LaScala AL5 Noise

[Kingdeezie]

Hello Klipsch Community, 

 

I just received a pair of LaScala AL5s in American Walnut. I am simplifying my set-up and wanted something with a known history of reliability and quality. Only have like 15 hours on them and have done minimal placement work, but WOW! I can actually enjoy all of my recordings! 
 

I noticed one problem last night however. When I was turning off the system and got closer to the speakers with nothing playing, I could hear a “hiss” or a “white noise” coming equally from both speakers. Having heard it now, with nothing playing, I can’t un-hear it. It’s faintly audible like 7-8 feet away on axis. 
 

I muted the preamp and still heard it, which I think means it’s not before the preamp’s input stage. 
 

I think it might be my amplifier. It’s a Pass 350.8. Complete overkill for a speaker that is 105 DB, but I have to sell my old speakers to recoup some cash before changing. 
 

The odd thing is when I first plugged the LaScalas in, I don’t think I heard it. Yesterday I played the system for 10 hours straight, so maybe it’s thermal noise from the Pass?
 

Internet searches don’t bring much clarity.
 

I guess my questions for the community here are:

 

1) Has anyone experienced this before with any of the Heritage high efficiency designs? 
 

2) Is the noise potentially damaging to the speakers? 
 

3) How can I rectify the issue? I thought that Pass amplifiers had a low noise floor. It never was a problem before with my normal 88-92 DB speakers.

 

Thanks all. Overall really happy so far with joining the Heritage family. 
 

 

[OO1]

 nothing to do with the speakers ,  although  the crossovers  are  breaking in for at least 100 hours  ,   the main issue seems to be the Pass amplifier 's  gain level  or a  ground loop  issue     ,   question   ?   are you using the  XLR inputs   

 

  swap  the speakers with another pair , re- test .   that will confirm the source of the hiss 

[babadono]

Can I hear a little hiss from my highly efficient horn speakers? Yes. It is called Gaussian noise. It is caused by the random movement of the atoms which is the left over energy from the Big Bang. Does yours not get completely masked when there is signal? It should. This white noise hissing is completely different than a hum or buzz which can be caused by ground loop problems or Common Impedance Coupling of equipment.

[Kingdeezie]

Thank you for the feedback. I haven’t listened today but just did some quick testing. 
 

Hiss is there with just the amplifier on (nothing hooked up to it). 
 

Hiss seems slightly louder when preamp is hooked up and on also. 
 

Hiss is audible right on top of speakers, less noticeable at 1M, barely perceptible at listening position. 
 

When I’m up on the speakers with my ear right on the horn, I hear a very slight hum. I guess this could be a ground loop but it quickly drops off when moving away from the speaker. 
 

Hiss doesn’t seem to change with volume.

 

When music/movies/games are coming through the speakers I don’t hear anything but the signal. 
 

I doubt it’s the speakers. At 105 DB per watt I think a mosquito farting near the speaker cables would be audible. 
 

My last speakers were 88 DB per watt, so it’s quite the delta in efficiency. Just haven’t heard any noise like this with this equipment. 
 

 

[pnort]

It's your amplifier. Try one with less power or lower noise.

[Peter P.]

Interesting problem. But since the noise is not detectable while listening to music, it should be a non-issue.

 

But the question remains; are amps supposed to be totally quiet when no signal is fed in to them?

 

As an experiment, I just turned on my stereo, with its Yamaha 80W/ch integrated amp and Heresy speakers, and switching to an unused input, turned the volume up to maximum. Surprise, I hear hiss! But it's at such a low level I have to place my ear directly in front of the tweeter to hear it.

 

Maybe other forum members could try the test and see if ANYONE has a completely silent amp. I'll bet no.

[sixspeed]

As others said it's the amp and/or it's gain setting if yours can be adjusted to lower. I'm not familiar with that model from Pass.

 

I went through a lot of solid state amps, integrateds and surround pre-pro combos before I found the quietest, best sounding amp and digital front end. It had to be dead quiet at the MLP at the very least. It cost me a lot of money and 3-4 years of trial and error but loving the sound of heritage and being invested in my speakers I wanted to get the most from them and have them be completely inaudible hiss wise. I ended up with a noise floor where I can't hear any hiss at all from drivers unless you put your ear up against the tweeter on the grille on all my speakers.

 

It's tough because some pre's are also far too noisy to be ideal for use with any high sensitivity horn as well. Some people don't mind it (vintage gear) especially if they can't hear it when playing but it personally bothers me and IMHO a great system should be technically sound from a noise standpoint and not only sound good when playing.

 

LS and KHorn are very similar, although my drivers are the gen prior to yours and equivalent to the LS II, but same sensitivity.

 

For 2ch, the quietest SS integrated I have used so far is the McIntosh MA5200 which sounded both incredible and was dead quiet. The Bryston 135 performs similar as I have heard the power amp section used in that amplifier in another Bryston product.

 

Overall I got the quietest noise floor, sound quality and dynamics with Bryston amps. For Heritage all you need is their "2" series amps like the 2.5b. I briefly had a 4BSST2 (300W/ch into 8ohm) in my system in 2ch which was dead quiet as well although I sold it when I went converted my system to multi-ch for mixed use.

 

Their vintage amps are nice too. Even the old 60w/ch 2B-LP Pros would sound great with a LS. Well engineered and designed Class AB I find has the best traits of Class A and Class D.
 

If you are into more of a warmer, more laidback sound then you might be more into something like a Luxman.

 

If you wanna try something cheap, the Schitt Vidar II is really nice and is 100w/ch into 8 ohms stereo. Very quiet.

[Islander]

On 7/2/2023 at 8:40 AM, Kingdeezie said:

Hello Klipsch Community, 

 

I just received a pair of LaScala AL5s in American Walnut. I am simplifying my set-up and wanted something with a known history of reliability and quality. Only have like 15 hours on them and have done minimal placement work, but WOW! I can actually enjoy all of my recordings! 
 

I noticed one problem last night however. When I was turning off the system and got closer to the speakers with nothing playing, I could hear a “hiss” or a “white noise” coming equally from both speakers. Having heard it now, with nothing playing, I can’t un-hear it. It’s faintly audible like 7-8 feet away on axis. 
 

I muted the preamp and still heard it, which I think means it’s not before the preamp’s input stage. 
 

I think it might be my amplifier. It’s a Pass 350.8. Complete overkill for a speaker that is 105 DB, but I have to sell my old speakers to recoup some cash before changing. 
 

The odd thing is when I first plugged the LaScalas in, I don’t think I heard it. Yesterday I played the system for 10 hours straight, so maybe it’s thermal noise from the Pass?
 

Internet searches don’t bring much clarity.
 

I guess my questions for the community here are:

 

1) Has anyone experienced this before with any of the Heritage high efficiency designs? 
 

2) Is the noise potentially damaging to the speakers? 
 

3) How can I rectify the issue? I thought that Pass amplifiers had a low noise floor. It never was a problem before with my normal 88-92 DB speakers.

 

Thanks all. Overall really happy so far with joining the Heritage family. 
 

 

 

1)  Yes, it's totally normal.  The hiss was always there, but your previous low-sensitivity speakers couldn't pick it up.  This is why it's important to have very quiet electronics with high-sensitivity speakers.

 

2)  No, the faint noise will not damage the speakers.

 

3)  You can do a search to find out which amplifiers and other electronics upstream from your speakers are very quiet.  However, as long as you can't hear the hiss at your MLP (Main Listening Position), it's not important and can be ignored.  In the case of my stereo, the speakers are bi-amped, with one amplifier for bass and one for treble.  There is a faint hiss from the speakers under all conditions.  It may be a bit louder when the turntable is selected.  The main thing is that it's inaudible at a distance of 1 metre/yard from the speakers, and is completely inaudible at the MLP.  And of course, you won't hear it if your music is playing at a volume level any louder than the faintest whisper.

 

The extreme sensitivity of the La Scalas reveals the faintest noise that is piped into if from your electronics, but in the same way, the faintest details in the music become audible, something that less sensitive speakers are unable to reveal.  As an example that I've m mentioned here once or twice, on the Jimi Hendrix album Electric Ladyland, during the song Rainy Day, Dream Away, there is a spoken sentence:  "Do you know what I mean?".  This is a song that I'm very familiar with, because I've heard it since I was a teenager.

 

After I installed the big K402 tweeter horns and the new (new at the time, anyway, 2019) K-691 compression drivers, sometime later I popped on this old familiar record and listened casually, and I heard Jimi say, "Do you know what I mean, brother?"  Wow!  The "brother" was faint, but it was there.  It had always been there, of course, but finally the system was able to reveal it.

 

I don't know what kind of music you prefer, but suffice it to say that your AL5s may show you details that will not only let you hear what you had not heard before, but with some recordings, they will also give you a better sense of being there, one small step closer to reality.

 

As for amplifier hiss, it doesn't seem to relate to the amp's power.  a 3 Wpc tube amp may be noisy, while a 500 Wpc solid state amp may be quiet.  In the case of my system, the power available at each driver is 500 watts, so that means 1000 watts per side (500 watts per woofer, 500 watts per tweeter).  That's the power available, but not what's normally going through, since in a normal-sized room in a home, most of the time less than 5 watts are going to each speaker, and more than 40 or 50 watts will drive everyone out of the room, to save their ears.  La Scalas seem to be happy with anything from 5 watts to 500-1000 watts, as long as the signal is clean and you use some common sense with the volume control.

 

Finally, welcome to the madhouse, err, Forum!  It's a good place to learn and share audio and music info, and maybe make some friends.

[Kingdeezie]

Thanks everyone for the input. I’ll start looking in to amplifiers that will be a little quieter. 
 

[JohnA]

'Deezie,

 

I had a similar problem with some old Parasound power amps.  The cure was turning down the amp's input gain controls. 

 

Contact Pass Labs.  Mr. Pass is well aquainted with Klipsch and horns.  I believe they will adjust your amp to reduce or eliminate your hiss.  Then, you can keep what I'm sure is a wonderful sounding amp. 

[henry4841]

Short the inputs on the power amp and see if you still have the hiss. If so it is your amp. Passlabs has one of the best warranties and customer support as any company I know. If the hiss is present with inputs shorted I would give PassLabs a call. 

[Kingdeezie]

Thanks for the suggestions! I tried the amplifier with nothing plugged in to it and the hiss was still present. 
 

I don’t think there is a way for the user to turn down the input gain, I would likely have to send the amplifier back to pass. 
 

As long as the hiss isn’t harmful I don’t know if I’d be pumped to send 150 pound (double boxed up) amp back and forth from the factory. Too expensive and risky for a quieter noise floor. 
 

I’m just assuming that the amplifier wasn’t made for something that efficient. My whole system was dead quiet before with speakers that were 88/1 watt. 
 

The combo does sound good. 

 

Edited July 6, 2023 by Kingdeezie

[henry4841]

That amp should not hiss with our speakers. That is a monster amp and I understand the reluctance of shipping it these days having gorillas handling it. The inputs do need to be shorted for testing to see if hiss is internal or just picking up hiss on the input. Something like these work. Pass will want to know if and when you ever talk to them. 

 

https://www.amazon.com/VANTRONIK-shorting-Terminators-Reducing-Insulation/dp/B0833S6X1B/ref=asc_df_B0833S6X1B/?tag=hyprod-20&linkCode=df0&hvadid=459618435588&hvpos=&hvnetw=g&hvrand=8605458350157429580&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9052440&hvtargid=pla-942094768696&psc=1

[Troll]

I’ve never heard a high power amp with no hiss.  It’s a thing.  You don’t need 350 watts for a 100 watt speaker, that kind of power for the AL5s, even if you put club grade woofers in, but if you think you do then you’re playing loud and noise floor is not an issue because you have giant HVAC and a nice crowd and bottles and glasses clinking.  
 

Go for an amp that produces legit specifications and communicates the noise floor like Yamaha which is very quiet, try the M-5000 you’ll love it!  I can vouch for them I have two with my AL5s.  Dead quiet, even in dual mono bridge mode.

 

https://usa.yamaha.com/products/audio_visual/hifi_components/m-5000/index.html

 

Here’s the manual: https://usa.yamaha.com/files/download/other_assets/0/1228260/web_VAQ1880_M-5000_om_U_EnFr_a0.pdf

 

If you can hear it then I’m just deaf.  Hold your ear next to a tweeter long enough you won’t hear it either!

 

PS I have seen people go to great lengths to clean up their power line noise for amps that failed to do it internally.  Get the right gear and it will work everywhere. 
 

PSPS I don’t need two amps I was just experimenting.  If the 2 channel amp is too powerful it messes up the levels for the other 9 channels.  Any ole amp will run you out of the room with AL5s.  

Edited July 6, 2023 by Stephen Buck

[OO1]

2 hours ago, Kingdeezie said:

 nothing plugged in to it and the hiss was still present. 
 

I don’t think there is a way for the user to turn down the input gain, I would likely have to send the amplifier back to pass.  

 

no doubt ,   the amp has a defective component 

[Kingdeezie]

2 hours ago, OO1 said:

no doubt ,   the amp has a defective component 

What defective component would cause the same exact sound/level of hiss through both speakers? 
 

4 hours ago, henry4841 said:

That amp should not hiss with our speakers. That is a monster amp and I understand the reluctance of shipping it these days having gorillas handling it. The inputs do need to be shorted for testing to see if hiss is internal or just picking up hiss on the input. Something like these work. Pass will want to know if and when you ever talk to them. 

 

https://www.amazon.com/VANTRONIK-shorting-Terminators-Reducing-Insulation/dp/B0833S6X1B/ref=asc_df_B0833S6X1B/?tag=hyprod-20&linkCode=df0&hvadid=459618435588&hvpos=&hvnetw=g&hvrand=8605458350157429580&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9052440&hvtargid=pla-942094768696&psc=1

Called Pass and believe I spoke with Kent. Very helpful. Wanted me to short the cables to isolate the amplifier output to see if the hiss was still there. Much like you described above. 
 

He thought, given the 105 DB efficiency, that hearing hiss from a short distance (inches) away might not be unreasonable. 
 

Ironically “downgraded” to the LaScalas to simplify my life and just start enjoying the hobby instead of obsessing. 
 

Now down another rabbit hole. 
 

Thanks for the help all.
 

 

[Troll]

1 hour ago, Kingdeezie said:

What defective component would cause the same exact sound/level of hiss through both speakers? 
 

Called Pass and believe I spoke with Kent. Very helpful. Wanted me to short the cables to isolate the amplifier output to see if the hiss was still there. Much like you described above. 
 

He thought, given the 105 DB efficiency, that hearing hiss from a short distance (inches) away might not be unreasonable. 
 

Ironically “downgraded” to the LaScalas to simplify my life and just start enjoying the hobby instead of obsessing. 
 

Now down another rabbit hole. 
 

Thanks for the help all.
 

 

Pass from my understanding does not claim to be the cleanest/quietest/most accurate amp offering.  The popularity, because Nelson plays with all sorts of amp designs as chips and tubes come out, is that people like the low damping factor and coloration of the sound, and I would classify his work as a craft more than a science, especially with his stockpiles of older components.  He might actually have a super clean/quiet/accurate amp offering because he plays with so many different amp designs and they do sound different on purpose in a crafty way.  

 

It's not right or wrong, good or bad, but from what I have seen with buyers, high power amps among hobbyists go with low efficiency speakers to achieve something, whatever it is.  Maybe the lower efficiency speakers hide the high noise floor of some amps.  Maybe it is high spl without breakage, or something else.  The low ohm speakers were originally designed for 12v car systems because the high voltage just wasn't available but the amperage was.  

 

All I know is I can buy high efficiency high wattage 8ohm woofers and compression drivers and they are usually more pricey than low efficiency lower watt low ohm varieties.  So I just haven't seen anything yet that points to the need for low efficiency speakers unless copper winding prices are high (more winds/length increases ohms) and the goal is to produce a cheaper speaker.  High power amps usually just drive more drivers/speakers at the same time, in parallel would mean lower ohms, series higher ohms.  If I was a manufacturer and my target audience was product abusive I might try to make speakers that are really hard to break, and that might cause me to choose materials that result in less sensitivity and/or create the distortion that people like similar to guitar amps that they can crank to distortion and yet won't break.  

 

Anyway for what it's worth this is just as confusing as car brands and performance upgrades.  Buyer beware because there are paths people take with mechanics and sales that can cost a whole lot of money with no measurable gain except the notion of exclusivity and fame, and of course just keeping a friend in the business.  I had the same feeling of stepping off the diving board a couple of weeks ago when I needed to replace tires that didn't last 30K miles and I wasn't going to buy that model/composition again....the ole tire hardness/grip/longevity battle.

 

We have all been the person with little time running to the store/online and buying out of excitement and haste only to have buyers remorse and perhaps remembering something someone said that we ignored.   So I think you put Prius tires on a Camaro but that's not really a fair statement when it comes to audio.  Maybe you put guitar wires on a bass, or bass wires on a guitar.  Best luck getting the setup you want!  Maybe your HVAC isn't loud enough.    But since the 80s when I bought my first Klipsch, it was Klipsch/Yamaha or Klipsch/McIntosh, or Klipsch/Denon.  My first combo was Klipsch/Denon and part of the sales process was to show me the low noise floor and I went to college with it and showed all my buddies to their amazement.  Signal to Noise ratio was all the rage when CDs were new.  That's all I know man!  It seems that was not the final argument though because many brands continue to sell with high noise floor, in trade for whatever they do.  Party on!

 

Just like a reputable car and mechanic shop though, your seller should let you swap out without a lot of trouble, just enough to cover the transaction/inventory holding/turnaround profit.  Since you have played with higher end gear, they should know you're not done yet, so they should want to make you happy today, in hopes of future purchases and good reputation.

 

 

Edited July 6, 2023 by Stephen Buck

[Kingdeezie]

Stephen, 

 

Thanks for the feedback. The Pass 350.8 is a hold-over from my previous speakers. They sound excellent but require the power. 
 

I knew I was going to have to eventually replace it as 350 watts is overkill. My system was quiet as a tomb before. Zero noise. 
 

I didn’t anticipate the 17 DB increase in efficiency would bring issues. I intend to keep the La Scalas, just will need to sort the amplifier situation out sooner rather than later. 

[OO1]

1 hour ago, Kingdeezie said:

What defective component would cause the same exact sound/level of hiss through both speakers?

He thought, given the 105 DB efficiency, that hearing hiss from a short distance (inches) away might not be unreasonable. 
 

 

 

very hard to pinpoint a hiss without testing on a bench + instruments , rough guess here  ......  a faulty component in the Power Supply  section .  which is an easy repair .

 

as far as the 105dB efficiency , all amps no matter the brand can handle 105dB efficient speakers , this does not cause  issues with a quality amplifier unless the amplifier has technical issues .

 

[Coytee]

Have you *actually* used a shorting plug on your inputs yet?

 

I read above and didn't ascertain that you actually did it.  perhaps you did....my wife says I'm too picky on the word someone uses and I don't read between the lines.

 

Anyway...  I had a similar issue and ended up with some amps that have variable gain so I could lower the gain and lower the noise.  When I discovered my issue, I had a dbx BX-1 which has a 1volt input sensitivity compared with (I forget) something like 2.25 with a McIntosh amp I also had.  Again, I forget the actual number but the dbx amp was a high strung amp!

 

Now, you can put your ear inside the tweeter and not hear any hiss BUT, I've got the gains turned to about 25% of their range.  I don't know what that infers the input sensitivity might now be.  I'm guessing you know this but, it's not your speakers.  It's the diet they're being fed.