Lascala cabinet resonance

[Tom05]

The level of annoyance that you experience here may indicate a hearing sensitivity that some people  develop at various frequencies ( hyperacusis ) . This could be at play here , equalization can help in situations like this , but if you’re listening at high enough levels , it will again  become apparent . Not saying that this is your problem , but this is  not uncommon , although it is more prevalent at higher frequencies. I have a sensitivity centered around 2500 hz ,showing up mostly with pure tones . There is nothing wrong with using good eq , after all our perception of sound isn’t likely to be flawless and may even be damaged ,so  it may need a little help .🤓

[Troll]

On 12/16/2023 at 12:34 PM, Flevoman said:

Thanks for the replys

When I switched from the CW4 to the AL-5, there were a few points that bothered me. Now, after trying various amps, adjusting placement, and making other tweaks, most of the issues have disappeared—enough for me to enjoy these speakers. However, there's one point of annoyance I would really like to eliminate or at least reduce significantly. It's a kind of resonance that I can hear in the mid-bass with certain tracks. It sounds like cabinet resonance, but honestly, I have no idea where it might be coming from. Midhorn? Bass cabinet? Or something else? Due to some factors (which would make this a longer story if I were to mention them all), I suspect it might be a form of cabinet resonance. Hence, my question. But from what I gather, the AL-5 should be free from this, according to feedback.

Unplug the top from the bottom to isolate what you are hearing. Also, throw one in your backpack and take it somewhere else and see if you still hear it.  Could be the room. 

[Troll]

On 12/16/2023 at 2:49 PM, mikebse2a3 said:

 

You can see the measurements made by Stereophile here and as can be seen there are some mechanical(sidewall) and acoustical resonances of it’s woofer horn in the 100Hz - 200Hz region that we need to be aware of.

https://www.stereophile.com/content/klipsch-la-scala-al5-loudspeaker-measurements

 

They show using a plastic-tape accelerometer attached to the center of the woofer horn’s sidewall (3) High Q resonances at (~125Hz, ~250Hz, ~500Hz). What signal type and level was used to produce the results aren’t mentioned in the article so how this relates to reproducing music isn’t fully clear for me. How audible and frequent this is in normal use while listening to music is questionable because any potential resonance becoming audible will depend on the exciting frequencies being present in the music and at what amplitude level and length of time applied to the resonance for it to develop it’s maximum audible effect.

 

Regardless of all the causes there is an apparent peak of up to +7db in the frequency response of the La Scala woofer-horn in the region between (100Hz - 200Hz) of it’s spectrum that we should be aware of.

 

IMHO based on experiences having owned both the original La Scala model as well a the La Scala AL5 is that it is very important to pay attention to how we position the speaker relative to (SBIR) Speaker Boundary Interference Response and Room Modes. What we must avoid is any additional SPL increase in this region of (100Hz - 200Hz) due to reinforcement from the Speaker-Boundary distance and Room Mode Coupling. IMHO if proper attention is given to the speaker’s location by again avoiding any additional reinforcement in the (100Hz - 200Hz region) then the La Scala Sidewall resonance potential hasn’t been an audible issue for me when listening to music.

 

miketn

Wouldn’t room correction hear this and minus it out from listening positions?  Might have to play to see though I don’t like what room correction comes up with.  
 

My sense is that speakers are also instruments and all instruments resonate.  It’s part of the experience.  Who wants to hear a non-resonant instrument?  But yea if it’s too loud just pull that peak down. There will be other room peaks to deal with as well as the peaks and valleys in your own set of ears. 

[Troll]

On 12/17/2023 at 6:26 AM, Flevoman said:

I was thinking of using a wedge in the bass cabinet. But you're right, I could also secure a thick plank to the side of the bass cabinet with clamps. Logically, this should reduce the resonance (if indeed it's the bass cabinet I'm hearing) from the side walls.

I was thinking about gluing shag carpet to the sides.  Jk it’s still an idea for a diy set because it was popular in Arkansas when I was a kid. 

[Troll]

On 12/17/2023 at 3:17 PM, Invidiosulus said:

Do you have formation on the reflections and specifically what they caused?

It’s a testament to fine engineering without waste if indeed 0.6 mm actually makes a difference.  I’d probably lose that much over time if a maid I used was still employed here.  She understood elbow grease, but not fine finishes. 

[Troll]

On 12/17/2023 at 11:38 PM, OO1 said:

not so fast ,   one installs braces to tame resonance in the LS bass bin  , but ,  in reality the braces reduce the bass output of the LS bass bin    

 

 

Wait, do you mean if I remove the resonance from an acoustic guitar it will play quieter???

[Troll]

On 12/18/2023 at 2:04 PM, Flevoman said:

I want to share some experiences and thoughts if that's OK, and I'd love to hear what you think about this.

 

Years ago, when I first started this hobby, I had the LaScala 1 paired with the Dynaco ST70 II. Back then, the internet was barely a thing, I had no friends who shared this hobby, and my only gateway to this hobby was a small audio shop that didn't deal with Klipsch or tube amps. Through them and a series of connections, I could gather information or get equipment. Regardless, I was advised to modify the Dynaco with KT88 tubes. After submitting the amplifier, when I got it back a few weeks later, the sound was very unpleasant – dark and with a bothersome resonance (similar to what I hear now but much stronger). I'm unsure if the modification was poorly done or if it was supposed to sound that way, but I increasingly grew frustrated with the dark sound and resonance. It's been so long that I can't remember if there was already resonance before the modification and if it only got worse afterward. In any case, after the modification, the enjoyment dwindled, turning into frustration until I eventually stopped the hobby. I was young, less vocal, had no internet support like now, and the audio shop couldn't help. This led to the LaScala being stored in the garage for years, while I listened to a Sonos set.

 

Now, revisiting this hobby with more resources, I've often read about the LaScala 1's resonance. Every time I read about it, I thought, 'Yes, I recognize this.' However, now that I hear a similar resonance with the AL-5 (though significantly less), knowing that this speaker is not known for resonance problems, I begin to think that the resonance I heard with the LaScala 1 may not have been related to the speaker. Perhaps the Dynaco modification exaggerated an existing issue, but the cause isn't the speaker.

 

So far, this all makes logical sense. But here's the confusing part (at least for me): Before buying the AL-5, I was torn between the newest Khorn or the LaScala. I had the opportunity to listen to the Khorn at someone's home. While listening, I immediately heard something I hadn't heard in all those years – that annoying resonance at precisely the same frequency in a specific song. I only noticed it in one song, but it was unmistakably present. And this is challenging to explain. Is this something inherent to the LaScala/Khorn that I'm particularly sensitive to, or do this person and I share the same issue?

 

By the way, I can best describe the sound as something similar to the boomy quality sometimes found in deep bass in some speakers. The bass tones sound well-balanced, airy, and then at a certain frequency, something goes wrong, and you have a boomy sound. That's roughly how the resonance sounds here and with that person, but in the mid-low frequency range.

I hear lots of notes I don’t like in live performances and it turns out it’s the instrument itself.  Then when amplified it gets worse.  I have been fooled by some EDM that injects bass distortion and thought I blew a speaker.  If you are isolating to a single song you need to also rule out that song with headphones although I suspect you already did.  Ruling that out then certainly room modes then finally yes rap your knuckles, preferably open fingertips on the side of the cabinet and that’s the natural resonance.  If that’s what you’re hearing it’s the cabinet.  But yes like mentions above anything that makes a noise has to vibrate so fast and with such energy you can feel it with fingers for it to be audible across the room.  That’s why speaker guys are always knocking the wood and walking around the units. If you’re like me you’ll start tapping everything in your house to hear the resonance.  A loose window is always interesting though. Watching a subwoofer that is off, moving back and forth because it is adjacent to another speaker is freaky. 

[Troll]

On 12/19/2023 at 1:00 PM, JohnA said:

 

I have 1980 LA Scala's.  It appears to me that the bass horn has 2 minor issues.  The similar Peavey FH-1s I owned and tested had a similar response rise between 100 and 200-ish Hz.  In addition, my La Scala's sidewalls will vibrate, but I didn't notice (and feel it) it until I played "I Don't Need No Doctor" at concert levels.  I'm sure I was peaking over 100 watts.  Later that session I lost 4 subwoofer drivers to heat!  At more sane levels, 100 dB and under, I don't hear or feel anything.  The AL-5 La Scalas can only be better, less resonant at high volumes. 

 

I got to spend 30+ minutes with them alone in a room at the KHMA at Subfest.  Even at quite loud levels, they were polished and refined and threw a stereo image that make mine envious.  Though instantly familiar, I did not notice the "resonance" at peaks easily approaching 100 dB. 

 

Bottom line, everything flexes, bends and resonates, but this is an overstated issue when the speakers are used at home and the resonance can be enjoyable on some music. 

I am looking at a graphic online of how to mix kick drums, the graphic highlights 200-300Hz as muddy murkiness, common to slightly cut this area.  A friend who intended to get kick drum sound out of some big Cerwin Vegas came over and heard my AL5s and said “yep that’s what I want to hear”.  Mind you he has VERY DIFFERENT EARS. 

[Troll]

On 12/23/2023 at 2:21 PM, Flevoman said:

@Khornukopia yes, I have tried different amps. All tubes by the way.

And the warmer the tubeamp

sound the more I can hear it.

 

@mikebse2a3 thank you again Mike 👍🏻.. Unfortentaly I don't know anything about damping factor or what it does. But I will try the 4 Ohm tab just to see if this makes any difference. 

 

@Marvel

If this is true, the more resolving they are, the more apparent it is, how come nobody else recognise directly what I am hearing on my system? Just trying to understand things. 

Think of damping factor as control.  If a big bass signal causes the woofer to punch, followed by nothing, a low damping factor will cause the woofer to swing the opposite direction like a pendulum until it eventually comes to rest at zero.  A high damping factor amp will return the woofer to zero without any reverse pendulum counter motion.  It’s basically a resister on the circuit.  Damping factor at 1Khz on the m-5000 is >=300 at 8ohms.  Some of the Burmester amps have an adjustable damping circuit and report >=1000 at 4ohms.  I will try the above songs on my m-5000 with both AL5 and NS-5000s and report back.  The Yamahas have high slew rate amps. Bringing life to a lifeless song with tubes is the same as choosing cabinet resonance.  Not bad or good but it’s “reproduction as a musical instrument” compared to some other objective. 

[OO1]

2 hours ago, Stephen Buck said:

 I will try the above songs on my m-5000  

 

Edited January 10 by OO1

[Troll]

On 1/4/2024 at 2:28 AM, Khornukopia said:

Sometimes I read elsewhere that folks with uber-expensive speakers wish they could re-create the rock concert sensation at home, and I just have to smile, thinking about how the La Scala does that so well, partly due to the rising bass response and the shape of the bass horn.

FYI the JBL 2226H also has a peak right about there without a cabinet.  I think it’s a function of the woofers themselves. Whether a cabinet hides or enhances it could be the question. 

[babadono]

I'm not a reproduction purist. I do not understand the desire to have nothing between a recording and my ears. We are listening after all to what some recording engineer/producer/mastering engineer and the artist decided we should be hearing. If they are messing with all types of equipment to manipulate the signal(s) recorded why shouldn't I do the same at the reproduction stage if it makes it sound better to me?

[Troll]

8 minutes ago, babadono said:

I'm not a reproduction purist. I do not understand the desire to have nothing between a recording and my ears. We are listening after all to what some recording engineer/producer/mastering engineer and the artist decided we should be hearing. If they are messing with all types of equipment to manipulate the signal(s) recorded why shouldn't I do the same at the reproduction stage if it makes it sound better to me?

***Word*** 

[Troll]

53 minutes ago, OO1 said:

 

Are you typing in disappearing ink?  I can read the email but not the post on browser. 

[OO1]

please give us your results with the M-5000 when you get a chance

[Invidiosulus]

1 hour ago, Stephen Buck said:

Are you typing in disappearing ink?  I can read the email but not the post on browser. 

He edits his posts all the time.

[Troll]

I have to report the YouTube  music video of Chris Isaak Baby Did a Bad Bad Thing did not appear to have any annoying resonance but alas that was the wrong song.  
 

Blue Spanish Sky at :37 has a good solid double speaker output of his voice that has a warble effect on my ears.  I remember vaguely Chris Isaac doing this on other systems.  I think it’s his thing.  I notice the bass also plays near the same or competing frequency for a bit and they together create this dissonance.  If I turn it up and play it over and over yea it kinda gets to me, but at lower volumes it’s a nice room filling deep sound. Engineers can play these games between channels as well to get effects so not sure if it’s by accident or on purpose to get you to recognize Isaac’s trademark sound.  I don’t perceive it as an AL5 error though at all.  I used to make really annoying bass sounds like this as a kid with my sears amp and slightly detuning one string against another.  To me it’s his voice plus the bass together.  I think that’s what you might also hear in a live venue.  For grins I unplugged the top cabinet and can hear the dissonance even more clearly between the bass and his voice.  It’s that warble you hear when two people sing next to each other and one slightly off key.  We used to do that in choir for fun.  Kinda reminds of the sound of singing through a fan.  So yes I think they did it for effects after maybe they at first realized something was off key then decided it was a cool effect anyway.  Is this comb filtering??? 
 

switching to ns-5000s, much less efficient, gone.  Sounds great.  Hang on I have to defeat my max vol for these speakers to hear at same level. Still great.  
 

I switch back to only left AL5.  Gone.  I switch to right AL5, mostly gone.    The annoying noise you hear is the bass bin interplay of the same signal in stereo.  You’re literally hearing the waves coming in from each at slightly offset arrival times or same time but slightly offset per ear.  This is literally what pops needles out of records and why they have to do mono bass on vinyl.  It’s what destroys bridges and Ella Fitzgerald Maxell wine glasses.  Run for your life.  

Now, AL5s are 12 feet tweeter to tweeter, listening is about 10 feet from face.  Ns-5000s are about 80” tweeter to tweeter same distance to listening.  There might be some magic to spacing.  But I suspect the way the bass bin throws the waves is the same reason for the live effect sound and this interesting artifact.  The ns-5000s have a rear port, currently unplugged.  My guess the waves are being distributed in a dispersed pattern I might expect to see some nulls as the front and rear waves collide throughout the room.  But from listening it sounds good.  
 

Now for someone else to do some homework.  Is it the spacing at all?  Is it the pure unadulterated direct bass wave from the horn design with no competing waves except the other channel?  
 

stuck my finger in one ear, then the other, the effect is lessened.  So it’s a combination of arrival time of each speaker to two ears not the same distance. But there’s some other things going on too.  My guess is that the AL5 throws bass in a unique singularity unlike passive radiation.  I think it’s an effect of the horn.  Very fun!

 

I’m too lazy to try the other songs and do all the unplugging and replugging for each, but I have to say our OP is NOT WRONG.  
 

Now whether you think it’s cool or you think it’s a defect is up to you.  I have a feeling chief bonehead and Dave Rat have something to offer for this phenomenon.  

My verdict is comb filtering, and why Dave Rat runs each instrument and singer out of only one line array and not both at concerts.  

Why does the NS-5000 not present the comb filtering of Chris Isaaks voice combing through both channels?  Is it just the dispersion pattern?

[Troll]

System shut down automatically from non-use while typing the above.  I reconnected everything…fired it up again on AL5 all drivers and what do you know it’s gone.  I don’t think I had a speaker plugged in out of phase. 
 

But reverse the polarity on one of your AL5 bass bin connections and see what you get. 

[mikebse2a3]

@Stephen Buck if you have the ability to use Roy’s PEQ of FREQ:148Hz / Q:8 / Gain: -7db then you will hear the excess “emphasis” on the Chris Isaak “Blue Spanish Sky” is gone.

[OO1]

2 hours ago, Stephen Buck said:

 gone 

aint that somethin