Hi everyone, long time lurker first time poster.
Done a few builds in the past, but my abilities are very much limited to the woodworking and presentation side rather than the cabinet/electrical design side! I have a working knowledge of the theory behind it all, but despite my efforts have never achived anything approaching enlightenment when it gets down to the nitty gritty of actually drawing up and perfecting designs.
I'm currently about to embark on a new build to someone else's design (specifically this one) and have a very quick question regarding inductor resistance.
The coils in the crossover design have a specified DCR. For the HF section I found one which matches, but for the LF section the closest I can get to the specification for both coils is about 0.1 Ohms lower than spec. Obviously I could simply add a 0.1 Ohm resistor in series to each coil, but I'm wondering whether this will even be necessary.
I don't speak German, so am relying on Google Translate here, but it seems from the write-up that the designer is saying that, whilst higher resistance coils should really be avoided, lower resistance may also adversely affect the sound.
I'm minded to experiment with/without the resistors, but can anyone with knowledge of these matters advise me whether doing so is likely to be a waste of time given the tiny differences* in coil resistance from spec?
* My impression only, i.e. the reason I'm asking, since I have no real idea of what sort of differences would be required before they became audible.
Sent from my XT1039 using Tapatalk
Done a few builds in the past, but my abilities are very much limited to the woodworking and presentation side rather than the cabinet/electrical design side! I have a working knowledge of the theory behind it all, but despite my efforts have never achived anything approaching enlightenment when it gets down to the nitty gritty of actually drawing up and perfecting designs.
I'm currently about to embark on a new build to someone else's design (specifically this one) and have a very quick question regarding inductor resistance.
The coils in the crossover design have a specified DCR. For the HF section I found one which matches, but for the LF section the closest I can get to the specification for both coils is about 0.1 Ohms lower than spec. Obviously I could simply add a 0.1 Ohm resistor in series to each coil, but I'm wondering whether this will even be necessary.
I don't speak German, so am relying on Google Translate here, but it seems from the write-up that the designer is saying that, whilst higher resistance coils should really be avoided, lower resistance may also adversely affect the sound.
I'm minded to experiment with/without the resistors, but can anyone with knowledge of these matters advise me whether doing so is likely to be a waste of time given the tiny differences* in coil resistance from spec?
* My impression only, i.e. the reason I'm asking, since I have no real idea of what sort of differences would be required before they became audible.
Sent from my XT1039 using Tapatalk
Last edited:
You may have to adjust tweeter padding for woofer coils that differ in DCR from the original spec.
0.1 may be a little or a lot, depending on the originally specified value.
0.1 may be a little or a lot, depending on the originally specified value.
Thanks. There are two inductors in the LF section and their spec'd resistance values are 0.8 and 0.5 Ohm. Since 0.1 is a not-insignificant proportion of both these values, I think I'll either simply include additional 0.1 Ohm resistors to bring them both up to spec, or - if I can - experiment with/without the additional resistors.
(Apologies everyone for the random asterisks all over my original post. Something to do with Tapatalk no doubt, which I'm using for the first time. Will edit when I get home later.)
Sent from my XT1039 using Tapatalk
(Apologies everyone for the random asterisks all over my original post. Something to do with Tapatalk no doubt, which I'm using for the first time. Will edit when I get home later.)
Sent from my XT1039 using Tapatalk
I think that you will find that the series coils in the bass section, it will not make much of a difference if you drop the dcr by 0.1 ohms. Assuming it is the middle one, the difference between 0.4 and 0.3 ohms percentage wise seems quite high, but when you compare that to the resistance of the voice coil it becomes a lot lower.
At most I would expect you to see a very slight rise in the lowest frequencies.
Differences with DCR in shunt coils in the tweeter section can make a much bigger difference though, and can affect phase matching, but since you have found one that matches for the tweeter section I think you should be fine.
just as an experiment I simulated the low pass crossover (standard version) with 0.4 and 0.3 ohms on the low pass. Note that the speaker in an SB accoustics one not the actual driver in the project, so is only to show the relative difference that 0.1ohms less DCR makes in the series coil.
As you can see the difference is very minimal. edit: I see it was the premium version... still I think it probably will not make a lot of difference.
Tony.
At most I would expect you to see a very slight rise in the lowest frequencies.
Differences with DCR in shunt coils in the tweeter section can make a much bigger difference though, and can affect phase matching, but since you have found one that matches for the tweeter section I think you should be fine.
just as an experiment I simulated the low pass crossover (standard version) with 0.4 and 0.3 ohms on the low pass. Note that the speaker in an SB accoustics one not the actual driver in the project, so is only to show the relative difference that 0.1ohms less DCR makes in the series coil.
As you can see the difference is very minimal. edit: I see it was the premium version... still I think it probably will not make a lot of difference.
Tony.
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