I think a sub would be fine on a concrete floor (with carpet or wood finishings) which is what you have, right? If possible it would be good to get it off the ground though as you will always get a mode just being near a single wall. As long as the sub is on something very solid, it should be able to go really wherever it sounds best. A concrete slab wouldn't hurt if that turned out to be the best position.

Would the water in a bowl exp really pick up that much? Would just touching give you enough of an idea? I really have no idea. Interesting idea though.

So on the sand stands, how do you guys like to make them? When I eventually make mine, I liked the idea of using two square sections of hardwood with a plastic pvc pipe as the 'stand' with the squares on either end. But then use a long threaded rod which fits inside the pipe and bolts onto the hardwood ends. Fill her up with sand (after you put in the metal threaded rod) and then tightly screw the top hardwood plate on top. Maybe use some gap filler on the base before the sand to prevent possible leakage. Paint the pvc pipe so it looks pretty (or go with black) and you're done!

That's the way I have always thought as most promising.

I hadn't thought about using PVC for stands...maybe ABS would work better, being more rigid?

But it seems to me that getting the subwoofer up off the floor should be a good idea.

Putting the sub on the floor can be just fine. The operating word being can. Not will. Have you hit chapter 13 in Toole's book yet?

Here is an interesting article on the use of granular material in heavy structures like machine bases.  The intro of the article gives a brief description of plausible mechanisms (from references) for vibrational damping (IMHO the discussion is not comprehensive or even completely coherent but it is thought provoking).

The article is addressing issues associated with large structural components but I think the principles apply.  Additionally, the modeling work showed that damping could be achieved using a low density fill versus the traditional high density fill (i.e., sand are steel shot).  The differences in the mechanism of the damping between the high and low density material is discussed in the conclusion.

http://www.mit.edu/people...lar%20media_spie02.pdf

I’ve pulled a few quotes from the introduction of the article dealing with high density fill material such as sand or metal shot:

“In these studies involving relatively large, high-density particles, the damping mechanism is strongly nonlinear because it is the result of impacts and sliding among the particles.”

“Cremer and Heckl suggested that a granular material can be modeled as a continuum, and that damping in a structure filled with granular material is facilitated by the relatively low speed of sound of the granular material. According to their model, vibratory energy in the structure is transmitted into the granular material and dissipated within it.”

“Wave propagation and flow of granular materials has been an active research area for many years. Nearly 175 years ago, Faraday studied the interaction between a vibrating body and a granular material and found that heavy particles move to the nodes of vibration, but light particles move to the antinodes. Such low-density particles were found by Fricke to produce relatively high damping, which he explained by radiation of vibratory energy into the granular material, as originally proposed by Cremer and Heckl.”

Putting the sub on the floor can be just fine. The operating word being can. Not will. Have you hit chapter 13 in Toole's book yet?

Coincidentally, chapter 13 was the first chapter I read (I often jump around in a new book before turning to page 1 for a proper read). My takeaway from that chapter was the use of multiple subwoofers to mitigate resonant nulls, a concept I wouldn't have put much stock in before reading that chapter.

But I didn't recall him addressing this topic specifically. I intend to re-read chapter 13 (probably more than once!) In the meantime, can you cite a specific page or section?

Seems like every time I come to the forum this discussion is on top.

I know I poked a little fun earlier, but I honestly think this is an interesting discussion and am impressed by the open, insightful dialog.  (Honestly, I feel bad now about the Greek columns remark.  It was meant in fun, but could've been taken as disrespectful.)

mike_mccue


I like the columns illustration.

:-)

Me too, I'm actually thinking the fluting up the length of the columns might play a significant part in dissipating vibrational energy too.

I could go surround and build a marble plinthed coliseum too.

Convex or concave flutes?

Hmmm... I'm going to need to resort to reliable testing in the end I just know it, because now until I do my ears are going to tell me strange things.

Why can't science be as much fun as hocus pocus?

droddey


What we really need are 'active stands'. So the signal goes through a box that splits it and sends the signal on to the speakers but also does a super-high speed analysis of the signal and decides how it's going to affect the stands, and engages piezo electric actuators under the speaker to make corrections to the speaker position, so that it remains absolutely still and vibration free.

You'd have some test tones and use a simple laser interferometry system to measure your stand's reaction to various types of signals in order to train the system.

sounds like you're onto something there, dean!  patent that idea before you post it in a public forum!  sheesh!

Hey Jeff, I'm really disappointed that after all the discussion about resonance that you insist that your conclusion is that weight is the primary factor.

If weight were the only factor why wouldn't you use the steel stands?

Concrete weighs approx 150 lbs/cu ft.

Steel weighs approx 490 lbs/ cu ft

Sand ranges from apprx 100-130 lbs/ cu ft.

Want to guess about gold? 1204.

The subwoofer in my mix room sits on cast iron legs that were meant to be the foundation of a cast iron wood stove. (450 lbs/cu ft.)

I like that because it gets the sub about 15" off the floor... and it's looks sharp because they are coincidentally sized to match.

Personally, I'd feel awfully foolish taking my satisfied experience and extrapolating a recommendation to others. There's no real info to work with.

What you are telling us is that after several years of your offering opinions based on your opinion that you have golden ears is that you had no idea what your monitors were doing and that you just now got around to doing something about what was apparently dreadful bass response. Do you perhaps remember engaging the -2dB low shelf?
 No wonder all you ever spoke about was high frequencies, panning and phase issues. It reminds me of when I was a stereo junkie in the 70's. We were all preoccupied with high frequency response and stereo accuracy and stuff like that. Later I learned that music happens below 10kHz and that emotion happens in the low mids and that's why I've been interested in detail and beauty in the lower mids for the past 20 years.

It's comforting to think that in the future your opinions will be based on having a better listening environment to reference.

With regards to your intention to AB test concrete vs sand. Please DON"T! If you are not going to ABX test than you'll just be presenting unreliable information to an already confused audience.
 
I don't like to seemingly harass you, but I am disturbed to think you might present your opinions unchallenged in your roll as a professional music instructor. I hope you'll consider the ideas we have been discussing about resonance and perhaps the comments about reflective surfaces and incorporate them into your understanding before you tell the next generation that you have concluded that heavy weight is the primary characteristic that effects performance.

What many here (including myself) have told you is that they have thought much more deeply about this subject than you have and they have lots of experience setting up and listening to systems and yet they are unwilling to draw conclusions.

best regards,
mike




PS: "If I can get my hands on either a light weight stand"

This is getting incredibly confusing. Didn't yo have a light weight stand?

Come on Fess up, you have avoided telloing us what your monitors have been mounted to in the past. You've implied it wasn't a shelf, desktop, console, top etc. So that left me thinking you had some sort of stand. Were the speakers on stands? Or was it a pile of books?

I think we deserve some clarification here... and no beating around the bush. IF we are to believe that you have experienced some remarkable improvement it's only fair that we get to have some idea of where you started. For example if yo tell us that the speakers were sitting on a stack of tom toms and now they sound better on concrete... well, you probably get the idea.

I have asked you 3 times to tell us what the speakers were sitting on previously... and I never saw actual answer. Since you are talking about walls and floors and desktops vibrating... I'd like to know the chain that went from the speaker cabinet surface to the floor. eg. Speaker>Foam Pad> Desktop>Floor.

best,
mike





 

One could say it is starting to sound like the forum police around here.  And only correct exact theories may be quoted. I am being harrassed. I spend time experimenting and coming here and putting forward honest experiments and observations. It is all intended with the best possible meaning. Please do not forget the nature of this open public discussion. There is so much incorrect and mis information bandied about in many other threads, so perhaps any forum police out there should go chasing them. I am talking about great practical results here.

I am very experienced and practical and do not necessarily get bogged down in theories. I do very practical things and report the results. I teach theories all the time. Sometimes things in the prac world match the theories, sometimes they dont. Everything I suggest is based on practical experience. So much so that I have survived professionally for the last 30 years either composing or producing original music or producing others. So I have picked up a few things along the way. This speaker experimentaion is based more around Hi Fi principles I suppose. I am encouraging people out there to think about their monitoring environment. Are you getting the very best out of your speakers?

I knew the weight refernece at the end of my last post might spark a reaction. But all I know is that by putting the speakers on these concrete stands I have experienced a major shift in the sound I am hearing. No theories about wether I am hearing any difference, it is fact.  The sound is for the better I am convinced of it.

Previous speaker support was a strong heavy table but higher and thinner and longer than a normal table. The speakers were right over the very strong legs. I reinforced the centre to minimise any movement. It seemed to be very good. My experienced ears did tell me though that the bottom end may have been a bit excessive and I have always believed it to be slightly coloured as well. The Acoustic space switch was obviously used to perhaps lower the bottom end and it worked I am sure. I have always felt a fair bit of vibration in my main table only with certain notes and up loud of course. It is easy to forget that other surfaces may be vibrating in your environment. No one has done any tests on this as I suggested or reported any results. You may be surprised.

It matters not what the scientific reason is why I am experiencing a different sound. The stands are heavy and obviously made of something that does a wonderful job of decoupling the monitors from the rest of the room. This is fact. The stand does not move and I mean nothing anywhere. My main table and rack experience no vibration (or very very low compared to before) of any sort now. The bass seems to have lost some colouration around that critical lower area from maybe 100 Hz to 300 Hz or so. Deeper notes seem smoother and more extended. Low end has completely changed. The bass just sounds very different. It freaked me a bit at first but now I am loving it.

As I have said, mids and highs are more exposed now and a result have made the monitors sound quite different.  There is definately more snap in the lower end overall too. Obviously things (cabinets) are stopping faster with things like kick notes etc.. All the sound coming out of the monitors seems to be very directed and focused at you and no where else. I can feel more sound in my body at times. I like Dave's approach that the speakers are now on a very rigid surface or support mechanism. I am starting to think that stereo imaging is improved and slightly better focussed as well. But this is hard to prove becase I cannot go back to my previous setup that easily.

The more I listen to well mixed CD's the more I love the sound now. Putting the Acoustic Space switch back to normal seems to have not changed things much at all. Surely if you lifted everything below 100 Hz up by 2db you would hear a fair difference. That is what I was expecting by putting the Space switch back to flat response. Only the very deep notes are slightly louder.

And please remember this all hinges around using a full range speaker on these stands and not a sub. I do not use a sub at the moment. I am so impressed with the bottom end now that I am almost convinced a sub is unnecessary. Also I am on a concrete slab. There is carpet over the slab of course but the heavy stands feel very stable on the floor. I am not sure what effect putting speakers on these types of stands would do on a movable floor half way up a building though. Could be very different.

Mike it sounds like you have set up your sub very well. Sounds like you have decoupled it well from the floor and the floor is not colouring the sound. And it is on a strong heavy stand which is not likely to vibrate in any way.

I think the vibrating surfaces in my previous setup was the cause of what I was hearing mainly and why the bottom end was like it was and now that it has all stopped I am hearing the speakers now more so and I am probably hearing what I should be.

So so for anyone thinking of putting ther monitors on some heavy concrete stands go out and do it! Dont waste time wondering and reading theories about why it might work, just do it. The plant stand idea is great as it is a cost effective option and if you dont like them you can put some plants on them instead.  But you will like them.

For me this action alone of redesigning the speaker support mechanism will change my mix decisions more than any software, plugin or piece of external hardware would. I have not mixed on them yet but looking forward to doing so. I imagine that sand filled steel stands are going to yield a very similar result. It was a cost thing for me to get the heavy concrete stands. I got both of them for $190 and thought it was a bargain and as it turned out very little cost for quite a major change in the monitoring environment.

Mike reminds me of a group of great enthusiastic hi fi enthusiats I was invloved with years ago. They were amazing people and I learned a lot from them and we did some incredible AB testing. But after a while I started to listen to something else apart from how something was being reproduced. I was starting to listen to the music! After a lengthy argument about how the double bass sounded on a track that featured Ron Carter, I turned to them and said hang on a minute isn't it what Ron played right there that was really important!.  And they looked at me with that horrified look of OMG he is listening to the music. I knew then I had to leave and start doing different things.

My next project is to remove a 6 foot rack which is in reasonable proximity to my left monitor. I only use half the stuff in the rack so I am going to cut it down to a half sze instead and remove a large part of a large structure in the room. I believe this will change things hopefully for the better too.

Thanks to Jeff and others for sharing information to help others with our own set-ups. I appreciate hearing what works for other people. I personally just have the Auralex pads for my monitors because I don't have room for stands, but I can see the benefit. If I stick my head under my mixing desk the sound down there is crazy, and I know some of that is leaking into my hearing when I mix.

"Mike reminds me of a group of great enthusiastic hi fi enthusiats I was invloved with years ago. They were amazing people and I learned a lot from them and we did some incredible AB testing. But after a while I started to listen to something else apart from how something was being reproduced. I was starting to listen to the music! After a lengthy argument about how the double bass sounded on a track that featured Ron Carter, I turned to them and said hang on a minute isn't it what Ron played right there that was really important!.  And they looked at me with that horrified look of OMG he is listening to the music. I knew then I had to leave and start doing different things. "

 This reminds me of a time when I was hanging out at Fox Audio after hours for our Monday night listening sessions back in 1979. Mr Fox broke out his treasured 12" Miles Davis Tribute to Jack Johnson (do you remember when you thought you might never get a another "print" of an album after you wore it out?) and we played it on one of the nicest systems.

 I was impetuous enough to say something like "it's ok but the scratches sort of sound real bad" and Mr Fox, this guy that sells all the top of the line gear, looks at me and says "kid... ignore the scratches... it's all about the music". I feel lucky that I got the point right then and there.

 Jeff, you get challenged because you continue to make presentations in such a way that suggests you think you have a more sophisticated conception of the aural arts than your colleagues.

all the best,
mike

Mike_McCue.......Jeff, you get challenged because you continue to make presentations in such a way that suggests you think you have a more sophisticated conception of the aural arts than your colleagues. I think you might be talking about yourself.

Without a doubt I would have far greater listening and aural skills than most of the forum members here. Not all but many I am sure. I don't have any doubts about my abilities in that area. I have done more listening than most people. But with regards to the speakers on the stands I don't think many people here would have had any difficulty in hearing the difference. It was not something that required a lot of listening skill at all.

After all you still think the analog track from the Summing thread sounds better and it surely does not. Does not say much about your listening skills Mike. You need to go back and listen carefully to those two tracks and see what I mean. Maybe one day you will hear it.