Pink? Noise Tests..... And Tone Uniformity Between Speaker Pairs

[mikebse2a3]

Here is the Barrier Strip installed on the woofer crossover section of the AK-2/3 access door. The yellow/gray wires were soldered to the woofer but with the barrier strip I can still easily remove the access door while still having a good connection to the woofer otherwise.

mike[]

[meagain]

That they sound different from each other is clearly significant and not normal. I may have missed someone else advancing this idea, but I wonder if one driver could be out of phase with the rest in the funny-sounding K-horn. That would mean, of course, that it's also out of phase with the corresponding driver in the other K-horn. That's especially something to think of if the qualities that bother you change as you move around the room.

On the whole, it does sound like an intermittent loss of something.

That's interesting because I received a comment from a visitor on "phase". We bought LaScalas & a CDP from him. Circumstances brought him here to the house for delivery. He never saw a khorn in person nor listened to them so we had a sit-down. He commented VERY favorably on the bass, but said they sounded very bright (harsh) and went so far as to ask if they were out of phase.

That's a pretty strong comment to get about your speakers! Can you imagine? If you visited another forum members house and was so troubled by 'something' that you asked if they were in phase? It really freeked me out considering he had LaScalas, etc. At that time, we attributed it to the amp. But that's a separate issue from the sound dropping out. Maybe.

Mike - I'll crack open the bass bin tomorrow. Mine are 1981's and I don't know if they have pins or not. Since I had/have an intermittAnt problem with a Cornwall woofer, I am starting to believe this could be the cause. A bad wire? Corrosion?

This 'dropping out' problem starts & fixes itself magically. Very weird.

[mikebse2a3]

Lisa said:

Do the different colors test different things? I thought it was across the board. White or Pink tests the full speaker? I wonder if there's some way to select things off. Oh - I can just unplug things from the crossover.

--------------------------------------

Hey Lisa try to find a Test CD that has Pink Noise (or possibly Warble Tones) thats been divided into 1/3 octave bandwidths. This would break the pink noise down into small bandwidths so that you can begin to get a handle on where the differences are between the Khorns. You still need to use good judgement with this test because especially in the lower bands speaker location can make a difference in your perception of the level of the Pink Noise coming from each speaker.

mike[]

[NOSValves]

Just to clarify -- we are strictly speaking the Klipschorns here -- not the Cornwalls, right?

Cornwalls sound great actually. When the one woofer that I need to tend to is working. We wished the khorn highs sounded as pleasing. Weird huh? These Cornwalls have the same sound/tone when the test noise runs thru them. At least compared to the khorns.

Craig! You are surely as stubborn as I. What sign are you anyway? If there is something amiss with one of my khorns as I've been suspecting, and.... surely you must agree that if I'm losing a whole section of music/tones sporadically (which is proof of a problem) - would I not be foolish to ignore it and merely sell them or toss them in the basement? I know you like LaScalas, but they aren't khorns. I'll go to the ends of the earth to retain that beautiful, deep, tight bass here. I cannot give up. Something's mechanically amiss for sure now. What sign Mr. Craig?

Lisa,

I'm not telling you to give up on the Khorns. I'm simply suggesting you eliminate one variable from the equation to see if the problem in upper end and lack of a proper sound stage is solved. Like I said before we can all suggest things till the cows come home but until you start doing some of them this is just going to end up a mass of confusion. Why the heck did you purchase the other speakers if your not going to give them a chance? You can't tell me your not curious on just how well they might do placed as they should be?

Craig

[sfogg]

Mike,

"Hey Lisa try to find a Test CD that has Pink

Noise (or possibly Warble Tones) thats been divided into 1/3 octave

bandwidths."

Just so she doesn't go crazy looking for this but that would be 1/3

octave warble tones, not pink noise. Pink noise by definition is a full

bandwidth signal with equal energy per octave.

Shawn

[Deang]

Doesn't anyone live reasonably close to her that can go over and check out her system for her -- and put an end to this madness?

[meagain]

Just to clarify -- we are strictly speaking the Klipschorns here -- not the Cornwalls, right?

Cornwalls sound great actually. When the one woofer that I need to tend to is working. We wished the khorn highs sounded as pleasing. Weird huh? These Cornwalls have the same sound/tone when the test noise runs thru them. At least compared to the khorns.

Craig! You are surely as stubborn as I. What sign are you anyway? If there is something amiss with one of my khorns as I've been suspecting, and.... surely you must agree that if I'm losing a whole section of music/tones sporadically (which is proof of a problem) - would I not be foolish to ignore it and merely sell them or toss them in the basement? I know you like LaScalas, but they aren't khorns. I'll go to the ends of the earth to retain that beautiful, deep, tight bass here. I cannot give up. Something's mechanically amiss for sure now. What sign Mr. Craig?

Lisa,

I'm not telling you to give up on the Khorns. I'm simply suggesting you eliminate one variable from the equation to see if the problem in upper end and lack of a proper sound stage is solved. Like I said before we can all suggest things till the cows come home but until you start doing some of them this is just going to end up a mass of confusion. Why the heck did you purchase the other speakers if your not going to give them a chance? You can't tell me your not curious on just how well they might do placed as they should be?

Craig

Yea, but I must say, I still have a hard time getting it into my head about the bass playing a role in the mix here. And isn't that what snugging them into the wall/corner does? Improve bass? My issue is in the horns. But I will do this in time. But what is a constant irritation with some harshness in the khorns, pales in comparison to what they sound like when they 'break' (as occurred today). It sounds really really bad when it happens and I feel the need to address that first. And it's got nothing to do with soundstage or my room. It's mechanical. Once I figure that one out, I'll move to my lesser of 2 evils. But for now, something's quite wrong with the guts of least one speaker. I've done every suggestion except for moving the khorns out of the room & putting the LaScalas in their place.

[mikebse2a3]

http://www.testaudio.com/testaudio/audio_test_3.asp

A quick Google Search: 1/3 octave pink noise test disc.

Shawn yes most of my Test CDs are 1/3 octave warble tones and thats why I mentioned possibly using Warble Tones.

mike[]

[meagain]

Doesn't anyone live reasonably close to her that can go over and check out her system for her -- and put an end to this madness?

I hooked up with MarkBK (has rf-5's) by me and he agreed to come over. However, the chances of them 'breaking' when he is here are astronomical. But for the rest of the more minor stuff - that's the plan.

[mikebse2a3]

http://en.wikipedia.org/wiki/White_noise

Description of White Noise

http://en.wikipedia.org/wiki/Pink_noise

Description of Pink Noise

For anyone interested[]

mike

[WMcD]

What is going on is not totally descibed.

Let me point out that broad band pink noise has the same energy in every octave. Broad band white noise has the same energy content at every frequency point. These are analogies to light.

Consider that white noise has equal energy at every point between 400 Hz and 800 Hz (400 points). It also has the same energy at points between 800 and 1600 Hz (800 points). So as you go up an octave band, there are twice as many points, and therefore twice as much energy in white noise, per octave.

Our ear pretty much hears things in octaves. So pink noise is more even in energy distribution. In pink noise, the energy is knocked down as freq goes up. So there is more of the lower freqs which are more "red" per the light analogy.

.Still, broad band pink noise not much of a test signal unless we can listen with a test set up which listens to only one band or narrows down to a narrow frequency range. That is tough at home. What to do?

The answer is to have a source of pink noise which is limited to one band. Our ears, or an RS meter is thereby only responding to the band limited noise which is transmitted by a CD track.. The signal could be limited to one octave of noise. Or maybe it could be limited to 1/3rd octave.

This makes a lot of sense. However, if it is even band limited noise, the sort term output and measurement is bouncy, because the noise is random. That is why RS measurement of band limited pink noise, or even a RTA analyzier is giving bouncing results over time. This occurs when you don't move the meter and mike around at all. Nonetheless, there is an average.

The real question above is just what the heck is going on when speakers in different locations "sound" different with all or any forms of noise or even a constant tone. I expect most of this is the influence of different placement in the room, and the room itself..

I'd suggest that you set your test tones, or noise to feed one speaker. Then move your ear or meter around the room. This is far more easy than moving the speaker and having your ear in one place, but has a similar effect. It is a form of reciprocity.

I sure you'll find that any constant test tone is very much different as you move about.. In fact, it will disapear entirely. You'll find a smilar effects with even band limited noise. There is a woooshing as you move.

I've writen about the above on several occasions. You have to do the single speaker test tone and move about the room yourself to believe it. This is the first "ear opening" test by which you become a believer in room effects.

Smile,

Gil

[mikebse2a3]

Great Post Gil

Thanks for adding more clarity to this type of testing.

It's important to be cautious when using these types of test because of the room's effects on these tests can create misleading results.

mike[]

[DrWho]

Doesn't anyone live reasonably close to her that

can go over and check out her system for her -- and put an end to this

madness?

lol, I'd be more than willing to in about a month (when school gets

out)...I would love to meet meagain (is it lisa?) - she sounds like

such a riot

[LarryC]

...He commented VERY favorably on the bass, but said they sounded very bright (harsh) and went so far as to ask if they were out of phase. That's a pretty strong comment to get about your speakers! Can you imagine? If you visited another forum members house and was so troubled by 'something' that you asked if they were in phase?

It's usually pretty easy to hear if a pair of speakers are out of phase with each other. They seem to fight each other, and their relative loudness changes dramatically as you move from one side to the other -- one can pop in or out of obvious hearing (you have to stand relatively close, not at the other end of the room). In some positions between the two, the "fight" can extend to your left vs. your right ear, and you feel like they're being pulled in different directions.

That mostly doesn't happen if the pair are in phase. I wonder if your visitor asked only because they were bright, or if he had the aural discomfort that out-of-phase causes (it does that to me, anyway).

Drivers out of phase within a two- or three-way speaker can be much tougher to detect and deal with. My formula: I have only one speak on at a time, and move my head back and forth between two drivers at a time to listen for what I described above. Tweeter vs. MR is easy, MR to bass more difficult (it no doubt helps to be experienced in this). Then, do the same with the other speaker by itself to see if it's different. If you feel that one of the pair is out of whack, it may be time to hook up only the two tweets and do the listening thing, then only the MR's, then only the bass horns, to see which pair (if any) fight each other (I've done this many times without damaging an amp, but YMMV). Obviously, reverse the wires only on the naughty driver only in the naughty speaker.

If you can't tell differences any more, you have ear fatigue, and need to take a break for a few hours or a day. Hope this can help sort it out. I agree with the rest that it's more likely an intermittent connection. I'd try to have just the wayward horn to catch what happens to the sound -- both on can be very confusing.

EDIT: Wow, md, I can see how an audio oscillator could really speed up the process!

[meagain]

Mark - I sent an email to hubby to see if his bandmates or techy types at his workplace has an occilator scope. Today I'll try cracking open the bass bin to do the tap/wiggle wire test. I wish they would 'break' more often as it might be 3 weeks before this happens again.

[Parrot]

Craig! You are surely as stubborn as I. What sign are you anyway? If there is something amiss with one of my khorns as I've been suspecting, and.... surely you must agree that if I'm losing a whole section of music/tones sporadically (which is proof of a problem) - would I not be foolish to ignore it and merely sell them or toss them in the basement? I know you like LaScalas, but they aren't khorns. I'll go to the ends of the earth to retain that beautiful, deep, tight bass here. I cannot give up. Something's mechanically amiss for sure now. What sign Mr. Craig?

Now we're getting somewhere! Why won't Craig reveal what his sign is?

[meagain]

Mark - Thanks. I said scope because I thought an oscillator 'was' a scope.

Larry - I'll reread your post again.... But maybe there's more to this phase thing than I understand. It's been my understanding that if all the wires go to the right places, that I'm covered & it's fine. Easy peasy. It's sounding more complicated than that and I have been misguided?

I'm just glad it's now narrowed down better and a slew of things I suspected have been eliminated as culprits. Hubby came home last night and I ran down everything I did when they broke to confirm that it must be the speaker.

About the noise tones (another issue I guess).... I did a quickie pillow test last night while sticking my ear to the horns. All I can hear from the tweeters is a hissssss. At first blush, they sounded the same. But when covering the tweeters, the right squawk sounded higher than the left. Since I did this with my ear against it - surely I can eliminate the room's influence. Yes? I'd think so. I've no clue how to account for it but will recheck the wires for the 100th time.

Going to check the woofer now. Watch, it'll be something crazy obvious.

[Strabo]

IMO this disc should be in every audiophile's library. Sound Check Disc

It is great for checking phase problems. I run tracks 36-40 every time I play with wiring. Those tracks give you frequency specific phase information so you can check woofer, mid, and tweeter phase without disconnecting everything.

If you try to find something similar make sure it has phase testing within different frequency bands. I haven't looked for one in a long time but the price on this website seems a bit steep. I paid less and for the MFSL version.

[Deang]

"Curiously, and Craig knows about this... I have an oddball intermittant issue with a lack of bass (depth), and blazing midrange. Like pure mid. Sibilance all over the place, hissy, snare drum overly insane, etc. This just occurred a 1/2 hour ago when I put in a CD. This makes about the 4th or 5th time it's happened."

I had been under the impression the excessive sibilance and overbearing midrange was there all the time as opposed to something that came and went. At any rate, since you don't have an oscillator, I suggest you just go with common sense.

1) Pull the Klipchorns out, and make sure you have good light.

2) Check for the factory mark on each driver. This is the mark that tells you which lead is "positive". It can come in the form of a X or / (slash) in black or red magic marker, which is typically on the rear of the magnet. The factory mark can also be red fingernail polish on the terminal or solder tab, or even a red, round sticker. With woofers, it's not uncommon to see the mark on the basket or frame. Find the mark for each driver, and wrap a piece of tape around each positive wire. Don't be surprised if you find a wire with the black dashes attached to the positive side of a driver -- human beings make mistakes and that's just a fact of life.

3) The woofers: Start with problem or right channel Kipschorn, and I want you use the HK receiver to do this. To make this easy you should disconnect the tweeters and midrange drivers from the network so you can be sure that what you are hearing (or not hearing) is from the bass bin -- and make sure you have the other speaker turned all the way down.

4) When you get into the bassbin, the wires may or may not be soldered to the tabs. If soldered, there is the possibility of a cracked joint. Even if the wires weren't soldered and disconnects were used, notice that the leadouts from the voice coil ARE soldered. IOW's, there are four connections you have to check on each woofer. DO NOT pull on the voice coil leadouts -- simply play some music -- and gently wiggle each speaker wire, and then reach around and gently move each leadout attached to it's solder tab back and forth.

[meagain]

Woofer & wires seem fine. Everything tight. Wires are soldered to the woofer prongs. I see 2 wires running to these prongs coming from inside the speaker. Voice coils? I was afraid to touch them but they seem connected nicely. I think I can live with this as it doesn't happen often. I saw some corrosion that I flaked off with my fingernail.