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Klipschorn Phase issue


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Hi

I read this forum quite often, but have only posted to it a few times. I am hoping someone could help me with a phase issue that I have with my loudspeakers. I used these two files to check the phase of my Klipschorn, but the results are backwards. I have better focus when I use the out of phase test.

Voice in-Phase [Technical Track]

The logical conclusion is that I have a speaker wire connected backwards either at the loudspeaker or at the amp. I checked both and they seem O.K. Next, I bypassed the crossover and ran the midrange full range. The results were better. The image was more tightly focused with the in phase test. Now what? These tests lead me to think that the crossover is causing the phase issue. Is this even possible?

1. Could someone verify that the files above are labeled correctly? They probably are, but this seems like it should be the first step.

2. My crossovers are original from the early 1980s. Could the old capacitors cause a phase issue (any EEs out there)?

3. Could this be an acoustic issue. I am in the process of building polycylindrical diffusers for the front wall, but so far only the right side of the wall is covered with diffusers. Could this cause a phase issue?

4. A component or cable could be wired backwards - How could I verify that the entire chain of componets do not have a wiring issue. I know you can test loudspeakers using a battery, but this would be difficult with Klipschorns since you cannot see the drivers. How about simulating the DC battery test with a DC signal played from a file through my computer. I could turn the preamp volume really low and play a DC signal while the speaker leads are connected to a driver that I could see. The cone should move in the same direction for both the left and right speakers. I do have 18 inch drivers that I could use for this test. I sure would hate to ruin them though. What do you think?

Thanks in advance for any advice.

Dan

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I read this forum quite often, but have only posted to it a few times. I am hoping someone could help me with a phase issue that I have with my loudspeakers. I used these two files to check the phase of my Klipschorn, but the results are backwards. I have better focus when I use the out of phase test.

The logical conclusion is that I have a speaker wire connected backwards either at the loudspeaker or at the amp. I checked both and they seem O.K. Next, I bypassed the crossover and ran the midrange full range. The results were better. The image was more tightly focused with the in phase test. Now what? These tests lead me to think that the crossover is causing the phase issue. Is this even possible?

DANG, I can't find it the nice, informative thread in just the last week or two in which someone tracked down exactly where in one of his K-horns there was ONE driver that was out of phase with the other 5! It took a lot of his time and effort, but he was very systematic and knew exactly how to do it.

IOW, I wonder if your phasing problem comes from a single driver (or maybe two drivers) being out of phase with the others. One driver out of phase is a much more vexing puzzle than whether an entire speaker is OOP. Can you find that thread, SF?

Although you'd think the xover diagram will solve the problem, the +'s and -'s are not always well marked on individual drivers.

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Thank you very much for the link. I read the post and downloaded the Audio SweepGen software. I drug out two subwoofer drivers that were in the closet and will use them to determine if my stereo outputs are in phase. I will hook up one driver each to left and right channel. Then I will play a 1 hz signal. Hopefully, I will be able to watch the drivers and determine visually if they are in phase or not. Then I will follow the same path from the link above.

Stay tuned.

Dan

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Phase check. This is what I did so far.

1. Disconnect speaker leads from Klipschorn.

2. Connect speaker leads to two 18 inch subwoofer drivers. Raw drivers - no box, no crossover, no nothing.

3. Run 1 Hz signal to both speakers. I was able to watch and feel both drivers moving up and down in phase.

4. Reverse phase in the software. Repeat test. Yep - Both drivers are moving out of phase.

5. Disconnect subwoofer drivers and reconnect Klipschorn.

What have I learned? I learned that the output of my system is in phase - from software, soundcard, A/D converter, preamp, amp, and cables. At least the left and right are in phase with each other.

Next step - not sure. I will let you know how it goes.

Dan

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I thought I would report back about the test I have done to figure out if any of the drivers on my Khorn are out of phase.

It turns out that the bass driver on the left channel was out of phase. It was really easy to figure it out. Thanks to Speakerfritz, LarryC and Rod.

Here are the steps that I took.

1. Verify that left and right signal from amplifier is in phase. See above post.

2. Disconnect left and right midrange and tweeter.

3. Position Khorns in corner.

4. Play stereophile Test CD2 Track 2 phase test of Fender bass guitar. It was obvious that the out of phase test was more focused than the in phase test.

5. Reverse leads to bass driver on left loudspeaker. I just guessed about which one to reverse, but the left loudspeaker did not have the original speaker wire and the right loudspeaker did.

6. Repeat step 4. This time the bass guitar is focused on the in phase test and out of focus on the out of phase test.

7. Connect both midrange drivers and repeat step 4. The results are good.

8. Play phase tests from these files. Voice in-Phase [Technical Track] Voice Out-Of-Phase [Technical Track] The results were good.

9. Just to be thorough, I disconnected both woofers and repeated steps 4 and 8 with just the midrange. The results were good.

10. Next, I disconnected left and right woofer and midrange. Reconnected left and right tweeter.

11. Played a test tone to verify that both tweeters were working. Results, both tweeters work.

12. Next, I played phase test from these files. HF 7KHz - oo & Phase Check This test is not as obvious as the bass and midrange test. I am really not sure if I could identify if the phase is correct. It sounded O.K. so I am going to leave the tweeters alone. Besides, the tweeters have a red dot on them from the factory. Per the red dot and the red labels on the crossover, I decided to leave the tweeters alone.

13. That's all there is to it.

I sure enjoy this forum and learn a lot by reading it. Thanks again for everyone's help. Please feel free to add comments.

Dan

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Guest " "

great approach....

I'm surprised that the thread did not get off track with recomendations to replace the capacitors, replace the woofers, replace all the diaphragms, etc.

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Your right. It is easy to get off track. I started to take a bunch of sound pressure measurements. Then after reading Rod's approach, I figured out a real easy method.

Besides, can bad capacitors, diaphragms, etc. emmulate the issue that I had? Beats me, but I am enjoying the Khorns more than ever.

Dan

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