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I had initially figured 60 degrees based on the acoustic wedge foam. But that actually has 10 wedges per 30 centimeters, so is a bit off (wider than) of 60 degrees

Actually, turns out that when...

Rob,

I came up with a new concept for the Heils that you may want to try. I've found that it increases the volume by ~0.5 (measured on a Quest 2900 Type 2 meter) and adds clarity and...

Got a compass??? ;)

What are people doing about the rear wave and what was done in other simulations? Is the elevated distortion at lower frequency possibly due to rear wave cancellation/destruction?

Would a set of...

Your plots confirm what I see on my RTA. I don't know why these people keep showing plots with a decrease in volume after the 5KHz hump. My plots, even without the crossover, show a continuing rise...

Mine came from the AMT 1D line. They actually look a bit different than the earlier/later versions.

Both of mine have a dc resistance of 2.9 ohms, which is why I run a 5 ohm resistor in series and use an 8 ohm L-pad.

When I close off the port, the 2251J just doesn't sound as good nor is as flat.

Most current version of the crossovers. The 0.9/30 ohm control the high cutoff frequency of the 2251J while the 6.8 "squares" off the top of the band. The 0.065/2.37 control the interface to the...

Yes, I built them and they are rear ported. The 2251J was actually designed to be used in a midbass horn enclosure. A 2241H is crossed over at 225Hz.

Lately I've taken to running the system as a...

I just slide mine back and forth and watch the results on the RTA looking for the smoothest curve.

2251J

http://www.audioheritage.org/photopost/data//500/medium/DSC_000413.JPG...

Not what mine looks like.:dont-know:

I use mine as a tweeter. This is the crossover, thought there have been changes to the mid.
...

The 2251J 10" actually crosses over ~2,500 Hz and peters from there. It doesn't like to go smoothly to 5KHz, or maybe even 4KHz. :blink: This is where it's dip lies before it increases in dB.

I...

The problem is that, outside of eq, if you pull the 10+KHz peak down to a reasonable level, you pull down everything, including the trough, and you end up with a "dark cloud." (In fact, I think that...

You can tell a lot from a well recorded YouTube video. You really think that Rob would do that? :blink:

I, for one, would like to hear a YouTube video when done. Preferably Tin Pan Alley (Stevie Ray Vaughn) that people at AK use for demo purposes.

I've made some recent revisions to my crossover...

I've devised a "band aid" (pun intended) for the 5kHz suck-out. :applaud:

Take an engineering scale and stand it vertically with one of the three points touching the Heil right at its centerpoint...

I tweak these crossovers on a regular basis. Tweak, listen, listen, listen, tweak, repeat.

Sometime the tweaks go better than others. For that photo, I had too much roll off at the top of the...

No Grumpy, this is wrong.

Just as with a cone speaker, there is a positive and negative phase and care must be used integrating the Heil with the next lower driver.

Also, while free placement...

It's 2.5 dB between the dotted lines. The full scale is set at 15 dB.

OK I did some testing and included some photos. My problem is an interaction with the midrange speaker. When I turn off the midrange, the tweeter spectrum is pretty much unchanged moving from the...

I get the same/similar notch. This is my point where I said that you need an RTA for the best placement.

In my system, the depth and bandwidth of the notch is directly related to where the Heil...