Series Xover, continued outside of Wolf / Ben’s post.

tajanes

Ben’s got me thinking (dangerous as it may be) about series (again) and a potential 1+1/2 build.

At my last attended event I brought a small 2-way with a broad ranger and woofer, so I’m thinking about pulling the Xover and try a series 1+½ way (Why?, Why not?).
Why; a) maybe see some advantage of driver interaction, and b) I’ve got the parts and the build to give it a go, could be entertaining?

Below I’ve presented a couple of diagrams and posted questions; generally looking for input as to placement of padding resistor(s) for the broad ranger (series and/or Lpad style around the driver), and placement of a series notch filter for the broad ranger.

Thoughts Ben and others?
Thx

Wolf

Without the cap across the woofer you are presenting a short to your amplifier. Period.
It is really hard to do a half-way with a series xover unless there was already a 2way present.

In theory, using a resistor where the cap would go would present a stable load. However, it will require a VERY high wattage, like a 100W panel mount style on a heatsink- EXTERNALLY. Here is the problem with that, the resistor is also directly across/parallel with the woofer, and can reduce its output. It also will minimize the Fs of the woofer because of this.

The way to avoid the woofer problems is to use a large value resistor, so this means a high sensitivity wide range driver as the tweeter. IIRC, that is right where you want it. ;^) Something like 20-25 ohms as a start or higher would be preferable, but likely still capable of dissipating some juice.

Then, place a coil either on the bottom line connecting 0.5 to the - input, or in series like I did in the Anomalies above it between the drivers. This will be your lower rolloff point.

So- that is 3 parts, including a questionable resistor usage.

tajanes

Thx.
I’m thinking the series notch filter (for the broad-ranger in the ‘point A’ position) with its resistor (if beefy) would address that issue? And if more padding needed the lpad around the broad-ranger as well.
And, pulling out the old amp just-in-case. 😆

Wolf

if you place the notch in that position, there will still be a short to the amp. It has to be a cap, resistor, or both.

tajanes

@Wolf said:
if you place the notch in that position, there will still be a short to the amp. It has to be a cap, resistor, or both.

Sorry if I'm missing this, but a series (in-line) notch R + C + I. Does the inductor in this circuit mess this up - create a short?

Wolf

Yes. An amplifier hooked up to 2 coils in series will pretty much be a short.

Wolf

Placing the notch on the top line in series with the wide range driver will not yield the same issues. The placement of the resistor for padding is key to both make the circuit stable, the amplifier happy, and retain the sensitivity of the woofer.

tajanes

Ben,
Thanks for taking time reviewing and discussing series Xovers. Your suggestion of imagining the path taken if high then low frequency through the circuit hit home. Very interesting.

Going forward (other than maybe a simple series 1st order and/or 1st + an additional cap), I’m thinking best for me, as with skiing, to stick with parallel and skip the double-black diamonds…