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Default Does anyone make a crossover to be used on an INPUT?

I want to rig up a subwoofer, but I know that crossovers are expensive,
and since I am running high powered commercial amps, I'd need a hefty
setup. Then comes the need to combine the left and right channels
without loosing stereo separation.

I decided to go another route, My power amp was 600W (RMS). stereo. I
got a good deal on another amp that is also a stereo commercial amp,
rated at 500W RMS. Both amps are bridgable. The plan is to run the
outputs from my preamp into Y adaptors and feed the left and right
channels to BOTH amps. One of these amps I'll bridge and use that to
power a single subwoofer speaker.

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?

I have also thought about just putting an equalizer into the input of
the amp that feeds the subwoofer and raise the low end of the frequency
and cut the highs. I'm not sure if that will adaquately work or not.
I'll probably try it, but I have not yet built my subwoofer cabinet.

Either way, I know that 1100 watts rms is more than enough for a home
stereo...

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https://www.crutchfield.com/S-YMAiep...-low-pass.html

Come in quite a range. 200hz is one of many. You could do it all with passive filters.

Most sub-woofers are configured as pass-through devices. Feed the full signal to the SW, and the filtered signal from the SW to the rest of the drivers. If you have separate amps, similarly, but the output from the SW is filtered line-level.

Peter Wieck
Melrose Park, PA
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On Thursday, December 7, 2017 at 3:34:36 PM UTC-5, wrote:

Either way, I know that 1100 watts rms is more than enough for a home
stereo...


I can make my ears bleed with Maggie speakers and a 200-watt amp in the one system, and AR speakers and also a 200 watt amp in another.

The difference between 200A and 1,100A is only a bit over 5dB anyway, so the question becomes "why"? And unless you enjoy flaming drivers, what sort of speakers are capable of handling that level of power for any sustained period of time? Sure, transients are a bitch, but a reasonable power-supply at 200 watts will handle them as well as 1,000+ amp.

Peter Wieck
Melrose Park, PA


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In article ,
wrote:

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?


Sure. http://www.marchandelec.com/xovers.html for one.

I use an XM9 in my own speaker system. Each side has a
midrange/tweeter/midrange array with a passive crossover, powered by
one amplifier, and a side-mounted subwoofer powered by a second
amplifier. The XM9 divides the signal, after the preamp and before
the amplifiers, crossing over at 200 Hz.

http://www.radagast.org/~dplatt/speakers/

20+ years since I build it, and I'm still thoroughly satisfied with
the results.

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Default Does anyone make a crossover to be used on an INPUT?

First of all, combining the channels by definition means losing all the separation. Also do not try to combine outputs of amplifiers, it has a very bad effect on some. It has to do with DC and is insidious, sits there dissipating power uselessly. It can actually fry the amp in certain cases.

They make what you want for cars. Those ones that drive around "BOOM mufuka BOOM mufuka BOOM mufuka...". This is exactly what you want. It is active so it needs power, if 12 volts that is a simple matter because it does not pull much current. A spare wall wart in your junk drawer should do just fine.. Most of them also have a continuously variable crossover frequency as well. That comes in handy. Crossover too high and the subs might be too boomy, too low and the highs are taking too much power which they frequently can't use. Some have the option of combining the two channels, but at line level you can do it with two resistors and have practically no loss.

If you want it really loud, you might want a low pass passive filter on the woofers, such as in a regular crossover. This way if the bass amp clips it does not screw up the sound as much. But you probably won't need it. You are not really likely to clip anything with that power unless you have a huge outdoor party. In fact, with some exceptions people go to a party to mingle. For me, I like loud good sounding music, but not the whole time. People who just crank up the radio bug me. When I listen, everybody shuts up while it is playing and then there is an intermission between songs. Then there is time to talk, or maybe take requests, or whatever.

But seriously, go with the active (line level) crossover, you'll be glad you did. Most of them even have level controls, some power amps do not. Solves that, that is burns that bridge if you come to it.

There is a way to combine to a woofer on the output side but it loses a bunch of power and is totally unsuitable for bi-amping. Actually if you want to change your mind and go with four really full range channels, I can build you a little box that is like quad which is almost the same as Dolby surround.I mean native Dolby surround that they should never have been allowed to put their name on because it was so common in the 1970s+. I used the technique for movies with my Advent five foot TV, which BTW was the only one in town with really hot tubes and near perfect geometry and convergence. But like on Days of Thunder you heard the cards actually go around you when the camera angle was that way. The Enterprise would take off and seem to go above you on the screen and the speakers sounded like it. It is good for some music, but not all. Some is mixed funny, like all the bass in one channel, like The Swinging Medallions - Double Shot Of My Bsby's Love or Beatles - Taxman. Those are not suited well for such a system.

It sounds like Dolby without any delay or anything like that. In that respect it is true high fidelity because it only puts out what goes in. With all the effects, Dolby surround is not high fidelity, it *******ises the sound with.

Actually with speaker that have really good imaging it almost sounds like there are rear speakers. But you'll probably not find them with that kind of power handling without mucho dinero, and very low efficiency.

So really, just go to one of those car audio places and tell them what you want, most likely they have it on the shelf already. You don't need an ultra high fidelity one,just low distortion, and very importantly, LOW NOISE. While the levels are line level, you are dealing with it after the volume control. So any noise introduced by the unit will still be there.
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Default Does anyone make a crossover to be used on an INPUT?

On Thursday, 7 December 2017 20:34:36 UTC, wrote:
I want to rig up a subwoofer, but I know that crossovers are expensive,
and since I am running high powered commercial amps, I'd need a hefty
setup. Then comes the need to combine the left and right channels
without loosing stereo separation.

I decided to go another route, My power amp was 600W (RMS). stereo. I
got a good deal on another amp that is also a stereo commercial amp,
rated at 500W RMS. Both amps are bridgable. The plan is to run the
outputs from my preamp into Y adaptors and feed the left and right
channels to BOTH amps. One of these amps I'll bridge and use that to
power a single subwoofer speaker.

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?

I have also thought about just putting an equalizer into the input of
the amp that feeds the subwoofer and raise the low end of the frequency
and cut the highs. I'm not sure if that will adaquately work or not.
I'll probably try it, but I have not yet built my subwoofer cabinet.

Either way, I know that 1100 watts rms is more than enough for a home
stereo...


resistor capacitor (RC) low pass filter.


NT
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On Thu, 7 Dec 2017 14:14:06 -0800, (Dave Platt)
wrote:

In article ,
wrote:

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?


Sure.
http://www.marchandelec.com/xovers.html for one.

I use an XM9 in my own speaker system. Each side has a
midrange/tweeter/midrange array with a passive crossover, powered by
one amplifier, and a side-mounted subwoofer powered by a second
amplifier. The XM9 divides the signal, after the preamp and before
the amplifiers, crossing over at 200 Hz.

http://www.radagast.org/~dplatt/speakers/

20+ years since I build it, and I'm still thoroughly satisfied with
the results.


Yep, this looks just what I want. I've seen these but never knew what
they were for....


Thanks
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wrote:
I want to rig up a subwoofer, but I know that crossovers are expensive,
and since I am running high powered commercial amps, I'd need a hefty
setup. Then comes the need to combine the left and right channels
without loosing stereo separation.

I decided to go another route, My power amp was 600W (RMS). stereo. I
got a good deal on another amp that is also a stereo commercial amp,
rated at 500W RMS. Both amps are bridgable. The plan is to run the
outputs from my preamp into Y adaptors and feed the left and right
channels to BOTH amps. One of these amps I'll bridge and use that to
power a single subwoofer speaker.

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?

I have also thought about just putting an equalizer into the input of
the amp that feeds the subwoofer and raise the low end of the frequency
and cut the highs. I'm not sure if that will adaquately work or not.
I'll probably try it, but I have not yet built my subwoofer cabinet.

Either way, I know that 1100 watts rms is more than enough for a home
stereo...


There no need to sum bass in stereo, just use one channel. That can cause
that channel to be different with loading. You make easy line level
passive, but what order, and how is that going to mix with upper, phase and
frequency. Seems like a full active crossover of all three speakers will
work best, but you still have to determine order of filter and frequency
for combining.

Greg


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"There no need to sum bass in stereo, just use one channel"

That depends on what you listen to. Some music is mixed differently.
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On Fri, 8 Dec 2017 07:52:47 -0000 (UTC), gregz
wrote:

wrote:
I want to rig up a subwoofer, but I know that crossovers are expensive,
and since I am running high powered commercial amps, I'd need a hefty
setup. Then comes the need to combine the left and right channels
without loosing stereo separation.

I decided to go another route, My power amp was 600W (RMS). stereo. I
got a good deal on another amp that is also a stereo commercial amp,
rated at 500W RMS. Both amps are bridgable. The plan is to run the
outputs from my preamp into Y adaptors and feed the left and right
channels to BOTH amps. One of these amps I'll bridge and use that to
power a single subwoofer speaker.

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?

I have also thought about just putting an equalizer into the input of
the amp that feeds the subwoofer and raise the low end of the frequency
and cut the highs. I'm not sure if that will adaquately work or not.
I'll probably try it, but I have not yet built my subwoofer cabinet.

Either way, I know that 1100 watts rms is more than enough for a home
stereo...


There no need to sum bass in stereo, just use one channel. That can cause
that channel to be different with loading. You make easy line level
passive, but what order, and how is that going to mix with upper, phase and
frequency. Seems like a full active crossover of all three speakers will
work best, but you still have to determine order of filter and frequency
for combining.

Greg


When I built my tube stereo around 1968 to 71, I had an idea that was
ahead of it's time, and that was to create a 3 channel system. I had 3
mono power amps so why not.... Back then, Quad sound did not exist yet,
at least not in consumer electronics. But my idea was to create a system
that not only had 3 channels, but the rear channel was to have a delay,
so it sounded like a huge auditorium. I got my hands on both a tape loop
delay unit, which was quite a neat sounding device, but needed constant
attention because I had to make my own tape loops using some
reel-to-reel tape and splicing it to form a loop. Eventually I got tired
of the constant hassle of making and replacing the tape (which did not
last long), and switched over to a spring reverb tank device, modified
from a guitar amp circuit.

Anyhow, to get that 3rd channel, I simply added a 3rd RCA jack to the
preamp, and put an equal value resistor from the Left and from the Right
channel to that 3rd jack. That worked, but I lost some stereo
separation. That lead to adding a switch for those resistors, so I could
switch off the 3rd channel but regain the true stereo sound. A year or
two later I found a better solution. I used a second stereo preamp with
the resistors in place but had all the inputs with Y adaptors feeding
each preamp. Eventually that too was replaced by an equalizer, which had
it's own preamp circuits and that became the final solution to achieve
the 3rd channel.

Back then, there was no such thing as a sub woofer, at least not for
home electronics. However I believe they had subs in use for theaters
and such.

But the Subs bring back the 3rd channel requirement (combined L + R).
So, I learned by my past trial and error that achieving a 3rd channel is
not all that difficult, as long as there is some sort of preamp circuit
in place, rather than just using resistors.

Since posting this message, I have looked at some schematics for these
low pass filters, as well as reading articles about them. They are
basically a preamp circuit combined with the filters to separate the
frequencies. Now that I have looked at these devices and understand how
they work, it's not all that difficult to achieve what I want. The only
drawback now, is the price of these filtering units. ($600 and Up).
Of course I'll have to see what I can find in the USED market, and I am
also wondering if they sell just the pre-assembled circuit boards on
ebay or other places. From what I'm seeing, these are just small circuit
boards, with a few Op-Amps and the passive components to achieve the
filtering. One board for each channel, a power supply, and a few
potentiometers to "tune" them....

These pre-assembled circuit boards seem to be the "kits" in this day and
age. You buy the boards, mount them in a box, add a power supply and
some pots, switches, jacks and you have a complete device. They are made
for amps, pre-amps, test equipment and lots of other stuff. So I wonder
if they are made for pass filters????


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wrote on 12/7/2017 5:10 PM:
On Thursday, December 7, 2017 at 3:34:36 PM UTC-5, wrote:

Either way, I know that 1100 watts rms is more than enough for a home
stereo...


I can make my ears bleed with Maggie speakers and a 200-watt amp in the one system, and AR speakers and also a 200 watt amp in another.

The difference between 200A and 1,100A is only a bit over 5dB anyway, so the question becomes "why"? And unless you enjoy flaming drivers, what sort of speakers are capable of handling that level of power for any sustained period of time? Sure, transients are a bitch, but a reasonable power-supply at 200 watts will handle them as well as 1,000+ amp.


Huh, what? If by 200A and 1100A you mean 200 watts and 1100 watts, then 5
dB is not accurate. It is more like 7.4 dB. I expect you did this in your
head and with a factor of 2 twice (6 dB) and accounted for the remainder in
the wrong direction.

I find oldschool amusing. I've read articles about using a 10 watt
amplifier (per channel) to fill a room with sound. So using a 50 or 100
watt amp to keep it far away from the slightly increased distortion from
running near the limit would be somewhat reasonable. But 1100 watts in a
home is pretty pointless. I guess you could get a volume control that goes
to 11 and keep it set below 1. Even then you might need a vernier
adjustment to be able to actually control the volume to a reasonable level.
lol

Think of it this way... In college I worked on a chemical instrument to
measure light absorption of solid samples by shining an intense
monochromatic, pulsed light source on the sample and then using a microphone
to detect the sound vibrations this produced. In that setup we used a light
source that produced around 10 watts of white light. If we had used 1100
watts we would have burnt up the sample we were working with... I'm just
sayin'

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998
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On 12/8/2017 1:07 AM, wrote:
The newest amp I got is a Crown brand. 500W.


Absolute Chinese crap amplifier.

--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com


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On Sat, 9 Dec 2017 08:59:59 +1100, Clifford Heath
wrote:

On 08/12/17 18:07, wrote:
On Fri, 8 Dec 2017 09:00:50 +1100, Clifford Heath
wrote:
On 08/12/17 08:35, Fred Smith wrote:
On 2017-12-07,
wrote:
However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?
Commonly done, even in my son's old Altec computer speakers.
Clifford Heath.

Funny you mentioned the Altec name. My 600W power amp and the preamp are
Altec Lansing brand. The speakers are Yamaha.


Haha - I have the opposite, a Yamaha A-520 amp and a pair of
Altec Lansing "Eights", upgraded with new kevlar dome tweeters
instead of the awful piezos, and fantastic new mids. The Eights
were their first entry into the audiophile market, I believe.

That's interesting. Altec Lansing made some great stuff back in the day.
I recently saw some computer speakers with their name on it. I had sort
of heard they went out of business, but it looks like they are still
around. Yamaha was not a name I was all that familiar with, but I like
these speakers.

That Crown amp is pretty decent too. I had heard of them, but this was
the first thing I own of theirs....

Are you familiar with the Grateful Dead's "wall of sound". That was
considered the biggest sound system ever made at that time (early 70s).


Yes, I recall watching a doco on Youtube about it.

Clifford Heath


I saw at least one of them videos too. The Grateful Dead was not only a
good band, but they played a big part in electronics as far as sound
systems. But that they had, was just too big for portable use. One of
them articles said they needed 4 semi truck trailers to haul everything
and a crew of something like 25 people to set it up at a huge cost.
After all, that was all setup for ONE SHOW. A show that was probably 3
or 4 hours long, and it said it took as much as a week to setup. They
almost went bankrupt doing it, but looking back, they played a huge part
in today's stage sound systems.

This may be of interest too. Back in the 80's I was told about a band
that used their sound system to simulate and earthquake. They were
playing at a fairly small bar/club in a nearby city. (Thats when I lived
in the city). I went to the show, and it was something I have never been
able to explain, exceot to say it was very awesome.

After playing a really good show of old rock music, they go to their
last song and all of a sudden the whole building began to shake. Just an
extremely powerful low bass sound that made me feel like I was detached
from the floor and there were literally glasses falling off tables and
you could see ripples in glasses of beer and drinks. I have never felt
anything like it..... Unfortunately I can not remember the name of that
band, that was many years ago, and I am sure they are no longer playing.
I remember after they finished playing, I asked a bartender who pays for
the broken glasses, and they said the band had in their contract to pay
for all damages, and explained the whole process, so as not to freak out
the bar owners/workers.

Actually, aside from a dozen or so drink glasses, there was no damages,
no broken windows in the building or anything like that. It was all
controlled well, but to this day, I wish I knew what they were running
for amplifiers and speakers.... I do think the sound was in the freq
range of around 28 to 32 cps. I have runs my audio generator thru that
range and gotten a similar feeling, but not as powerful. For some
reason, that frequency range has a very powerful effect.

I have often wondered if that has anything to do with it being half of
the cps of our 60 cycle voltage we use???? But I cant see how the two
have any relation except that it's a mathematical fact.....

I have always had a fascination with sound systems since I was in my
teens and I did sound for several bands over the years. Everytime I
think I'm too old to do that stuff anymore, some band comes along, and
I'm doing it again. The latest is a local small band who are excellent
musicians but they were trying to run the sound on the stage and play at
the same time. They did a halfway decent job running the sound, but I
offerred to run sound for them at an outdoor show, which was part of a
very poorly organized new festival which got few people to attend. They
were playing to a crowd of about 10 people and during their break, they
said they considered it "practice", but they were getting paid to do it,
regardless of the audience. That's when I asked if I could run the sound
system, after telling them what I did in the past. Ever since, I run
their sound when they play locally. They cant really pay me, but usually
buy me dinner and stuff, but I just like doing it, so what the heck!!!
I'm having fun and they like the results....

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On Thursday, December 7, 2017 at 6:46:39 PM UTC-5, wrote:


They make what you want for cars. Those ones that drive around "BOOM mufuka BOOM mufuka BOOM mufuka...".




I read this twice today, and laughed both times... I guess this must be a nearly universal occurrence nowadays.

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On 09/12/17 10:33, wrote:
On Sat, 9 Dec 2017 08:59:59 +1100, Clifford Heath
wrote:
On 08/12/17 18:07,
wrote:
On Fri, 8 Dec 2017 09:00:50 +1100, Clifford Heath
wrote:
On 08/12/17 08:35, Fred Smith wrote:
On 2017-12-07,
wrote:
However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?
Commonly done, even in my son's old Altec computer speakers.
Clifford Heath.
Funny you mentioned the Altec name. My 600W power amp and the preamp are
Altec Lansing brand. The speakers are Yamaha.

Haha - I have the opposite, a Yamaha A-520 amp and a pair of
Altec Lansing "Eights", upgraded with new kevlar dome tweeters
instead of the awful piezos, and fantastic new mids. The Eights
were their first entry into the audiophile market, I believe.

That's interesting. Altec Lansing made some great stuff back in the day.


They used to do theatres etc originally, no domestic stuff.

I recently saw some computer speakers with their name on it.


We've owned a few of those, I don't mind them, but they're not
designed for home HiFi (though they're better than a lot of the
crap for that, too). I have one of those on my desk right now
actually. Two-way (treble&mid) L&R, with a sub box under the
desk.

Lansing was the guy who started JBL (that's his initials).

The Grateful Dead was not only a good band,


I would have described them as more of a tribal movement,
considering the number of people who played with them.

Clifford Heath.
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On Sat, 9 Dec 2017 21:24:05 +1100, Clifford Heath
wrote:

Clifford Heath.
Funny you mentioned the Altec name. My 600W power amp and the preamp are
Altec Lansing brand. The speakers are Yamaha.
Haha - I have the opposite, a Yamaha A-520 amp and a pair of
Altec Lansing "Eights", upgraded with new kevlar dome tweeters
instead of the awful piezos, and fantastic new mids. The Eights
were their first entry into the audiophile market, I believe.

That's interesting. Altec Lansing made some great stuff back in the day.


They used to do theatres etc originally, no domestic stuff.


That's how they became one of the top producers of audio gear.
Commercial gear of this sort was originally made for being installed at
theaters and other similar venues. Then their stuff began getting used
in a portable manner for rock bands and similar. Using that kind of gear
in a home is usually superior to most of the "consumer grade" stuff.


I recently saw some computer speakers with their name on it.


We've owned a few of those, I don't mind them, but they're not
designed for home HiFi (though they're better than a lot of the
crap for that, too). I have one of those on my desk right now
actually. Two-way (treble&mid) L&R, with a sub box under the
desk.


Most of them cheap computer speakers are garbage. I went thru several of
them before I finally just took a small stereo with bookshelf speakers
and plugged my computer into that, For portable use of my laptop comp.,
I bought a very small amplifier (about 6 inches) made for kids to plug
in an electric guitar. I think I paid $3 for it at a rummage sale. It
works with batteries or a wall wart adaptor. It's only mono, but it has
better sound than any of them computer speakers.


Lansing was the guy who started JBL (that's his initials).


Yep, I knew that, and JBL makes good quailty stuff for the most part.

The Grateful Dead was not only a good band,


I would have described them as more of a tribal movement,
considering the number of people who played with them.

Clifford Heath.


They were a very unusual rock band. For most rock bands people would buy
a ticket and go to a concert. Then they go home at the end of the
concert. But the G.D. were more like a "happening". People followed
them, camped at the shows, and for some that became a way of life,
similar to a traveling carnival, where they had businesses selling G.D.
shirts and other stuff and that is how they lived. It was almost like
Woodstock went on the road and kept moving around. I went to a few of
their shows, and I did camp at them, before and after the show, but it
was for a few days, then I went back home. It was fun!!!

I cant see anything like that happening today though.


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wrote:
On Fri, 8 Dec 2017 07:52:47 -0000 (UTC), gregz
wrote:

wrote:
I want to rig up a subwoofer, but I know that crossovers are expensive,
and since I am running high powered commercial amps, I'd need a hefty
setup. Then comes the need to combine the left and right channels
without loosing stereo separation.

I decided to go another route, My power amp was 600W (RMS). stereo. I
got a good deal on another amp that is also a stereo commercial amp,
rated at 500W RMS. Both amps are bridgable. The plan is to run the
outputs from my preamp into Y adaptors and feed the left and right
channels to BOTH amps. One of these amps I'll bridge and use that to
power a single subwoofer speaker.

However, I need a means to send only the bass to the amp that powers the
Subwoofer. Is there any sort of crossover made that goes in the input of
the power amps, after the preamp?

I have also thought about just putting an equalizer into the input of
the amp that feeds the subwoofer and raise the low end of the frequency
and cut the highs. I'm not sure if that will adaquately work or not.
I'll probably try it, but I have not yet built my subwoofer cabinet.

Either way, I know that 1100 watts rms is more than enough for a home
stereo...


There no need to sum bass in stereo, just use one channel. That can cause
that channel to be different with loading. You make easy line level
passive, but what order, and how is that going to mix with upper, phase and
frequency. Seems like a full active crossover of all three speakers will
work best, but you still have to determine order of filter and frequency
for combining.

Greg


When I built my tube stereo around 1968 to 71, I had an idea that was
ahead of it's time, and that was to create a 3 channel system. I had 3
mono power amps so why not.... Back then, Quad sound did not exist yet,
at least not in consumer electronics. But my idea was to create a system
that not only had 3 channels, but the rear channel was to have a delay,
so it sounded like a huge auditorium. I got my hands on both a tape loop
delay unit, which was quite a neat sounding device, but needed constant
attention because I had to make my own tape loops using some
reel-to-reel tape and splicing it to form a loop. Eventually I got tired
of the constant hassle of making and replacing the tape (which did not
last long), and switched over to a spring reverb tank device, modified
from a guitar amp circuit.

Anyhow, to get that 3rd channel, I simply added a 3rd RCA jack to the
preamp, and put an equal value resistor from the Left and from the Right
channel to that 3rd jack. That worked, but I lost some stereo
separation. That lead to adding a switch for those resistors, so I could
switch off the 3rd channel but regain the true stereo sound. A year or
two later I found a better solution. I used a second stereo preamp with
the resistors in place but had all the inputs with Y adaptors feeding
each preamp. Eventually that too was replaced by an equalizer, which had
it's own preamp circuits and that became the final solution to achieve
the 3rd channel.

Back then, there was no such thing as a sub woofer, at least not for
home electronics. However I believe they had subs in use for theaters
and such.

But the Subs bring back the 3rd channel requirement (combined L + R).
So, I learned by my past trial and error that achieving a 3rd channel is
not all that difficult, as long as there is some sort of preamp circuit
in place, rather than just using resistors.

Since posting this message, I have looked at some schematics for these
low pass filters, as well as reading articles about them. They are
basically a preamp circuit combined with the filters to separate the
frequencies. Now that I have looked at these devices and understand how
they work, it's not all that difficult to achieve what I want. The only
drawback now, is the price of these filtering units. ($600 and Up).
Of course I'll have to see what I can find in the USED market, and I am
also wondering if they sell just the pre-assembled circuit boards on
ebay or other places. From what I'm seeing, these are just small circuit
boards, with a few Op-Amps and the passive components to achieve the
filtering. One board for each channel, a power supply, and a few
potentiometers to "tune" them....

These pre-assembled circuit boards seem to be the "kits" in this day and
age. You buy the boards, mount them in a box, add a power supply and
some pots, switches, jacks and you have a complete device. They are made
for amps, pre-amps, test equipment and lots of other stuff. So I wonder
if they are made for pass filters????


I've built boards to high/low pass, etc. Not much to it. Look around, I
think Marchand was mentioned.

Greg


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Default Does anyone make a crossover to be used on an INPUT?

On Sun, 10 Dec 2017 08:44:05 -0000 (UTC), gregz
wrote:

for amps, pre-amps, test equipment and lots of other stuff. So I wonder
if they are made for pass filters????


I've built boards to high/low pass, etc. Not much to it. Look around, I
think Marchand was mentioned.

Greg


Marchand has a lot of them, but the cheapest one was well over $600.
Thats out of my price range.

I found some boards on ebay, they look to be complete two channel in,
one out, with all the filtering. They need to be put into a box and a
power supply added, as well as in/out jacks. They cost $10 or less. I'm
thinking about ordering one of them. I can easily build a power supply
or maybe just use a wall wart. They are pretty simple, one op amp IC for
each channel and some passive parts. One model only had 2 pots, (volume
in, volume out). The other model has 3 pots, the third one is to adjust
the cutoff. If I get one, I'll probably choose the 3 pot one.

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Default Does anyone make a crossover to be used on an INPUT?

On Sunday, 10 December 2017 15:36:30 UTC, wrote:
On Sun, 10 Dec 2017 08:44:05 -0000 (UTC), gregz
wrote:

for amps, pre-amps, test equipment and lots of other stuff. So I wonder
if they are made for pass filters????


I've built boards to high/low pass, etc. Not much to it. Look around, I
think Marchand was mentioned.

Greg


Marchand has a lot of them, but the cheapest one was well over $600.
Thats out of my price range.

I found some boards on ebay, they look to be complete two channel in,
one out, with all the filtering. They need to be put into a box and a
power supply added, as well as in/out jacks. They cost $10 or less. I'm
thinking about ordering one of them. I can easily build a power supply
or maybe just use a wall wart. They are pretty simple, one op amp IC for
each channel and some passive parts. One model only had 2 pots, (volume
in, volume out). The other model has 3 pots, the third one is to adjust
the cutoff. If I get one, I'll probably choose the 3 pot one.


sounds crazy


NT
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Posts: 73
Default Does anyone make a crossover to be used on an INPUT?

Once upon a time on usenet wrote:
On Fri, 8 Dec 2017 07:52:47 -0000 (UTC), gregz
wrote:

wrote:
I want to rig up a subwoofer, but I know that crossovers are
expensive, and since I am running high powered commercial amps, I'd
need a hefty setup. Then comes the need to combine the left and
right channels without loosing stereo separation.

I decided to go another route, My power amp was 600W (RMS). stereo.
I got a good deal on another amp that is also a stereo commercial
amp, rated at 500W RMS. Both amps are bridgable. The plan is to run
the outputs from my preamp into Y adaptors and feed the left and
right channels to BOTH amps. One of these amps I'll bridge and use
that to power a single subwoofer speaker.

However, I need a means to send only the bass to the amp that
powers the Subwoofer. Is there any sort of crossover made that goes
in the input of the power amps, after the preamp?

I have also thought about just putting an equalizer into the input
of the amp that feeds the subwoofer and raise the low end of the
frequency and cut the highs. I'm not sure if that will adaquately
work or not. I'll probably try it, but I have not yet built my
subwoofer cabinet.

Either way, I know that 1100 watts rms is more than enough for a
home stereo...


There no need to sum bass in stereo, just use one channel. That can
cause that channel to be different with loading. You make easy line
level passive, but what order, and how is that going to mix with
upper, phase and frequency. Seems like a full active crossover of
all three speakers will work best, but you still have to determine
order of filter and frequency for combining.

Greg


When I built my tube stereo around 1968 to 71, I had an idea that was
ahead of it's time, and that was to create a 3 channel system. I had 3
mono power amps so why not.... Back then, Quad sound did not exist
yet, at least not in consumer electronics. But my idea was to create
a system that not only had 3 channels, but the rear channel was to
have a delay, so it sounded like a huge auditorium. I got my hands on
both a tape loop delay unit, which was quite a neat sounding device,
but needed constant attention because I had to make my own tape loops
using some reel-to-reel tape and splicing it to form a loop.
Eventually I got tired of the constant hassle of making and replacing
the tape (which did not last long), and switched over to a spring
reverb tank device, modified from a guitar amp circuit.

Anyhow, to get that 3rd channel, I simply added a 3rd RCA jack to the
preamp, and put an equal value resistor from the Left and from the
Right channel to that 3rd jack. That worked, but I lost some stereo
separation. That lead to adding a switch for those resistors, so I
could switch off the 3rd channel but regain the true stereo sound. A
year or two later I found a better solution. I used a second stereo
preamp with the resistors in place but had all the inputs with Y
adaptors feeding each preamp. Eventually that too was replaced by an
equalizer, which had it's own preamp circuits and that became the
final solution to achieve the 3rd channel.

Back then, there was no such thing as a sub woofer, at least not for
home electronics. However I believe they had subs in use for theaters
and such.

But the Subs bring back the 3rd channel requirement (combined L + R).
So, I learned by my past trial and error that achieving a 3rd channel
is not all that difficult, as long as there is some sort of preamp
circuit in place, rather than just using resistors.

Since posting this message, I have looked at some schematics for these
low pass filters, as well as reading articles about them. They are
basically a preamp circuit combined with the filters to separate the
frequencies. Now that I have looked at these devices and understand
how they work, it's not all that difficult to achieve what I want.
The only drawback now, is the price of these filtering units. ($600
and Up).
Of course I'll have to see what I can find in the USED market, and I
am also wondering if they sell just the pre-assembled circuit boards
on ebay or other places. From what I'm seeing, these are just small
circuit boards, with a few Op-Amps and the passive components to
achieve the filtering. One board for each channel, a power supply,
and a few potentiometers to "tune" them....

These pre-assembled circuit boards seem to be the "kits" in this day
and age. You buy the boards, mount them in a box, add a power supply
and some pots, switches, jacks and you have a complete device. They
are made for amps, pre-amps, test equipment and lots of other stuff.
So I wonder if they are made for pass filters????


https://www.aliexpress.com/item/Low-...590327578.html

I've used one of these and it seems to work fine. For $5 delivered it's hard
to not try it.
--
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)


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Default Does anyone make a crossover to be used on an INPUT?

On Tuesday, 26 December 2017 01:09:43 UTC, ~misfit~ wrote:
Once upon a time on usenet wrote:
On Fri, 8 Dec 2017 07:52:47 -0000 (UTC), gregz
wrote:
wrote:

8

I want to rig up a subwoofer, but I know that crossovers are


https://www.aliexpress.com/item/Low-...590327578.html

I've used one of these and it seems to work fine. For $5 delivered it's hard
to not try it.


What's the point of it? A couple of RCs does the job without waiting for delivery or paying a thing. Or using a psu, or adding noise to your signal.


NT
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Posts: 73
Default Does anyone make a crossover to be used on an INPUT?

Once upon a time on usenet wrote:
On Tuesday, 26 December 2017 01:09:43 UTC, ~misfit~ wrote:
Once upon a time on usenet
wrote:
On Fri, 8 Dec 2017 07:52:47 -0000 (UTC), gregz
wrote:
wrote:

8

I want to rig up a subwoofer, but I know that crossovers are


https://www.aliexpress.com/item/Low-...590327578.html

I've used one of these and it seems to work fine. For $5 delivered
it's hard to not try it.


What's the point of it? A couple of RCs does the job without waiting
for delivery or paying a thing. Or using a psu, or adding noise to
your signal.


NT


'RC's?

The point is easy adjustability, both frequency and volume of bass.
--
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)




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Posts: 12,364
Default Does anyone make a crossover to be used on an INPUT?

On Tuesday, 2 January 2018 05:16:23 UTC, ~misfit~ wrote:
Once upon a time on usenet tabbypurr wrote:
On Tuesday, 26 December 2017 01:09:43 UTC, ~misfit~ wrote:
Once upon a time on usenet wrote:
On Fri, 8 Dec 2017 07:52:47 -0000 (UTC), gregz
wrote:
wrote:

8



I want to rig up a subwoofer, but I know that crossovers are


https://www.aliexpress.com/item/Low-...590327578.html

I've used one of these and it seems to work fine. For $5 delivered
it's hard to not try it.


What's the point of it? A couple of RCs does the job without waiting
for delivery or paying a thing. Or using a psu, or adding noise to
your signal.


'RC's?

The point is easy adjustability, both frequency and volume of bass.


both of which are easy with an RC filter.


NT
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