i use that setup for 30 years.
I have a lot of visitors and no one complains about the sound.
Especially 3 dimensionality is what i am proud of and my setup works great to enhance that. I do not know who came up with all that rules that sitting far from walls is better.
I have certainly not read any paper, even popular, that certifies that method.
The depth of research is very thin ice and the studies that i have seen do not come even close in depth compared to what we did in the 90th.
Mr. Theiß was even working on an " Artificial Listener" where no human subjects where needed any more to take out any peaking or other problems that come up in listening tests. See the Blowtorch thread about the contrary opinions.
It was a kind of artificial head that gave out numbers. Unfortunately that PHD study was never finished.
Mr, Theiss decided to leave and work as a journalist.
That was a great loss. That guy was really competent.
I have a lot of visitors and no one complains about the sound.
Especially 3 dimensionality is what i am proud of and my setup works great to enhance that. I do not know who came up with all that rules that sitting far from walls is better.
I have certainly not read any paper, even popular, that certifies that method.
The depth of research is very thin ice and the studies that i have seen do not come even close in depth compared to what we did in the 90th.
Mr. Theiß was even working on an " Artificial Listener" where no human subjects where needed any more to take out any peaking or other problems that come up in listening tests. See the Blowtorch thread about the contrary opinions.
It was a kind of artificial head that gave out numbers. Unfortunately that PHD study was never finished.
Mr, Theiss decided to leave and work as a journalist.
That was a great loss. That guy was really competent.
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Thanks for answers!
Once I listened to my Loudspeakers(Coral Flat 5II + bass) at friend's home, and the chairs were so near the wall, and it sounded like crap, I couldn't believe it, but maybe it's his repaired amp and his cheap cd player that trashed the sound, there was literaly no stage...
Once I listened to my Loudspeakers(Coral Flat 5II + bass) at friend's home, and the chairs were so near the wall, and it sounded like crap, I couldn't believe it, but maybe it's his repaired amp and his cheap cd player that trashed the sound, there was literaly no stage...
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You get of cause much more bass when you sit near the backwall. That requires the speakers to be put away from the frontwall or an active, adjustable bass under 80 - 100 Hz like i do.
Placing the speaker away from boundaries also helps to atenuate eary lateral relexions that blurr the sound and specifially image focus.
Placing the speaker away from boundaries also helps to atenuate eary lateral relexions that blurr the sound and specifially image focus.
I see that you are keeping an adventurous mind.
But your papers show that long ago you have indulged in scientific scrutiny too. Did you alredy have the same scrutinizing look at the radiation pattern of that Acoustic Resistance Frame? Does any of its "response of plus-minus 2dB from 150Hz to over 20kHz" translate into the room?
Rudolf
Hi Joachim,
looking forward to your diagrams.
I have this habit to let others do the experiments for me. Or better said, learn the most from what others have already done.
With your "home-grown" open baffles I'm never sure, if the choosen materials are "I just had it lying around" or "I have tried ten different acoustic foam materials in 50 different combinations and this was the one that worked best". Would be nice to smell some of the sweat, that went into the development, too.
Rudolf
I found that the amount of damping material is critical.
Without any damping there was a suckout maybe between 300 and 500Hz.
I added just enough damping so that this notch disappeared.
I am using acoustic foam with a density of 30kG per cubic meter.
I ended up with half a plate around the driver ( magnet cut out ) and a full plate over that.
When i added another plate holes developed at other frequencies.
It even matters how the plates are fixed. When i press them down too strong again notches come. So somehow this design does not allow for many options.
I could of cause try another material like rock wool or glass wool.
Actually i wanted to avoid such material because of the fibers flying around and entering my lung.
I could try a hybrid from sheep wool and foam. Maybe the sheep wool near the driver.
There is also Twaron, known
as angel hair. I think that is from Kevlar.
Felt could work too.
Without any damping there was a suckout maybe between 300 and 500Hz.
I added just enough damping so that this notch disappeared.
I am using acoustic foam with a density of 30kG per cubic meter.
I ended up with half a plate around the driver ( magnet cut out ) and a full plate over that.
When i added another plate holes developed at other frequencies.
It even matters how the plates are fixed. When i press them down too strong again notches come. So somehow this design does not allow for many options.
I could of cause try another material like rock wool or glass wool.
Actually i wanted to avoid such material because of the fibers flying around and entering my lung.
I could try a hybrid from sheep wool and foam. Maybe the sheep wool near the driver.
There is also Twaron, known
as angel hair. I think that is from Kevlar.
Felt could work too.
Here is a measurement comparison of the acoustic properties of Panzerholz against Aluminum.
The Virtues of Panzerholz : An Investigation into the Acoustical Properties of Aluminum and Panzerholz
I used Panzerholz in the original Medea from 1991 and later in the Cerubin from 1996.
I think it is one of the best materials for High End Audio cabinets.
The Virtues of Panzerholz : An Investigation into the Acoustical Properties of Aluminum and Panzerholz
I used Panzerholz in the original Medea from 1991 and later in the Cerubin from 1996.
I think it is one of the best materials for High End Audio cabinets.
Yes, it is made by a german company and they deliver.
I think Clearaudio makes some turntables with it.
As far as i know i was the first that used it in Audio.
It is a bit hard to handle because it can bend after a while and then cabinets can crack open. We solved that by going in the factory and selecting straight plates. It is also expensive so when Audio Physic got more commercial we used other material.
It is the best i ever tried though.
I think Clearaudio makes some turntables with it.
As far as i know i was the first that used it in Audio.
It is a bit hard to handle because it can bend after a while and then cabinets can crack open. We solved that by going in the factory and selecting straight plates. It is also expensive so when Audio Physic got more commercial we used other material.
It is the best i ever tried though.
See post 251. The Acoustic Resistance Frame is an open frame that is damped in the back.
By doing that i can get the same low frequency response then in an open dipole that is 2 times wider. It is also not that sensitive regarding placement to the back wall and frequency response is more linear. A point source on an open baffle always has comb filtering effects.
By doing that i can get the same low frequency response then in an open dipole that is 2 times wider. It is also not that sensitive regarding placement to the back wall and frequency response is more linear. A point source on an open baffle always has comb filtering effects.
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Here is some material about that problem.
Electro-acoustic models
In my case i got a hole centered at around 300 - 400Hz that disappeared with the right amount of damping on the back of the frame.
The generally " open " sound of an open baffle that reminds us on electrostatics or ribbons
remains.
That is because that frame still releases the pressure in the deep bass.
Electro-acoustic models
In my case i got a hole centered at around 300 - 400Hz that disappeared with the right amount of damping on the back of the frame.
The generally " open " sound of an open baffle that reminds us on electrostatics or ribbons
remains.
That is because that frame still releases the pressure in the deep bass.