Spikes versus Rubber on wood floor?

Nsgarch, even though we "beat a dead horse" for a while, I do appreciate your willingness to offer your expertise. I have learned a lot from many like you here on the 'Gon who have always been eager to help.

And just as an aside, I don't believe "incompetants" is a word. But what do I know since I am not one of the...uh huh...brilliant ones :)

There are many threads on Audiogon and AA about suspended hardwood floors.

I tried many solutions on my suspended hardwood floor and the only thing that worked was to decouple the speaker from the floor. Coupling the speaker to my suspended hardwood floor was a disaster. All coupling does to many suspended floors is excite the floor which creates a delay in the sound traveling in the floor and it muddies the bass badly.

You will find in the many threads here and on AA that the vast majority of suspended floor owners had much better success with decoupling. I know...I searched every thread available and the over-whelming consensus was coupling was bad, decoupling worked. All of the theories you will hear are great, but there is nothing like actual experience. Search "suspended hardwood floor" and "suspended floor" here and especially on AA and you will find a lot of "actual experience" from owners with suspended hardwood floors, not a bunch of theories. That is not to say that coupling may not work on "any" suspended floor, but the preponderance of evidence from owners is that coupling is not good.

And as far as movement of a speaker goes, there are also those here or on AA who have suspended their speakers from the ceiling with absolutely no movement of the speaker when playing...none, zilch. Once again, theories are nice, but actual experience is soooo much better.

Nsgarch, thanks for the feedback, but number 1, 2 & 3 won't work simply because the floor is being excited by certain frequencies. The problem is not floor flex, per se. The floor is acting like a drum head. It doesn't much matter where you strike the drum head, it will still resonate. Until the frequency vibrations are sinked to something with a much lower resonant frequency (such as, the ground or a concrete pad on the ground), they just rumble around until they dissipate. So moving the speakers over joists won't make a big difference. Believe me, I tried.

Stiffening the floor would cure the problem, but most effectively if it is stiffened by applying pressure from the floor to the ground, i.e. using floor jacks and posts or footings and pilings. These solutions simply change the resonant frequencies and the problem can be eliminated. But the simpler solution is to decouple the speakers. Do a search for actual results.

And according to other users, hanging a speaker from a single chain does not produce any movement of the speaker when the speaker is playing. I personally have no experience with this, but that is what has been reported from actual use.

Nsgarch, I have a 3 year old home and I seriously doubt it was under-engineered. Apparently you are missing the point. I don't have a bouncy floor. I have a resonant floor. They are the result of the same problem, just a long way apart. When I walk on the floor it is not bouncy. But certain bass frequencies made it resonate when I had rear ported speakers. Now that I have changed speakers to OB's and a Velodyne DD12, I don't have the same problem.

However, with my previous speakers, when they were coupled to the floor they made the floor resonate badly. One of the reasons you are reducing the resonance of your clients floors is that you are adding mass, not just stiffness. The more mass you add the lower the resonant frequency.

There's no sense in us going round and round here. If you will just take the time to do a search, you will see the resonance problem is very common to suspended floors. And I am sure that all of the guys who have reported a similar problem here and on AA didn't have "under-engineered" floors.

"My solution in such cases (when none other was possible or practical) was to add a couple more layers of plywood subfloor, with the sheets staggered and edge and face nailed very well. This acts like a stressed skin and keeps the floor from bouncing excessively."

I can promise you that if you do a search you will find a very "possible and practicle" solution to the problem other than the expensive, time consuming and unnecessary fix that you employed.

And I appreciate the fact that you are an architect, but when I built my business, both I and my contractor found many practical, economical and more effective methods of doing things than my architect had drawn and submitted. Any good contractor with a lot of real-world experience will take virtually any plan drawn by an architect and improve it. No intentional slam here, but like I said earlier, give me actual experience any day.

Nsgarch, you could be right, but I doubt it since I fixed the problem with decoupling like many others have here.

I might not have a minor in acoustics from MIT and I also don't have an engineering degree either, but I can tell when my car is spark knocking and how to fix it from the experience of others. But I certainly don't need to tear the engine down!

The fact is, I did cure the problem in my room without having to tear my floor up or re-engineer the joists as you suggested. But I guess if you can't find a simple solution like decoupling there's always the big hammer approach, huh? And btw, being a licensed contractor doesn't mean you are an experienced builder. You know there are licensed contractors and licensed contractors!

And I anticipated your, "There are architects and architects; sorry you didn't find a better one.", after your, "apparently you have a very under-engineered floor."

From your attitude, it appears that you are the only competent architect around. Too bad everyone just doesn't hire you.