Nipper1,
You've thrown a lot of weird curveballs into this thread, starting with some not-great advice (randomly swapping caps as the first fix for some speakers); and then the bit about discrediting everyone that doesn't know exactly what swapping a mouthpiece on a French horn would do; and finally clinging to your insistence that working at Bell Labs has made you orders of magnitude more knowledgeable than everyone else on the forum.
So, I had a quick look at the Wiki page on Bell Labs. Wanna know how many mentions there are of loudspeaker design? None what so ever.
I know they did do some work with speakers, but I don't think you could argue it was top priority for the R&D department.
If you'd like to compare credentials, I'm a live sound and studio engineer. I work with acoustic instruments almost daily. I play some of them. I also have a Physics degree, and put that to use designing speakers which I use for home HiFi as well as for professional sound reinforcement. In both cases, listeners are often very impressed with the results.
So, when you say something like
I have to call BS. The effects you're talking about would be a component that is seriously malfunctioning and ought to be replaced immediately. No exceptions. If you work through the physics, component non-linearity (stuff like capacitor inductance) shows up at radio frequencies, and if your amp is putting out frequencies that high, you've got bigger problems.
I don't think for a moment that the components in the Dynaudio speakers are malfunctioning, and given that, I think other avenues for improving the sound should be explored. Their crossover appears adequate.
I'd try the following:
- More cabinet bracing
- Ensuring the port isn't leaking midrange
- Room treatment
After some response sweeps at various levels to confirm the speakers aren't being pushed outside of their limits.
Chris
You've thrown a lot of weird curveballs into this thread, starting with some not-great advice (randomly swapping caps as the first fix for some speakers); and then the bit about discrediting everyone that doesn't know exactly what swapping a mouthpiece on a French horn would do; and finally clinging to your insistence that working at Bell Labs has made you orders of magnitude more knowledgeable than everyone else on the forum.
So, I had a quick look at the Wiki page on Bell Labs. Wanna know how many mentions there are of loudspeaker design? None what so ever.
I know they did do some work with speakers, but I don't think you could argue it was top priority for the R&D department.
If you'd like to compare credentials, I'm a live sound and studio engineer. I work with acoustic instruments almost daily. I play some of them. I also have a Physics degree, and put that to use designing speakers which I use for home HiFi as well as for professional sound reinforcement. In both cases, listeners are often very impressed with the results.
So, when you say something like
I have to call BS. The effects you're talking about would be a component that is seriously malfunctioning and ought to be replaced immediately. No exceptions. If you work through the physics, component non-linearity (stuff like capacitor inductance) shows up at radio frequencies, and if your amp is putting out frequencies that high, you've got bigger problems.
I don't think for a moment that the components in the Dynaudio speakers are malfunctioning, and given that, I think other avenues for improving the sound should be explored. Their crossover appears adequate.
I'd try the following:
- More cabinet bracing
- Ensuring the port isn't leaking midrange
- Room treatment
After some response sweeps at various levels to confirm the speakers aren't being pushed outside of their limits.
Chris
Bell Labs did very little with loudspeakers that's true. They did, however have a very huge impact on the study of acoustics, sound "quality", etc. ever since day one. I have no clue what they are up to these days under Nokia; I just know what they used to do and how much of a significant impact they had.
What about Edward C Wente?
One can interpret phase from lissajous curves by sight and plot them with a SOA HB pencil with comparable results.
GREAT, love it! The original Acoustic Research AR-1 had a Western Electric 8 inch full range that was used as a tweeter.
Speaker System AR-1 Speaker-P Acoustic Research Inc.; Cambri
The earliest movies with sound were by Western Electric; I remember even silly things like the sound on Bugs Bunny cartoons was by Westrex
A number of symmetrical, narrow dispersion, usually exponential horns can be combined in an array driven by a single driver to produce multicell horns. Patented in 1936 by Edward C. Wente of Western Electric,[9] multicell horns have been used in loudspeakers since 1933 to address the problem of directivity at higher frequencies, and they provide excellent low frequency loading. Their directional control begins to beam both vertically and horizontally in the middle of their target frequency range, narrowing further at high frequencies[2] with level changes as great as 10 dB between lobes.[10] Multicell horns are complex, difficult to fabricate and thus have a higher associated expense. They persisted in public address applications for many years because, even with their faults, they sounded relatively good.[11] The revolutionary coaxial driver, the Altec Lansing Duplex 601 and 604, used a multicell horn for its high frequency component from 1943 to 1998.[12]
And so on...
So now you've read the Wikipedia page on horns and copied / pasted its paragraph on multicell types above, you've decided that Bell did have a lot to do with pioneering loudspeaker design (which they damn well did, as most people with any knowledge of the history of audio is familiar with) after all?
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No, I meant that Bell Labs did not have it's main focus on loudspeaker design as someone else pointed out earlier. They averaged 3 patents a day for a very long time and were involved in more basic research and development than any other company world wide. Some of it was for government classified projects and so that part of it may never be published or known to the general public. They were involved in so many different programs and projects relating to almost anything science; it wasn't just about making a better telephone.
Hah, that's a good one; you did almost the exact, very same thing. I decided not to copy and paste the entire paper; just the section showing another work of the very same inventor you yourself also mentioned. I was agreeing with you on that.
Er, speaking as a practicing academic, I should gently point out that the paragraph you copied and pasted from Wikipedia (without citing said source -one of the greatest sins in academic or popular practice) is not a 'paper'. It is not even remotely akin to a 'paper'. The information contained is correct to the best of my knowledge, but that does not make it a 'paper' any more than any other article, let alone sub-section of an article, on Wikipedia is a 'paper'.
Be that as it may, yes, I think you'll find most people with even a modicum of knowledge of engineering history (such as most people here) are perfectly well aware of all those things, what Bell Labs were and what they did. You are not telling anybody anything new here. And every one of their former engineers that I have met or spoken with would, while applauding sensible experimentation, advise people first assess the macro technical performance of a device when attempting to establish the cause of a particular issue, rather than flailing about in the dark changing components for alternatives of identical value without a clue what they are doing, especially since, if these are not the cause of a given issue (which it is probable they are not), there is no way they can fix it.
Be that as it may, yes, I think you'll find most people with even a modicum of knowledge of engineering history (such as most people here) are perfectly well aware of all those things, what Bell Labs were and what they did. You are not telling anybody anything new here. And every one of their former engineers that I have met or spoken with would, while applauding sensible experimentation, advise people first assess the macro technical performance of a device when attempting to establish the cause of a particular issue, rather than flailing about in the dark changing components for alternatives of identical value without a clue what they are doing, especially since, if these are not the cause of a given issue (which it is probable they are not), there is no way they can fix it.
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Yes, of course. Go back to the very beginning of this thread if you would please. Most people don't have access to any high quality test equipment, calibrated microphones, etc. As I said recently, it is a very quick, easy and inexpensive experiment to swap a few components. I also gave a suggestion as to how to do that while still preserving the original crossover. I never tried to say or even imply that it was the best solution or the first choice of things to try to do. The OP was asking about improving sound qualities by upgrading crossover parts. I stand by what I have said as well as others here agreeing with me, sometimes it can make a huge difference (not always obviously).
You don't need access to expensive or high quality test equipment to make a macro assessment of many technical characteristics. Since there are a number of reasonable (well, John Atkinson) measurements available, along with the filter topology and a reasonable knowledge of the drive unit characteristics, that is sufficient in itself to make at least a basic assessment as to where issues lie. And what I said from the off hasn't changed. The balance of probability is that it is simply that the inherent design goals and characteristics of this loudspeaker do not meet those of the listener.
For example, the electrical high pass clearly does not provide particularly strong electrical protection to the tweeter / a heavy limit on its excursion below the XO frequency, and the issues the OP refers to are precisely what could be reasonably predicted from this. This is a basic engineering matter rather than anything surprising. Other examples are apparent enough. None of these can be fixed by swapping components randomly for components of identical value. Thus my advice to the OP holds: don't waste your money buying new components in the hope they will fix what is likely an issue elsewhere. Save your cash, learn a bit more about how speakers work, and what characteristics tend to go hand in hand with what compromises, and replace them with something more to your taste based upon that extra knowledge.
For example, the electrical high pass clearly does not provide particularly strong electrical protection to the tweeter / a heavy limit on its excursion below the XO frequency, and the issues the OP refers to are precisely what could be reasonably predicted from this. This is a basic engineering matter rather than anything surprising. Other examples are apparent enough. None of these can be fixed by swapping components randomly for components of identical value. Thus my advice to the OP holds: don't waste your money buying new components in the hope they will fix what is likely an issue elsewhere. Save your cash, learn a bit more about how speakers work, and what characteristics tend to go hand in hand with what compromises, and replace them with something more to your taste based upon that extra knowledge.
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Say hello to HolmImpulse. It takes accurate measurements. It will measure phase using a single channel. It can gate and smooth, and export for further analysis.. and it's free.
Then there is the Behringer ECM8000. Satisfactory for producing quality speakers and less than $100.
Then there is the Behringer ECM8000. Satisfactory for producing quality speakers and less than $100.
Attachments
Cool, good to know for sure. Just be clear, some of the caps I would recommend only cost $20 to maybe $35 a piece; My most expensive capacitor is an Audyn "true copper foil" that cost just under $70 each. For my super-tweeter circuit, they were too "bright" sounding so now they sit in a box. I replaced it with a $20 Jantzen Superior-Z capacitor which worked much better; more neutral and "musical" to my ears.
Cheers and peace!
Ha! Here we have it! In other words you're saying that even you as a retired Bell Labs engineer are unable to exactly judge the impact of audiophoolished and super expensive capacitors on your own speaker design that you supposedly know very well, don't you? But you dare to encourage the OP to randomly swap capacitors in a speaker that you, also supposedly, don't even know?
Best regards!
Quite the opposite actually. After allowing time for break-in; I realized I didn't like the sound quality. I said many times price of a component cannot necessarily be used as a good indicator of sound quality. I have all the time in the world to experiment which is what I do. Again, I never said or implied component upgrades were the best or first thing one might wish to try; I was trying to explain that yes, higher quality components can and do make a significant difference. As I also said many times; sometimes it makes very little difference. If people were to go back to the very beginning of this thread; you will see how things developed. Again; I have no problem doing a complete and exhaustive test to find the root cause of the problem; again I am saying we have many tricks in the toolbox.
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