Wirrunna

TexDrone, I found that the miniDSP added noise that did not increase when the volume control on the preamp was turned up. After a bit of googling I found a suggestion to use an L-Pad to reduce the speaker output which included the noise and that in turn required an increase in gain to bring the level back up to where it would be without the L-Pad, but the noise stayed reduced. http://www.sengpielaudio.com/calculator-Lpad.htm shows how. My project is https://community.klipsch.com/index.php?/topic/195572-bc-dcx464-as-the-mid-hi-drivers-for-a-k-horn/

TexDrone, I tri-amped my K-Horns with a miniDSP 2X4HD for each channel. I had noise in the mid and hi speakers and made L-Pads to drop the sensitivity of the speakers. The noise is generated by the DSP. Chris, I have often wondered if on the DSP I could up the gain at the input by say 3db or even 6db and then drop the gain on the DSP outputs by a corresponding 3 or 6 db on the theory that if the low level signal from the pre-amp is down near the noise floor of the DSP then by boosting the signal level as it enters the DSP the noise added by the DSP will also be attenuated when the gain is cut as the signal leaves the DSP. I have also noticed that noise is far more evident when a USB cable is attached to the miniDSP.

I recommend a polyswitch - https://www.parts-express.com/electronic-parts/Fuses-Fuse-Holders/polyswitch-resettable-fuses At around 60c , buy a few pairs in increasing amperage, put the lowest in circuit and try it, if it cuts out too often then move up to the next value. Auto bulbs are going LED, which don't work as well due to much lower wattage. Edit: Good description of how they work here - https://www.jaycar.com.au/rxe075-ptc-fuses-speaker-protection/p/RN3460

Why the 5" length ? I went with the 4" as Claude specified when I swapped the Dayton into my Super Heresy back on page 14 of this thread.

erez, the ALK Extreme Slope networks are expensive to build. I know, as I built some a few years ago - https://www.stereo.net.au/forums/topic/118361-k-horn-crossovers-from-ak-3-to-universal-to-es/ and have recently replaced them with an active system using miniDSP 2X4HD - I spent a lot less on the miniDSP 2X4HD and Audiophonics Hypex N-Core amps than I did on caps for the ES networks. ALK pulled the DIY instructions for his networks some time ago.

Here is the T2A spec sheet

How did your search go ? Here https://community.klipsch.com/index.php?/topic/122257-klipschorns-can-i-sealclose-the-back-w-plywood-or-smth-else-instead-of-adding-walls-to-the-room-do-not-kill-me-for-asking/&do=findComment&comment=1355838 is Don Davis' simple solution attached to the mounting boards on the grill with 4 screws.

Madman, A good starting point is https://www.parts-express.com/Loudspeaker-Design-Cookbook-7th-Edition-Book-500-035 and here is a primer on crossovers - https://sound-au.com/lr-passive.htm

Here are two more threads about ALK Universal crossovers, this one which includes changes to crossover at 4500Hz if you are using an upgraded tweeter . and this one shows how to utilise an AK3 woofer section with the Universal

What driver did you use for the measurement ? The thread is a really good read, lot of good information.

Apologies in advance if this is the wrong thread - I'm pretty sure that this https://community.klipsch.com/index.php?/topic/42953-false-corners-screwed-into-k-horns/showed Khorns being in false corner cradles but it appears that Deang has deleted all the images ! In fact this is not the first thread I've found that Dean has deleted text and pics, what's going on ?

For completeness - https://community.klipsch.com/index.php?/topic/105239-another-tractrix-horn-design-program/ Also, the Eliptrac is FC310Hz - https://community.klipsch.com/index.php?/topic/122814-round-tractrix/&do=findComment&comment=1358020

Is the K400/401 a CD horn ? It is a bit hazy now, but I seem to remember a wider coverage when I swapped to the Eliptrac.

Thoughts ? Eliptrac horns have been around for a while now. I believe Dave Harris is still making the kits although his web site has been gone for a while. First, replacing a K400/401 with an Eliptrac is a modification and will alter the sound of a Klipschorn. Second, as far as I can tell most people that use Eliptrac horns no longer use the K55 drivers. Third, as they are a kit and take quite a bit of effort to build, I suspect there is a fair bit of self fulfilling expectations in the evaluation of their performance. Having said that, I built a set for my 1990 KHorns, initially using Bob Crites A55G drivers with an Al Klappenberger designed Extreme Slope 400/4500 crossover and Bob Crites DE110 tweeters. I found the modified KHorns lost the harshness that was evident on some orchestral music and completely eliminated listener fatigue. The sound was smoother and more open with a more detailed soundstage. I then had an opportunity to purchase a second hand pair of B&C DCX464 co-axial drivers locally (a unique opportunity in Australia where most HiFi components are imported with associated freight, customs duties and delays due to shipping). Attempts at passive crossovers were disappointing at best so I went active with very pleasing results. I don't know how much you have read, so I will list a few links that I have bookmarked - https://community.klipsch.com/index.php?/topic/122814-round-tractrix/ https://community.klipsch.com/index.php?/topic/144700-eliptrac-400-kit-finishing-update/&ct=1557489906 https://community.klipsch.com/index.php?/topic/124081-testing-the-faital-pro-hf200-driver-on-the-eliptrac400/&ct=1612245896

Dave, I have never seen a precision L-Pad. One of the problems in calculating L-Pad values is that a speaker's impedance varies non-linearly with frequency, and the manufacturer's publish a "nominated" impedance. One way of getting there would be to measure the system response, determine the tweeter attenuation needed, refer to the manufacturer's impedance curve for the impedance at the passband and use https://sound-au.com/articles/l-pad-calc.htm to calculate the values needed.