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La Scala with a static-ish hum


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Hey All,

New to the forum here. I recently obtained a La Scala speaker. It seems to have a static hum sort of like the radio station isn't coming in really well. But it is not loud and I can hear the music clearly, it just has this hum. I haven't had much time to play with it much, I'm not 100% sure that it is the speaker and not the receiver. The receiver is quite possibly he culprit as well. I don't know the model number just yet, but it is a Fisher, so it is prolly dated about the same as the speaker. I will play with it more to see for sure if it is the receiver or not, but looking for some advice as to what the problem may be if I find that it prolly is in the speaker unit and not the receiver. The reason that I suspect the speaker the most is because it did spend 2 years or more in an enclosed porch in Michigan. Not like where snow, rain, or any weather got to it, but it was not heated whatsover...So I'm sure the components in the crossover didn't appreciate the cold.

The model and serial numbers are LS-BLSw/s and 20T846 and it has a AA crossover. Does this help with putting an age on them? Also I was curious as to what the difference is with the crossovers. I have read on this forum that there are A, AL, AA and what not.

Any help is greatly appreciated,

Eric

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Welcome to the forum.

There is nothing in the speaker which can cause a hum. Save of course for Michigan bees. Smile.

The hum - noise carried to the speaker, like the music, on the speaker feed wires.

Why the amp is creating the hum-noise is a more difficult question.

We should first note that the LS is a very efficient or sensitive speaker. Even small amounts of noise-hum or distortion caused by the internals of the amp (or what is feeding the amp) will be detectable by your ear.

An amp can have noise or hiss just because if its design. But bad power supply capacitor or rectifiers in the amps power supply can cause an increase in hum. In these cases, the hum and hiss does not increase with the volume setting. It is always there in the background. You can try this with the CD player or whatever is turned off or not playing.

If there is a poor connection between the player and the amp, the hum created will increase with volume setting. You have to try twisting the volume knob (reasonably) with the CD player off or not playing. In this case, please check the RCA plug connection and maybe give it a little twist to clear corrosion on the sleeve of the connection. But don't do this if you're using Monster Wire type RCA connections. They are so stiff that any sort of force can damage the relatively weak RCA jacks on the back of the receiver.

You can try another amp and see what you find. There is some chance it has low level hiss just like the Fisher. But it is good to compare and contrast.

In this vein: you describe one speaker. If the Fisher is a stereo amp you can try connecting it to the other channel and determine what there is to be learned.

You can try other speakers or headphones on the receiver. Ordinary speakers might not be sensitive enough to show up the problem.

Someone else will direct you to date codes.

Wm McD

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Probably the receiver.
Speakers don't originate sound or noise on their own; they just pass it on to the listener. On the other hand, they can distort when stimulated to do so. Does it happen when music is not playing, but the receiver is on and set at normal volume? If so, then it is the receiver. When you said "static-ish" it made me wonder if it only happens when the music is playing ... the sound of a previously abused (overdriven) speaker can occasionally sound like something scraping or rubbing, or crackling, and I guess that could sound static-ish. In other components, I've heard of capacitors "motorboating," but I don't know if the caps in the speaker's crossover network are the kind that can do that.
LaScalas are among the most efficient speakers on earth, and it's wouldn't be surprising for them to reveal noise coming from the receiver that doesn't get heard when using other speakers. This noise can happen even with the volume turned way down, if the noise source is between the volume control and the speakers. My Klipschorns & Belle (same efficiency as La Scaa) have passed on noise originating in every amplifier I've ever used with them -- usually pretty subtle, until I got my current AV preamp, which produces very noticeable noise (it has been checked by the manufacturer, and is up to spec). If I turn off the preamp, the power amp produces minimal and barely noticeable noise. That's the price we pay for high efficiency and superb dynamic range, even with a modest amp or receiver.
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No, the reason I have one speaker is because my buddy's uncle got them from his brother and lives in a single wide trailer, so limited space and one speaker roars through the entire house so he had the other one sitting out on his enclosed porch. I was setting up some speakers in my buddies garage when his uncle was there and he mentioned the speaker and that he'd bring it over so it is out of his way, and actually getting used. Needles to say, I took all the other speakers down cuz this speaker is all that is needed to FILL the garage with sound at a very low volume.

Thank you for all the suggestions of my noise. I sort of figured that it wouldn't be in the speaker itself, but just wanted the reassurance before I start tearing into stuff. Like I said previously, I haven't had much time to mess with it so it could be anything...Last night I had some time...(we were hanging out in the garage drinking "soda") and I think it is as simple as being the lack of a good antenna getting proper reception...but not positive on that just yet...but will get to it in due time. Thanks again

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CAUTION! Since you may be having reception difficulties, don't let the station drift out of tune and produce LOUD "between the station noise," or "detuning noise" on either radio or TV! Under the right circumstances, this noise can damage or burn out your tweeter. Keep the volume low until you know the station or channel is tuned in and will stay in tune. Although many FM/AM tuners in receivers have automatic muting to help prevent this noise, some don't work too well, and some need to be turned on. As to TV, I'm not sure if digital transmission made this a thing of the past. Did it guys? All I know is that I damaged a Klipschorn tweeter back in the '90s with this kind of noise --- our TV tuner in the VCR we had then could be detuned by someone walking around elsewhere in the house.

If this caution no longer applies, I'm sure someone on the forum will tell you.

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Just for the record, does anyone know about what these speakers costed in 79?

I'm speculating since it's been a couple days since then. I bought my LaScalas in 1979, unfinished raw birch. I want to say I paid $1,300 (?) but probably no more than $1,500 (?)

Just a guess at this point.

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Cool, thanks for all the info. Another thing though...I read in a few other threads, references to WAF...then one of those threads mentioned that if you hang around this forum long enough you will learn what WAF means...the suspense is killing me. Could someone tell me what it is, especially so I can understand a lot of the posts that mention it??

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Found the main culprit. It ended up just being reception issues. Just needed the time to mess with it. Bought a Dipole antenna and fixed it right up. When was it that Radio Shack was the only place that sold the cheap ribbon T antennas? They seem so basic that you could buy them from Walmart or Target or anywhere. But no, the only place in town was Radio Shack. EVeryone else only had the powered FM/HDTV antennas.

Now my only problem is when I crank it up a bit, the woofer crackles like it is torn, but turn it back down to resonable listening level and it is crystal clear. Any cluesas to why this may be?

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Now my only problem is when I crank it up a bit, the woofer crackles like it is torn, but turn it back down to resonable listening level and it is crystal clear. Any cluesas to why this may be?

Maybe it is torn? Or, would voice coil scraping be apparent only at high volume? Don't know. Do you know how to open a LaScala to look at the woofer? If not, perhaps someone on the forum can tell you ..... Also, are you sure that the crackle is not coming through the midrange or the tweeter?

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You also could have a leak in the LF section...Check the bottom of the cabinet for air leaks.

That does make sense, The cabinet was sitting on an enclosed porch for years with no heat in Michigan weather...the expansion/contraction of the joints could have caused the seal to break. Like I said, low-ish volume it is crystal clear...kinda loud, but low enough to still be able to talk to each other in a 20x20 garage. It's really gotta be cranked to crackle...like ot the point it is too loud in the garage, and the neighbors will surely complain. But with the woofer thumping that hard, it very well could be squeezeing air through unsealed joints in the cabinet...and that MAY be what I am hearing. I figured it'd be something odd like that because usually if the woofer is torn you'd hear it all the time

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If your woofer was sitting outside in winter for many years you might want to think about buying a new one from Klipsh of $150 or having it reconned for about $100. It's easy to pull out from the bottom of the speaker. You probably need a new base panel too. You can use 3/4 plywood for that. Seal it up tight with double stick tape or something similair.

As far as finding di-pole antennas and such at Wal-mart - forget about it. They only sell what is popular now. Try finding items like Chromium cassette tapes, LP cleaner, and the such. Radio Shack even stopped selling individual speaker drivers a few years back. Fortunatly, all the good stuff can still be found on-line. You'll just have to wait a few days and maybe pay a little more to get it.

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