Infinite Slope by Joseph Audio, please explain
BKo127
Could someone please explain Joseph Audio's Infinite Slope crossover? How it
works and what it does? I'm just curious, and does Joseph Audio have a
website? There's none listed at WWWHIFI. Thank you.
BK
AudiolabPA
I copied Jeff Josephs reply to this question for you.
"The patented "Infinite Slope" Crossover is one of the key technologies
responsible for the superior sound of our speakers.
Individual loudspeaker drivers (woofers, tweeters, midranges) cannot accurately
reproduce the full range of sound detectable by the human ear. For this
reason, crossover networks are employed, dividing the sound, and directing it
to the appropriate driver, thereby allowing the drivers to be combined into a
speaker system that can reproduce the audible range with improved accuracy.
The "slope" of a crossover refers to how its rolloff appears on a graph of
sound level versus frequency. Crossovers are charted in decibels (dB) per
octave. The faster the rolloff, the steeper the slope when it is graphed.
Before the invention of the Infinite Slope Crossover, typical crossovers
featured gradual slopes from 6dB per octave to 24 dB per octave -- in a two way
speaker system featuring a single woofer and a single tweeter, this meant that
as one driver was gradually reduced in sound output, the other would gradually
increase, allowing a broad part of the spectrum where both drivers were
producing sound.Because the drivers were often of differing sizes,shapes,
materials and play from different points in space,
the drivers interact with one another. This well-documented interaction, known
to loudspeaker scientists as "Wave Interference" is a serious obstacle to
building accurate speaker systems. Even if a speaker exhibited perfect
behavior on one axis when measured in
a anechoic testing lab, a small shift from that point would destroy the
accuracy of the system.
Slow-slope crossovers also present other problems. The drivers
must be chosen not only on the basis of how they respond to their
part of the range, but also with concern about how they react outside their
optimum range. Tweeters must be selected that can handle the additional low
frequency energy without self-destructing.
Exotic woofer/midrange cone materials such as Aluminum, Kevlar, and Hexacone
exhibit lively activity at high frequencies that slow slope crossovers cannot
attenuate satisfactorily. Loudspeaker designers excited by the midrange clarity
and dynamic snap of these materials cannot use these drivers without adding
additional circuitry to tame the high frequency resonances.
Our "Infinite Slope" crossover resides in the speaker cabinet, just like
conventional networks. It is not an active filter. It is not a DSP chip. It is
a passive circuit (some would say "passive-aggressive") that is carefully
designed to maximize the performance of the speaker elements while providing a
convenient standard connection to the system's amplifier or receiver. The
speaker system presents an easy load to the system's amplifier, getting the
most out whatever amplifier you decide to use--whether tube or transistor."
All I can say is they sound great.
David
bko...@aol.com (BKo127) Wrote
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Mikeylikst
>From: audio...@aol.com (AudiolabPA)
>"The patented "Infinite Slope" Crossover is one of the key technologies
>responsible for the superior sound of our speakers.
While I am aware that they make an excellent product, it is entirely possible
to make great, even world class systems without "infinite" slopes. Dynaudio,
Focal, Dunlavy, just to name a few.
>Slow-slope crossovers also present other problems. The drivers
>must be chosen not only on the basis of how they respond to their
>part of the range, but also with concern about how they react outside their
>optimum range.
And there are plenty of great examples of 6,12,18,24 db xovers in world class
speakers.
>Tweeters must be selected that can handle the additional low
>frequency energy without self-destructing.
>
>
Like the Dynaudio D28/2 with an fs of 880Hz.
>Loudspeaker designers excited by the midrange clarity
>and dynamic snap of these materials cannot use these drivers without adding
>additional circuitry to tame the high frequency resonances.
So?
>Our "Infinite Slope" crossover resides in the speaker cabinet, just like
>conventional networks. It is not an active filter. It is not a DSP chip. It
>is
>a passive circuit (some would say "passive-aggressive") that is carefully
>designed to maximize the performance of the speaker elements while providing
>a
>convenient standard connection to the system's amplifier or receiver.
So in other words, they use drivers with a nturally steep rolloff of their own.
This way a 1st order circuit, causes an accoustic rolloff that is very steep.
There is no such thing, in anything I have ever read on the subject of
crossovers that describes anything other that the normal slopes.
The
>speaker system presents an easy load to the system's amplifier, getting the
>most out whatever amplifier you decide to use--whether tube or transistor."
>
>
>All I can say is they sound great.
>
>David
No argument.
Mike McKelvy
No one ever went broke
underestimating the taste
of the American public.
Jeff Joseph
>>From: audio...@aol.com (AudiolabPA)
>>"The patented "Infinite Slope" Crossover is one of the key technologies
>>responsible for the superior sound of our speakers.
>While I am aware that they make an excellent product, it is entirely possible
>to make great, even world class systems without "infinite" slopes. Dynaudio,
>Focal, Dunlavy, just to name a few.
Hello Mike!
I'm sure there could be a lively debate in rec.audio.opinion about what
constitutes a "world class" system. The posting that Dave (AudioLab)
quoted was an explanation of our technology, in direct response to
the question "What Is Infinite Slope?"
>>Slow-slope crossovers also present other problems. The drivers
>>must be chosen not only on the basis of how they respond to their
>>part of the range, but also with concern about how they react outside their
>>optimum range.
>And there are plenty of great examples of 6,12,18,24 db xovers in world class
>speakers.
Exactly my point.
>>Tweeters must be selected that can handle the additional low
>>frequency energy without self-destructing.
>>
>>
>Like the Dynaudio D28/2 with an fs of 880Hz.
Perfect example of a driver designed to withstand the added low frequency
stress of slow slope crossovers. Happily we can use a tweeter that has
a higher f(s) but exhibits smoother response at a lower cost.
>>Loudspeaker designers excited by the midrange clarity
>>and dynamic snap of these materials cannot use these drivers without adding
>>additional circuitry to tame the high frequency resonances.
>So?
By not including LRC networks to tame those resonances, we can simplify
the signal path, reduce cost by eliminating unecessary parts, and preserve
a nice impedance curve with low phase angles in that region.
>>Our "Infinite Slope" crossover resides in the speaker cabinet, just like
>>conventional networks. It is not an active filter. It is not a DSP chip. It
>>is
>>a passive circuit (some would say "passive-aggressive") that is carefully
>>designed to maximize the performance of the speaker elements while providing
>>a
>>convenient standard connection to the system's amplifier or receiver.
>So in other words, they use drivers with a nturally steep rolloff of their own.
> This way a 1st order circuit, causes an accoustic rolloff that is very steep.
>There is no such thing, in anything I have ever read on the subject of
>crossovers that describes anything other that the normal slopes.
No Mike, the drivers do not have a "naturally steep" rolloff of their own.
The Infinite Slope crossover is not a standard topology that you will find
in a textbook. It is decribed in US patent #4771466.
The creator of Infinite Slope, Richard Modafferi, was Senior Engineer at
McIntosh Labs- where he designed the MR-78 tuner (with a patented "RIMO"
filter) He is the Chief Engineer at JosephAudio.
> The
>>speaker system presents an easy load to the system's amplifier, getting the
>>most out whatever amplifier you decide to use--whether tube or transistor."
>>
>>
>>All I can say is they sound great.
>>
>>David
>No argument.
>Mike McKelvy
None here either!
According to The Audio Critic (issue 24)
"this is a major advance in crossover design"- David Rich
"...I am always happy to come across an audio device that performs in
every way as represented by its makers, and this is one of them"
"The impedance curve of the RM7si in magnitude above the box-influenced
frequencies, varying only from 7 ohms to 12 ohms. I n the entire
audio range, the phase variations are also small, with +/- 20 degrees
the biggest swings above the tuned box range. I bet Rich Modafferi did
that on purpose, to allow you to use just about any half decnt amplifier
to drive the speaker."
"The audible outcome of all these good desing characteristics is very
favorable, the speaker has a basically neutral tonality, with very smooth
highs, a thoroughly transparent midrange, and a surprsingly solid
satisfying bottom end. The soundstage is open and plausible; the imaging
is all it should be. The total noninterference of the two "brick-walled"
drivers is clearly an advantage, with no negative aspects that I can
discern (all you first-order crossover cultists take note-- maybe you've
got it all wrong, huh?) The totally low-end protected tweeter can be
played louder , and the absence of interference patterns in the crossover
region appears to remove a layer of veiling that I often hear in speakers
with lower-order crossovers. So--- what we have here is indisputable
high-end loudspeaker sound in a compact package, at a price still well
below the loony category. Only the deepest bass is missing , but you know
that coming in , just by looking at the size of the box. the JosephAudio
RM7si is therefore highly recommended" - Peter Aczel
(from the review of the $1299/pair RM7si in Issue 24 of the Audio Critic)
Jeff
--
* JosephAudio (Infinite Slope Speakers) *
* Internet: kil...@panix.com *
NigelBD
Jeff:
To quote you:
>The Infinite Slope crossover is not a standard topology that
> you will find in a textbook. It is decribed in
> US patent #4771466.
Then why all the online and marketting material BS??? I've never seen such
obfuscation outside of Shun Mook's marketting.
I don't think anyone asked for the WHY it's better, just a simple
semi-technical explanation of the filter topology, and wether they are truly
infinite slope, or just very high slope crossovers.
Hiding behind this much BS really makes me wonder wether you even beleive in
your own crossover designs.
Regards,
Nigel
Jeff Joseph
In <199805042258...@ladder03.news.aol.com> nig...@aol.com (NigelBD) writes:
>Jeff:
>To quote you:
>>The Infinite Slope crossover is not a standard topology that
>> you will find in a textbook. It is decribed in
>> US patent #4771466.
>Then why all the online and marketting material BS???
marketing BS? Huh? Where?
I've never seen such
>obfuscation outside of Shun Mook's marketting.
Well, I'm sorry you feel that way, but I don't know what you're talking
about. I didn't come on the newsgroup and spam away. In fact I didn't post
that response in this thread - David from AudioLab did. It's a general
description of what a crossover is, and why ours is different.
I actually emailed it directly to the original poster without posting it.
>I don't think anyone asked for the WHY it's better, just a simple
>semi-technical explanation of the filter topology, and wether they are truly
>infinite slope, or just very high slope crossovers.
I'd be glad to provide a semi-technical explanation, but I was really only
responding to correct an earlier poster's statement that our design
used some special drivers with a steep rolloff of their own (which, of
course, we don't!)
The Infinite Slope crossover works by shifting a pair of zeros from
infinity to a cluster of poles. this is accomplished by the use of
a pair of mutually coupled inductors.
>Hiding behind this much BS really makes me wonder wether you even beleive in
>your own crossover designs.
>Regards,
>Nigel
Not only do I believe in our crossovers, but so do reviewers from
Stereophile, The Audio Critic, and Audio magazine. They've each measured
and documented the technical excellence of the Infinite Slope design.
As for the question posed earlier- is it really infinite?
the answer is no- such a crossover is considered impossible to
physically realise. However, at 120 dB per octave (it drops this quickly
for the first 42 dB) it is sufficiently steep enough to realize the
benefits of an Infinite slope, could one be built.
By the way, try giving them a listen sometime. It's easy to get mired
in technical issues and forget what it's all about: The music.
Sunshine Stereo (Steve Zipser)
NigelBD wrote:
>
> Jeff:
>
> To quote you:
> >The Infinite Slope crossover is not a standard topology that
> > you will find in a textbook. It is decribed in
> > US patent #4771466.
>
> obfuscation outside of Shun Mook's marketting.
>
> semi-technical explanation of the filter topology, and wether they are truly
> infinite slope, or just very high slope crossovers.
>
> your own crossover designs.
>
> Regards,
>
> Nigel
Nigel:
I do not sell Jeff Joseph's speakers, but I sold the forerunners (JSE
Infinite Slopes) years ago. The crossover design is a product of
Richard Modifiere - who is the brilliant designer of the McIntosh MR-78
tuner - and he is absolutely brilliant when it comes to filter theory &
design. The designs are patented, and you can read all about them.
There is no hype, and no bullshit - except in your post. You are
completely off bass with your post.
The fact is his speakers are excellent. Jeff, himself, is a terrific
person and he is as honest as they come. I cannot fathom why you would
attack someone like Jeff Joseph. Do not for a moment mistake him for
marketing weasels like Dave kersh.
Cheers
Zip
--
Sunshine Stereo, Inc http://sunshinestereo.com
Tel: 305-757-9358 Fax: 305-757-1367
9535 Biscayne Blvd Miami Shores FL 33138
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*** ENJOY THE MUSIC! ***
youn...@vislab.com
> By the way, try giving them a listen sometime. It's easy to get mired
> in technical issues and forget what it's all about: The music.
I must agree with Jeff here as his speakers are some of the best sounding
out there, IMO. Specially, the RM7si signature which is a great
sounding speaker for the size and price ( a classic) as well as RM22 and RM50.
Also, not only do they sound great but also look great, a big plus.
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/ Now offering spam-free web-based newsreading
Stats
> > By the way, try giving them a listen sometime. It's easy to get mired
> > in technical issues and forget what it's all about: The music.
So are there any Joseph Audio authorized dealers located anywhere
near Chicago or Milwaukee?
Dana
NigelBD
>marketing BS? Huh? Where?
>
>
I thought an earlier post gave all the reason's Infinite Slope crossover's
would sound better, but no clear technical information. Perhaps being online
so long has sensitised me to this. :)
>I didn't come on the newsgroup and spam away.
Thank you.
> and why ours is different.
>I actually emailed it directly to the original poster without posting it.
>
>
Ahh, I may have taken your post out of context then, in which case I apologise.
>The Infinite Slope crossover works by shifting a pair of zeros from
>infinity to a cluster of poles. this is accomplished by the use of
>a pair of mutually coupled inductors.
>
>
Great information, thank you. This is the sort of stuff I was hoping to see,
as I've been very interested in the crossover design since I first heard about
it.
>By the way, try giving them a listen sometime. It's easy to get mired
>in technical issues and forget what it's all about: The music.
>
>
I'd love to, but I'm in Massachusetts, our selection of high end gear is rather
limited I'm afraid, despite having so many manufacturers in this state.
Nigel
NigelBD
Zip:
>The crossover design is a product of
>Richard Modifiere - who is the brilliant designer of the McIntosh MR-78
>tuner - and he is absolutely brilliant when it comes to filter theory &
>design.
I wasn't attacking him or his design, just the post wich seemed very "soft" for
the question originally asked. I'm glad to see Jeff's added some thickener to
the information on this post.
> The designs are patented, and you can read all about them.
Gee Zip, I don't have very easy access to the patent files, do you?
>There is no hype, and no bullshit - except in your post.
No, not when the post is taken in the context of not being an answer to the
original question of how they work. But in that context, which I thought it
was, it seemed that way.
> I cannot fathom why you would
>attack someone like Jeff Joseph
Read carefully, I didn't attack Jeff. Just the post, which in case I haven't
made it clear, I took out of context, and I apologise for it.
Nigel
Dennis Yarak
In article <199805052350...@ladder01.news.aol.com>,
nig...@aol.com (NigelBD) wrote:
> Zip wrote:
>
> > The designs are patented, and you can read all about them.
>
> Gee Zip, I don't have very easy access to the patent files, do you?
>
If you have web access & a browser, you do.
Armand
In article <199805052350...@ladder01.news.aol.com>, nig...@aol.com says...
>
>Zip:
>
>>The crossover design is a product of
>>Richard Modifiere - who is the brilliant designer of the McIntosh MR-78
>>tuner - and he is absolutely brilliant when it comes to filter theory &
>>design.
>
>I wasn't attacking him or his design, just the post wich seemed very "soft" for
>the question originally asked. I'm glad to see Jeff's added some thickener to
>the information on this post.
I must admit Jeff's response was lacking. But you can get more info from the
Audio Critic review. Just spare yourself the condescending "Uni-Bomber" commentary.
And remember, it is proprietary. Shhh..... ;}
Armand
Mikeylikst
>Infinite Slope by Joseph Audio, please explain
>From: kil...@panix.com (Jeff Joseph)
My apologies, having not seen any information on this type of xover, I shot
form the hip. I look forward to reading more about this circuit topology.