"Jerry Stuckle" wrote in message
...

snip

In addition to the splitter losses, you have coax and connector loss. Coax
loss probably isn't too bad, but unless you use a high quality crimping
tool, connector loss can easily approach 0.25 to 0.5 db. Even with a high
quality crimping tool, you can get around 0.1 db per connector.

There is also the possibility of a slight phase difference of the signals
coming out of the combiner, which would also affect the output
(splitters/combiners aren't perfect, either). But I wouldn't think this
would show up at such low frequencies unless you have lab-grade test
equipment (microwave frequencies and above are a different story).

All correct. As I said to Ian, I wanted to show I could create two matching
signals then add them and the passive splitter/combiner output would be
greater than either input, alone. Accuracy within a dB or so was sufficient
to make the point. I wouldn't go to a professional meeting with the
demonstration rig I used last night.

Another experiment I ran (back around 1975) was to take 100 feet of cable
and measure the loss, then repeat the measurement using a different 100 feet
made from ten different pieces. Yup, the loss was about 3 dB more,
indicative of an average 0.3 dB loss per joint, neatly within the range you
specified.

"Sal"

"Jerry Stuckle" wrote in message
...


OK, so instead of putting out 100W to one eight-ohm speaker, you're
putting out 100W to two eight ohm speakers. So you have a 3db gain,
assuming the speakers are in phase.

It is no different than feeding two eight-ohm speakers from separate 100W
amplifiers, and the results are the same.

Discussion of audio amplifier power in home systems always prompts me to
relate this: I worked for a guy who was formerly a projectionist at Radio
City Music Hall in New York. He told me the sound system used amplifiers
rated at 70 watts per channel. That's a 6,000-seat theater.

He worked there a long time ago, so this not a claim of what they use today.
Use for perspective only, please.

"Sal"

"Sal" salmonella@food poisoning.org wrote:
"Jerry Stuckle" wrote in message
...


OK, so instead of putting out 100W to one eight-ohm speaker, you're
putting out 100W to two eight ohm speakers. So you have a 3db gain,
assuming the speakers are in phase.

It is no different than feeding two eight-ohm speakers from separate 100W
amplifiers, and the results are the same.

Discussion of audio amplifier power in home systems always prompts me to
relate this: I worked for a guy who was formerly a projectionist at Radio
City Music Hall in New York. He told me the sound system used amplifiers
rated at 70 watts per channel. That's a 6,000-seat theater.

He worked there a long time ago, so this not a claim of what they use today.
Use for perspective only, please.

"Sal"

Some of the early amps were smaller. I remember a discussion about a movie
coming in that suggested higher power. Those speakers were typically at
least 100 times more power efficient than average home speakers, or 10 dB
spl. Many were altec a7's.

Greg

On 1/9/2014 11:21 PM, Ralph Mowery wrote:
"boomer" wrote in message
news:_fDzu.213384$4q1.203346@en-nntp-
PS some have actually used #00 wire to their speakers. Without
experimenting myself I feel by guessing that this is over-kill. I could be
wrong, I was before.

While going from # 20 or so speaker wire to # 10 is often helpful, I doubt
going much larger is going to help unless you have a very long run.

Lots of things are over sold to te audio people. Best one I know of is some
special oxygen free teflon wire ( or something like that) that replaces the
line cord to the wall outlet for over $ 100. Even if it actually did
something, that extra 50 or so feet of regular wire back to the breaker box
and other wire to the main power feed would make it worthless.


Definitely! A lot of audio people want the best sound, but are
unfamiliar with the technical aspects. This leaves them ripe for greedy
salespeople.

I remember going into circuit City a few years ago. All I needed was a
few feet of speaker wire. The salesman tried to sell me a 50' spool of
16 gauge wire for about $50. I asked him why it was so expensive - he
replied "Because it's (brand name here)". I then asked him what was so
special about Monster. His only response was "It's (brand name here)!".

I went down the street to Radio Shack and got something similar for
under $10. That was 15 or more years ago, and it's still working fine.

If you want to sell me something that's 5x the price of the competition,
you need to be ready to tell me WHY it's 5x the price. And just saying
it's because it's a certain brand doesn't work.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.

==================

On 1/10/2014 12:45 AM, Sal wrote:
"Jerry Stuckle" wrote in message
...


OK, so instead of putting out 100W to one eight-ohm speaker, you're
putting out 100W to two eight ohm speakers. So you have a 3db gain,
assuming the speakers are in phase.

It is no different than feeding two eight-ohm speakers from separate 100W
amplifiers, and the results are the same.

Discussion of audio amplifier power in home systems always prompts me to
relate this: I worked for a guy who was formerly a projectionist at Radio
City Music Hall in New York. He told me the sound system used amplifiers
rated at 70 watts per channel. That's a 6,000-seat theater.

He worked there a long time ago, so this not a claim of what they use today.
Use for perspective only, please.

"Sal"



Yes, this is where speaker efficiency comes into play. Due to the need
for stiffer cones, larger voice coils, etc., higher-power speakers are
generally less efficient than lower power ones. So 10W into a 10W-rated
speaker will provide a higher SPL than that same 10W into a 100W speaker.

And, of course, speaker placement is also critical, especially in larger
venues. You can cover a large area with not a lot of power if the
system is designed properly.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.

==================

On 1/9/2014 11:06 PM, gregz wrote:
boomer wrote:
snip
I personally have a Crown 810 powering a couple of AR SRT380s. The
amplifier has 4 ohm outputs and the speakers are 4 ohms. There is nothing
to be done to increase sound power except buy more efficient folded horn
types. I have neither the space nor money to do so. However, at 420 watts
rms per channel as it is now, I really don't require more power. Jimmy
Hendrix sounds just fine to me. :-)


What, horns produce magical gain.


They don't have gain, but some speakers are more efficient, so you have
less loss.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

In a circa 1970s issue of Stereo Review there was a cartoon showing the
Front Window of a Stereo Dealers. There was a sign advertising an OLD
FOLKS SPECIAL -- a speaker with a frequency response of 500Hz to
5KHz. A caption stated 'Why Pay Good Money For Sound You Can
No Longer Hear?'

Incidentally, if you Google Wickipedia there are a number of articles
on 'speaker damping factor'. In those days I didn't know much math
or physics, so I just used line cord to hook up the speakers. They
sounded great to me! Those were also the days when if you turned up
(or down) the Bass and Treble controls you were in danger of being
poo-pooed by your audiophile friends!

Irv VE6BP


--
Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rapidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a piece
of **** by the clean end.



"Jerry Stuckle" wrote in message
...
On 1/9/2014 11:21 PM, Ralph Mowery wrote:
"boomer" wrote in message
news:_fDzu.213384$4q1.203346@en-nntp-
PS some have actually used #00 wire to their speakers. Without
experimenting myself I feel by guessing that this is over-kill. I could
be
wrong, I was before.

While going from # 20 or so speaker wire to # 10 is often helpful, I
doubt
going much larger is going to help unless you have a very long run.

Lots of things are over sold to te audio people. Best one I know of is
some
special oxygen free teflon wire ( or something like that) that replaces
the
line cord to the wall outlet for over $ 100. Even if it actually did
something, that extra 50 or so feet of regular wire back to the breaker
box
and other wire to the main power feed would make it worthless.


Definitely! A lot of audio people want the best sound, but are unfamiliar
with the technical aspects. This leaves them ripe for greedy salespeople.

I remember going into circuit City a few years ago. All I needed was a
few feet of speaker wire. The salesman tried to sell me a 50' spool of 16
gauge wire for about $50. I asked him why it was so expensive - he
replied "Because it's (brand name here)". I then asked him what was so
special about Monster. His only response was "It's (brand name here)!".

I went down the street to Radio Shack and got something similar for under
$10. That was 15 or more years ago, and it's still working fine.

If you want to sell me something that's 5x the price of the competition,
you need to be ready to tell me WHY it's 5x the price. And just saying
it's because it's a certain brand doesn't work.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.

==================

"Jerry Stuckle" wrote in message
...

If you want to sell me something that's 5x the price of the competition,
you need to be ready to tell me WHY it's 5x the price. And just saying
it's because it's a certain brand doesn't work.


Had he told people the wire was teflon coated so the electrons flowed beter
and the copper was oxygen free so the electrons would not be degraded, he
could have sold it..

From what I have been seeing the TV people are about the same, Selling high
dollar hdmi cable or special high defination antennas with the same snake
oil pitch.



---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

"Sal" salmonella@food poisoning.org wrote in message
...

Discussion of audio amplifier power in home systems always prompts me to
relate this: I worked for a guy who was formerly a projectionist at Radio
City Music Hall in New York. He told me the sound system used amplifiers
rated at 70 watts per channel. That's a 6,000-seat theater.

He worked there a long time ago, so this not a claim of what they use
today. Use for perspective only, please.

I wonder if that was 'real watts' instead of inflated watts. I have seen
some wall wart computer speakers rated at 50 watts or so. Open them up and
inside the speaker may have 3 watts on the lable.

Same as with the listed gain of antennas for hams and especially the CB.
One antenna of modern times had a gain listed of several times more than it
should. Claimed to be the gain from one of the computer programs. It may
have been,but they were adding in a lot of ground gain and certain take off
angles.

Not sure where they were getting the gain numbers from,but he old CC 11
element 2 meter beams had a number that was way too high if you compaired it
on the air with another antenna.



---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On 1/10/2014 10:55 AM, Ralph Mowery wrote:
"Jerry Stuckle" wrote in message
...

If you want to sell me something that's 5x the price of the competition,
you need to be ready to tell me WHY it's 5x the price. And just saying
it's because it's a certain brand doesn't work.


Had he told people the wire was teflon coated so the electrons flowed beter
and the copper was oxygen free so the electrons would not be degraded, he
could have sold it..

From what I have been seeing the TV people are about the same, Selling high
dollar hdmi cable or special high defination antennas with the same snake
oil pitch.



Yup, I know what you mean. There are some major differences between
different HDMI cables; they'll all work pretty well at five feet, but
many of the cheaper brands (and a bunch of what you see on TV) won't
work at 50 feet (the maximum for the spec). For some, even 15 feet is
problematical.

Best is to buy from a reputable high-end dealer, especially if it's a
local store and not a chain. They know their stuff.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================