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Talk but not walk?

Hi Guys

This isn't meant to start a fight, but it is important to on lookers. As a qualifier, I have my own audio forum where we report on audio issues as we empirically test them. It helps us short cut on theories and developing methods of listening. We have a wide range of systems and they are all over the world adding their experiences to the mix. Some are engineers, some are artist and others are audiophiles both new and old. One question I am almost always asked while I am visiting other forums, from some of my members and also members of the forum I am visiting is, why do so many HEA hobbyist talk theory without any, or very limited, empirical testing or experience?

I have been around empirical testing labs since I was a kid, and one thing that is certain is, you can always tell if someone is talking without walking. Right now on this forum there are easily 20 threads going on where folks are talking theory and there is absolutely no doubt to any of us who have actually done the testing needed, that the guy talking has never done the actual empirical testing themselves. I've seen this happen with HEA reviewers and designers and a ton of hobbyist. My question is this, why?

You would think that this hobby would be about listening and experience, so why are there so many myths created and why, in this hobby in particular, do people claim they know something without ever experimenting or being part of a team of empirical science folks. It's not that hard to setup a real empirical testing ground, so why don't we see this happen?

I'm not asking for peoples credentials, and I'm not asking to be trolled, I'm simply asking why talk and not walk? In many ways HEA is on pause while the rest of audio innovation is moving forward. I'm also not asking you guys to defend HEA, we've all heard it been there done it. What I'm asking is a very simple question in a hobby that is suppose to be based on "doing", why fake it?

thanks, be polite

Michael Green

www.michaelgreenaudio.net


michaelgreenaudio

Showing 8 responses by shadorne

shadorne's avatar
shadorne
7,477 posts
 
Yup. Some Girls just confirms my experience with HD tracks is they are more money for POS recordings. Really annoying to pay more for less quality. I will never buy from them again as there is no quality control - just high prices.
shadorne's avatar
shadorne
7,477 posts
 
@bdp24

+1 Drum set are tuned in a different way to every other instrument. It is extremely complex. Being able to get the right sound for the room or venue is an art.

The only way to learn to “tune” a drum set is to tune a drum set so many times that you train your ears to know what to adjust.

I have a Pearl reference kit and it is amazing for large venues but too resonant for a practice room. I have found Evans controlled resonance heads along with Evans ringed batters to work best for this kit in a small room. I find Evans dry heads with perforations work for the snare is a small room.

I have a drum drum tuner also but frankly by ear is the best and fastest.

Trick is

1) Choice of heads (the sound of the stick hitting the head is very important as well as longevity of the skin) Drum heads have an incredible range of sounds.
2) tuning to the drum shell
3) relative tension between the heads - create down pitch or up pitch and decay rate ( tuning both heads to each other and to the shell results in longest sustain)
4) Generally Major thirds or descending fourths works as a starting point.

Snare tuning is a dark magic art that requires a decade or more of training.

Finally - what the drummer hears from the throne is very different from what is projected to a listener.

Drum set tuning is the most difficult instrument to “tune”.

Cymbals are just as complex - choosing those is also an art.

The complex harmonics of drums mean that drums are the most important instrument to get right in order for a band to sound good.

It gets much worse for the drummer....how you hit the heads and how much rebound you allow the stick can change the tonal character of the sound too - not only loudness.

shadorne's avatar
shadorne
7,477 posts
 

Geoff is spewing even more jumbo-jumbo gobbledygook than usual. He has outdone himself. Definitely worthy of a Gold Star, a Mars bar and extra playtime.
shadorne's avatar
shadorne
7,477 posts
 
+1 Elizabeth

And the answer to Geoff’s quiz is

It depends. If the fridge that supplied the ice cold water has an ordinary stock fuse then there is no improvement. If the fridge used to supply the ice cold water has an SR Blue aftermarket fuse then the sound will improve more significantly than any other tweak Evah!
shadorne's avatar
shadorne
7,477 posts
 
Wow. 

Audio is an elastic compressional - rarefaction acoustic wave. Audio has nothing to do with flow. Nothing flows from speaker to listener. You only get a tiny bit of air flow directly around the transducers edges and the reflex port.

A display of such ignorance as I have rarely seen.

Hel-loooo!!!
shadorne's avatar
shadorne
7,477 posts
 
Since there is no air flow in a listening room you can’t create turbulent flow. You don’t even have laminar flow in a listening room.

Reynolds numbers?

Good grief.

We have such a conflation of different applied sciences here - none of which applies to audio! We are venturing into aerospace engineering and motor vehicle drag perhaps but this is nonsense in audio.

Waves on a beach? Good grief - waves in the sea are NOT elastic acoustic waves at all. Again conflating completely different phenomenon. Surface waves at an interface have orbital progressive properties. The interface is key - just like the major damage from earthquakes comes from “ground roll” at the interface.

The reason acoustic energy varies in a room is due to the reinforcement and interference of a multitude of reflected acoustic waves along with the primary. Since the reflection surfaces are rigid compared to air there is also a build up of pressure very close to the wall. Listeners should keep at least 3 feet from a wall - 6 feet is better.

A little knowledge is a dangerous thing.



shadorne's avatar
shadorne
7,477 posts
 
@geoffkait 

Wrong. You are conflating flow and vibration. The air particles in the room vibrate elastically at musical frequencies they do NOT “flow” around the room. There is no net air movement Flow = Zero, Capiche?
shadorne's avatar
shadorne
7,477 posts
 

Shear waves are just transverse vibrational waves. In solids you get both P (longitudinal) and S (transverse) waves. In liquids and air you get only P waves.
At interfaces you can get rolling or orbital progressive waves travelling along the interface.

Generally the goal is to try and damp shear waves in speaker cabinets, baffles and speaker drivers. The term most people use is critically damped. This means the system will return to zero (stop vibrating) once input excitation stops without any further positive and negative oscillations? This is what your car shock absorbers do....it prevents your springy car suspension from boinging around after a bump.

Tuning speaker cabinets in order to have them resonate at specific frequencies is adding coloration at any other frequencies than specifically to match the woofer and porting to get an optimal response from the system. Best response is flat in the bass (no resonance peaks) and critically damped - generally this produces a smooth 12db per octave roll off below corner frequency.



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