Being a loudspeaker designer, I always thought that the biggest factor in the "jump factor" was the speakers. Going from a dynamic cone point speaker to line-source ribbons would make the biggest difference because the drivers have such low mass (more efficient and effective use of amplifier power), and the way the line-source radiates (- 3dB/double of distance instead of - 6dB/double of distance). Thus, the biggest leap in "jump factor" in my own line is not from the two-way monitor G7p to the 4-way bass amplified G5 (7 times more expensive), but from the G5 to the line-source G2jr (3 times more expensive). Of course, the disclaimer is that this must be in appropriate size rooms for the comparisons.
However, I was humbled in the past 2 months. The biggest change came about with the turntable/tonearm combination. Going from the Xerses 20 + Artemiz to the Air Force One + Vertere Reference made a huge difference in the jump factor of the G2jr.
This was amply displayed on Side 1 Track 2 of this:
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The jump factor is one of the critical elements to fool us into suspending disbelief and getting into a state flow listening to music.
When it comes to speaker design, what is it about the "jump factor" that only very expensive speakers seem to get it right?
Jump factor (as it applies to loudspeakers) is the opposite of compression. Compression is mostly related to thermal issues.
Thermal compression comes in two styles: Long-term and short-term. Both originate from voice coil heating.
Short-term thermal compression could be called thermal modulation, and occurs within milliseconds of a high power signal hitting the voice coil. The hotter voice coil has a higher resistance. This compresses the entire envelope, not just the peaks, so it sucks the life out of crescendos. Once the crescendo passes, the voice coil cools off, but a lot more slowly than it heats up.
Long-term thermal compression happens when the magnet itself starts to heat up and lose strength. It can happen within a few seconds with pink noise but in practice usually takes a lot longer than that with program material. It is normal for a speaker to experience about 1 dB of thermal compression when operated at 1/10th its rated power, and about 3 dB of thermal compression when operated at its rated (by whatever AES standard) power. This isn't totally reliable because nowadays speakers can be made with very high-temperature-tolerant materials that will not fail at temperatures which result in severe thermal compression. There have even been tests in which increased input power resulted in decreased SPL because the driver was already so far into deep thermal compression, but nothing had melted yet.
Back to jump factor. The solution is to have a whole lot of thermal headroom. This can come in the form of high efficiency, or high thermal power handling, or both. If you have one speaker seeing 1/10th its rated power on peaks, while another speaker is taking its full rated power on peaks, the first speaker will exhibit far less thermal compression, both short term and long term. Horns tend to have very high efficiency, and expensive direct radiator speakers tend to have very high thermal power handling, so they both usually have a lot of thermal headroom. My idea of "adequate thermal headroom" is for the drivers to be seeing no more than 1/10th their rated AES power handling on anticipated peaks. This isn't guaranteed to give you that elusive jump factor, but it's a good start, and you're not going to get it if your speakers are suffering from significant thermal compression.
Note that with vintage horn systems, you can probably make your calculations based on 1/5th their rated power handling, because the glues and voice coil formers they had back then would fail at lower temperatures than their modern counterparts so the ratings were more conservative accordingly.
Aside from vintage horn systems (which is where all the killer deals are in high jump factor speakers), imo one of the more cost-effective approaches is to use high quality prosound drivers and beat them into submission with a thorough crossover design.
Having adequate thermal headroom isn't the only thing that matters as far as jump factor goes, but I think it's arguably the most critical.
What about estats that can have that elusive aliveness?
I think that 'jump factor' in uber-expensive speakers comes from over-the-top ease related to both efficiency facing the amplifier and plenty of driver surface (and cabinet design) in the typically difficult to render mid-bass area....
as speakers get less expensive this mid-bass area is more and more compromised, since cabinet size and driver compliment becomes relatively limited. it becomes degrees of 'less good' and the 'jump factor' lowers relatively. sometimes less expensive speakers might have the 'jump factor' but maybe not the bottom octave too. choices get made on what priorities might be to hit price points.
What about estats that can have that elusive aliveness?
Nothing as long as you limit the max SPL. On the low end they can't move enough air, it doesn't matter how big the panel is if you can't get more than 50 mil excursion peaks. They don't have the physical impact dynamic drivers can have especially on the low end.
That can make a big difference depending on the program material.
Rob
The Duke said, "A friend of mine used to have a pair of old SoundLab B-1 electrostatic subwoofers. He had a recording with very strong low frequency content that he claimed would make his vision go blurry on certain notes. That made no sense to me, until I later found out that the resonant frequency of the human eyeball is 19 Hz!"
Right, and thats why I limit my freq response to 30hz. Below that and I start to get a queasy feeling in my stomach! And my system is capable of below 15hz! But I think it does depend on loudness levels, I listen to live sound levels at 110db+.
I know other posters here listen louder still....Bass Pig and Atmosphere do but how low do their systems go?
Wendell
Isn't it because they are using extremely efficient speakers, often horns, and backing it up with some big solid state power?I have often wondered why many PA systems with live microphone feeds running through a mixer have a higher JF than vastly more expensive audiophile systems DESPITE higher distortion. I believe it is all because of higher dynamics, probably resulting from shorter, more direct signal path.
Personally, whenever, I got a new component that increases JF, it typically goes hand in hand with a heightened concern about blowing up the drivers of my speakers; higher dynamics.
Isn't it because they are using extremely efficient speakers, often horns, and backing it up with some big solid state power?
I'm a horn convert for home listening after more than 30 years of various Quad electrostats (with add-on woofs, tweets, etc.) I didn't page back through this thread, but horns can do LOUD effortlessly. The trick is to make them sound good, tonally, without squack, and mate them seamlessly with the bass (unless you have a monster sized horn for the woofs). It ain't easy, but I get the transparency of the electrostat and the 'startle' factor that horns can deliver, provided the source material is dynamic (and otherwise well recorded). The 'cost' in my experience has been to get the right associated components in the chain upstream, and deal with the (noise) issues associated with a speaker that is 104db (or more) efficient.