The idea of DDR, how it sounds and how it can be measured has come up on another thread I no longer see on the forum. Being a music lover and full range driver fanatic I feel there is such a quality drivers posses that have what I would call DDR. It's not only associated to full range drivers and I'd even say electronics exhibit varying degrees of DDR.
The way I've always perceived DDR is how a driver remains composed and controlled during complicated passages allowing small details of the music to come thru without being masked or overwhelmed.
I've typically associated this with more expensive drivers using better quality materials and wonder if I've been tricked into hearing something that's not there... but I don't think so since I am a critical listener and have a decent collection of drivers with varying prices. Maybe some of us describe DDR as 'tone' or something else but when a driver produces the details (without being in your face) and allows you to hear deeper into the music it's a very enjoyable event.
For example, for me the Pioneer B20 has less DDR than a Fostex 168z. This could be related to frequency response. Or could it be related to how well a driver tracks electrical impulses, the weight of the cones, the flexibility of the spider, the strength of the magnet, etc??? Additionally, a 'hot' driver like a Fostex 127e has less DDR (because it becomes congested) than a 'dull' sounding TB 1320 (which to me, sounds more relaxed and composed). So it may or may not be related to frequency response.
Just my curiosity peaking.
The way I've always perceived DDR is how a driver remains composed and controlled during complicated passages allowing small details of the music to come thru without being masked or overwhelmed.
I've typically associated this with more expensive drivers using better quality materials and wonder if I've been tricked into hearing something that's not there... but I don't think so since I am a critical listener and have a decent collection of drivers with varying prices. Maybe some of us describe DDR as 'tone' or something else but when a driver produces the details (without being in your face) and allows you to hear deeper into the music it's a very enjoyable event.
For example, for me the Pioneer B20 has less DDR than a Fostex 168z. This could be related to frequency response. Or could it be related to how well a driver tracks electrical impulses, the weight of the cones, the flexibility of the spider, the strength of the magnet, etc??? Additionally, a 'hot' driver like a Fostex 127e has less DDR (because it becomes congested) than a 'dull' sounding TB 1320 (which to me, sounds more relaxed and composed). So it may or may not be related to frequency response.
Just my curiosity peaking.
The so called DDR is the acoustic aftertaste that results from a cone with a ringing impulse response. The ringing extends the duration of transient peaks or impulses in time, thereby increasing their audibility. DDR will be exhibited by drivers with non smooth frequency response having major breakup mode peaks. The peaks and the ringing are Fourier transforms of each other. Listen to the impulse response wav file from a driver with clean IR and listen to one with a ringing response and hear for yourself which is more audible. This enhanced audibility is what some call more low level detail but it really isn't there in the original recording. It may sound good - I am not saying it is bad sounding. But look at the IR to find a clue of DDR. Conversely, a driver with smooth response and no ringing will not have DDR. If so, please look for an example of one and post its frequency response and IR.
Listen to the IR's of a ringing vs non ringing IR here and see which is more audible:
http://www.diyaudio.com/forums/full-range/269391-usefulness-room-lf-measurements-vs-no-measurements-ref-fh-3.html#post4217091
Listen to the IR's of a ringing vs non ringing IR here and see which is more audible:
http://www.diyaudio.com/forums/full-range/269391-usefulness-room-lf-measurements-vs-no-measurements-ref-fh-3.html#post4217091
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The term was originated by an electronics designer. It is applicable to the entire hifi chain.
I think wintermute did a very good job of defining it (from here)
I do not see how antone can dismiss the concept, It is the subtle details that give a voice or instrument their body and nuances. It is essential for producing a good 3D image/soundstage.
HiFi is about creating an illusion and these small details are essential.
The difference between a good hifi and a great one is 30-50 dB down.
dave
It's easy to dismiss because it has never been well defined. And it's been touted by users of systems with (on a good day ) 70dB of SNR.
Im only dismissing the term DDR not a concept.
In fact radio and telecommunications has been dealing with the concept for decades.
trying to pull in weak station in the presence of a much stronger station.
the selected test tones are key ( eg Doppler distortion is a killer )
Intermodulation - Wikipedia, the free encyclopedia
In fact radio and telecommunications has been dealing with the concept for decades.
trying to pull in weak station in the presence of a much stronger station.
the selected test tones are key ( eg Doppler distortion is a killer )
Intermodulation - Wikipedia, the free encyclopedia
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Hi,
AFAIK its "downward dynamic range" and applicable to any system.
It is somewhat different to signal to noise ratio, and generally means
where does the sound descend to mush, for poor cabinets its not low.
Same with poor electronics. For speakers its about how high level
energy is eventually dissipated in the structure, if this resolves
to resonances you get masking, same to a degree with a cone.
rgds, sreten.
AFAIK its "downward dynamic range" and applicable to any system.
It is somewhat different to signal to noise ratio, and generally means
where does the sound descend to mush, for poor cabinets its not low.
Same with poor electronics. For speakers its about how high level
energy is eventually dissipated in the structure, if this resolves
to resonances you get masking, same to a degree with a cone.
rgds, sreten.
Using the prefix down is just saying that it is important to look at the bottom of the dynamic range and what happens to it in the precense of a much stronger signal.
Allen defined and started using the term in the early 90s so that is decades. I have been using it since the late 90s because it just makes sense.
dave
Allen defined and started using the term in the early 90s so that is decades. I have been using it since the late 90s because it just makes sense.
dave
It is the nonlinear distortion that is limiting the dynamic range at the low end. One does not need new term for that. Any standard nonlinearity test will do.
.
it's all related to linearity
please read sections G & J Frontiers
from multi-tone tests you can get a SNR
I have found these and other types of multitone test signals useful for sorting and relative ranking of drivers. Their subjective evaluation when part of a complete speaker correlates closely with the measurements. It should be understood that distortion has audible effects long before it is perceived as distortion. For example, it might enhance sonic detail, analogous to contrast enhancement in a photo
please read sections G & J Frontiers
from multi-tone tests you can get a SNR
I have found these and other types of multitone test signals useful for sorting and relative ranking of drivers. Their subjective evaluation when part of a complete speaker correlates closely with the measurements. It should be understood that distortion has audible effects long before it is perceived as distortion. For example, it might enhance sonic detail, analogous to contrast enhancement in a photo
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As I see it, the definitions by Godzilla & Wintermute are pretty much the same. And, the importance of this thing is no doubt.
Two (interesting) observations:
1. The best I've heard (to my ears) are generated by 2 very different types of speakers -- compression driver with horn, and DML. They both are capable of preserve blossoming small details in dense and loud passages, but in overall quite different ways.
2. I think of the advertisements of TV and (digital) camera nowadays. Many of them are emphasising the ability of revealing the details in dark zone. I think it's pretty much the same idea in the visual side of thing.
How to measure it objectively? I don't know. Personally, I use my ears & brain. (and luckily, I don't have to persuade anyone... )
Two (interesting) observations:
1. The best I've heard (to my ears) are generated by 2 very different types of speakers -- compression driver with horn, and DML. They both are capable of preserve blossoming small details in dense and loud passages, but in overall quite different ways.
2. I think of the advertisements of TV and (digital) camera nowadays. Many of them are emphasising the ability of revealing the details in dark zone. I think it's pretty much the same idea in the visual side of thing.
How to measure it objectively? I don't know. Personally, I use my ears & brain. (and luckily, I don't have to persuade anyone... )
I concur about the use of a suite of multitones. From the anecdotal evidence of DDR I've read, it seems to support the notion that there is some sort of 'noise floor' for each driver. A possible way to measure it would be two tones at 1 kHz and perhaps 10 kHz, plus a lower level signal at 5 kHz. We then measure the intermodulation and compare how much the fundamental at 5 kHz sticks out of the spuriae, artefacts and associated gunk. If there is a sharp spike at 5 kHz that correlates with perceived DDR, we may consider the potential that DDR is a result of this clean resolution of low-level signals at the same time as several higher-level signals.
Of course, this is all just a layman with an objective bent rambling. Feel free to poke holes in the theory or ground it in more concrete science.
One issue I foresee would be the possible need to equalize FR to keep things constant; this would remove some DDR, were it to really stem from impulse ringing as a result of break-up, as postulated in previous threads on this issue.
I would also argue that an open motor with lots of empty space to reduce backwave reflections may be relevant too. But most competently designed motors seem to minimize such problems to a great extent already. Can't really measure backwave reflection and its effect on driver performance directly though.
Thinking out loud here: could it be possible that the extremely thin cone of high-DDR drivers are more susceptible to allowing backwaves to pass through? These backwaves then create response and energy storage anomalies that are perceived as DDR. Dunno.
I also feel that a high resolution burst decay and CSD (50 dB scale or more) may go some ways in trying to quantify DDR. But that'd only be possible in an anechoic chamber with a low noise floor. However, the typical room noise floors would likely mask such low-level behaviour, rendering such a possibility quite moot.
Hopefully more voices on both sides of the coin will chime in.
Thinking out loud here: could it be possible that the extremely thin cone of high-DDR drivers are more susceptible to allowing backwaves to pass through? These backwaves then create response and energy storage anomalies that are perceived as DDR. Dunno.
I also feel that a high resolution burst decay and CSD (50 dB scale or more) may go some ways in trying to quantify DDR. But that'd only be possible in an anechoic chamber with a low noise floor. However, the typical room noise floors would likely mask such low-level behaviour, rendering such a possibility quite moot.
Hopefully more voices on both sides of the coin will chime in.