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In the Forum: Horn-Loaded Speakers
In the Thread: It's might be another project...
Post Subject: Edger fell off his seat!Posted by Edgar= on: 10/19/2024
Howdy Romy and all. It's a pleasure to visiting the site again, AND again I found myself flabergasted by the words coming out of your mouth Romy! Now dipole bass! What would the cat of 15 years ago say to the cat now?!?
I make fun but I too have had good moments with simple dipole bass. In its limitations...
I'm still formulating my theories but I'm interested on your thoughts regarding any correlation in your experience between how reverb injection changes your subjective experience of the sound, and how the 'incorrect' dipole bass also make you perceive sound in room?
Also, if any correlation in your subjective experience with Dannoy?
Would you say Dannoy and the dipole corner cabinets have a similar lower rolloff? Subjectively? Dannoy is also kind of dipole around 25hz. Others might disagree with that statement.
I still listen to Dannoy regularly. 
But back to the dipoles. If I had to take a stab in the dark about the source of the phenomena showing up that you are enjoying Romy, I would guess it has to do with your loudspeaker as a microphone. I think this also applies to Dannoy phenomena. Specifically the way they build harmonics in the room.
I believe reverb injection is also doing something similar, restructuring the pressure in the room at lower registers, allowing the harmonics to build properly, in natural order.
To explain, everytime our loudspeakers pressurise the room, as in each cycle, the room also depressurises. that depressurisation then drives the loudspeaker and generates a signal out of the driver into the amplifier's output stage, as we know. But how much do we think about how this phenomena effects our playbacks?
This is from an AI - 

The principle of reciprocity in electroacoustics is a fundamental concept that applies to transducers, including loudspeakers and microphones. Here are the key points:

  1. Bidirectional conversion:
    • A transducer can convert energy in both directions.
    • For a loudspeaker, this means it can convert: a) Electrical energy into acoustic energy (its primary function) b) Acoustic energy into electrical energy (the reverse process)
  2. Loudspeaker as a microphone:
    • Due to this principle, a loudspeaker can actually function as a microphone.
    • When sound waves hit the speaker cone, they cause it to vibrate.
    • These vibrations move the voice coil within the magnetic field of the speaker.
    • This movement induces a small electrical current in the voice coil, effectively generating an audio signal.
  3. Implications for audio systems:
    • In a high-powered audio system, this effect can contribute to feedback.
    • The speaker-generated voltage can be fed back into the amplifier, potentially causing distortion or oscillation.
The difference in dampening factor between solid state amps and valve amps has a dramatic effect  on how this room/driver/output-stage feedback loop behaves/sounds. if the loudspeaker topology is complex, the distortion generated in this feedback loop will be complex. If the loudspeaker topology is simple, the distortion will have more simple, naturally ordered harmonics. And you know how the old adage goes, "if we have to have distortion in our output stage, let's make sure its structured properly"
That's not an adage, I just made it up. but if it was an adage, it would be one I'd be happy to say.
With all due respect Romy, the 5 channels of your main playback = 5 isolated feedback loops. The harmonics of the distortion in the output-stage feedback loops can only restructure themselves within the limited bandwidth of the DSET xformers before they are reintroduced into the room, not across the entire bandwidth of the playback. So whilst your main playback will generate very linear pressure on the first cycle, once the room feeds back into the isolated xformers, the order of the harmonics is de-structured. 
Also, the most charge back into the output stage is generated at resonate freq of the drivers, which may be why the two different resonance frequencies create such different subjective experience in your corner cabs. I don't really know. Just guessing.
Interested in your thoughts.
Lastly, I remember I started following your adventures back when you were adding two more drivers to the top of you line arrays in your Boston Apartment. I have enjoyed following along and have benefited from the discoveries of each of your adventures since then. The pilot system experiments, the mid bass horns of course, the multiple house moves and the family and the many others. I look forward to the developments of this humble project.
Ed

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