Connect L1, R1 and L2 together in a straight line.
The amp connects to the free end of L1 and the junction between R1 and L2.
The tweeter connects to the free end of L1 and the junction between L1 and R1.
The woofer connects to the junction between L1 and R1 and the free end of L2.
(Observe the tweeter and woofer polarities, i.e., ensure the + terminal of each goes to the junction between L1 and R1.)
Is this helpful in laying out the crossover?
Why does Acoustic Reality say this series crossover is an "amplifier's best friend"? Is it the lack of capacitors in the circuit?
Or does it have more to do with flattening the impedance spike at the crossover freq?
I have become quite curious about series crossovers for a 2.5 way, using some Wavecor 4 ohm woofers I have but keeping the overall impedance above about 4ohm (ideally up at 6-8ohm or so).
Or does it have more to do with flattening the impedance spike at the crossover freq?
I have become quite curious about series crossovers for a 2.5 way, using some Wavecor 4 ohm woofers I have but keeping the overall impedance above about 4ohm (ideally up at 6-8ohm or so).
I have doubts since the impedance tends to be lower this way. The impedance at lower frequencies is fairly dependent on the resistor value. The main effect of changing the resistor is setting the tweeter level. So a sensitive tweeter is useful, and it should preferably be more sensitive than (the woofer - baffle step) to keep the system impedance above half the woofer impedance.
Without the cap missing in series with R1 in the same leg (Rabbitz' network has the cap as I am suggesting), the resistor there will get VERY hot as it is the amplifier load without the cap there. 100W heatsunk externally mounted resistors are recommended for best practices. It will also kill the output of the woofer as the resistor is directly in parallel with it without the cap. The cap should be 15-25uF range if you are looking to voice by ear.
The reason it is touted as amplifier's best friend is the resistive load the capless network makes.
The result of a series xover does not add the impedances for a higher load value. This is incorrect internet lore.
The reason it is touted as amplifier's best friend is the resistive load the capless network makes.
The result of a series xover does not add the impedances for a higher load value. This is incorrect internet lore.
The AR series xo tends to have a flatter impedance plot around the xo frequency rather than the usual roller coaster shape you get with other xo's. Most of mine fall within a 4 ohm envelope excluding the woofer Fs rise.
AllenB is correct about the tweeter sensitivity as if it's too close to the woofer sensitivity R1 becomes too low and the xo impedance drops dramatically. A few dB higher for the tweeter SPL is the aim.
An AR series is not going to help with impedance of the 2.5 way with 4 ohm woofers as the 0.5 woofer is still in parallel. OK for an MTM with woofers in series. I've seen a trick in the fullrange forum using a cap for a 0.5 woofer but never tried it.
AllenB is correct about the tweeter sensitivity as if it's too close to the woofer sensitivity R1 becomes too low and the xo impedance drops dramatically. A few dB higher for the tweeter SPL is the aim.
An AR series is not going to help with impedance of the 2.5 way with 4 ohm woofers as the 0.5 woofer is still in parallel. OK for an MTM with woofers in series. I've seen a trick in the fullrange forum using a cap for a 0.5 woofer but never tried it.
Troels Gravesen, who is a well known enthusiast in diy loudspeakers, had nothing good to say about the Acoustic Reality series crossover. He felt it plain didn't work well with most drivers.
Firstly, you need very well behaved drivers that for the bass, sound reasonable without any filtering at all beyond a bass coil. Which usually means plastic cones. For treble, they need to be robust enough to run on a single capacitor and a resistor for level adjust.
Second, some control of time alignment of the drivers is usually required.
Thirdly, you run into problems with the bass boost known as bafflestep, and impedance correction is usually necessary.
The late Jeff Bagby was a great theoretician and published this table of values for 8 ohm speaker filters:
I tried this in Boxsim 1.2 simulator and the results were impressive, albeit they might be bass light:
The circuit was this with visaton drivers and time alignment:
More detail:
https://www.diyaudio.com/community/threads/driver-for-b-o-cx50-3-25l-cabinet.377578/#post-6800634
You'll be very lucky if whatever drivers you have chosen work well on a first order circuit.
If you want to try Boxsim 1.2, it is here:
https://www.diyaudio.com/community/...-from-visaton-free.267787/page-2#post-7126272
I have never built a series filter, but have looked at them in simulation. Sorry if that takes you out of your depth. Best, Steve.
Firstly, you need very well behaved drivers that for the bass, sound reasonable without any filtering at all beyond a bass coil. Which usually means plastic cones. For treble, they need to be robust enough to run on a single capacitor and a resistor for level adjust.
Second, some control of time alignment of the drivers is usually required.
Thirdly, you run into problems with the bass boost known as bafflestep, and impedance correction is usually necessary.
The late Jeff Bagby was a great theoretician and published this table of values for 8 ohm speaker filters:
I tried this in Boxsim 1.2 simulator and the results were impressive, albeit they might be bass light:
The circuit was this with visaton drivers and time alignment:
More detail:
https://www.diyaudio.com/community/threads/driver-for-b-o-cx50-3-25l-cabinet.377578/#post-6800634
You'll be very lucky if whatever drivers you have chosen work well on a first order circuit.
If you want to try Boxsim 1.2, it is here:
https://www.diyaudio.com/community/...-from-visaton-free.267787/page-2#post-7126272
I have never built a series filter, but have looked at them in simulation. Sorry if that takes you out of your depth. Best, Steve.