...Is this what the new "Klipsch" dsp box does to the Klipsch Jubilee, Klipschorn & LaScala loudspeakers to make them sound passable?
The Heritage Jubilee (with internal bass ports) has a similar sort of "smiley" EQ. Here is a plot of the output voltage of the Klipsch-provided DSP box (without external API adjustment that's available to the owners). Note that the bass bin is actually EQed so that it has flat response while being positioned in-room away from the room's walls (at least 3-4 feet). If the bass bin is closer than this, the bass EQ below ~60 Hz must be changed to significantly reduce that big bass boost, otherwise the bass response in the deep bass region below 40-50 Hz will be unbalanced (too much):
The La Scala AL6 with tri-amped DSP option and Klipschorn AK7 with tri-amped DSP option both use a new controlled directivity midrange horn and (I believe) a new tweeter. They both come with passive crossovers, and have the option of being upgraded via the DSP kit that Klipsch sells (for a price). It has been noted that the DSP tri-amp option blows away the passive crossover version in listening trials. Since I wasn't there, I can't personally attest to the magnitude of the difference, but I can say that
my efforts tri-amping a Belle center loudspeaker between two TAD-4002/first gen Jubilees was like the difference between the living and the dead. When I first got the Belle pair, after listening to one of them using only passive crossover between the Jubilees in my listening room, I was ready to sell them. Only after I tri-amped and EQed/time aligned them did the Belle start to become useful in the setup.
The Heritage Jubilee bass bin is "cheating" in that it is losing sensitivity below 70 Hz (as can be seen in the EQ plot above). The Celestion Axi2050 on a K-402 also loses sensitivity as the frequency increases above ~2.5 kHz. These are not new revelations.
When a Company or individual DIYer states Frequency Response how can EQ or DSP be added to the results?
All controlled directivity horns (i.e., midrange and tweeter) require EQ. That's just physics.
But the question you really should be asking is: how much sensitivity loss in the driver is acceptable across its operating band, and does this limit the output of the entire loudspeaker. In the case of the Heritage Jubilee, that big EQ boost is a bit too much (IMO). The solution is to place the loudspeakers much closer to the corners of a room (or at least place them with their backs touching the wall)--then re-EQ the loudspeakers individually.
Otherwise, the listening performance of these EQed-flat loudspeakers (and time aligned--unlike any of the other Klipsch Heritage loudspeakers) far exceeds in terms of sound quality their predecessors.
Things change over 59 years, and
one of the biggest changes that has significantly increased the sound quality of loudspeakers is in the area of in-room EQ and time alignment of drivers/horns to each other.
It would seem that any old conglomeration of components could be made to look wonderful as far as stated frequency response.
You say this as if it is a disadvantage. It's not. It's a big advantage over loudspeakers designed using only passive crossovers without DSP amplitude response EQ or time alignment/flattened phase response. The old passive crossover loudspeakers really can't be easily upgraded or even refreshed (if old drivers develop issues over time), because the passive crossovers were custom designed for those particular drivers when new. If anything changes, you've just compromised the "frequency response" (a.k.a., transfer function) of the loudspeaker.
Nowadays, you don't even need a loudspeaker company like Klipsch if you've got access to competitively priced drivers and horns that you can integrate together yourself using a DSP crossover. Suddenly, the goal of the "tinkerer" hi-fi guys is a reality: they can now switch out drivers and even horns in their loudspeakers, then measure/redial-in their transfer functions (amplitude and phase) using a high quality DSP crossover.
Things just got better...a lot better. But first, you need to learn
how to do in-room acoustic measurements and how to dial-in a DSP crossover to flatten response. It's a much more straightforward process that takes mere minutes instead of days/weeks/months to modify passive crossovers, I've found.
Chris
