info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Powering Cambridge 210w 8ohm Sub woofers
91 views
Skip to first unread message
skybu...@hotmail.com
Jul 25, 2017, 5:37:01 AM7/25/17
to
Hello People,
On this website you can see a picture of a three voice coil sub woofer:
http://www.ecoustics.com/electronics/forum/home-audio/646685.html
Also known as Cambridge 210w 8ohm Sub woofers (taken from creative gigaworks s750 7.1's).
Apperently this is a subwoofer which requires 3 amps of each 70 watts of power to bring this beast alive !
I have mine still stuck in my Gigaworks S750 enclousure. I am thinking/would like to bring it back alive and thus I would like to replace the very shady creative labs electronics with some kind of alternative.
Perhaps the best option is a "plate amp". Apperently this is some kind of plate with some amp electronics attached to it. This could then probably be used to seal the enclosure, it would need to happen to have the same dimensions.
For now this is an experiment mostly to see if it would work, if it is possible and what kind of sound it would give so I can compare it to my memory recollection.
A repairman claims that it is best for the sound quality to have the Gigaworks fulled repaired/restored, however I am not so sure of that claim and I highly doubt it because I cannot imagine how the electronics would improve the sound of other amps.
However there is some speak of "cross-over" frequencies, though this seems to be handled by software and can be set between 10 hz and 200 hz.
Furthermore the creative x-fi elite soundblaster has 3 outputs on the back which split into 9 outputs via special video cables which are used as audio cables, where one output probably has no signal.
So it seems these cables either duplicate the output signals or split them. I confident that there is a subwoofer signal on one of them, going into my receiver and I could probably connect any amp to the receiver, or perhaps even directly to one of these outputs.
My main issue is:
Will this idea work ? Also how to connect amplifiers to this subwoofer ? Is it as easy as simply plugging some cables into the amp and then connecting it to the 3+ and 3- ?
Also my other main question is:
Which equipment is suited for this ? My guess would be some kind of plate amp which can deliver 3x70 watts ? Does such an plate-amp exist ?
If it doesn't would I need to buy 3 amplifiers each of 70 watts ? Perhaps duplicate the subwoofer signal to all 3 with cables ? How would that work ?
An amplifier in a box could also be interesting to play with, but perhaps the amp plate might be a good solution for this gigaworks if it happens to have the same dimensions or otherwise maybe a little bit of extra wood work or so could enclose it ? Perhaps the heatsink of such an amp plate is also enough to cool it and the subwoofer itself doesn't need any cooling.
So please advise if you have any insight or experience into this matter because my experience with "amplifiers" is zero.
I do own a denon receiver 1909 which is used to power the 7 satelitte speakers and this works fabolously.
My main concern is also the safety of the electronics, I kinda don't trust the gigaworks electronics because of all this brown (conductive) glue that might have damaged it and the designs looks kinda shady ! ;) :) but perhaps I am a bit to untrusty of that :) also I like to give other electronics a try just to see what it's like.
So if you have any recommendations please share ! ;) It will be very highly appreciated not just by me, but by many many many many owners of gigaworks s750 that have the exact same problem as me.
Bye,
Skybuck.
On this website you can see a picture of a three voice coil sub woofer:
http://www.ecoustics.com/electronics/forum/home-audio/646685.html
Also known as Cambridge 210w 8ohm Sub woofers (taken from creative gigaworks s750 7.1's).
Apperently this is a subwoofer which requires 3 amps of each 70 watts of power to bring this beast alive !
I have mine still stuck in my Gigaworks S750 enclousure. I am thinking/would like to bring it back alive and thus I would like to replace the very shady creative labs electronics with some kind of alternative.
Perhaps the best option is a "plate amp". Apperently this is some kind of plate with some amp electronics attached to it. This could then probably be used to seal the enclosure, it would need to happen to have the same dimensions.
For now this is an experiment mostly to see if it would work, if it is possible and what kind of sound it would give so I can compare it to my memory recollection.
A repairman claims that it is best for the sound quality to have the Gigaworks fulled repaired/restored, however I am not so sure of that claim and I highly doubt it because I cannot imagine how the electronics would improve the sound of other amps.
However there is some speak of "cross-over" frequencies, though this seems to be handled by software and can be set between 10 hz and 200 hz.
Furthermore the creative x-fi elite soundblaster has 3 outputs on the back which split into 9 outputs via special video cables which are used as audio cables, where one output probably has no signal.
So it seems these cables either duplicate the output signals or split them. I confident that there is a subwoofer signal on one of them, going into my receiver and I could probably connect any amp to the receiver, or perhaps even directly to one of these outputs.
My main issue is:
Will this idea work ? Also how to connect amplifiers to this subwoofer ? Is it as easy as simply plugging some cables into the amp and then connecting it to the 3+ and 3- ?
Also my other main question is:
Which equipment is suited for this ? My guess would be some kind of plate amp which can deliver 3x70 watts ? Does such an plate-amp exist ?
If it doesn't would I need to buy 3 amplifiers each of 70 watts ? Perhaps duplicate the subwoofer signal to all 3 with cables ? How would that work ?
An amplifier in a box could also be interesting to play with, but perhaps the amp plate might be a good solution for this gigaworks if it happens to have the same dimensions or otherwise maybe a little bit of extra wood work or so could enclose it ? Perhaps the heatsink of such an amp plate is also enough to cool it and the subwoofer itself doesn't need any cooling.
So please advise if you have any insight or experience into this matter because my experience with "amplifiers" is zero.
I do own a denon receiver 1909 which is used to power the 7 satelitte speakers and this works fabolously.
My main concern is also the safety of the electronics, I kinda don't trust the gigaworks electronics because of all this brown (conductive) glue that might have damaged it and the designs looks kinda shady ! ;) :) but perhaps I am a bit to untrusty of that :) also I like to give other electronics a try just to see what it's like.
So if you have any recommendations please share ! ;) It will be very highly appreciated not just by me, but by many many many many owners of gigaworks s750 that have the exact same problem as me.
Bye,
Skybuck.
Peter Wieck
Jul 25, 2017, 9:43:42 AM7/25/17
to
A couple of things: This is a 3-voice-coil woofer. The reason for it is quite simple:
a) Left Channel
b) Right Channel
c) Center Channel
Thereby allowing it to be used in a "modern" TV sound reinforcement system with a center channel, and include all three feeds in one box.
Some points:
- you do not need to use all three voice coils.
- you do not want to parallel any of them, much less all three of them.
- Conversely, there is no benefit in running them in series.
Now. More *stuff*. Bass is directionless only below -about- 500 hz. So, any speaker less than 10 - 12" or so will struggle to produce decent volumes below 500 hz. Meaning that there might be some undesirable 'directionality' with this speaker.
let's analyze 3 amps & 70 watts. That suggests that your amp needs to put out a nominal 24 v. This is trivial to a modern amplifier. That is part A. Part B is the likelihood that the rating you suggest is the Maximum Sustained Rating this speaker can handle over a normal distribution of frequencies, not the REQUIRED rating. Example: I have a pair of speakers 'rated' at 50 watts. I feed it from a 200 WPC amp. and whereas I will seldom clip, the speakers will see all 200 watts briefly on loud passages quite often, and sustain no damage. But, most of the time, the speakers will be seeing just a few watts. Seldom does much musical signal sustain a high output, and seldom do most users play at an ear-bleed level.
All of the above is very broad-brush, without any information on your source, amplifier, actual listening conditions, ultimate purpose and application of the speaker.
Peter Wieck
Melrose Park, PA
a) Left Channel
b) Right Channel
c) Center Channel
Thereby allowing it to be used in a "modern" TV sound reinforcement system with a center channel, and include all three feeds in one box.
Some points:
- you do not need to use all three voice coils.
- you do not want to parallel any of them, much less all three of them.
- Conversely, there is no benefit in running them in series.
Now. More *stuff*. Bass is directionless only below -about- 500 hz. So, any speaker less than 10 - 12" or so will struggle to produce decent volumes below 500 hz. Meaning that there might be some undesirable 'directionality' with this speaker.
let's analyze 3 amps & 70 watts. That suggests that your amp needs to put out a nominal 24 v. This is trivial to a modern amplifier. That is part A. Part B is the likelihood that the rating you suggest is the Maximum Sustained Rating this speaker can handle over a normal distribution of frequencies, not the REQUIRED rating. Example: I have a pair of speakers 'rated' at 50 watts. I feed it from a 200 WPC amp. and whereas I will seldom clip, the speakers will see all 200 watts briefly on loud passages quite often, and sustain no damage. But, most of the time, the speakers will be seeing just a few watts. Seldom does much musical signal sustain a high output, and seldom do most users play at an ear-bleed level.
All of the above is very broad-brush, without any information on your source, amplifier, actual listening conditions, ultimate purpose and application of the speaker.
Peter Wieck
Melrose Park, PA
skybu...@hotmail.com
Jul 26, 2017, 6:36:06 AM7/26/17
to
On Tuesday, July 25, 2017 at 3:43:42 PM UTC+2, Peter Wieck wrote:
> A couple of things: This is a 3-voice-coil woofer. The reason for it is quite simple:
>
> a) Left Channel
> b) Right Channel
> c) Center Channel
So are you "saying" that the bass of the left chanel speaker is re-router into this subwoofer, and same for right and center ?
> A couple of things: This is a 3-voice-coil woofer. The reason for it is quite simple:
>
> a) Left Channel
> b) Right Channel
> c) Center Channel
So that would mean the subwoofer is than capable of playing bass from left/center/right speaker.
An interesting hypothesis...
However there could also be a special subwoofer signal which already contains all information for subwoofer.
So this confuses me a little bit.
It might be possible that this design would take additional frequency range from above 200 hz from speakers and re-route it to the subwoofer.
That would make a bit more sense to me...
Hmmmm...
This subwoofer is from a 7.1 speaker system... so there would be 7 speakers...
You only describe 3 so that leaves an additional 4 speakers...
Maybe the electronics would mix even more or so... from those 7... hmm..
Or you could be completely wrong and it has nothing to do with channels.
Well if I do decide to have this gigaworks fixed then I will surely test this hypothesis by generating 500 hz waves, disconnecting all speakers and see what the subwoofer does ! =D
Very interesting experiment ! ;) :) Wish I had one right now to test with ! =D
Peter Wieck
Jul 26, 2017, 8:42:58 AM7/26/17
to
You are entirely missing the point. There is no shame in this, perhaps I was not clear in the description, so I will try again.
a) Bass is omnidirectional below ~500 Hz. What this means is that even a "7.1" system does not need bass at all seven speakers.
b) A standard stereo system typically delivers full range signal to both the left and right speakers.
c) A sub-woofer system will use either an electronic crossover-&-blend system - not cheap - or a dual-voice-coil driver. The dual-voice-coil driver is considerably less costly than an electronic option.
d) Some systems, even from far back in the day, had center-channel outputs from either amplifiers or receivers to accommodate early stereo recordings that greatly exaggerated separation, or for individuals who wanted a wide sound-stage and needed center channel reinforcement.
e) Such a system will also deliver full-range signal to the center channel.
f) Many multi-channel (AKA Surround Sound) suffer from too wide a speaker separation, most especially as they tend to use tiny little speakers with tiny little drivers.
g) With that in mind, a three-voice-coil driver is a standard, relatively low-cost, device to provide sufficient bass for a multi-speaker surround sound system.
To your point - the internal crossover does take all the '200 Hz' signal and direct it to the sub-woofer. But there need not be any fancy blend circuitry as would be required for a single-voice-coil driver.
Against your point - you do not need to deliver any bass to any of the peripheral speakers, at all. A single point-source for bass is sufficient for the need, and the entire purpose of any sub-woofer.
And, a general observation: surround sound systems are similar in application to vehicular sound systems. When typically deployed for movies or listening when driving, fidelity is simply not possible nor the goal. The goal is to create an environment. Between action on the screen, road and wind noise, whatever, again, there is no such thing as fidelity despite much blather to the contrary.
a) Bass is omnidirectional below ~500 Hz. What this means is that even a "7.1" system does not need bass at all seven speakers.
b) A standard stereo system typically delivers full range signal to both the left and right speakers.
c) A sub-woofer system will use either an electronic crossover-&-blend system - not cheap - or a dual-voice-coil driver. The dual-voice-coil driver is considerably less costly than an electronic option.
d) Some systems, even from far back in the day, had center-channel outputs from either amplifiers or receivers to accommodate early stereo recordings that greatly exaggerated separation, or for individuals who wanted a wide sound-stage and needed center channel reinforcement.
e) Such a system will also deliver full-range signal to the center channel.
f) Many multi-channel (AKA Surround Sound) suffer from too wide a speaker separation, most especially as they tend to use tiny little speakers with tiny little drivers.
g) With that in mind, a three-voice-coil driver is a standard, relatively low-cost, device to provide sufficient bass for a multi-speaker surround sound system.
To your point - the internal crossover does take all the '200 Hz' signal and direct it to the sub-woofer. But there need not be any fancy blend circuitry as would be required for a single-voice-coil driver.
Against your point - you do not need to deliver any bass to any of the peripheral speakers, at all. A single point-source for bass is sufficient for the need, and the entire purpose of any sub-woofer.
And, a general observation: surround sound systems are similar in application to vehicular sound systems. When typically deployed for movies or listening when driving, fidelity is simply not possible nor the goal. The goal is to create an environment. Between action on the screen, road and wind noise, whatever, again, there is no such thing as fidelity despite much blather to the contrary.
skybu...@hotmail.com
Jul 26, 2017, 9:41:01 PM7/26/17
to
The denon 1909 receiver is probably capable of stripping of all the frequencies below a certain threshold and is probably capable of forwarding this to the subwoofer or even better to an intermediate amplifier which forwards it to the subwoofer.
From what you wrote it seems the three voice coil design might have been a cheap way to mimic what a receiver does. Now that a real receiver is in play, would it still be necessary to power all three voice coils ? Could that be a problem somehow or does it not matter ?
I would guess that if only one voice coil was powered that that would be insufficient and the device would be underpowered and not operating well.
The only thing which might be special about gigaworks electronics is that it maybe had a higher cross over frequencies than usual, but perhaps that's just my fantasy :)
Other possibilities include special subwoofer audio processing but probably not...
Bye,
Skybuck.
Peter Wieck
Jul 27, 2017, 7:27:38 AM7/27/17
to
The sub-woofer wants to capture bass signal from both stereo channels A and B - so at least two of the voice-coils will be powered. If the Denon has a center-channel-out, that would be the third. Any additional channels are not relevant to this discussion.
KISS.
Peter Wieck
Melrose Park, pA
KISS.
Peter Wieck
Melrose Park, pA
skybu...@hotmail.com
Jul 27, 2017, 7:27:48 AM7/27/17
to
I have some data sheets available about this device on my webdrive located here:
http://www.skybuck.org/GigaWorksS750/
(It's a rar file and will need to be extracted with something like winrar, though windows 7 has it also built-in)
Perhaps these data sheets can shed some more light on this device.
Alternative data sheets might also be located here:
http://www.tgahinfo.homecall.co.uk/S750%20PSU/
Bye,
Skybuck.
http://www.skybuck.org/GigaWorksS750/
(It's a rar file and will need to be extracted with something like winrar, though windows 7 has it also built-in)
Perhaps these data sheets can shed some more light on this device.
Alternative data sheets might also be located here:
http://www.tgahinfo.homecall.co.uk/S750%20PSU/
Bye,
Skybuck.
skybu...@hotmail.com
Jul 27, 2017, 7:27:55 AM7/27/17
to
I came across this website:
https://en.wikipedia.org/wiki/Audio_crossover
This is one of the few references to "three-way" I came across my investigation as to why a subwoofer would have three voice coils:
"Crossovers are often described as "two-way" or "three-way""
So my latest hypothesis is that this cambridge subwoofer uses different wattage levels to reach different frequency ranges.
https://en.wikipedia.org/wiki/Audio_crossover
This is one of the few references to "three-way" I came across my investigation as to why a subwoofer would have three voice coils:
"Crossovers are often described as "two-way" or "three-way""
So my latest hypothesis is that this cambridge subwoofer uses different wattage levels to reach different frequency ranges.
Peter Wieck
Jul 27, 2017, 9:18:36 AM7/27/17
to
Are you sure you are not a troll?
A 3-way crossover divides the input into three separate output curves covering three different frequency ranges. These curves are not "square", but typical rounded curves with almost flat tops. So, the woofer covers everything from 0 HZ to, perhaps, 1,000HZ - BUT! the curve drops off pretty seriously from about 480 HZ. The midrange covers everything from about 150 HZ to, say.... 10,000 HZ with similar drops at either end. The Tweet starts in at about 1,000 HZ to ∞.
Not intended to be actual frequencies, offered for illustrative purposes only.
http://images.audiojudgement.com/2016/02/crossover-types.jpg
THESE DO NOT GO INTO A SINGLE VOICE COIL. Full Stop.
Do not over-complicate what you have. Which is an inexpensive means to mix bass signal from multiple sources without the need for additional electronics.
A 3-way crossover divides the input into three separate output curves covering three different frequency ranges. These curves are not "square", but typical rounded curves with almost flat tops. So, the woofer covers everything from 0 HZ to, perhaps, 1,000HZ - BUT! the curve drops off pretty seriously from about 480 HZ. The midrange covers everything from about 150 HZ to, say.... 10,000 HZ with similar drops at either end. The Tweet starts in at about 1,000 HZ to ∞.
Not intended to be actual frequencies, offered for illustrative purposes only.
http://images.audiojudgement.com/2016/02/crossover-types.jpg
THESE DO NOT GO INTO A SINGLE VOICE COIL. Full Stop.
Do not over-complicate what you have. Which is an inexpensive means to mix bass signal from multiple sources without the need for additional electronics.
skybu...@hotmail.com
Jul 27, 2017, 9:18:39 AM7/27/17
to
Maybe something like this might work:
https://www.crutchfield.com/p_021AMP1200/AudioSource-AMP1200VS.html?tp=48757
Crutchfield seems to have all kinds of amplifiers...
Expensive though...
https://www.crutchfield.com/p_021AMP1200/AudioSource-AMP1200VS.html?tp=48757
Crutchfield seems to have all kinds of amplifiers...
Expensive though...
Peter Wieck
Jul 27, 2017, 11:39:56 AM7/27/17
to
skybu...@hotmail.com
Jul 27, 2017, 2:17:31 PM7/27/17
to
So the subwoofer apperently has 6 wires. 3 wires for + 3 wires for -.
So these wires probably have to be plugged into an "amplifier". Problem with that is probably that most amplifiers are "stereo" based and only have 4 connection points.
The amplifier should then be plugged into "pre sub out" or something like that from receiver... receiver is connected to PC/soundblaster/audio connections.
What I would like to try is:
1. Provide power to the subwoofer.
2. Get a signal from receiver to subwoofer to see if it can work.
Which is basically the same thing as 1 more or less.
Perhaps going this route might not give exact sound as it was... or maybe it will, not sure about that... but it's worth a try.
Or I could try taking this device to some shop and see if they can get it powered up.... but that is a bit risky... unless they know what they are doing concerning the 8 ohm rating of this thing... and the 70 watts power requirement hmmm...
Not sure if stores will try and power it up ! ;)
Peter Wieck
Jul 27, 2017, 4:01:55 PM7/27/17
to
NONONONONONONO
Did I mention NO?
You are making this WAYYYyyyy too complicated, and why I asked the question in the first place, and why I mentioned KISS earlier, AKA, K-eep I-t S-imple S-tupid.
Please go back and look over what has been posted to-date:
a) This speaker is designed to accept *UP TO THREE* separate outputs in the same speaker.
b) Those outputs, typically are Channels A, B, & Center. Or, Right, Left & Center.
c) You *DO NOT* have to drive all three voice-coils.
d) You should *NOT* run the voice-coils in Series or Parallel.
e) You may need some sort of crossover system from your A & B & C outputs I do not know what sort of speakers you have, or their impedance. Hence the term "May".
f) It !! DOES NOT !! require 70 watts to drive it. That rating is for the maximum average power over a specified range of frequencies over a specified time. Were you to run 70 watts into that device continuously, it would burn up. Don't understand? How long can you hold onto a (lit) 60-watt incandescent light bulb without damage? That speaker will make plenty of noise on as little as 2 or 3 watts.
Essentially, you have a sub-woofer designed to accept input from Channels A, B, & Center from the receiver detailed below.
https://www.amazon.com/Denon-7-1-Channel-Multizone-Discontinued-Manufacturer/dp/B001BKND5W
You need to find a way to provide mid & tweet to your main speakers for channels A, B & Center. That is your ONLY task here. This may involve some sort of crossover, or some sort of careful wiring of your existing speakers. Please note the impedance range on the Denon, and do not go outside those nominal ratings.
It seems to me that you are expending a great deal of effort to use a marginal far device outside of its design parameters.
Did I mention NO?
You are making this WAYYYyyyy too complicated, and why I asked the question in the first place, and why I mentioned KISS earlier, AKA, K-eep I-t S-imple S-tupid.
Please go back and look over what has been posted to-date:
a) This speaker is designed to accept *UP TO THREE* separate outputs in the same speaker.
b) Those outputs, typically are Channels A, B, & Center. Or, Right, Left & Center.
c) You *DO NOT* have to drive all three voice-coils.
d) You should *NOT* run the voice-coils in Series or Parallel.
e) You may need some sort of crossover system from your A & B & C outputs I do not know what sort of speakers you have, or their impedance. Hence the term "May".
f) It !! DOES NOT !! require 70 watts to drive it. That rating is for the maximum average power over a specified range of frequencies over a specified time. Were you to run 70 watts into that device continuously, it would burn up. Don't understand? How long can you hold onto a (lit) 60-watt incandescent light bulb without damage? That speaker will make plenty of noise on as little as 2 or 3 watts.
Essentially, you have a sub-woofer designed to accept input from Channels A, B, & Center from the receiver detailed below.
https://www.amazon.com/Denon-7-1-Channel-Multizone-Discontinued-Manufacturer/dp/B001BKND5W
You need to find a way to provide mid & tweet to your main speakers for channels A, B & Center. That is your ONLY task here. This may involve some sort of crossover, or some sort of careful wiring of your existing speakers. Please note the impedance range on the Denon, and do not go outside those nominal ratings.
It seems to me that you are expending a great deal of effort to use a marginal far device outside of its design parameters.
~misfit~
Jul 28, 2017, 9:52:18 AM7/28/17
to
Once upon a time on usenet Peter Wieck wrote:
> Are you sure you are not a troll?
I don't see the posts you're replying to Peter so that means the person
> Are you sure you are not a troll?
you're replying to most likely *is* a troll and is in my killfile. I can't
tell as you don't quote.
It probably heard that this group is no longer moderated....
--
Shaun.
"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)
> A 3-way crossover divides the input into three separate output curves
> covering three different frequency ranges. These curves are not
> "square", but typical rounded curves with almost flat tops. So, the
> woofer covers everything from 0 HZ to, perhaps, 1,000HZ - BUT! the
> curve drops off pretty seriously from about 480 HZ. The midrange
> covers everything from about 150 HZ to, say.... 10,000 HZ with
> similar drops at either end. The Tweet starts in at about 1,000 HZ to
skybu...@hotmail.com
Jul 28, 2017, 9:57:38 AM7/28/17
to
(Small corrections made compared to posting on other newsgroups ;))
My original hypothesis for this three voice coil design is for 7.1 operation could be the correct one:
Low Frequencies from Channels is send to the subwoofer's 3 voice coil.
This hypothesis is confirmed by this document stating different magnetic fields will result in a net magnetic field describing the action/motion taking by the subwoofer. So three voice coil would give more precise control over waves/cosinus/sinus waves inteferring with each other.
http://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf
Since there are only 3 voice coils and 8 signals it would require a mapping for example:
Voice 1: Left+Center+Right
Voice 2: Side Left + Side Right
Voice 3: Rear Right + Rear Left + LFE
This mapping/hypothesis makes the most since to me.
One other hypothesis is that this company wanted to use the same amplifiers to make production easy.
However this does not cancel out my hypothesis either, this is just a convenient/bonus.
My guess is that each 70 watt amplifier is being used to cause this mapping effect.
Thus if I would simply wire a single amplifier in parallel to this subwoofer it would not be the same as wiring three individual amplifiers being driven with a specially processed or mixed signal.
Knowing creative labs they would probably have jumped upon this oppertunity to use a three voice coil system to it's maximum audio quality potential.
This is probably simply new technology that the mainstream market has not yet catched on too, shown by the simple single pre-amp subwoofer out port.
To duplicate this technology it would require at least 3 pre-amp subwoofer out ports and special signal processing or at least mixing of these input signals.
Bye,
Skybuck.
My original hypothesis for this three voice coil design is for 7.1 operation could be the correct one:
Low Frequencies from Channels is send to the subwoofer's 3 voice coil.
This hypothesis is confirmed by this document stating different magnetic fields will result in a net magnetic field describing the action/motion taking by the subwoofer. So three voice coil would give more precise control over waves/cosinus/sinus waves inteferring with each other.
http://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf
Since there are only 3 voice coils and 8 signals it would require a mapping for example:
Voice 1: Left+Center+Right
Voice 2: Side Left + Side Right
Voice 3: Rear Right + Rear Left + LFE
This mapping/hypothesis makes the most since to me.
One other hypothesis is that this company wanted to use the same amplifiers to make production easy.
However this does not cancel out my hypothesis either, this is just a convenient/bonus.
My guess is that each 70 watt amplifier is being used to cause this mapping effect.
Thus if I would simply wire a single amplifier in parallel to this subwoofer it would not be the same as wiring three individual amplifiers being driven with a specially processed or mixed signal.
Knowing creative labs they would probably have jumped upon this oppertunity to use a three voice coil system to it's maximum audio quality potential.
This is probably simply new technology that the mainstream market has not yet catched on too, shown by the simple single pre-amp subwoofer out port.
To duplicate this technology it would require at least 3 pre-amp subwoofer out ports and special signal processing or at least mixing of these input signals.
Bye,
Skybuck.
skybu...@hotmail.com
Jul 28, 2017, 9:57:40 AM7/28/17
to
I want to accomplish the following for a full picture:
I want the denon receiver to power 7 satelite speakers which it is doing fine as I write this.
But I also want *something* to power the subwoofer.
Now if I was a millionare I could:
1. Buy 1 receiver + 1 subwoofer per channel + 1 speaker per channel.
For a total ammount of 7 speakers + 7 subwoofers + 7 receiver.
Every receiver would then be in control of 1 speaker + 1 subwoofer.
The receiver would split the signal of the channel in two signals 1 for the speaker 1 for the subwoofer.
2. There would be an 8th subwoofer and 8th receiver to simply process the LFE signal.
So in total there would be 7 speakers 8 receivers 8 subwoofers.
However a cheaper solution costing less space would be:
3 receivers + 7 satelites + 3 subwoofers.
Receiver 1 processes left/center/right and splits this off to 3 speakers and 1 subwoofer.
Receiver 2 processes side left/side right and splits this off to 2 speakers and 1 subwoofer.
Receiver 3 processes rear rear/ rear left and LFE and splits this of to 2 and 1 subwoofer.
So then I would some something like "surround bass".
However I suspect the Gigaworks S750 is already doing this.
It's electronics seperate the signals as above but instead of three receives and 3 subwoofers it's simply 1 subwoofer with three voice coils for more fine grained bass/more control over bass.
So at least we agree on something: the tripple voice coil subwoofer is accepting 3 inputs.
However those 3 inputs could be a mixed signal as described above as sinus/cosinus signals should mix quite easy.
What the Gigaworks is actually doing will remain a mystery for now.
One possible way to reverse engineering it is to place a monitor/volt meter or something on each coil, one at a time and play the same audio file and see what happens.
Also disconnecting some plugs/signals could shed further light on this.
This subwoofer is part of a 7.1 surround sound set.... so sending only left/center/right to it makes no sense what's so ever.
Why not send all 8 signals to it by mixing them down to 3 first ? ;)
Also the subwoofer is rated at 210 RMS.
So how can you say it's only 3 watts ? Sounds weird to me.
This subwoofer is according to repair man and pictures and guys on forum powered by 3 amplifiers each of 70 watts so you were dead wrong there or something is amiss ;) :)
Also pretty much all speaker outputs are already used from the denon receiver.
You did give me an idea though.
I could re-write some off the speaker outputs directly into the subwoofer, perhaps even the three seperate coils.
Then I would indeed how to get rid of cross over frequencies and make sure all signals are passed raw/unmodified or reverse it and send low frequencies... not sure if denon can do this... but it's beside the point since denon in normal operation mode only has 1 subwoofer output.
So this *main stream* device can simply NOT do with the Gigaworks might be doing.
Which could mean the Gigaworks is a revolutionary home theater system which could explain why a Saboteur sabotaged the production facility to use "conductive glue" ;) :) Which would only reveal it self after Q&A already passed the devices.
The Q&A did not test the devices properly to simulate prolonged use of heat.
Bye,
Skybuck.
~misfit~
Jul 28, 2017, 10:31:52 AM7/28/17
to
Once upon a time on usenet Peter Wieck wrote:
He's been trolling for many years now and is quite good at it.
Peter Wieck
Jul 28, 2017, 12:57:10 PM7/28/17
to
That makes sense. I was about to quote Schiller - well, perhaps I will anyway.
Against stupidity the very gods Themselves contend in vain.
I am no god, so I will quit contending.
Against stupidity the very gods Themselves contend in vain.
I am no god, so I will quit contending.
~misfit~
Jul 29, 2017, 8:53:00 AM7/29/17
to
Once upon a time on usenet Peter Wieck wrote:
> That makes sense. I was about to quote Schiller - well, perhaps I
> will anyway.
>
> Against stupidity the very gods Themselves contend in vain.
>
> I am no god, so I will quit contending.
That's the policy I adopt with people like this too. :)
> will anyway.
>
> Against stupidity the very gods Themselves contend in vain.
>
> I am no god, so I will quit contending.
0 new messages