Putting weights on speakers?


IME, putting 20 lb ankle weights on my 150 lb speakers greatly tightened and improved the bass and sound overall. Only problem is that the wife hates it... 
mglik
I put 75 pounds of concrete on top of my Mission Cyrus 30 pounds speakers....With great success....

My wife dont have access to my audio room and dont want to either.... :)
I'd be interested to know what speakers this works on.

I've always assumed this had to do with the woofer rocking the cabinet back and forth, but didn't think a 150 lb speaker would have this effect. 

OP:  What speakers are you using??
Wow, I actually thought of putting more weight on them.
It seems the speaker weight is very significant. Wish I had a dedicated audio room but we both listen and enjoy. I just put on the Mad Max soundtrack and after about 5 minutes Nina ran in from another part of the house and demanded I take it off. I don’t blame her. WAF has always been a factor to consider. Especially since she is pretty agreeable to my spending thousands on my “addiction”.
But, mostly, she comes to quickly appreciate and enjoy. I do still love it when she comes over and picks up the record cover to read!
I am using Tetra 606s. It is especially convenient that they are open baffle on the mid and tweeter and have a separate bass cabinet behind. So I am able to put the weight on the back of the speaker. Much nicer than putting weights on the top of a regular speaker.
But maybe I can find a weight that is more attractive than an ankle weight to increase the amount of weight.
Look closely at the design of your speaker. Notice they have a very thick strong and heavy baffle. Its open, but that is their little design hook. Open baffle is kind of a thing lately. Its an opportunity to learn about the tradeoffs of loudspeaker design, I guess.

The change you heard is exactly what I would predict, even without knowing what speakers or how they are designed. Notice mahgister has great results from adding even more mass to his. Whatever they are. Nobody asks mahgister. Interesting....

Basic Newtonian physics, F=MA, force equals mass times acceleration. Our goal is to have the driver move the air while the speaker cabinet remains fixed, so all the sonic energy goes into the air. Obviously if the speakers are just hanging from strings in the air they are going to move a lot, much of the energy gets wasted moving them back and forth instead of moving air, and they sound like you know what. 

That is the ultimate open baffle, you may like it. I can imagine the superlatives. Among them will not be dynamics. All the dynamics will be sucked out. Adding mass to the drivers will restore the dynamics. And detail. Tremendous amount of detail is lost in cabinet vibrations.

So you want to add mass. They already added as much as they could with that big thick front baffle and a woofer cabinet about ten times as big as it needs to be. Still the open baffle design forces them to eliminate the #1 easiest and best thing they could do to improve dynamics and detail and that is reinforce the baffle with a cabinet with sides and back. Oh well. 

So this is your challenge. How to add mass without compromising the sonic and aesthetic integrity of the design.

In a word, you can't. Sorry. But you just can't. Mass would be most effective on top. But you can't put it there because there is no top. Mass would be second most effective behind the baffle. But you can't put it there because baffle shape and size affects frequency response. You could install some struts running from the top corners down to the back corners of the sub cabinet. That would effectively mass load and stiffen the baffle but look like absolute crap.

The closest I can think of would be to make a cast concrete slab several inches thick and shaped to sit on top of the bass cabinet. If done right, tapered and painted, it would blend almost seamlessly with the bass cabinet. To get some idea what cast concrete can be, look at my turntable rack. https://systems.audiogon.com/systems/8367

This would be a bit of a project. But if you put in the time you could make it look good enough to keep the wife happy. Maybe. I know all about audio. Women, on the other hand.....
Just discovered a 8.75 lb vest plate at Rougefittness.com
they are sold in pairs and are black. $56 a pair. I am buying 4 pair for $225. Considering my speakers are $33k, not a big deal. So, would increase the weight from 20 lbs to 36 lbs and have good WAF!
Hi millercarbon,
Thanks for the thoughtful post.
The original design of the Tetra 606 had exactly what you suggest with struts going from the speaker top to the bass cabinet.
I admire your deep knowledge and application in your posts and, certainly, your system. I see the very nice concrete block under your TT. Very attractive. Think the Rouge Fitness vest plates will do the job of mass loading nicely. They are almost exactly the right dimensions. 4 plates would only be 1 inch and 4/16ths and they are black. Have you thought of mass loading your speakers? My speaker designer didn’t like it when I told him but did respect my ears.
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A fun note...

The mass of concrete i added was bricks and slab of concrete... Around 80 pound more than 75 i think... The look is disguised with homemade resonators glued to the slabs... I will lie if this can be described as beautiful.... This look more like a " mad scientist lair" improvised apparatus.... My speakers are modified with stones and cables and little resonators etc.... My little children are baffled by the look tough.... :)
@mglik those Tetra speakers are so underrated you have no idea. You have a great taste.
I have to say I'm surprised that helps at all.  Those cabinets being that heavy and the woofer being low to the ground (relatively) I would not think that was an issue.  I'm curious, when they play, can you feel vibration from the top of the woofer cabinet, or the top of the mid/tweeter frame, without the weight?
I use the same tweeters by the way, and those are phenomenal. :)  It's interesting the woofer is crossed as high as it is.  1 kHz... Hmmmmmmm...
mahgister, what happen's in the audio room stay's in the audio room. I imagine this is the look your wife give's when you explain your tweeks. 🙄
basically you added mass and therefore reduced the natural frequency of the enclosures. 
is there a limit to heading in this direction where the sound becomes something we do not car for?  
example- Magico aluminum enclosure speakers and subwoofers.  
somehow the bass response of these speakers was foreign and disorganized.  the midrange and treble were phenomenal but the bass was horrible.  i suspect that the enclosure was too rigid and actually causing the drivers to resonate.  just a guess.

if we made enclosures from concrete, would the same thing happen?  

i believe we are used to a certain amount of cabinet resonance and like what it does for the sound.  
mahgister, what happen’s in the audio room stay’s in the audio room. I imagine this is the look your wife give’s when you explain your tweeks. 🙄
You are right on the spot.... :)

But she know i love my audio system much then approve me without saying it too much openly....

By the way one of the most precious thing to have is a room only dedicated to the audio system.... With this you can made many improvement which are impossible in a normal room used for socializing reason....

for example for the active acoustical controls:

a- I use a grid of active metal resonator (50)
b- I use 20 Helmholtz bottles of different sizes
c- I use a grid of connected stones and crystals
d- I use a grid of cheap 10 Schumann Generators modified with crystals and stones...
e- I use a grid of 90 little bells or cones of 2 different sizes(7mm or 9 mm)

and many others things like passive acoustic materials etc....

I also has modified all the main electrical grid of my house.... :)
mahgister, your tweaking program is far beyond my comprehension. I'm sure it does wonders!
MAGICO makes some of the best speaker enclosures made and the bass is accurate with the right cables and amp and preamp.MAGICO makes some of the best speakers such as Q3s, M3,M2 these are some of the best speakers with great soundstage,detail,depth, and great bass as well.However there are other great speakers out such as Tidal and Vimberg.
Pour molten lead over the top. Much better than concrete; better aesthetics and makes a strong  connection with the Earth's magnetic field. See page 34 of my recent tome.  
"Pump up the Volume or Weighting in a Rubber Room."
mahgister, your tweaking program is far beyond my comprehension. I’m sure it does wonders!
Without it the same "supposed to be good" speakers i own, Mission Cyrus 781, sound without life at all like all the others one at various degree before this embedding program ( tweaking dont describe the real problem and dont systematically adress it, and the word tweaking betray it)

With this program implemented i started to smile at  any upgrading urgency like to a no more useful dream finally...This is the results of my rightful triple embeddings problem in audio solved with low cost materials: mechanical resonance dimension, electrical grid dimension, and acoustical dimension....Calling it tweaking dont do justice to this very misunderstood problem nowwhere to be exposed with low cost solutions....

It was not like that at all in my journey beginnings 7 years ago, my journey to makes my dream of a true audio Hi-Fi system true.... But i have very little money to make it so then i was very frustrated reading reviews of my dreamed inaccessible components...

I take the task in my own hand, with serious experiments in listenings.... The rest is my history.... In my thread for details and in my virtual system page....

:)
I had twenty five pound barbell plates on my ProAc studio twos and it helped quite a bit with suppressing cabinet resonance 
I'm one of those guys that pull the drivers and rolls the inside with soundcoat and then peel and stick rubber, (very porous), to boot.

Concrete does work well but it's best to use a very course fiberglass batting also..I used a 20 CF underground vault.. Bell shaped...A block of bass. 1500 lb at least..Depends on the drivers..too.

Weight is good...I have a pair at 395 each. Weight is good...They don't rock. I've never added weight. they always were heavy...250 and up..
Bass bins, who knows.. HEAVY....little ones are 200 lb or so..

Regards
I added 25 lbs to the top of my Maggie's but it was one hell of a balancing act!!
Speaking of cabinet resonances and vibrations. I have never put weights on any of my audio equipment.  Reading many years ago that if you can balance a nickel on edge on top of your speakers and play at very loud volumes and not have the nickel move, you're good.  So, of course, I tried it, much to my surprise the nickles never moved.  That's with 24" woofers and 1.1kw of ARC power going to the woofers in a tri-amp system. Left the nickels there for weeks and finally got tired of looking at them. Try it, let me know. Regards, Barts
Mass loading can affect/improve cabinet resonance issues but is not a one size fits all path as it can affect resonant frequencies and will respond differently for different speakers depending on the many design choices made by the designer.
One loading option I have found to improve focus, bass and stability of my speakers is the use of heavy Sound Anchor stands, which they can make for any speaker. Another consideration for more decor-friendly weights are the brass weights from edenSound. Many believe the resonance of brass is musical, and many like the look of brass. However, Dan at edenSound can also make his brass weights in a black finish, like the four black fat boy weights he recently finished for me.
I am trying to adapt this from work.  We used electric motors and bolted them to a concrete base.  The mass of the base was 3-5X the mass of the motor.  The same would hold true for a driver and the enclosure.  If the speaker cabinet is vibrating then that is the resonant frequency.  An accelerometer placed on the cabinet would also tell you what that frequency is.  Another way is to hit the cabinet with a rubber mallet while the accelerometer is attached.  If weight is added to a certain portion of the speaker enclosure that would help but would not solve the resonant frequency for the entire cabinet, I don't think.  It got more complicated with motors if they were mounted on springs, which I think is what you have with a speaker driver.  But in general weight is good, unless you want to move them.
For ~$30:
Reverse some (just longer than speaker to ceiling measure) bar clamps to spread mode. Attach some wood pads to spread out the pressure to the ceiling. Apply fo.Q tape to the pads. It is then easy to apply hundreds pounds of pressure to the speaker assemblies.. AND to remove them if you want soup tonight.
If you have high ceilings live without.
A few months ago I put together a small, simple system while away from home and my TAD Cr-1’s.

The speakers I chose were the LSA statement 10’s from Underwood, which very recently TAS have a great review. I paired them with a Hegel h190 and an old furman power conditioner.

Since the rather small speakers are only 25lbs, I decided to try placing some 8lb neooprene covered hand weights on top.

While the difference isn’t night and day, with the weights on, I get the sense of really listening to a “high end” speaker. Sure I could site a slightly better disappearing sense of the speaker as well as slightly better imaging, but it’s mostly an intangible sense. I wish Steve Stone had listened to the speakers with weights- his review might have been even more glowing.

I especially think with light speakers There is a larger possible improvement (and also 8lbs is almost a third of added mass to 25lb speaker).

I haven’t tried adding weight to my tad’s which are about 130lbs with the attached stands. 

I guess looks don't matter to you ,but they do to your wife.I hope with a 80 lb weight on top of your speakers  you dont have children roaming around ....Really man.or 25 weights.
mglik-
Hi millercarbon,
Thanks for the thoughtful post.
The original design of the Tetra 606 had exactly what you suggest with struts going from the speaker top to the bass cabinet.
Yeah that one's a no-brainer. They will never admit this but its clear to me they got rid of the struts for aesthetics not sonics. 

I admire your deep knowledge and application in your posts and, certainly, your system. I see the very nice concrete block under your TT. Very attractive.

Thanks. The entire rack is my own design. I made the molds to cast the curves. The columns are filled with concrete. Its a modular design, the columns and shelves being bolted together on site. Otherwise the whole rack at 700+ lbs would be too hard to move. 

The top and bottom shelves of cast concrete incorporate sand beds. Concrete and granite are nice and dense and stiff but not very well damped and have a nasty habit of ringing. A layer of sand between them damps the majority of the ringing. Incredibly high damping factor BDR Shelf and Cones takes care of the rest.

The lesson for your situation is its the same but different. Its the same because in both cases, rack and speaker, we want a rigid stable platform. Mass resists motion improving dynamics but releases it back into where we don't want it at rates determined by how stiff and damped the mass is. Stiffness improves transient response but without mass and damping it just vibrates noisily like a tuning fork. Damping lowers the noise floor but sounds lifeless and dull unless combined with mass and stiffness.


Think the Rouge Fitness vest plates will do the job of mass loading nicely. They are almost exactly the right dimensions. 4 plates would only be 1 inch and 4/16ths and they are black.

If you experiment with the vest plates, etc, and listen the combined effects of mass, stiffness and damping will become clear. You will be able to hear it. You will even be able to fine tune your results by tweaking even small things like putting a layer of material between the plate and the speaker. Sorbothane, vinyl, leather, fabric, etc.

Have you thought of mass loading your speakers? My speaker designer didn’t like it when I told him but did respect my ears.

Well, they never do. Anyone designing a speaker knows everything I just explained, and then some. They tried all this same stuff, and then some. They played with wood species, thicknesses, shape, different gasket materials between the driver and baffle, on and on. Then they balance all that against cost of production and consumer acceptance. Finally they have to try and convince buyers the resulting pile of compromises is in fact the absolute best anyone could ever do, period, no matter what. For some strange reason a lot of people buy into this. 

So of course they are not going to like you messing with their masterpiece. At the same time though they want you as a customer. Thus the respect for your ears. Try telling them you sold their masterpiece for Tekton Moabs, see how much they respect your ears then! (That's a joke, btw. But not really.) ;) 

My last speakers were Talon Khorus, and I did think of mass loading them but their tapered shape made it hard to do anything but put more mass in the base, where they were already pretty darn heavy. https://systems.audiogon.com/systems/8367
The Tekton Moabs that are due in a week or so may or may not be another story. Will have to check them out and see. But probably what will happen is, I have gone so far beyond mass loading it would seem like going backwards to be doing that now.


I  put a pair of my 20lb PowerBlock  weight handles I use for working out, on top of my approximately 75lb  Opera loudspeakers.  

I put on a RL Zep II and heard a normally punchy, dynamic recording become somewhat wimpy. My speakers are sealed, spiked on suspended wood floor

The biggest regret of doing this now dumb experiment is I managed to put a ding on the otherwise nice Cherry finish removing one of the weights! I'm naturally an accident prone goofball.

Lesson learned- leave my damn system alone.

The only method to put some weigh on top of speakers is adding the load "incrementally" and listen in between each addition... Then we touch the optimal spot without degrading the sound....I was using myself some slab of around 10 pounds each and after some additions i experiment a dregradation or a stop in the increasing positive effects, i substract the last one and this was job done.....Almost all speakers will gain with this method....

If you put a definite amount of weigh in one shot without adding the weigh incrementally you will not know where is the optimal point....

There is a precise amount of load different for each speakers....

Overdamping can kill the dynamic and the clarity....But no damping most of the times dont gives to the speakers the card he will need to play at the top of his potential....
You would be much better off putting something extremely hard and pointy 🔝 on top of the speakers, you know, like the Totem Beaks, or even better Super DH Cones. For the more adventurous my large size crystal pack works wonders. The idea is to give the stored energy In the speaker cabinet an EXIT point. The energy will tend to go where the hardest material is, the path of least resistance is where the atoms ⚛️  are the most tightly bound. A pathway outta here! 🔝 The same idea applies to tube traps, makes them operate more efficiently. Yeah, baby! 🤗
If you really believe that it is beneficial to put something heavy on top of the speakers and your wife understandably dislikes the look of weights, try finding a pair of something decorative, like marble or granite vases or large crystal balls.
Another approach is DIY some Helmholtz resonators of the correct dimensions and nozzle geometry and put them on top of the speakers as there’s a surprising amount of energy directed upwards from the speakers. 🔝
Uh oh...I sense a project coming on...I have DYI cinder blocks as speaker stands. What if I add more cinder blocks to surround the sides and rear of my speakers?

https://systems.audiogon.com/systems/8722#&gid=1&pid=1


Hmm...my speakers weight more than 400 lbs. each.  I think adding weight would just turn my spikes into nails that I'd never get out.....
I mass loaded my old pair of ProAc EBS out of necessity, as they are just the right height to support a one-inch piece of plywood used as a large display table beneath the windows in our bedroom. The table holds a heavy 28" brass Buddhist statue and a collection of fluorescent rocks at one end and displays some of my tungsten element collection and more rocks at the other. Having the ProAcs on the floor eliminates any chance of imaging, of course, and the bass is now unfortunately exaggerated, but the speakers still fill the room with beautiful music, and the subwoofer I had intended to add to the system ten years ago sits unopened in its box. The added mass improved the sound of the ProAcs overall (with the noted exception of the additional bass boost), and they admirably support the makeshift table. :-)
I know a dealer who has the same ProAc D48 that I have and he has puts some gym bumper plates on them. Instead of doing that, I changed the footers to make the speaker sound better, albeit at a higher price.
A friend bought lead shot. Put 50 pounds on each speaker. He had someone sew velvet bags the fit that space exactly. He is pleased. 
Mike Lenehan of Lenehan Audio developed this same technology maybe 10 years ago and eventually sold it to ETI. Some of you may know who Keith Eichman ETI research?

@mglik I have had them for some years now, and it's well established technology.

Springs under the speakers with "toppers" as Mike calls them makes for good cabinet resonance control and as noted, better bass.



https://www.stereo.net.au/news/eti-and-lenehan-audio-team-up-amg-topper


@maghister -
My wife dont have access to my audio room and dont want to either.... :)
that is brilliant, one day I aspire to have that kind of love..hehehehe
rixthetrick159

She also think that i am the first and last fool that she will love.... :)

My best regards to you....
@mglik - I am sorry I can't tell you what is used specifically.
But a tuned mass with vibration isolation as per the ETI AMG topper is better than simply plonking extra mass on the cabinet.

Of course, that is unless you're supremely lucky and you do actually find a weight changing the resonant frequencies to optimal ones (by pure good luck).


Of course, that is unless you're supremely lucky and you do actually find a weight changing the resonant frequencies to optimal ones (by pure good luck).
Adding 5 or 10 pounds at times incrementally  will gives you the best tuning frequencies with the load....