploring sideways, one should detect locations of higher and lower levels identifying the lobes.
This is theory. Practice, TBH, I do not know.
In experiments, using interferences, usually gives accurate and sensitive results.
Measuring the lobing effect might be a way.
Set both speakers close side to side, tweeters at the same height, some short distance apart.
Send same level same pitch tone.
With a mike or a young ear at the height of the tweeters, exploring sideways, one should detect locations of higher and lower levels identifying the lobes.
This is theory. Practice, TBH, I do not know.
In experiments, using interferences, usually gives accurate and sensitive results.
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^ Good. There are many ways to do it. Swapping polarity back and forth with a switch while you listen. Moving your head to detect lobes is good but better at the crossover frequency as they are larger. You could also do it with pink noise and listen for the blend as you move your head, or pink noise RTA and microphone in front and swap polarity, or sweep the mic up and down looking for the null.
>And, it shows that the right speaker in both systems is phase reversed from what is marked on the speaker terminals.
Holy Smokes! What are the chances?
I would be amazing to hear you got a super deal on both sets, because the previous owner couldnt sort it out, gave up 'n sold 'em.
Holy Smokes! What are the chances?
I would be amazing to hear you got a super deal on both sets, because the previous owner couldnt sort it out, gave up 'n sold 'em.
I disagree about "better at the crossover frequency".
Referring to my post #21
We are interested in the interference from the left and right channel tweeters. We must use a frequency above the cross over frequency, that is to make sure the other drivers do not interfere.
Choosing the cross over frequency, is a worst choice for this experiment.
Choosing 3400 Hz the sound wavelength is 10 cm, about 4".
With a frequency above cross over, listening right in front of the two speakers side by side at the tweeters height, the sound level is maximum in case the tweeters are in phase, minimum in case the tweeters are phase reversed.
In this set up, there is equal distance from ear to tweeters. The two sounds add or cancel depending of tweeter phasing.
We are interested in whether the tweeters are in phase with each other, not to mention which one is correct. Perhaps you are thinking I meant putting the two speakers together like you had suggested? If working at the crossover it's about how the woofer and tweeter work together.
In case you are interested about phasing of your left and right channel tweeters as in my post #21,
I give some results.
Assume:
Tweeters are at same height, 40 cm apart.
Same level sent to the two HPs.
Frequency 3400 Hz. ( so wavelenth is 10 cm ).
Listening 2 meters ahead. ( at tweeters height ).
Then.
Maxima and minima alternate 50 cm sideways.
With tweeters in phase, straight ahead, there is a maximum, 50 cm left or right is a minimum, 1 meter left or right is a maximum.
If phase reversed then the lobe pattern is 50 cm side shifted. Straight ahead, there is a minimum, 50 cm left or right is a maximum.
Because we cannot afford an anechoïd chamber, this pattern will be blurred by wall reflections.
Using a filter to play with phases continuously would exhibit a continuous side shift of the lobing pattern.
I give some results.
Assume:
Tweeters are at same height, 40 cm apart.
Same level sent to the two HPs.
Frequency 3400 Hz. ( so wavelenth is 10 cm ).
Listening 2 meters ahead. ( at tweeters height ).
Then.
Maxima and minima alternate 50 cm sideways.
With tweeters in phase, straight ahead, there is a maximum, 50 cm left or right is a minimum, 1 meter left or right is a maximum.
If phase reversed then the lobe pattern is 50 cm side shifted. Straight ahead, there is a minimum, 50 cm left or right is a maximum.
Because we cannot afford an anechoïd chamber, this pattern will be blurred by wall reflections.
Using a filter to play with phases continuously would exhibit a continuous side shift of the lobing pattern.
Couldn't one Simply drive one speaker at a time with an oscillator.
Place a mike on axis starting with the woofer one wavelength in front of the speaker.
Monitor the output of the oscillator on one scope channel and the mike output on the other.
Then note phase relationship.
Reposition the mike on axis to the mid range horn, again 1 wavelength in front of the speaker and repeat.
All phase relationships should be consistent.
Joe, I got the first pair new in 1977 and paid full price.
I got the second pair around 1997 for $300, a pretty good deal even then.
Place a mike on axis starting with the woofer one wavelength in front of the speaker.
Monitor the output of the oscillator on one scope channel and the mike output on the other.
Then note phase relationship.
Reposition the mike on axis to the mid range horn, again 1 wavelength in front of the speaker and repeat.
All phase relationships should be consistent.
Joe, I got the first pair new in 1977 and paid full price.
I got the second pair around 1997 for $300, a pretty good deal even then.
That's a way to do it.
As "oscillator " and "scope" you can use "audiotester" a freeware running under Windows, using the sound card.
Using the appropriate frequency to see the phasing for each driver.
audioTester
As "oscillator " and "scope" you can use "audiotester" a freeware running under Windows, using the sound card.
Using the appropriate frequency to see the phasing for each driver.
audioTester
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Or use audacity to generate 3 Hz and play it. Watch the speakers wiggle 🙂
I also have one of these somewhere... Phase Checker WG-360-A Equipment RCA RCA Victor Co. Inc.; New York NY
I also have one of these somewhere... Phase Checker WG-360-A Equipment RCA RCA Victor Co. Inc.; New York NY
As long as you can take a measurement run a full range sweep w/tweeter polarity inverted and non inverted @ a meter distance or so. Set the mic between the drivers. Keep woofer non inverted for both sweeps. One sweep should produce a null someplace near the xo ... unless it's 3rd order Butterworth filter. The polarity setting that produced the null would be incorrect.
I find if you play a mono source and it doesn't sound like its inside the middle of your head, the phasing is wrong 🙂
There's a speaker out of phase at the local liquor store and it drives me nuts while I wait in line.
There's a speaker out of phase at the local liquor store and it drives me nuts while I wait in line.
Not sure why I'd need one. I'd just switch the wires on the offending speaker 🙂 That is, if it wasn't a government store (Liquor Control Board of Ontario - Wikipedia)... Sometimes it's just easier to live with it than offer your findings to the appropriate legal channels....
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I decided the easiest thing to do was open up on of the offending speakers and see how it was wired. Sure enough, at the terminal strip to the crossover network the wire labeled input was backwards. All other wiring looks correct.Drivers and crossover were as expected for 1983, and should be the same in the 1977 pair.
I will open the one downstairs later and see if it is also wired wrong as well.
I will open the one downstairs later and see if it is also wired wrong as well.
That's interesting, no possibility at all that the pairs got mixed up at some point in time? (Different finishes and grill cloths would preclude that obviously)
Manufacturers IMVLE can be inconsistent about speaker phasing from model to model and sometimes even revisions of the same model, but this is very strange, I did not think Klipsch had such quality control issues in those days. I've heard a number of pairs of Heresys of those vintages and never noted this problem.
I did more than one set up for people who were interested in rocking out the house, the heresy is efficient and can handle some power = winner of loudness wars in my apartment building unfortunately, and elsewhere.. LOL
Manufacturers IMVLE can be inconsistent about speaker phasing from model to model and sometimes even revisions of the same model, but this is very strange, I did not think Klipsch had such quality control issues in those days. I've heard a number of pairs of Heresys of those vintages and never noted this problem.
I did more than one set up for people who were interested in rocking out the house, the heresy is efficient and can handle some power = winner of loudness wars in my apartment building unfortunately, and elsewhere.. LOL
One is pair 1977 Black lacquer walnut.
The second pair is 1983, Black birch plywood.
Grill cloth is also different.
No way to get them confused.
The downstairs pair had one speaker with the wires backwards at the terminals. Different errors, same effect.
The drivers are supposed to be the same, but there is different construction of the woofer, and the end cap of the mid-range horn is different in addition to the crossover networks being different.
Klipsch claims the same response from both as they are the original series, not Series II, Series III, or Series IV (current version).
I am sure there have been numerous changes throughout the history of the original speakers as they were supposed to be the same from the time they were introduced (1957) until 1985 when the II was introduced.
The second pair is 1983, Black birch plywood.
Grill cloth is also different.
No way to get them confused.
The downstairs pair had one speaker with the wires backwards at the terminals. Different errors, same effect.
The drivers are supposed to be the same, but there is different construction of the woofer, and the end cap of the mid-range horn is different in addition to the crossover networks being different.
Klipsch claims the same response from both as they are the original series, not Series II, Series III, or Series IV (current version).
I am sure there have been numerous changes throughout the history of the original speakers as they were supposed to be the same from the time they were introduced (1957) until 1985 when the II was introduced.
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Scroll down to post 5 here for a list of changes.
Is there a timeline of Klipsch speaker model releases? - General Klipsch Info - The Klipsch Audio Community
Is there a timeline of Klipsch speaker model releases? - General Klipsch Info - The Klipsch Audio Community