Question 1
How do you bridge two already 'bridged amplifiers'? I never seen this before.
Can someone draw a schematic or block diagram on
how this works?
http://www.carsound.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=001731;p=1
Richard Clark posted;
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ok--now for some amp in series info---for starters i took a pair of amps--one was a kicker and the other was a dei--they were of similar power--each was a two channel unit---in the first test i measured the power of a single channel from each amp---4 ohm power was about 150 watts at 1% for each amp--i then put one channel of each amp in series and tested them into 4 ohms--power went up to over 500 watts--since each amp could drive 2 ohms per channel all did well--the results of this test can be seen at---Single Channel Test ------in the next test i put each amp in bridge mode---and measured the power into 8 oms--the dei did about 400 watts into 8 ohms and the kicker did about 250 watts----then i put the two bridged amps in series (bridged the bridged amps)and they produced about 700 watts into 8 ohms--see Bridge Test-they would have done more but my powersupply was a little too small for the test--thats why i did this test at 8 ohms---4 ohms would have been really drawing the current and our really big supply was tied up doing some other tests for the magazine--but these tests should get the point across----if you need big power at higher impedances like 4, 6, or 8 ohms or if you want big power at lower impedances and the amps really have a lot of current reserves then series connections are a consideration-------but wait before doing any of this---i will explain some of the complications and wiring quirks in the next post------
**************************************************
Question 2
If you read the link above, prior to this discussion he talks
about paralleling the outputs of similar amplifiers using a
0.1 ohm resistor to isolate amplifiers and matching the
amplifiers is critical. Has anyone done this ?
How do you bridge two already 'bridged amplifiers'? I never seen this before.
Can someone draw a schematic or block diagram on
how this works?
http://www.carsound.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=001731;p=1
Richard Clark posted;
**************************************************
ok--now for some amp in series info---for starters i took a pair of amps--one was a kicker and the other was a dei--they were of similar power--each was a two channel unit---in the first test i measured the power of a single channel from each amp---4 ohm power was about 150 watts at 1% for each amp--i then put one channel of each amp in series and tested them into 4 ohms--power went up to over 500 watts--since each amp could drive 2 ohms per channel all did well--the results of this test can be seen at---Single Channel Test ------in the next test i put each amp in bridge mode---and measured the power into 8 oms--the dei did about 400 watts into 8 ohms and the kicker did about 250 watts----then i put the two bridged amps in series (bridged the bridged amps)and they produced about 700 watts into 8 ohms--see Bridge Test-they would have done more but my powersupply was a little too small for the test--thats why i did this test at 8 ohms---4 ohms would have been really drawing the current and our really big supply was tied up doing some other tests for the magazine--but these tests should get the point across----if you need big power at higher impedances like 4, 6, or 8 ohms or if you want big power at lower impedances and the amps really have a lot of current reserves then series connections are a consideration-------but wait before doing any of this---i will explain some of the complications and wiring quirks in the next post------
**************************************************
Question 2
If you read the link above, prior to this discussion he talks
about paralleling the outputs of similar amplifiers using a
0.1 ohm resistor to isolate amplifiers and matching the
amplifiers is critical. Has anyone done this ?
thylantyr said:
I'm not sure you can do it.
When you make a bridge you invert the phase of the audio going to one amp. So what would you feed to a bridged amp as phase inverted on this "super bridge"?
I think you would be nulling the signal, but my reasoning maybe flawed.
On the other side you would also be increasing your distortion, so I'm not sure another alternatives would not be better. Like increasing voltages.
Carlos
You can do it under certain conditions but I wouldn't recommend it.
Look for inspiration here:
http://www.national.com/an/AN/AN-1192.pdf
Look for inspiration here:
http://www.national.com/an/AN/AN-1192.pdf
At the moment I can only think of paralleling to amps but they must be identical with the same gain, etc. But you must also insert resistors, rather big ones.
But I use to say "think Decibel"! How many more dB can you get by this dubious actions, virtually nothing.
My opinion at this: Forget it.
Change to more efficient speakers and/or a substantially more powerful amp, at least 5-10 times!
If you play at 500 watts how much more is really 3dB (1000 W)? _very_ little. You can hear the difference but I don't think you experince 500 watts more. Test this by simply doing a 3 dB attenuator.
But I use to say "think Decibel"! How many more dB can you get by this dubious actions, virtually nothing.
My opinion at this: Forget it.
Change to more efficient speakers and/or a substantially more powerful amp, at least 5-10 times!
If you play at 500 watts how much more is really 3dB (1000 W)? _very_ little. You can hear the difference but I don't think you experince 500 watts more. Test this by simply doing a 3 dB attenuator.
@peranders,
just think of what those guys (at carsound.com) want to do with it. EVERY 1/10 dB is interesting.
In that topic I read about a guy using 7 DD subs and 28 amps. With that setup (a good install, way to much DC-power, probably running at about 16V) it's possible to hit about 170 dB.
In dB dragging, every bit of a dB is interesting. Here in holland there are a few guys who also use this technique (using Digital Designs or Resonant Engineering woofers). For those guys, there are now woofers with 4 voicecoils available, so the can use 8 to 16 amplifiers for each woofer.
@thylantyr,
don't try this it home! For that, I totally agree with peranders, and most of the rest here: it's not interesting, you'll have to match your amps VERY good, and if you go from 2 to 4 amplifiers it only gives you a 3 dB extra. For use at home it's completely useless.
Grtz, Joris
just think of what those guys (at carsound.com) want to do with it. EVERY 1/10 dB is interesting.
In that topic I read about a guy using 7 DD subs and 28 amps. With that setup (a good install, way to much DC-power, probably running at about 16V) it's possible to hit about 170 dB.
In dB dragging, every bit of a dB is interesting. Here in holland there are a few guys who also use this technique (using Digital Designs or Resonant Engineering woofers). For those guys, there are now woofers with 4 voicecoils available, so the can use 8 to 16 amplifiers for each woofer.
@thylantyr,
don't try this it home! For that, I totally agree with peranders, and most of the rest here: it's not interesting, you'll have to match your amps VERY good, and if you go from 2 to 4 amplifiers it only gives you a 3 dB extra. For use at home it's completely useless.
Grtz, Joris
Re: Re: Re: How do you bridge two bridged amplifier?
According to Richard Clark (first post) he's using generic
car audio amplifiers, nothing special about their design.
In fact, he's using different amplifiers from different manufacturers
with different power ratings.
(assuming X1000 is special - hehe).
A few people say you can do it (two bridged series amplifiers),
but none can offer a method, not even a block diagram.
AudioFreak said:
According to Richard Clark (first post) he's using generic
car audio amplifiers, nothing special about their design.
In fact, he's using different amplifiers from different manufacturers
with different power ratings.
(assuming X1000 is special - hehe).
A few people say you can do it (two bridged series amplifiers),
but none can offer a method, not even a block diagram.
Even if find a way to do it there will be a question of the load as "seen" by the amp. Normally, a bridged amp will see an 8-ohm load as 4-ohms and a 4-ohm load as 2-ohms. I don't know what would happen in a double bridged configuration but I would sure want to know **before** throwing the switch.
There is something called a "Zero autoformer" (I think) that might be an aid to deal with the situation but they are not cheap. I note that professional amps like QSC, CarverPro etc, often specify configuration option that sound like double bridging. I would bet that they use a transformer to accomplish this. QSC has the schematics for some units available on their website. Maybe you can figure out something from one of those.
My take on bridging is that under most conditions buying a bigger amp is the better an often cheaper solution.
There is something called a "Zero autoformer" (I think) that might be an aid to deal with the situation but they are not cheap. I note that professional amps like QSC, CarverPro etc, often specify configuration option that sound like double bridging. I would bet that they use a transformer to accomplish this. QSC has the schematics for some units available on their website. Maybe you can figure out something from one of those.
My take on bridging is that under most conditions buying a bigger amp is the better an often cheaper solution.
Re: Re: Re: Re: Re: How do you bridge two bridged amplifier?
/agree
Richard Clark is an audio celebrity, and many many
people take his word and methods to be valid without
bias.
This is one scenerio where he didn't provide the data... yet ...
to support the claim of his experiment.
People on the other forum are very curious too.
I don't want to discredit his experiment, the reason
I came here to find out if someone has seen this before.....
peranders said:
/agree
Richard Clark is an audio celebrity, and many many
people take his word and methods to be valid without
bias.
This is one scenerio where he didn't provide the data... yet ...
to support the claim of his experiment.
People on the other forum are very curious too.
I don't want to discredit his experiment, the reason
I came here to find out if someone has seen this before.....
crown amps have this
i read in audio magazine, i'm trying to retrieve my copy, crown came up with this type of amp...essentially the principle is that two bridge amps completely isolated from each other electrically but sharing the same chassis....now, since the inputs/outputs are balanced, one is operated in inverting mode, while the other in a non-inverting mode, a bridged out put then can be taken off the red terminal, whilst the black output terminals are tied up....this is how i understand it, maybe djk can explain it better....
i read in audio magazine, i'm trying to retrieve my copy, crown came up with this type of amp...essentially the principle is that two bridge amps completely isolated from each other electrically but sharing the same chassis....now, since the inputs/outputs are balanced, one is operated in inverting mode, while the other in a non-inverting mode, a bridged out put then can be taken off the red terminal, whilst the black output terminals are tied up....this is how i understand it, maybe djk can explain it better....
Series connection of two bridge amps seems perfectly possible to me. Say that one has two (car or others) amps which both have (switching) supplies where the output of the PSU is isolated from the (12 VDC) common ground which they usually are as the PS uses a transformer, AFAIK, so that the supplies for the two amps have no galvanic connection. At the same time assume that they use input transformers (or coupling caps on input AND ground if that should work well) to achieve lift/isolation from the input ground (possibly in order to remove possible ground loop/hum problems common in cars). Each amp is bridged and the respective output voltages have no reference to each other. Now connect two of those amps in series and you have two bridged amps in series. Should work but possibly not that well.
As always I could easily be completely wrong but it seems fairly simple and straightforward to me. No need for anything special or unusual.
Ref: http://sound.westhost.com/project89.htm
As always I could easily be completely wrong but it seems fairly simple and straightforward to me. No need for anything special or unusual.
Ref: http://sound.westhost.com/project89.htm
Urban, the concept of series connection is that everything is connected in a long chain. If you have a bridge amp with a connected load how (where) can you put in the another amp?UrSv said:
I think (convinced) that it's impossible.....stop I think I have an
Whay happens if I have transformer connected inputs and the both amps have isolated PS?
Still, less than 3 dB and does it produce high fidelity?
peranders said:
Urban, the concept of series connection is that everything is connected in a long chain. If you have a bridge amp with a connected load how (where) can you put in the another amp?
I think (convinced) that it's impossible.....stop I think I have an
Whay happens if I have transformer connected inputs and the both amps have isolated PS?
Still, less than 3 dB and does it produce high fidelity?
I must be hopelessly unclear today as that is EXACTLY what I tried to describe when I mentioned transformers on the input and isolated PSUs which you repeated again. AudioFreak provided the schematic for it and the only question is what phase he's feeding the setup and depending on that he might have to connect plus to minus or minus to minus.
AudioFreak:
The question was not how to do it technically, as that is quite simple, but rather I was suprised that it could be done with the X1000 as I thought they would not be isolated from eachother thinking they would be sharing a ground connection but then that seems not to be the case. If it was to provide the pic then thanks. Otherwise thanks again...
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