Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

"Is it possible to cover the whole spectrum, high spl, low distortion with a 2-way?"

That simple question has a simple answer: No! Subwoofer(s) must be added, and the "ways" you divide up the audio spectrum to do so, is 3 or more, not 2. WHG

Yes Bill, I agree, but my point is a little different.

IF all system need subs to be considered ideal then we should seperate the discussions into two parts. The common part - the subs - and the different part - the mains. If we do that then we get a different answer.

I see audio as three main octaves:

20Hz - 100Hz - dominated by the room and requiring a sub solution
100Hz - 1kHz. - a critical region for sound quality
1kHz - 10kHz. - an equally critical region

No single system can cover all three with just two drivers, but the other two can be done quite effectively.
 
I see audio as three main octaves:

20Hz - 100Hz - dominated by the room and requiring a sub solution
100Hz - 1kHz. - a critical region for sound quality
1kHz - 10kHz. - an equally critical region

No single system can cover all three with just two drivers, but the other two can be done quite effectively.
Earl,

I'd be hard pressed to choose just three "main" octaves between 20Hz and 10kHz.

You probably meant "decade" rather than octave, skipping the octave from 10-20Hz, and that other octave that recedes with age, 10-20kHz.

Art
 
Potpourri

Yes Bill, I agree, but my point is a little different.

IF all system need subs to be considered ideal then we should seperate the discussions into two parts. The common part - the subs - and the different part - the mains. If we do that then we get a different answer.

I see audio as three main octaves:

20Hz - 100Hz - dominated by the room and requiring a sub solution
100Hz - 1kHz. - a critical region for sound quality
1kHz - 10kHz. - an equally critical region

No single system can cover all three with just two drivers, but the other two can be done quite effectively.

Hi Earl,

We are not disagreeing here.

It's top-down, wholistic system design, and there are 3 loudspeaker subsystem's to deal with; each, with its own unique design issues and challenges, not to mention the signal conditioning subsystem that is also required to feed drive signals to them.

Latest Thread Topic
Suspension systems while presenting a host of design problems, may also include features that suppress rocking modes and reduce the magnitude of waves traveling through the cone/diaphragm material. It is apparent that suspension (surround/spider) design is not well understood here, as abolition of its use is being promoted by presentation of questionable science.

Earl, you are certainly being kept busy here at the moment!

Regards,
Bill
 
Hi, it was harmonic excitation . Here is a quote from the paper:


Finally, in the third step the same measurements were performed after removal of the membrane cone, leaving only the spider and voice coil (configuration L3).
<...>
It is worth emphasizing that, in the third configuration (L3), for driving currents lower than 1 mA (amplitude less than 0.05 mm), the system can not be put into vibration and measurements were not performed. This was being led us to a conclusion, that there is a considerable amount of residual strain accumulated in the spider material, which in turn acts as a friction giving rise to the over-damped non-oscillatory mode, similarly as in a conventional LRC electric circuit, when R is much higher than ωL. The mass is analogous to the inductance L, and over-damping is stimulated when membrane cone mass is removed. At lower rates of change, residual strain in the spider affects strongly the effective stiffness, and resistance to vibration is higher, that is to say, effective stiffness is higher. For increasing driving currents, that is, for higher rates of change, residual strain resistance is gradually suppressed and effective stiffness decreases, which results to the decreasing resonant frequency.

Doesn't this imply (relatively) high(er) power requirements for extremely stiff spiders, like double and triple layer silicone?
 
Earl,

You probably meant "decade" rather than octave, skipping the octave from 10-20Hz, and that other octave that recedes with age, 10-20kHz.

Art
Yes, orf course. My bad.

Hi Earl,

We are not disagreeing here.

Earl, you are certainly being kept busy here at the moment!

Regards,
Bill

I didn't disagree at all.

These have been some interesting discussions and surprisingly we seem to be moving past "Well it sounds good to me!" as presentable evidence to prove a point. Not much - although some - common erroneous dogma, mostly pertinent issues.

I'd love to see someone do the low signal level test. I could be blindsided on this. And given the fact that IF stiction is an issue then it is a serious issue because we become far more sensitive to nonlinearity at low levels than high levels. A finding of significant effects would be groundbreaking. But I won't be holding my breath as groundbreaking in loudspeakers has been virtually nonexistent in the last few decades.
 
Sticktion, true, i think of the belt servo subs with a bit more distortion below 90db.

Maybe we need a new term ?


How about i have a professional driver, able to withstand 400wrms, for hours.

The spider, surround, cone, etc must be able to take that abuse, all day long, years.

Do you think the driver will flexible as it should (could?) be at less than 10 watts, or will some energy be absorbed by the materials stiff/strong to take 400 punishing watts ?

Perhaps a floppy (high) qms is a helpfull indicator to how well a driver will behave (absorbing signal) going up closer to its cutoff. Not mentioning cone break-up, or mod distortion, or intermod, or energy storage.
 
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This stiction effect makes me think that motion feedback amplifiers could see an interesting revival in order to manage this artefact.

Only IF the effect is common and significant, which has yet to be shown.

Do you think the driver will flexible as it should be at less than 10 watts, or will some energy be absorbed by the materials stiff/strong to take 400 punishing watts ?

If a driver is linear then how it acts at high power is exactly the same as how it acts at low power. If it doesn't then it's nonlinear. All systems are nonlinear at some point, but for the most part, good drivers are linear over there intended operating range.

Since power is dissipated only in the resistive components this problem falls almost entirely in the voice coil, which as we all know, are highly prone to overheating.
 
Currently I am listening to some tech house music through some Totem 2-way Monitors, specs:
<32 Hz - 21 kHz ± 3 dB
2.5 kHz, 1st order
Scanspeak 5.5" long throw miniscule woofer.

Typical one note bass and lacking definition in the midrange > modulation distortion?

In about 2 hours, I'll be listening to the same music through a pair of these beasts:
J1-Front-View-Orange-Horn.jpg
 
smiles.

There is a quality in quantity !!!!!!!!!!!!!!!

lol.

Yea, had a good thump thump sound from my 2-ways today ("Radar love").

And it ain't happening at 40db either.
I thought I needed 6db time alignment, guess not.

And I'm sticking to good sounding horns and 12's crossed at 1.2khz.

I loved my double 15 to 2384 @ 750hz, but with current setup, voice is definitely better.
Better horn, definitely (but crosses higher), and maybe getting crossover point higher up.
Maybe both were little improvements that made the impression of a bigger improvement.

Now to get the bass closer to a double 15, that's what I'm working on.



So, where are we at with the original question ?

Answer is our typical "it depends ?"

lol

either way, great discussion.
 
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