2. amps-preamps
  3. 1108496641

the 4 ohm rating

im a little confused as to why buyers choose 4 ohm products.

now here's what got me thinking about all of this 4 ohm stuff.

i took a pair of mids into my rebuilders shop the other day to get new surrounds installed & we started talikng audio & he told me that about 75% of the blown driver's he takes in for rebuilding are 4 ohms & the other 25% was split between 8 & 16 ohms.

correct me if im wrong but when you run a amp in 4 ohms as opposed to 8 ohms isnt the amp working much harder to produce the inflated wattage at the lower ohms? & isnt a amp thats getting worked hard a bad thing?

the same goes for 4 ohm speakers,the 4 ohm rating only makes the speakers to appear to be more efficient & also creates the need for thicker cabeling for the lower ohm's.

i hope the answers can remain civil as i didnt start this thread to be a smart ass but i am wondering what(if any)advantages there are to having 4 ohm gear over 8 ohm gear.

take me to school here & learn me somthing because all im seeing is drawback's to owning 4 ohm gear.

mike.
128x128bigjoe
aball
2,016 posts
 
I feel the same way you do. I spend my time avoiding inefficiency - especially for speakers. I feel that inefficient speakers cannot reproduce all nuances of music. This has been my experience anyway.
iseekheils
131 posts
 
It's not that simple. No speaker has a perfectly flat resistance curve. A speaker may be called an 8 ohm because it averages 8 in the midrange but frequently may jump to 16 ohm or higher in the bass and may also jump in the higher frequencies as well. If you get a chance, look at a speaker performance graph in a catalog or on the Madisound website. It ususlly shows the frequency response and Ohm graphs.
Sonny
http://www.info@madisound.com
morbius396c
134 posts
 
Bigjoe,

You are drawing incorrect conclusions.

For one, the requirement for an 8 ohm load as opposed to a
4 ohm load is a constraint on the speaker designer. All
product engineering and design is a series of trade-offs.
By placing this constraint on the designer - you may be forcing
the designer to trade-off the sonic performance in order to
meet the load constraint.

You are also incorrect at saying the the wattage, i.e power
at the lower impedance of 4 ohms is "inflated". The power
IS the power. It is true that for a given voltage, the
lower impedance will result in more power being delivered
to the speaker because of the need for greater current.
However, there's nothing "inflated" about that
power - you are truly putting more power into the speaker.

For the best sonic results - don't constrain the designer.
If the design naturally gives you a 4 ohm impedance - so
be it. Don't make the designer trade off sonic performance
in order to match your minimum impedance specification.

Now it is true that you may need a heftier amplifier to
drive that speaker - the lower the impedance the more load
on the amp. However, there are many amplifiers that are
up to the task. That's just the "cost" of doing business
with that particular speaker.

So for the cost of a more powerful amp, you've lessened a
constraint on the speaker designer - who can use that to
better advantage to give you better sound.

Don't go to the other extreme and conclude that 4 ohm
designs are inherently better than the 8 ohm designs - they
are not. Neither has an advantage.

However, when the speaker designer is engineering the
speaker, the laws of physics and electronics may naturally
lead him/her to one side or the other. What is best for
the listener is to allow the speaker designer the flexibility
to choose the best load impedance for that speaker -
unfettered by a requirement to meet some artificial minimum.

"Que sera sera" - what will be; will be.

Dr. Gregory Greenman
Physicist
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