Hi Tim
I would have to agree with you on that with horns in a general way and I have a theory why that is.
One can say that loudspeaker flaws come in several flavors. If you ignore where the sound goes vs frequency and only examine the sources, one finds the flaws fall into two general categories. It is the sound the driver makes it’s not told to and not producing the signal it is told to or when it was told to do it.
The “free sound” (distortion and noise) increases in level faster than the desired signal and so at some level, the free sound is strong enough that you judge the speaker is over driven. This problem is somewhat like analogue tape where high levels of distortion are not audible as a flaw if it’s only on short peaks. On the other hand, when compared to not distorted or limited, that case sounds more dynamic.
Everyone knows what clipping sounds like, how bad it sounds but LONG before it makes a sound that you recognize as a flaw, clipping on peaks can simply rob the dynamics. Very few people ever look at their amplifier Voltage with an oscilloscope to see if there is any short or instantaneous clipping at levels they listen at. It is funny how often one finds this to be the case too, people are often robbed of musical dynamics because of instantaneous clipping. This normally doesn’t show on a VU meter or clip lights (which take time to trigger) but an oscilloscope looking at the amp output shows it if present.
Thus, when one switches to a speaker that is say 6 or 10dB more sensitive and if it’s a commercial sound horn, one that can go a lot louder than a direct radiator hifi speaker, one has significantly enlarged the region of linear dynamic operation and raised the level where driver distortion comes into play.
Don’t forget measuring dynamic linearity isn’t something that is normally done, at most some measure power compression but NO speaker company is willing to advertise that ALL voice coil drivers begin to show the effect of VC heating (power compression) typically between 1/8 and 1/10 rated power.
Very few measure to see at what power does the frequency response change significantly or distortion skyrocket.
With these things being unspecified, a proper horn system can be very different, very live sounding. As a 10 dB increase sounds like maybe twice as loud or a bit more, if one has a high efficiency speaker that can go loud, also using a larger amplifier may provide another audible dynamic difference as well.
The down side is horns & drivers like most normal drivers are limited frequency devices but the larger size and not flat raw response makes them that much harder to integrate with an adjacent source (such as a tweeter horn coupling to a mid horn).
The load they present electrically can also make them more difficult to make a crossover for, the famous “horn honk” has usually turned out to be a crossover issue related to the drivers impedance peaks and not an acoustic one, at least in most horns I have played with.
The other potential issue is horns can have significantly more directivty than direct radiators and so an impulsive event emanating from the speaker arrives with less echo or delayed sound behind it.
The cascade of delayed reflected sound is one of those free sounds, they are all tiny snippets of the original signal but delayed and transmogrified according to your room /speaker /listening position geometry.
They all sound real, they are real reflections but they all potentially detract from the original signal which had the recorded image and had already arrived.
In this case, the Energy Vs Time curve for a horn speaker vs a direct radiator, AT the listening position can show significant differences.
The less interaction there is with the room (via directivity), the more like the close up measurements the listening position measurements look AND the direct arrival stands out more as a single big peak with less level trailing off in the time (say 10-30 ms) immediately following. This I think makes the impulsive sound more impactful if that makes sense.
In our Synergy horns, the object there is to make all two, three or four frequency ranges within one horn and using the physical offset of the drivers in the horn to compensate the time delay present in higher order crossovers, so that what emerges appears to have been from one very broad band driver.
In this case, an impulsive signal is reproduced such that all of the harmonic components are preserve in the proper time order so that on a microphone a similar looking signal emerges. This maybe goes one step further in preserving “the real” part of impulsive sounds .
I don’t know if anyone here has Altec A-7’s but I re-worked one of those a while back that turned out very well. By using two modern drivers, a few minor cabinet mods and a new modern computer assisted crossover I was able to greatly extend the bandwidth, eliminate the on axis crossover phase shift and raise the sensitivity too, better than that, it sounded great, effortless. If someone has a pair they are considering re-building, I can dig out my notes, some pictures and crossover schematic .
It is a pretty big speaker for a normal living room though I suppose, sometimes it’s good not to be normal haha.
Best,
Tom Danley
Danley Sound Labs