yes, I know
and damping factor makes no or little difference to a guitar speaker with a 200hz rolloff
I was more interested in upper frequency limit
but any small difference that might occur at highest frequency are not likely to be audible with a screaming guitar on hard overdrive
we basicly agree
just looking at it differently
why I hear tweeters sound very different depending on parallel vs series, I do not know the reason for that
I have a suspicion
tweeters are not the topic
but I still find it interesting
now that its mentioned that a tweeter could be an important part of the complete speaker
I would suggest to use multiple cheap tweeters
then try to connect them either in parallel or series
could even have a switch mounted for that
and you might have a two-in-one package
why I hear tweeters sound very different depending on parallel vs series, I do not know the reason for that
I have a suspicion
So do I - because they are a LOT louder in parallel than in series
They also need completely redesigned crossovers, so differences in your perceived sound from them is down to those reasons, not their parallel/serial connection.
yes, that too
but they were never implemented in any speaker
yes they are louder in parallel
that would be obvious
but its more than a simple matter of SPL
a cheap horn tweeter sounding like a real softie ...
In theory there's no difference if the drivers are identical.
In practice there's subtle audible difference.
In theory, if the drivers are different at all, their differences are exaggerated in series but are not in parallel. Say one driver has some frequency where the impedance goes high, but the other doesn't. With the two in series the one with the high-impedance anomaly may be quieter there, and that increased impedance in series will also turn down the volume of the other driver.
In practice, this exaggeration of anomalies is further exaggerated in cabinets that share the back volume with multiple drivers. When one driver pushes less than the other at some frequency anomaly, the back pressure from the stronger driver works against the weaker one to further decrease its output. Just like series wiring, sharing a cabinet volume requires matched drivers and anomalies are exaggerated.
But this is in high-fi terms. In loud distortion guitar sometimes the designer is actually going for some weird honking resonances and flutter modes, and just loves the horrible uncontrolled things that hi-fi engineers try to control.
IMHO for bass, or for clean guitar, in closed-back cabinets where the cabinet volume is not isolated for each driver, parallel works better. For loud distortion guitar you have to experiment but sometimes the worse theoretical wiring sounds "better" to some esthetic standards. With well-matched drivers in open-back cabinets or individual cabinets or cabinets where the internal volume is partitioned and isolated, either wiring works OK. When you have more than 2 drivers, the theoretical "clean" way is to first parallel drivers so that their anomalies are statistically averaged, then put those more-consistent parallel sets with their more consistent averaged response and averaged impedance curves' combined and reduced anomalies in series to achieve the desired impedance.
Some famous rock amps put the drivers in series, then those series strings in parallel. I doubt it was planned, but the 'non-optimal' wiring adds to the honking characteristic signature sounds, and extreme complexity of overtones especially when close-miked.
So 2X16 in parallel is playing it safe and the hi-fi preference, but in the rock world you may find some greenbacks in series sounding very British...but they won't be 4 ohms, you might be looking for a 32-ohm tap on the output transformer.
In practice there's subtle audible difference.
In theory, if the drivers are different at all, their differences are exaggerated in series but are not in parallel. Say one driver has some frequency where the impedance goes high, but the other doesn't. With the two in series the one with the high-impedance anomaly may be quieter there, and that increased impedance in series will also turn down the volume of the other driver.
In practice, this exaggeration of anomalies is further exaggerated in cabinets that share the back volume with multiple drivers. When one driver pushes less than the other at some frequency anomaly, the back pressure from the stronger driver works against the weaker one to further decrease its output. Just like series wiring, sharing a cabinet volume requires matched drivers and anomalies are exaggerated.
But this is in high-fi terms. In loud distortion guitar sometimes the designer is actually going for some weird honking resonances and flutter modes, and just loves the horrible uncontrolled things that hi-fi engineers try to control.
IMHO for bass, or for clean guitar, in closed-back cabinets where the cabinet volume is not isolated for each driver, parallel works better. For loud distortion guitar you have to experiment but sometimes the worse theoretical wiring sounds "better" to some esthetic standards. With well-matched drivers in open-back cabinets or individual cabinets or cabinets where the internal volume is partitioned and isolated, either wiring works OK. When you have more than 2 drivers, the theoretical "clean" way is to first parallel drivers so that their anomalies are statistically averaged, then put those more-consistent parallel sets with their more consistent averaged response and averaged impedance curves' combined and reduced anomalies in series to achieve the desired impedance.
Some famous rock amps put the drivers in series, then those series strings in parallel. I doubt it was planned, but the 'non-optimal' wiring adds to the honking characteristic signature sounds, and extreme complexity of overtones especially when close-miked.
So 2X16 in parallel is playing it safe and the hi-fi preference, but in the rock world you may find some greenbacks in series sounding very British...but they won't be 4 ohms, you might be looking for a 32-ohm tap on the output transformer.
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Hi, sorry for hijacking this thread, I just wanted to ask Nigel or Cyclecamper a question about wiring a 4x12 cabinet as they seem very knowledgeable about this.
So I want to wire the cabinet using a pair of greenbacks (25W/16 ohm) & a pair of Vintage 30's (60W/16 ohm). I want to wire them with 1 greenback & 1 Vintage 30 in each series wired pair then parallel the 2 pairs. My question is, with the 2 speakers having different power handling capability, should I wire the + to the Vintage 30 & the - to the greenback in each pair or the other way around, or does it not matter either way. Thanks in advance. Cheers
So I want to wire the cabinet using a pair of greenbacks (25W/16 ohm) & a pair of Vintage 30's (60W/16 ohm). I want to wire them with 1 greenback & 1 Vintage 30 in each series wired pair then parallel the 2 pairs. My question is, with the 2 speakers having different power handling capability, should I wire the + to the Vintage 30 & the - to the greenback in each pair or the other way around, or does it not matter either way. Thanks in advance. Cheers
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It's essential to connect the series pairs +ve to -ve, otherwise they cancel each other out to some degree.
Thanks for the responce Nigel. While I know extremely little regarding speakers, I was aware I how to connect them correctly is series. Maybe I didnt phrase my question correctly (appologies). What I wanted to ask about was the positioning of the 25W & the 60W speaker in the series chain. It doesnt really matter, right??? They both have the same power on them??? Thanks again.
Cheers
Cheers
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being different speakers, some of the possible 'variations' may sound different
I guess you may have to experiment a little
powerhandling
two in paralel means they play louder
and thus needs less power
don't know if series connection has any effect on power handling
btw, did you post the actual impedance of your different drivers ?
I guess you may have to experiment a little
powerhandling
two in paralel means they play louder
and thus needs less power
don't know if series connection has any effect on power handling
btw, did you post the actual impedance of your different drivers ?
Hi,
You have a choice of a 4 ohm (all parallel) or 16 ohm cabinet.
Listen to the drivers and put the brightest pair on the top.
I'd wire the two left in series in parallel with the two right in series.
rgds, sreten.
Thanks again for the responces. I want the cabinet wired for 16 ohms (I was aware of the all parallel @ 4 ohm etc choices). The amp running thru the cab is a M@rsh@ll 1987 50W clone with a Tim Caswell #39 added triode mod(all triodes cascaded, 4 gain stages + cathode follower), so any volume loss isnt really a problem. The reason for wiring the 2 different speaker types in series is for the "exagerated anominallies" effect Cyclecamper mentioned earlier. I was just wondering if there is a more correct way to place the 25W/16 ohm speaker & the 60W/16 ohm speaker in each series wired pair (eg, jack tip connection to 25W's + & jacks sleave connection to 60W's -, or the other way around) but as no one has commented on I take it that it doesnt matter either way. Thanks again. Cheers
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The order of the speakers makes no difference in series (which is nearer the + supply versus the -).
In series, or in parallel, the wiring also must operate the drivers in-phase. Otherwise drivers will not be pushing out (or in) together at the same time and you get a huge loss of output (especially bass) and projection. Well, really the correct word for the wiring is "polarity" but it's commonly called "in-phase" or "out of phase".
So in series, between drivers you always connect a + terminal to a - terminal.
In parallel you always want to connect all + terminals together, and all - terminals together.
When you're done, put a battery on the input. If all the cones move in the same direction when you connect the battery then the speakers are phased OK with respect to each other. If you are going to occasionally (ever) use the cabinet with other cabinets, then you also want the cabinet phased the same as them. Hmmm, I don't know what the correct "standard" phase is for a guitar cabinet, but I'm sure someone will tell us. It is worth wiring it "standard", in case someday you plug in different bottoms to work together. I never remember because I just wire them all to work like my Fender cabinets: Battery + on the tip of the 1/4" plug, - on the sleeve, and when I connect the battery all of the cones move (which way, in or out???).
In series, or in parallel, the wiring also must operate the drivers in-phase. Otherwise drivers will not be pushing out (or in) together at the same time and you get a huge loss of output (especially bass) and projection. Well, really the correct word for the wiring is "polarity" but it's commonly called "in-phase" or "out of phase".
So in series, between drivers you always connect a + terminal to a - terminal.
In parallel you always want to connect all + terminals together, and all - terminals together.
When you're done, put a battery on the input. If all the cones move in the same direction when you connect the battery then the speakers are phased OK with respect to each other. If you are going to occasionally (ever) use the cabinet with other cabinets, then you also want the cabinet phased the same as them. Hmmm, I don't know what the correct "standard" phase is for a guitar cabinet, but I'm sure someone will tell us. It is worth wiring it "standard", in case someday you plug in different bottoms to work together. I never remember because I just wire them all to work like my Fender cabinets: Battery + on the tip of the 1/4" plug, - on the sleeve, and when I connect the battery all of the cones move (which way, in or out???).
Thanks for the tip with regard to phasing. Their both Celestion drivers, both designed for 4x12 application so I would expect them to have the same phasing, Celestion list the 2 as a "recommended mix n match pair", even tho there's about a 3db SPL difference between the 2 types. At some point in time Marshall appears to have changed the way in which they wire their cabs as I've seen both 2 seried pairs paralleled at the jack as well as 2 paralleled pairs seried at the jack.
So in a series wired pair there id the same power across both drivers regardless of power handling capability, right? Thanks again. Cheers
So in a series wired pair there id the same power across both drivers regardless of power handling capability, right? Thanks again. Cheers
As far as same phasing, yes some mfgrs have in the past labelled + and - backwards to the standard, but nowadays they're pretty standardized.
Yes, I think early Marshall were 2 seried pairs paralleled at the jack (which exaggerates anomalies) and later 2 paralleled pairs seried at the jack (the hi-fi way).
How you arrange them in the cabinet will alter the directions different frequencies will disperse. You may want something symmetrical in one direction or another.
How the power divides in series depends on how the impedances compare. The listed impedance is really just a 'mininal' or minimum value for computing load, but one model of driver will actually have a complex impedance curve with peaks and dips at different frequencies (and one big dip at resonance).
Well thanks for the answers guys, I've definitely learnes from them. I also definitely prefer the sound of the cab wired the "old way" with 2 seried pairs in parallel, (I tried it the other way too), & it seems from looking online that I'm not alone in this with people rewiring newer cabs to the old way even with all the same speaker types, just to get that "good sound". Thanks again. Cheers
Hi,
If you wire two different drivers in parallel and then wire them
in series with the same, there is no "exaggeration" effect.
Driver bass resonances will not interact due to impedance.
If you wire two different drivers in series and then wire them
in parallel with the same, there will be a difference in sound,
the higher inductance unit will effect the lower inductance one,
the result likely being an overall somewhat darker tone.
Driver bass resonances will interact due to impedance.
(Assuming significant driver differences.)
I'd go for the first wiring method.
rgds, sreten.
If you wire two different drivers in parallel and then wire them
in series with the same, there is no "exaggeration" effect.
Driver bass resonances will not interact due to impedance.
If you wire two different drivers in series and then wire them
in parallel with the same, there will be a difference in sound,
the higher inductance unit will effect the lower inductance one,
the result likely being an overall somewhat darker tone.
Driver bass resonances will interact due to impedance.
(Assuming significant driver differences.)
I'd go for the first wiring method.
rgds, sreten.
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Thanks for the tips Sreten. Caswell's #39 mod is a very bright sounding circuit so a little darkening up isnt a bad thing. I prefer the sound of the different drivers in series , with the series'd pairs paralleled at the jack, at least with this amp. My other 50 watter is running thru a later 4x12 so I imagine (havent looked) it is wired the way u suggest. Cheers
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