I don't know exactly what it is doing electrically but the description of the change in sound with the device in place, suggest that psychoacoustically, the attack portion of notes are being perceived in a different way - probably as a result of some noise reduction in the replay?
It all depends on what's inside the box, what's inside the box sets up a 'coherent earth/reference' for the whole system.....and an identifiable signature/characteristic sound.
This is old hat, there are better ways.
Dan.
Then for a lot of music masking isn't an issue as it has been dealt with by the music players/composers? And then how are the tests which show 2H for example to be interpreted as to significance?
THx-RNMarsh
That makes sense re stretching strings over time to settle.
the center keys all seemed reasonable like one other in the store. But only the bass was very noticeably different from one piano to the next.
THx-RNMarsh
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It also involves the concept of auditory streaming which is explained in Auditory Scene Analysis & how we interpret & group the jumble of frequencies, amplitudes arriving at our ears into coherent auditory streams & a coherent auditory scene
That's what it seems to me from experience and why I said a full orchestra playing.....
??
THx-RNMarsh
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Yes, this is the nature of perception - it is adapted to (uses as it's learning space) the sound profiles found in nature where signals with coherent modulated amplitude are commonly found. Obviously for our perceptions to be useful interfaces to nature they need to be a useful processing model for the signal space encountered & this signal space is, in the case of auditory perception, the sounds encountered in nature
That's why the simplicity of tone tests can be misleading. This is a current hot topic in psychoacoustic research.
Try it for yourself with this working example:
Comodulation Masking Release | Auditory Neuroscience
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Interesting. When using that flash demonstrator you have to be careful to get valid results. I found if my system volume is too low, I'll have persistent auditory memory reading a tone into the noise like a Rorschach test. I'll note that when this happens it's like I'm hearing a bell rather than a tone (or like the dull ring of a soup bowl). Increasing the level so that my brain isn't drawing on memory to fill in the blanks, it starts to behave like the research paper describes.
This example is just one type of CMR where the broadband masker noise is comodulated with the tone - the more interesting CMR is where a comodulated tone at a frequency far removed from the tone being masked also unmasks.
There is still great debate about the psychoacoustic mechanisms in operation that enable CMR.
Some of it involves the underlying mechanisms for how individual sounds in the cacophony of sound reaching our ears are processed/analysed psychoacoustically & grouped together into different auditory objects in the scene
On a different topic, I just refoamed and replaced the electrolytic crossover capacitors with a polypropylene type in my 40 year old Dahlquist DQ-10s. Also cleaned out a lot of dust. Surprised at how good they still sound.
I did look for a thread here about which upgrades to make and didn't find much.
Currently running on a 10 watt class A amplifier. More importantly the room was built to enhance reproduction. No doors to the next room, took out a bit of wall to be sure the space coupled. Wood floor with two oriental rugs. 10' ceiling and artwork on the walls. The largest is about 25 square feet and makes a nice bass disperser.
Unlike RNM I am using an indirect field for the sweet spot.
Next step to build a bit of a larger amplifier. I have a JC clone for the phono stage and will get around to a blowtorch sort of for the preamp.
Derfy,
I see the piany question has slowly drifted to the issues at hand.
Long ago the IEEE spectrum did an article on one of the first top octave generator chips for electronic organs. A letter to the editor asked about frequency stability. The response didn't get the gist. It was to the effect that since the master clock was crystal controlled it would be perfect.
Tuning a scale is the best example of what you measure often doesn't correspond to what you hear. Or in simple terms a tight octave based scale doesn't sound as good as a human tempered one.
I did look for a thread here about which upgrades to make and didn't find much.
Currently running on a 10 watt class A amplifier. More importantly the room was built to enhance reproduction. No doors to the next room, took out a bit of wall to be sure the space coupled. Wood floor with two oriental rugs. 10' ceiling and artwork on the walls. The largest is about 25 square feet and makes a nice bass disperser.
Unlike RNM I am using an indirect field for the sweet spot.
Next step to build a bit of a larger amplifier. I have a JC clone for the phono stage and will get around to a blowtorch sort of for the preamp.
Derfy,
I see the piany question has slowly drifted to the issues at hand.
Long ago the IEEE spectrum did an article on one of the first top octave generator chips for electronic organs. A letter to the editor asked about frequency stability. The response didn't get the gist. It was to the effect that since the master clock was crystal controlled it would be perfect.
Tuning a scale is the best example of what you measure often doesn't correspond to what you hear. Or in simple terms a tight octave based scale doesn't sound as good as a human tempered one.
That's part of it, in conjunction with the connection wires,what's in the 'earthing' box sets up a 'vibe' that influences the behavior of the whole system and forces the system components to 'play nice'....or not.
Music theory/practice dictates tones that 'play nice' or 'not nice' together with consequent influence of mood/vital signs of the listener.
Physical elements that comprise the system cause subtle system sounds that similarly influence the listener.
Toxic elements used in circuit paths and enclosures/insulations cause toxic subtle sounds and consequent toxic effects in the listener....ROHS directive benefits go deeper than keeping heavy metals out of land fills/water tables.
Earthing boxes and the likes of BQP set a 'tone' in the system, good or bad.
Dan.
Hi Ed,
I used to sell those, and there is a change that improved the highs. I don't know if you can find the parts these days.
Remove the Philips AD0162T8 (?) tweeters and install Philips AD0163T(same impedance 4/8/15)
Remove the two piezo tweeters, you won't replace them with anything.
The AD0162Tx tweeters have a broad peak from approx. 12 KHz to 16 KHz. The piezo is there to fill in the top end. The AD0163Tx tweeters are pretty flat by comparison and should sound smoother. The best thing about this modification is that it doesn't require any other change and can be backed out of without any damage to your speakers.
I still have a pair of the AD0163T8 tweeters in a pair of prototype speakers that sound okay. The newer Peerless tweeters sound a lot better and you could probably find a Vifa or Peerless tweeter that you could try with a soft dome. If they don't fit in the hole, just hang them over the hole with some wire. They should be in front of the baffle of course. If you like them better you can modify the tweeter mounting holes.
My favorite speakers back then were the AMT tower 1A. The Dahlquist DQ-10s were the second, without the "gas bag" mod. That was a large bag of Helium that made the box "look" larger to the woofer. Completely uncontrolled modification that was popular in the Toronto area back then. I don't know if that rage was spread further or not.
-Chris
I used to sell those, and there is a change that improved the highs. I don't know if you can find the parts these days.
Remove the Philips AD0162T8 (?) tweeters and install Philips AD0163T(same impedance 4/8/15)
Remove the two piezo tweeters, you won't replace them with anything.
The AD0162Tx tweeters have a broad peak from approx. 12 KHz to 16 KHz. The piezo is there to fill in the top end. The AD0163Tx tweeters are pretty flat by comparison and should sound smoother. The best thing about this modification is that it doesn't require any other change and can be backed out of without any damage to your speakers.
I still have a pair of the AD0163T8 tweeters in a pair of prototype speakers that sound okay. The newer Peerless tweeters sound a lot better and you could probably find a Vifa or Peerless tweeter that you could try with a soft dome. If they don't fit in the hole, just hang them over the hole with some wire. They should be in front of the baffle of course. If you like them better you can modify the tweeter mounting holes.
My favorite speakers back then were the AMT tower 1A. The Dahlquist DQ-10s were the second, without the "gas bag" mod. That was a large bag of Helium that made the box "look" larger to the woofer. Completely uncontrolled modification that was popular in the Toronto area back then. I don't know if that rage was spread further or not.
-Chris
Ed, it is great to see you contributing to hi fi rather than something else. Changing out the Dahlquist coupling caps is a real improvement. This is one place where PP caps are best. The best pair of Dahlquist speakers that I ever heard, was at Saul Marantz's house in 1985. His sounded really good, better than usual, perhaps he got a hand selected pair, as he was president of the company at one time. I remember that about the same time, a guy first told me of this mod using PP caps. They were very new then, and this guy was ahead of the curve.
Hi John,
I sure you know that crossovers don't work as designed with film capacitors in place of the electrolytic capacitors they were designed with. It's different of course if the crossover is completely reimagined with film types if you must use them.
I designed speakers for the first 10 years (or so) of my career. I even learned a few things by making mistakes that people are still making today. That would be a solid 25 years ago when I designed my last pair of speakers when I think of it.
One of the biggest improvements you can make to a set of store bought speakers is to approximately double the internal volume of the box and retune (if needed). If you can figure out the proper size by measuring the woofers, then you just need to get the bracing right along with the damping material.
-Chris
I sure you know that crossovers don't work as designed with film capacitors in place of the electrolytic capacitors they were designed with. It's different of course if the crossover is completely reimagined with film types if you must use them.
I designed speakers for the first 10 years (or so) of my career. I even learned a few things by making mistakes that people are still making today. That would be a solid 25 years ago when I designed my last pair of speakers when I think of it.
One of the biggest improvements you can make to a set of store bought speakers is to approximately double the internal volume of the box and retune (if needed). If you can figure out the proper size by measuring the woofers, then you just need to get the bracing right along with the damping material.
-Chris
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