Serious audio question

[CC]

Greetings:

I discovered the other day that my 15 year old Realistic Mach II
speakers have disintegrated. The outer foam woofer suspension, that is.

In the past I imagined one day procuring a set of Klipsch speakers. Now
I see I could get an entry level setup for about $800. I don't listen
much anymore, and live in an apartment so something small but precise
and a good value is what is needed. $800 is about the upper limit of
what I'd consider.

Are Klipsch the best thing going or should I consider others? I used to
be into audio quite a bit (not the nonsense) but haven't paid attention
for a long time.

I also have a 100W/ch Kyocera integrated amplifier. It makes popcorn
noise when first turned on, for a few minutes until it warms up. Been
like that for years. I guess it's not necessary to replace it as long
as it quiets down eventually. It wouldn't be pleasant to consider the
price tag of a similar performing replacement. The thing can do 60A peak.


Good day!

 

[mc]

I suggest asking on rec.audio.tech.

 

[scada]

Greetings:

I discovered the other day that my 15 year old Realistic Mach II
speakers have disintegrated. The outer foam woofer suspension, that is.

Check out www.mcminone.com They have speaker repair kits. They replace the
foam surrounds, a common problem with aging speakers. I have used this
product before, and it does work. You did not mention the speaker size! The
kits are around $20 depending on size. Good luck.

 

[Walter Harley]

Check out www.mcminone.com They have speaker repair kits.

Or Google for "replacement foam surround". As scada suggests, it is a
common problem with a common solution, available from numerous vendors.

60A, eh? It takes 480V to push 60A into an 8 ohm speaker, so those must be
some pretty impressive supply rails that it has.

 

[Paul E. Schoen]

Or Google for "replacement foam surround". As scada suggests, it is a
common problem with a common solution, available from numerous vendors.

60A, eh? It takes 480V to push 60A into an 8 ohm speaker, so those must
be some pretty impressive supply rails that it has.

Audio systems often have two or more speakers in parallel, and the actual
impedance at low frequencies approaches the DC resistance, which is closer
to 6 ohms. So, 60 amps into four speakers in parallel would require about
90 volts peak. At this level you will be pumping out about 3000 watts RMS.
That's just a bit much, unless you are doing the sound for a Rolling Stones
or ZZ Top concert. I think they are the world's loudest? Eh? Say again?

Paul

 

[CC]

Or Google for "replacement foam surround". As scada suggests, it is a
common problem with a common solution, available from numerous vendors.

60A, eh? It takes 480V to push 60A into an 8 ohm speaker, so those must be
some pretty impressive supply rails that it has.

It's not that simple.

8ohms is impedance, not resistance. The speaker is a linear motor, and
at any particular instant depending on which way the signal changes
might develop a back emf which adds to the amplifier's voltage across
the DC resistance of the motor coil, which is much lower than 8ohms.

Imagine spinning up an unloaded DC motor to full speed (at which point
its back emf would about equal the power supply voltage), then suddenly
reversing the power supply. You could now develop a peak current equal
to twice the power supply voltage divided by the DC resistance of the motor.

So 60A is not out of the question even if the amp has typical power
supply voltages for a 100W amp.

It might be unlikely to ever deliver that current except perhaps with
paralleled speakers, or whatever.

It is simply specified as being capable of delivering 60A peak.


Good day!

 

[CC]

I suggest asking on rec.audio.tech.

An excellent idea. Except perhaps if I was looking for the unique
perspective of electrical engineers, much like I might ask about
preferred toilet plunger brands on rec.food.cooking.

:->

There's also sometimes the motive of just wanting to hear the responses
of ones peers, having participated in a group for a long time. Hence
the cooking and BBQ grill questions, etc.

 

[GregS]

Check out www.mcminone.com They have speaker repair kits. They replace the
foam surrounds, a common problem with aging speakers. I have used this
product before, and it does work. You did not mention the speaker size! The
kits are around $20 depending on size. Good luck.

On a unit I aquired, I replaced the foam with rubber surround. It did not fit exactly, at least
in the usual sense. The rubber lip was a bit small, but I managed.
I probably bought the kit from Parts Express. All woofers are not
exactly the same sizes. The rubber will last much longer.

That speaker I also treated the midrange with some Airflex 400, and
tightened up the connections and screws. I always solder the crimps.
I redid the wood and cleaned the front grill.

I sold the speaker back to the orginal seller.

greg

 

[almo]

I haven't read all of the posts, just the topic, and yes you can buy
kits to replace that foam stuff, but I once had a really nice pair of
Infinity speakers a while back, lost them in a divorce, but anyway, the
foamy stuff rotted out, so I took them to a place that "repaired
speakers," in fact it was somewhere like Westminster, or Huntington
Beach, California/Orange County/USA. And that place fixed those
speakers like absolutely good as new. And the price probably, roughly
[1-arm + 1-leg]/4. Not trying to be funny, all I remember is that the
price was "reasonable." Although, I think I'll write down that
equation, because now that I see it, I think it's funny. In fact, I'm
just going to go file>print... right now, so I have it.

Maybe that's of some help.

 

[joseph2k]

Audio systems often have two or more speakers in parallel, and the actual
impedance at low frequencies approaches the DC resistance, which is closer
to 6 ohms. So, 60 amps into four speakers in parallel would require about
90 volts peak. At this level you will be pumping out about 3000 watts RMS.
That's just a bit much, unless you are doing the sound for a Rolling Stones
or ZZ Top concert. I think they are the world's loudest? Eh? Say again?

Paul

Excessive assumptions that the 60 A rating is for anything other than a
short term (<0.5s) or neglects that its use is for damping as much anything
else is arguing from false premises. If you had proper context your
response to transient ratings would be to read them as transient ratings,
rather than untutored rantings.