Hello!
Some asked where I did anechoic chamber tests...
My invention crossover tests were done at tech center at Binghamton University, about 4 miles from my home. Wife taught there (retired).
RIMO.
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Thanks @audiocaseevan
His posts were such a ramble I found it hard to find anything specific, but "hooray me."
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@erik_squires
looks like he cites ‘Binghamton University’ as the University with the anechoic chamber that corroborated his measurements in his first post to this thread.
Thanks for sharing your knowledge of crossovers with us! Great post.
-Evan |
RIMO :
What university did you use for the anechoic chamber?
And what you are describing hearing is more akin to comb filtering. What speakers were you listening to?
Erik
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Hello!
Mr. Squires is correct when I said no crossover can sometimes be best choice for a loudspeaker system, even if is denial of my work on infinite slope patents, including new patent this year, discussed in previous postings.
My design approach has always been to maximize towards uniform spectral energy in listening room, which with infinite slope means no sweet-spot and flat frequency response in entire listening space, limited only by polar response of drivers in box. Recent patent also achieves good time response, as observed in FFT measurements in home lab and in Tech Center at University's anechoic chamber.
Expensive speakers with elaborate crossovers often fail. Recently I heard example of non-uniform spectral energy distribution from a $30,000+ box. As I sat, I moved head slightly back and forth, no more than 6". The sound changed. Rising and moving about in listening room, I heard many sounds. Some months ago I was demonstrating my 2-wy prototype in same room with myself and 3 others, everyone observed SAME sound balance everywhere in room! That's uniform spectral energy at work! No sweet spot! Here's the catch - the box with no crossover and small driver has also no sweet spot! Uniform spectral energy!
Therefore you can approach uniform spectral energy with one good small driver in a box, no crossover, and some bass enhancement by bass-reflex loading. System gets midrange OK, with loss at frequency extremes, and distortion from cone breakup at high frequencies (generally 4KHz and above). Generally sounding well at low power and on material not too challenging, for easy listening for non-critical audiophiles who listen for the music and not the sound.
RIMO
RIMO
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Erik
+1 for this topic.
this topic is why Dennis Murphy... and a few others... are geniuses in this area... when they do their best work... you don’t even know there is a crossover at work!
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Hey there @RIMO,
Listen, I'm having a real tough time following your meaning. First you post some really interesting things about crossover design and then you write that the best crossover is no crossover.
Aren't you essentially denying your own work?
Erik
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Hello!
I saw my recent post just finished, and noticed "dentdog's" post right above mine. He said to "do without a crossover" He's right and correct. Install a very-good 4" or 5" driver without crossover in a "transmission-line" box (lossy bass-reflex) and acheive near-perfect reproduction over much of the audible frequencty range limited only by driver performance. Try a coaxial driver, can be larger up to 8" for more bass (and larger box). System will have nearly flat frequency response and linear phase over much of audible frequency range in midrange but with limited sound power. There will be no sweet spot (limited only by driver polar response). If you live in apartment and cannot play loud, and can do without low bass, this kind of system will do well on small-combo jazz and classical chamber music. Observe if a coaxial it may have built-in crossover which may not work as well as no crossover.
Mechanical crossover ("wizzer cone") might be OK.
RIMO
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Hello!
At age 81 I say I've been doing speaker crossovers for about 60 years. Began in college in late 1950's. By late 1990's I thought I was finished, holding patents licensed to Joseph Audio's lineof "infinite-slope" loudspeakers. License expired in 2005 and I went into blessed retirement atage 67. Thought I was done but......
Forget Joseph's record winning "best-sound" at audio shows and well-regarded reviews in audio press. Three pesky audiophile friends all owning Joseph's products demanded better sound from me and pushed me at age 79 in 2017 to perform research into possible improved crossover performance. Retrieved my notes now housed in local tech museum which led me to try idea: Merge my infinite-slope theory (based on high-selectivity filters in radio circuits) with "constant-resistance" technology.
Modeled crossovers in computer merging both concepts. Looking for a way to optimize frequency-response and time-response in midrange frequencies simultaneously, something I have only been able to attain nearly optimum in either frequency or time but not in both.I needed to minimize errors in both. By late 2018 I had models which in cyberspace appeared to have flat frequency response and linear-phase (flat time response) through midrange!
Built and tested physical crossovers, finished 2-way prototype speaker system.Prototype worked well in frequency-time measurements in my home instrumentation (FFT analyzer, 1/3 octave pink noise, etc.) showing flat frequency response, seamless "join" at 2KHz crossover! Repeat tests in anechoic chamber at Binghamton University which corroborated measurements. Box even had decent square-wave response 150Hz-2.5 KHz.
Listen test with 3 Joseph owners (myself included) at home lab and in audio showrooms and 2-way prototype had easily discernible "best-sound" against 3-pairs of Joseph Pearls, as well as against other $33,000+ loudspeaker systems. Word came out and I was invited to demonstrate speakers before audience of 300 at a symposium in August, with great success!
Installed 3-way invention crossover in three sets of Pearls, with astonishing results. Happy pesky audiophile friends rejoiced.! With performance validated, filed patent on July 2019.
RIMO
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Erik you are spot on ,that is why I Always recommend upgrading or modifying the Loudspeaker Xover for
over 85% of speakers have average at Best quality a Xover parts, What is the heart of the Speakers and can make a Dramatic sonic improvement if voiced correctly ,Quality most certainly count. |
Amateur application of bi-amping with DSP for example misses several critical functions that a good passive crossover performs.
The bad pattern of DSP crossovers usually goes like this: 1 - Set arbitrary crossover points, with extremely high slopes (4th or higher) 2 - Use global EQ to hammer the design into place. I wouldn’t say amateur, I would say naive. I encourage everyone who wants to learn more, get the tools and ask for help from experienced builders. |
very well said- and not understood by many. Some of those functions are not necessarily available in active systems and as such people assume active is always better which is not the case.
Amateur application of bi-amping with DSP for example misses several critical functions that a good passive crossover performs.
However there is lots of art and black magic "taste testing" etc that goes into the equalization "voicing" phase of the design. More black magic happens when the crossover frequency and slopes between drivers is selected- they can sound completely different for better or worse depending on the frequency- and change radically going up or down half an octave or so. Voicing and frequency selection can make or break the sound of a speaker- even with the best drivers and enclosures- and it is very subjective, you really need golden ears to make some magic. |
I don't know if anyone noticed but I did not ascribe any sort of desirability to my list.
That is, I point out types of things crossovers may be designed for.
And so the trolls go hungry.
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Hi @timlub!
Thanks for the kind words.
Those discussions are happening on Audiogon from time to time. When I wrote my post I wanted to stick to those things which are not arguable.
I am confident that D'Apppolito and Toole would agree with everything I wrote up there.
The target curves, quality of a type of filter, and component parts are all areas we can discuss but which fall far short of universally agreed to electro-acoustic physics.
Best,
E
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Very well said Erik. The only thing that I might add is parts selection in crossovers.
The type and quality of caps and resistors change the character of how a speaker sounds. The coils combined with the resistance and inductance of the drivers also change phasing. As well as how a steel core, an iron ferrite core vs and air core sound.
Nice write up brother. |
This could be a very interesting thread. For example: do high order crossovers (24 db/oct.) rob the drivers of speed and dynamics?
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Group delay, phase response, blending of sound from each driver at the crossover frequencies, and flat frequency response "in your room", are most important IMO!
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Thanks @asvjerry -
I just described a type of technology and gave some idea of it's uses and parameters. It's physics, so I'm not really going to engage with the peanut gallery on it. It will be useful to those who like to talk speaker tech and DIYers, and drive the trolls a little nutty.
Best,
E
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Cross overs are electronic devises (bandaids) for problems inherent in dynamic drivers that can not be fixed (made reasonably listenable) any other way introducing a lot of other problems that make dynamic speakers unlistenable. If crossovers were that bad at what they did, why do the most high end speakers use crossovers? |
So, you've listened to over 2500 different speakers? I dont need to. I listened to the top 10 of each price range. These included the likes of kef, B&w, focal, dynaudio and others |
Cross overs are electronic devises (bandaids) for problems inherent in dynamic drivers that can not be fixed (made reasonably listenable) any other way introducing a lot of other problems that make dynamic speakers unlistenable. Sounds like a Catch 22 to me. The best crossover is no crossover. If you absolutely have to use one a digital one is best. |
*hmmm* Good luck, eric...'gird your loins', as the knights used to advise.
The Horde is gathering... |
Oh Kenjit. You must be one busy guy. Most of the speakers on the market? Impressive! Most, means more than half. You know that, right? Best Buy currently lists over 2000 items in their speaker section. World Wide Stereo lists over 450. Granted, there are some repeats because of color choices etc, but that is a LOT of speakers. and only two retailers. Suspect it isn't a stretch to suggest that there are currently over 5000 different speakers being manufactured. So, you've listened to over 2500 different speakers? And have done so with a critical ear to fully grasp the complete sonic picture each of them makes?
Surprised you have not worn out your "Golden Ears"
Oh, right, the post. Yeah, I guess crossovers do do a lot of things :)
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Danny Richie explains all in his series of GR Research Tech Talk Tuesday You Tube videos. |
In my continuing efforts to encourage informed dialogue, I want to talk about how much a speaker crossover has to achieve, sometimes simultaneously.
"Sometimes"? |
Please invent a complex crossover with at least twelve different variable control knobs, so that kenjit can experiment to his heart's content with an infinitude of perms and coms of all the different parameters. |
I have a theory that Kenjit and erik_squires are the same person. That’s pretty rude, especially given I tried to help you find an amplifier. Is there a specific point you wish to make, @mayoradamwest? Or are you just being a troll because it's Sunday? |
I have a theory that Kenjit and erik_squires are the same person. |
Speakers need to be tuned by ear by the owner not by the designer. Simple as that. There are no hard and fast rules about how to do a crossover. Ive heard most speakers on the market. Most of them sound horrific even though they have been tuned by experts using all the measurements and tools. Obviously, something has gone wrong. The point is, designing a crossover, whether active or passive, is not as simple as often assumed. Active is simple. You have less variables with active than passive. |
