hello! I apologize in advance if I ask stupidity, but nevertheless: why in all forums the conversation around the bass section is built exclusively around the "native" drivers from Klipsch (K-31 or K-33), and, literally, a couple or three others? I have never seen an option anywhere, for example Acoustic Elegance SBP12-4. Yes, throw stones at me, they are for a sealed box, they have a Qts of 0.48 and so on. Have you tried to make a calculation with these speakers for the bass reflex cabinet? They can go down to 18 Hz in 230 liters (which you can have in the back of the drivers in Jubilee cabs). And this is just one example. Does anyone else have any suggestions? Or i'm completely wrong?
Greets!
Like any speaker alignment, (matching to) horns require a specific set of specs for best performance, especially WRT its inductance spec/proper HF response (no longer have the latter
).
I use to have a copy of the original Eminence specs + changes over the decades now 'lost' in two damaged HDs and not sure which version I have in HR, but FWIW, the closer you can come to the attached specs (~ +/- few %) should in theory perform plenty 'good enough' with modern high DF Class A and A/B amps if at least 10 W in 'A'.
Like any speaker alignment, (matching to) horns require a specific set of specs for best performance, especially WRT its inductance spec/proper HF response (no longer have the latter
).I use to have a copy of the original Eminence specs + changes over the decades now 'lost' in two damaged HDs and not sure which version I have in HR, but FWIW, the closer you can come to the attached specs (~ +/- few %) should in theory perform plenty 'good enough' with modern high DF Class A and A/B amps if at least 10 W in 'A'.
Attachments
I hate to say this, but every DIY first-gen Jubilee-clone bass bin made from those plans that I have helped others try to EQ, i.e., using DSP crossovers (four instances in total) have had terrible performance relative to my first-gen bass bins made by Klipsch. I believe that the issue is in the first or perhaps second bend of the horn, apparently traceable to the clone layout plans linked above (counting the throat as the datum).
If you are planning to build your own (i.e., you can't buy them new anymore), make sure that you lay out the folded horn expansion piecewise using something like Hornresp to see if you can locate the source of the horn expansion profile issues in the plan layout above. The DIY bass bins have severe SPL output problems starting at 100 Hz, and continuing down to ~50-55 Hz, whereupon the output basically is non-existent even though they are in full room corners. The stock Klipsch KPT-KHJ-LF bass bins in my room have -3 dB response down to ~31 Hz in full room corners (raw response plotted below):
(The apparent 135 Hz drop out is the 1/4 wave floor bounce cancellation to the measurement microphone: 25 inches/64 cm). Below is a plot of the excess group delay of the same measurement, showing the effects of any non-minimum-phase boundary reflections (i.e., non-flat excess group delay regions). The cursor is at the 31 Hz -3 dB SPL cutoff point:
Chris
Last edited: