And can burn a lot off as heat with a possible fire hazard. Once you get below about 40 ohms, the current demand will rise dramatically.
Wolf
Wolf
Not dramatically. I have a nominal 60W into 8 ohm amp which is about 22V rms continuous rating. I am using a 3.3mH inductor with about 1 ohm resistance plus whatever the reactance at various bass frequencies. The 26 ohm is in parallel with a driver which is 7 ohm in the mid band. The specs show 32 ohm resonant impedance. I'm using bass reflex so the Z will change. But using say 26 ohm peak for driver Z in parallel with 26 ohm resistor we have 13 ohm in series with say 1.5 ohm. We would have a maximum of about 20V across the resistor which is about 15W. I only have my amp up about a third max. So maybe there is about 2W dissipated in the R ((7V x 7V) / 26 ohm = 1.9W) worse case continuous). This is only the case when the driver Z is high, for other frequencies the combined Z will be lower than 13 ohms and therefore the V across the parallel Z will be lower and therefore less current flows through the resistor and more through the driver. Music power on average is lower than a continuous sinusoidal signal therefore the average power through the resistor is negligible. I am using a 10 ohm in series with a 16 ohm and both are I think rated at 15W. I did try a 10 ohm resistor only in parallel with the woofer and it didn't even get warm. The bass was a bit anaemic though. But I take you point that if people what to try this they should be aware of power ratings etc.
A conventional 2 way (x over around 2 kHz) would use a smaller inductor with virtually zero reactance at bass frequencies and also a lower series R. So the woofer parallel R would look more like it is directly across the amp and wouldn't divert any appreciable current from the driver and therefore would not have the same tuning/damping effect and would likely get a bit warm.
I have a Woofer Assisted Wideband speaker (which the Halcyons are also) so woofer crossover is similar to a 3 way.
A conventional 2 way (x over around 2 kHz) would use a smaller inductor with virtually zero reactance at bass frequencies and also a lower series R. So the woofer parallel R would look more like it is directly across the amp and wouldn't divert any appreciable current from the driver and therefore would not have the same tuning/damping effect and would likely get a bit warm.
I have a Woofer Assisted Wideband speaker (which the Halcyons are also) so woofer crossover is similar to a 3 way.
This is ok. I wonder whether you could control your damping by taking out your impedance peak with a tuned circuit?
Yes but one of my points earlier is that large inductors and capacitors are expensive and I wanted to tune the crossover with existing components. Resistors are cheaper. By paralleling an R with and 8 ohm driver you can effectively change the Z of the driver at the x over frequency. Lower Z means lower value inductors which means cheaper. Also one can fine tune sensitivity, damping and X over freq just by changing the R.
I notice that the Halcyons impedance sweep http://speakerdesignworks.com/Halcyon_5.html dips to 3 ohms so after all said and done my suggestion would probably not be suitable.
Finally, after waiting almost the entire year of 2021, I am starting final assembly of my Halcyons this week (while on PTO from work). I am modifying my wiring to make it possible to drive the A10p separately from the woofers so future experimentation might be possible. I have read with great interest the posts above and as a result, purchased a bit of extra foam and Acousta-stuff to be prepared for more.
Thanks for all the comments!
-david BTW
Thanks for all the comments!
-david BTW
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I decided to put in speakon connectors for a separate feed to the woofers, and the A10p. I drilled 1" holes into the back and then installed wires inside the cabinets. I also put in the sonotubes after fitting the 1" foam and made the 5-6" plug out of multiple circles of the 1" foam. After talking with my woodworker, we decided to put the acousta-stuf in before glue on the sides and front baffle. Wiring up the crossovers it today's challenge while I wait for the final cabinets. Finally!!! I am making some progress on these. What a year 2021 was!
Holes in bases for speak-on connectors going in. The crossover board and my huge and too expensive air-core inductors all mounted on bottom plate of the base and ready for final wiring.
First time i have noticed: seems strange that the sealed sonoTube is in its own sealed enclosure.
And dave, all your acoustaStuff needs to come out and get properly teased, doesn’t look like you are even close to enuff teasing.With that amount it will take hours to do.
dave
And dave, all your acoustaStuff needs to come out and get properly teased, doesn’t look like you are even close to enuff teasing.With that amount it will take hours to do.
dave
Hi Dave. I did spend hours (Several) teasing the acousta-stuff. But I will check it again. If it doesn't look right to you then thanks!
wolf_teeth. To get the same DCR for the air core inductor as the sledgehammer inductor that came with the crossover board it took 10 AWG wire!
There should be no lumps, it should be very consistent density.
Re Wolf’s comment, i would use much skinnier solid core wire on the A10p. I suggest trying a pair of 24g solid strands pulled from a CAT5/6 cable.
At least make sure it is easy to change the wire.
dave
Re Wolf’s comment, i would use much skinnier solid core wire on the A10p. I suggest trying a pair of 24g solid strands pulled from a CAT5/6 cable.
At least make sure it is easy to change the wire.
dave
Why did you change it if you had it already? I guess I'm not following what you're doing if you have both in there.
24g solid for the coil, or wiring it up? I never use less than 16AWG for internal wiring, no matter the coils used.
Wolf+teeth: So, I didn't want to use an iron core inductor at all. I will unwire it from the crossover for sure and only use the air core. I didn't want the hysterisis distortion of the iron core. Some may disagree but that was my thinking. The wire you see inside the cabinet is what came with the madisound kit.
Dave at planet_10. I will work on the acoust-stuf again for sure.
Dave at planet_10. I will work on the acoust-stuf again for sure.
For eiring the midTweeter up. Big coil is in the woofer LP i expect. Series XO does make things a bit different.
dave
Of course it does, as I've done several SXO designs, but going to 24AWG wire is awfully thin. I'd at least use CAT5 evenly split with more conductors than single strands of 24.
davetw, now I understand your methods, and I think your wiring is fine. Of note though, hysteresis distortion is at very high power levels that you'll likely never reach in speakers. For this reason iron cores are okay.
Ferrite or Permite cored coils are however not recommended in this approach, as they saturate very early, and earlier than previously thought considering some recent testing by fellow builders. That said, both of these can impart a midbass 'slam' to the bass region. In my own testing, this is easily accepted by most listeners, but incorrect tonally.
I think your air cores will yield less peaking in the bass, and sound more natural. I would encourage you to try both and make your own conclusions.
Please continue, I look forward to your progress.
Wolf
davetw, now I understand your methods, and I think your wiring is fine. Of note though, hysteresis distortion is at very high power levels that you'll likely never reach in speakers. For this reason iron cores are okay.
Ferrite or Permite cored coils are however not recommended in this approach, as they saturate very early, and earlier than previously thought considering some recent testing by fellow builders. That said, both of these can impart a midbass 'slam' to the bass region. In my own testing, this is easily accepted by most listeners, but incorrect tonally.
I think your air cores will yield less peaking in the bass, and sound more natural. I would encourage you to try both and make your own conclusions.
Please continue, I look forward to your progress.
Wolf
I saw that too. I think he is going to have a baffle mounted atop of that face with the drivers installed in it.