[JohnR]

Nice build, Teflon!

[JohnR]

How does the speaker stay out of its on way to produce highs and lows at the same time?

Hi eclein, the question doesn't make sense. (Sorry...) Any driver has to produce a range of different frequencies. With a typical two-way crossover, a driver may be producing frequencies ten to a hundred times higher than the lowest frequencies.  With a full-range driver - and accepting some limitations inherent to the driver - you may be talking several hundred times for highest frequency over lowest. It's a matter of degree, gradations, and compromises. While many like to choose their own compromise and then paint it as a black-and-white issue (and beat everyone else over the head with it), many others feel that a little forgiveness and greyness may give more love, when all is said and done.

Now, as for breaking in these little FR89s... I'm driving them pretty hard  Anyone here heard of Midnight Oil - their second album is one of my favorites - http://en.wikipedia.org/wiki/Head_Injuries  

[Cacophonix]

I think eclein is asking how a single driver is be able to reproduce two different frequencies at the exact same time?

[JohnR]

All drivers have to do that  [Heh heh edit... doen't Bose sue anybody for having the P taken of of them all the time?]

[JLM]

With harmonics, virtually all music involves playback of complex waveforms.  When you consider the driver's job reproducing (trying to reproduce) the sound of each bristle of a brush striking a cymbal at once it can boggle the mind.

[JohnR]

I think eclein is asking how a single driver is be able to reproduce two different frequencies at the exact same time?

Sorry, let me try to provide a more helpful response than my last one

Any "signal" (such as that coming out of a CD player) could be said to consist of a range of frequencies. By the conventional measure, those frequencies encompass 20 Hz to 20 kHz.

A device that takes a signal as input and produces a signal as output does something to that signal. Ideally (for us anyway) it would simply magnify that signal - the output is exactly the same as the input, but with more voltage or current. Take the (idealistic) power amplifier for example. It gets an input signal; which it magnifies in voltage and then produces on its output terminals. Because of its nature, it is also provides a substantial increase in current capability - which a low-impedance device such as a loudspeaker will happily use. In other words, the amplifier can drive a loudspeaker with the full range (20 Hz - 20 kHz) of frequencies that we expect to come off the CD.

Now, if we look at the loudspeaker itself, an idealistic/simplistic loudspeaker would simply take whatever electrical signal the power amplifier delivered to it, and convert it into the equivalent acoustical signal, which after a short time delay you would hear. Thus, the default scenario is one in which a single loudspeaker driver generates an acoustical signal that is equivalent to the electrical signal which is coming from your source device. If your amplifier can amplify the full range of frequencies coming off the CD in both voltage and current, then the loudspeaker driver should do the same in converting the electrical signal into an acoustical one.

So, the question should not be "how a single driver is be able to reproduce two different frequencies at the exact same time" but "why is a single driver not able to reproduce two different frequencies at the exact same time"?

Let me know if that makes sense so far

[eclein]

Thanks guys...yep I was thinking about how say a Cymbal crash and Low Tympani strike that were both done at the same time could be reproduced effectively with a full range driver. I'm not saying one system is better then another I'm just curious as to how it all works. I see drivers like on the Zu speakers with that extra small inverted cone inside the the normal cone and I was thinking is that how you get both sounds at the same time.
I know that in a 2-way or higher system the high note would go to one driver and the low note to another and they would be able to make that happen at the same time. So I was curious how that could happen with only one driver.
 I understand exactly what your saying John....I'm thinking two people originally play two different notes (note A)(note B) at the same time and how does a full range driver play that info but I'm over simplifying it, what is created by those two notes being struck at the same time is a signal that represents both A & B combined, I think....
 I think its time that I start reading more about the technical aspects of this hobby...

[JohnR]

Thanks guys...yep I was thinking about how say a Cymbal crash and Low Tympani strike that were both done at the same time could be reproduced effectively with a full range driver.

Well... why not? If you think about it, when you were there (at the hypothetical event where that happened) then you heard both the cymbal and the tympani at the same time, right? And if there were a microphone there that captured both of those for a recording, it got both of them at the same time. Right?

So why (fundamentally) couldn't a loudspeaker do the opposite of what the microphone did (in capturing that signal to put on the recording in the first place)?

[Teflon]

Think of it this way, the speaker cone "doesn't know" it's producing two frequencies or more, it simply moves in response to the changing current flowing through the voicecoil. This waveform is the music and the cone follows it's movement. Analysing the music by considering it to be the sum of many different frequencies is a convenience for us, not the speaker

[eclein]

Thanks Teflon....I got it now.

[Russell Dawkins]

Another way of thinking about this is to first realize that all of the complexity of any sound we hear is being sensed by a single small diaphragm on each side of our head.

All of the sounds produced by the most complex source - a large orchestra, for example, can be thought of as resolving to the movement (in three dimensions) of a single molecule of the air that our eardrum is sensing.

In reality, of course, we are sensitive to a small mass of molecules, but all this resolves to the simple (relatively) in-out motion of the eardrum. This is reproduced by the simple in-out movement of the single driver cone.

Just as the eardrum can only and need only be in one position at any one instant to capture this phenomenon fully, the same is true of a cone.

[Teflon]

hey eclien, I like your avatar - I'm old enough to remember when this was a tv advert in england for blank cassette tapes

[doorman]

Maxell, or Memorex??
So old I can't remember!
Don

[eclein]

I'm 53 so I remember... I think. 

[Russell Dawkins]

"Maxell, or Memorex??
So old I can't remember!
Don"

Maxell: http://www.youtube.com/watch?v=B2WcBi9mu6A

Memorex was the breaking glass.

[Teflon]

Yup, that's the one !

We should co-opt and edit the sound track from that video to make something along the lines "Full Range Drivers - blows you away" - who's up for it ??

[jeffh]

I don't know about the FR89EX but I just made a pair of 2litre flare-slot ported desktops using the FR88EX which looks a remarkably similar driver - also 3" so perhaps this is of interest.

Teflon,

Those speakers look great. I have been looking for a small project like that.  Are the plans available anywhere?

Jeff

[Teflon]

Plans: not sure if this forum allows big enough images to read it, if not, PM me your email and I'll send you a pdf file.

[JohnR]

Link to post with bigger drawing (it's OK, we're not insecure here) -

http://www.diyaudio.com/forums/full-range/175056-martello-enclosure-fr88ex-3.html#post2372793

[JohnR]

Back on the FR89EX - these sound a lot "bigger" than they are. Something about very small baffles perhaps? Admittedly I am using them with a sub