Question about using more than one amp
Malfist
of a few days ago I had a fully working Logitech X-540 speaker system
for my computer. Not the loudest in the dorm, but able to contend
with
them. Then my subwoofer went out. Logitech, being the great company
that they are offered me a full replacement if I sent them the wired
control module (set won't work without it).
So.
I have a fully fuctioning new set in the mail, destined to arive
sometime soon, and the old set with 5 fully functioning speakers (5
of
6, minus sub). I'm going to buy spliters so I can hook both sets up
(10 satellites, 1 sub). The problem is power consumption. I know from
my digital electronics class that a system pulling nearly double it's
recommened power isn't good.
The subwoofer doubles as the amp/hub of the system so I don't think
it's replacable. Is there a way I can suplement it with another 120
watt amp? Or should I buy an amp that can handle both systems and a
new sub (because the sub doesn't have an output)?
William Sommerwerck
news:1bb5a7a8-6602-46c6...@k2g2000hse.googlegroups.com...
> Okay, I'm a newbie when it comes to speakers and that kinda stuff. As
> of a few days ago I had a fully working Logitech X-540 speaker system
> for my computer. Not the loudest in the dorm, but able to contend
> with them. Then my subwoofer went out. Logitech, being the great
> company that they are, offered me a full replacement if I sent them
> the wired control module (set won't work without it).
> So.
> I have a fully fuctioning new set in the mail, destined to arive
> sometime soon, and the old set with 5 fully functioning speakers (5
> of 6, minus sub). I'm going to buy splitters so I can hook both sets up
> (10 satellites, 1 sub). The problem is power consumption. I know from
> my digital electronics class that a system pulling nearly double it's
> recommened power isn't good.
If, by splitters, you mean attaching two speaker to each amplifier output,
you might run into problems. You'll pull twice the current from the amp, and
the amplifier might not like that (ie, it will pop fuses or even blow the
output stages). It's not a good idea.
> The subwoofer doubles as the amp/hub of the system so I don't think
> it's replacable. Is there a way I can suplement it with another 120
> watt amp? Or should I buy an amp that can handle both systems and
> a new sub (because the sub doesn't have an output)?
If I read you correctly, you want another amplifier that can, at least,
drive the five "windfall" speakers.
Here's what I'd do...
When the replacement unit arrives, set up the system, make sure it works
correctly, and give yourself a few days to kick back and think about what
you want to do.
Adding a second 5.1 amp is no big deal; you'd simply split the sound card
outputs with Y cables to feed the Logitech system and the new amp.
Furthermore, you should be able to open the "dead" woofer to access the
driver directly.
There are other possibilities, such as using a second amp to drive all 10
mid/tweeter speakers. Each channel of the amp must be able to drive two
speakers at the same time. For example, if the speakers are 8-ohm, the amp
must be able to handle 4-ohm loads.
By the way, when I attended Caltech many years ago, we were awakened on exam
mornings with Wagner.
Malfist
Let me clarify.
On Feb 6, 8:29 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:
> "Malfist" <jeromehol...@gmail.com> wrote in message
> If, by splitters, you mean attaching two speaker to each amplifier output,
> you might run into problems. You'll pull twice the current from the amp, and
> the amplifier might not like that (ie, it will pop fuses or even blow the
> output stages). It's not a good idea.
Yes, that is what I planned on doing and I figured that would be what
would happen if I did it.
> > The subwoofer doubles as the amp/hub of the system so I don't think
> > it's replaceable. Is there a way I can supplement it with another 120
> > watt amp? Or should I buy an amp that can handle both systems and
> > a new sub (because the sub doesn't have an output)?
>
> If I read you correctly, you want another amplifier that can, at least,
> drive the five "windfall" speakers.
Yes
> Here's what I'd do...
>
> When the replacement unit arrives, set up the system, make sure it works
> correctly, and give yourself a few days to kick back and think about what
> you want to do.
>
> Adding a second 5.1 amp is no big deal; you'd simply split the sound card
> outputs with Y cables to feed the Logitech system and the new amp.
So I would have two speaker systems basically going to one sound card?
> Furthermore, you should be able to open the "dead" woofer to access the
> driver directly.
What is the 'driver'? I've already taken it apart and thrown some of
it away (mainly the box and the speaker). What I have left is what I
would call the 'motherboard' it has the I/O and a bunch of capacitors,
but I don't think it would work considering I had to cut the power
cord, and the controls have been cut off to be shipped back to
Logitech to prove I had a X-540
> There are other possibilities, such as using a second amp to drive all 10
> mid/tweeter speakers. Each channel of the amp must be able to drive two
> speakers at the same time. For example, if the speakers are 8-ohm, the amp
> must be able to handle 4-ohm loads.
I think the speakers are 8 ohm's, were would I hook up an ohmmeter to
tell? The specs on Logitech does not say. Logitech says this:
Total RMS power: 70 watts RMS
Satellites: 45 watts RMS (2 x 7.4W front, 15.4W centre, 2 x 7.4W
rear)
Subwoofer: 25 watts RMS
Total peak power: 140 watts
Frequency response: 40 Hz - 20 kHz
From: http://www.logitech.com/index.cfm/speakers_audio/home_pc_speakers/devices/234&cl=ca,en
If they were 8ohm speakers, whouldn't the amp need to support 16 ohms?
If I go this route, can any system hook into a computer sound card? I
have both digital and analog outputs on my sound card.
> By the way, when I attended Caltech many years ago, we were awakened on exam
> mornings with Wagner.
Wagner? How plays clasical music at that high of a volumn?
Thank you for your time, I apprecate any help I can get
Malfist
http://www.retrevo.com/search/v2/jsp/downloadPage.jsp?doc=dbee8e022f8c4aea9b838cd3973499de&q=Panasonic+SA-HT40
Would it work. I'm going to buy more wattage than I need so I can
upgrade later if desired.
What would the requirements for the longitech speakers be?
Is there a guide that can help me? Cause I have a million questions :P
William Sommerwerck
> A lot of this is Greek to me.
And that's the problem with having to help someone at a distance.
I would simply suggest setting up the replacement system and enjoying it.
Even if you connect the windfall speakers to another amp, the system is only
going to play slightly louder -- 3dB -- which isn't worth the investiment in
another amplifier.
Ask Logitech whether you can safely parallel the windfall speakers with the
new ones. They'll probably say "no".
Malfist
On Feb 6, 4:29 pm, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:
> "Malfist" <jeromehol...@gmail.com> wrote in message
Paul Stamler
<<Why only 3dB?>>
Two identical signals (correlated) will add to be 6dB louder. But these
signals aren't identical:
The speakers will be in physically different positions, so the arrival times
will be different.
The speakers will excite the room differently because they're in different
places.
The speakers will, unless extremely high-precision devices (which they
aren't) differ from unit to unit.
Two completely uncorrelated signals will add to be 3 dB louder. These won't
be *completely* uncorrelated, though; my guess is they'll add to be maybe
4dB louder, depending on the room. And your imaging will be significantly
worse because of the multiple starting points for each signal.
I'd go with this suggestion:
> I would simply suggest setting up the replacement system and enjoying it.
To which I'd add: keep the windfalls for spares the next time something
blows up.
Or get another amp and set them up in another room.
Peace,
Paul