Stacking

NO. 

Full stop. 

Interesting bryston has a t rex that is 2 model t stacked one onto of the other and they use a rubber mat according to factory.enjoy the search

@mark200mph Thanks. I have them under my MK-125 & I'm very happy w/them. I have these under the LaScalas, & helps with the uneven floors.

Yes there are plenty of things that isolate speakers and slow vibration transmission.svs has some reasonable feet put 8 on the bottom of each klipsch and see what happens.this experiment would cost you a few hundred dollars.you could always use these somewhere.enjoy the science.

@lanx0003 good point!

I was thinking between the fireplace & the speaker, where the MK subs & my networks sit.

Not wise. 

The subwoofer generates strong low-frequency energy and vibration, which can transfer to the speaker and create additional resonances that interact with the speaker’s own natural resonance. Additionally, the La Scala is 40 inches tall, with the horn located around 33–34 inches—right at typical ear level when seated. Placing it on top of a subwoofer would raise the tweeter and upper midrange horn above the ideal listening height, potentially affecting the speaker’s imaging and soundstage precision.

Over time, the continuous vibration can compromise the structural integrity of the speaker cabinet. By the time cracks appear—either internally or externally—it may already be too late to prevent damage.

Thank you for the reminder. This makes me realize that next time I’m considering a used pair of speakers, I should ask the seller whether they’ve been placed on top of a subwoofer for an extended period.

Lastly, the ideal placement for a subwoofer is not necessarily directly beneath or near the speakers. Experimenting with different positions is key to seamlessly integrating the sub into your system. Limited space should not be an excuse — it may even be possible to place the subwoofer along a side wall.

Right now, I have not run all HT wires under the floor, so my subs are stacked in the corner. It works, but it's not optimal. DSP helped, but they need to be moved. 

What did help was putting isolation pucks under both subs, decouple the subs from each other and the floor. 

From what I've been gathering is, I would need a larger sub than the Tuba 24. People have been suggesting the table Tuba. With that unit, I haven't any room upfront. Right now my LaScalas are 9.5 center. If I add the bass units up-front, that would make the LaScala s 7' on center. That would be my best bet ,I guess. 

@danmar123 Wouldn't smaller subs remedy the need for stacking?

I would never stack speakers on top of subs!! Way too many vibrations going both ways. If space is limited put the subs next to the speakers or stuffed in the corner of the room. Put them next to a couch or chair and stick a lamp and a plant or some coffee table books on the subs. Blocky end tables. 

Thank you for your post.

I think I'll have to buy a bigger home. LOL

I hear people have been having success in putting their subs behind their listening position. Just a thought.💭 

Yes, negative effect(s).  Perhaps too numerous and/or unknown to list here.  To include possible instability of a large objects.  Best of luck on a viable solution.

@larryi , I'm using the altec 311/60 & Fostex 925 horns. So I can dial in per say the directions of the horns.

@abnerjack That's the reason of my post.

 Thanks 

I would think the vibrations transmitted from the sub would have a negative effect on the speakers.  Maybe build some sort of stand to isolate the speaker from sub.

It is hard to guess what will happen.  For one thing, you will now be seated much lower with respect to the height of the drivers, particularly, the midrange and tweeter.  You might have to angle the speaker downward to restore the same axis to get the right frequency balance and timing of sound arrivals from these drivers.  The woofer of the Klipsch is now higher off the floor and will be loaded differently and it will be delivering a different sound.  The path of the sound from the various drivers to the floor and then bouncing up to your ears will be lengthened, and this will affect how that sound and the direct sound from the speaker will interact.  The floor-bounce effect, and sometimes ceiling bounce effects are figured into the design and voicing of speakers; some manufacturers even figure this into crossover design.

You will just have to experiment and perhaps change the placement of speakers and/or the listening position and mess around with other aspects of system tuning to get things right as would be the case with any major change like this.  It

probably can be made to work.