I am ready to order parts for the above but am not sure of the DCR values for the inductors. They are not specified on the schematic. I plan to use quality air cores.
The internal wiring for the drivers is 20 gauge, rather thin I believe. These speakers are used at relatively low volume settings sometimes with my 8 wpc SET amp and sometimes with my Hegel 250 wpc ss amp.
I will use 10w wire-wound resistors because that's what is in my OEM crossover. I am considering upgrading the internal cabinet wiring to either 18 gauge or 16 gauge. My inclination would be to pick inductors with the same AWG. Of course that alters the DCR value which is why I'm asking for advice here.
Note: the OEM inductors are iron core and the wire leads look to be 20 gauge.
Opinions and suggestions please!
Many thanks, Fred
The internal wiring for the drivers is 20 gauge, rather thin I believe. These speakers are used at relatively low volume settings sometimes with my 8 wpc SET amp and sometimes with my Hegel 250 wpc ss amp.
I will use 10w wire-wound resistors because that's what is in my OEM crossover. I am considering upgrading the internal cabinet wiring to either 18 gauge or 16 gauge. My inclination would be to pick inductors with the same AWG. Of course that alters the DCR value which is why I'm asking for advice here.
Note: the OEM inductors are iron core and the wire leads look to be 20 gauge.
Opinions and suggestions please!
Many thanks, Fred
Do you have any reason to believe it's not the most common type?
Dealing with slight voicing issues would be the worst case. If you modelled it you could learn the potential to adjust it using other parts of the crossover.
Dealing with slight voicing issues would be the worst case. If you modelled it you could learn the potential to adjust it using other parts of the crossover.
@AllenB
Last year I built crossovers for my Altec 604Es. The design was by Jerry Ballard, an Altec engineer. The schematic includeds the DCR value for each inductor as well as the inductance value. This resulted in some pretty hefty inductors.
The crossover schematic I am planning to build for my Altec 14s does not include this requiring me to make a choice. I am not equipped to do any modelling or engineering on my own so my instinct leads me to choose inductors with the same wire gauge as my speaker cabinet wiring at least for the woofer. This might result a DCR less that the OEM inductors which could increase the loudness of the woofer a bit. With the Altec 14, this might not be a bad thing.
I was just looking for someone to poke holes in my thinking here or, better yet, tell me what they did to their 14s to make them sound better.
Last year I built crossovers for my Altec 604Es. The design was by Jerry Ballard, an Altec engineer. The schematic includeds the DCR value for each inductor as well as the inductance value. This resulted in some pretty hefty inductors.
The crossover schematic I am planning to build for my Altec 14s does not include this requiring me to make a choice. I am not equipped to do any modelling or engineering on my own so my instinct leads me to choose inductors with the same wire gauge as my speaker cabinet wiring at least for the woofer. This might result a DCR less that the OEM inductors which could increase the loudness of the woofer a bit. With the Altec 14, this might not be a bad thing.
I was just looking for someone to poke holes in my thinking here or, better yet, tell me what they did to their 14s to make them sound better.
I originally intended to post something different.. but it is all guesswork.
So, one thing you'll notice about iron cored inductors is they use less wire. Their resistance will be lower. Moving to air core typically means going down a few gauges.
Not that inductor resistance is necessarily a bad thing. I suspect many use iron cored inductors in their bass circuit for their low resistance, whether that is necessary or not, but the main reason to use them may be their cost.
So, one thing you'll notice about iron cored inductors is they use less wire. Their resistance will be lower. Moving to air core typically means going down a few gauges.
Not that inductor resistance is necessarily a bad thing. I suspect many use iron cored inductors in their bass circuit for their low resistance, whether that is necessary or not, but the main reason to use them may be their cost.
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Yes, I have read comments by others to that effect. It seems that, in a woofer circuit, an iron-core inductor might be less "detectable", i.e. won't affect the performance very much so a speaker's cost can be kept down somewhat.
I think that's a misunderstanding. Changing the resistance can make a small difference in response, whether it's more or less. If you design for more resistance then you wouldn't want less.
In any case this is a fresh crossover design so we have no idea what the best resistance is.
In any case this is a fresh crossover design so we have no idea what the best resistance is.
Agreed. I've yet to see any comments from someone who has built, used, or even heard a Model 14 with this particular crossover.
Richard C. designed it to reduce the harshness of the 14 which is what I'm attempting to do. What little discussion there was occurred a long time ago.
I'm an old guy with lots of time to make mistakes. I will build a pair and choose air core inductors a couple of wire gauges heavier per your suggestion and see what happens. Hopefully, with a higher crossover point and better quality components, I can tame the nasties a bit. As it stands now, the 12" woofer/mid sings a lot prettier that the 902 tweeter in the midrange.
Thanks for your thoughts here. As with GM, I have learned a lot from your many posts here on this forum.
Best, Fred
Yeah, I was supposed to audition it and some others, though health restricted me to the Compostela. Re-reading it reminded me just how wide the gap is between my 'pioneer' ways of sound reproduction Vs the incredibly diverse DIY crowd, though did get some satisfaction re how well the much maligned Lansing/Altec sectoral horns performed when properly implemented WRT for what passes for 'HIFI' nowadays.
My exposure to the M14 and the 9842 studio monitor it's based on left me n' the distributor wondering what market it was supposed to target. 🙁 We much preferred the 9842, but to date have yet to see them in an install nor for sale, so at this late date no clue if it was a complete market fail or so good they're either still 'working' and/or more likely, kept by those who did remodel/tear down and sold privately since by then (sadly thanks to me and my 'kind') anything bone-fide Altec/JBL was quickly shipped overseas regardless of price.
Anyway, the two are functionally the same except for horn/driver spacing with the 9842 just barely meeting the 1 WL rule and the M14 somewhat further apart, hence basic XOs would ideally be different; then of course there's the 2pi wall loading Vs 2pi floor loading differences to account for.
No clue what 'harshness' he refers to, but then my comparison was in a warehouse near the loading bays and the one time in a CMC showroom full of other speakers acting as absorbers made the M14 sound dull/flat, though the Barcelona managed to 'punch' through doing Brubeck's 'Take Five'. 😎
Once upon a time there was a M19 parts list, but the Hostbard is in shambles ATM, so links go nowhere, but you can try posting; ditto the Z19 variant.
My exposure to the M14 and the 9842 studio monitor it's based on left me n' the distributor wondering what market it was supposed to target. 🙁 We much preferred the 9842, but to date have yet to see them in an install nor for sale, so at this late date no clue if it was a complete market fail or so good they're either still 'working' and/or more likely, kept by those who did remodel/tear down and sold privately since by then (sadly thanks to me and my 'kind') anything bone-fide Altec/JBL was quickly shipped overseas regardless of price.
Anyway, the two are functionally the same except for horn/driver spacing with the 9842 just barely meeting the 1 WL rule and the M14 somewhat further apart, hence basic XOs would ideally be different; then of course there's the 2pi wall loading Vs 2pi floor loading differences to account for.
No clue what 'harshness' he refers to, but then my comparison was in a warehouse near the loading bays and the one time in a CMC showroom full of other speakers acting as absorbers made the M14 sound dull/flat, though the Barcelona managed to 'punch' through doing Brubeck's 'Take Five'. 😎
Once upon a time there was a M19 parts list, but the Hostbard is in shambles ATM, so links go nowhere, but you can try posting; ditto the Z19 variant.