Question about KG 3.2's DCR

[MKAZ]

Hi,

New to the forum but have and love a few pairs of Klipsch.

I have a pair of KG 3.2's.

They seem to sound good. All drivers work.

I know they are 8 ohms impedance.

Typically my other 8 ohm speakers have a DCR of 5 or 6 ohms give or take.

 

DCR on my KG 3.2's is approximately 4.2 ohms.

Is this normal for these speakers or do I need to replace crossover parts etc.?

[billybob]

Welcome! Bumping this up.

[winglet]

15 hours ago, MKAZ said:

Hi,

New to the forum but have and love a few pairs of Klipsch.

I have a pair of KG 3.2's.

They seem to sound good. All drivers work.

I know they are 8 ohms impedance.

Typically my other 8 ohm speakers have a DCR of 5 or 6 ohms give or take.

 

DCR on my KG 3.2's is approximately 4.2 ohms.

Is this normal for these speakers or do I need to replace crossover parts etc.?

I assume you're measuring the resistance of the entire speaker from the terminals? 

 

The k-1002 woofer in the kg3.2/3.5 is a 4 ohm woofer.  Probably accounts for your lower total resistance reading of all the drivers and network together.

[Jhakobe]

When I had my speakers apart I tested each one individually (woofer and tweeter) and they both were 4 ohm. I assumed the crossover network along with the load of both speakers is what produced the nominal 8 ohm rating. I thought I looked into it and confirmed, but I’m drawing a mental blank if that was generally accurate or if there was something else involved.

[Peter P.]

Resistance and impedance differ in that impedance in a speaker is a complex result of the influence of frequency. Also, you're measuring THROUGH the crossover AND the drivers are in parallel, all of which will affect your DC measurements.

 

In fact, since the drivers are in parallel when you measure the DC resistance, by Ohm's Law the DC measurement will be lower than that of any individual driver.

 

In the end, don't sweat it.

[MKAZ]

Thank you all for helping me with this.

Especially Peter P's bottom line: " In the end, don't sweat it." 

 

To winglet: Yes, I was measuring the resistance of the entire speaker from the terminals.

 

To Jhakobe: I too occasionally suffer from C.R.S.(Cant Remember S...)

 

And to billybob: Thanks for the welcome and the bump.

 

I was a little concerned because my amp has capabilities that far exceed these speakers ratings.

Although I listen at comfortable levels, I was worried that peaks might have caused damage over time.

 

Would it benefit me to use fuses to protect them going forward?

If so what size fuse?

Would there be any drawbacks to fuses (sound wise)?

 

[Peter P.]

Most people never fuse their speakers. But then again, most people probably don't overdrive their amp or speakers, either of which can smoke a driver.

 

If you want to experiment, you can start with a 3 amp fuse. That will meet your speakers' 65W continuous rating. If you are routinely blowing the 3A fuse,

try a 3.5 or 4A. The 4A should blow at 108W peak. Look for fast blow fuses.

[HiFi Heaven]

Hi MKAZ -  4Ω is normal DC terminal resistance for many Klipsch "8Ω" speakers.

DCR at the input terminals = woofer DCR + negligible lowpass inductor resistance.

Zero DC current flows through the crossover network to Mid, Tweeter, or Ground.

Static 4Ω DCR rises to 6-8Ω AC in the bass musical range inside a tuned enclosure.

Be aware a 3A fuse offers no protection for 1" voice coils - start with 1.25A fast blow.

We used 3A fuses to protect commercial ALTEC 100-watt woofers with 3" voice coils.

Music is dynamic.  Fuses are rated to blow within 10-30 seconds after 200% overload.

Way too late for your charcoaled voice coil...

 

 

 

 

[CCG]

On 4/4/2023 at 5:12 PM, MKAZ said:

Hi,

New to the forum but have and love a few pairs of Klipsch.

I have a pair of KG 3.2's.

They seem to sound good. All drivers work.

I know they are 8 ohms impedance.

Typically my other 8 ohm speakers have a DCR of 5 or 6 ohms give or take.

 

DCR on my KG 3.2's is approximately 4.2 ohms.

Is this normal for these speakers or do I need to replace crossover parts etc.?

Yes the 8 ohm rating in specification is correct (not 6 ohms). Your woofer reading of 4 ohm is correct and so as your reading in the cabinet speaker jack.

To simplify your search, the whole cabinet with the speakers connected to the original simple crossover / dividing network will give you a total sum of 8 ohms when it is in operation. You wont be able to measure it accurately not running. Don't worry and you should be fine. I been in your situation before asking the same question and I found out that is the design for these speakers.Not just that model but there are lots of klipsch speakers reads and behave similar to yours. The owners just dont pay attention to it. Anyways no need to worry, you're just fine.

[Peter P.]

17 hours ago, CCG said:

 

To simplify your search, the whole cabinet with the speakers connected to the original simple crossover / dividing network will give you a total sum of 8 ohms when it is in operation. You wont be able to measure it accurately not running.

You should not measure resistance while power is applied to any circuit. Or maybe I am misunderstanding your statement.

[MKAZ]

Thank you all again.

You all have confirmed that my speakers seem to be "normal".

For right now, I think I am going to exercise a little caution with the volume and skip the fuses.

 

 

[MKAZ]

Based on HiFi Heaven's answer:

When it becomes time to rebuild the crossovers it would seem to make sense to fuse the woofer and tweeter separately.

Tweeter with 1.25A fb and woofer with maybe 2.5A fb or 3A fb.

[HiFi Heaven]

Those fuse values offer NO protection for your speakers, MKAZ. 

See my earlier comment about fuse specs - it takes a while to blow a fuse at 200%.

Or save yourself the trouble, just keep the volume below the threshold of distortion.

 

 

 

 

[MKAZ]

Thank you again HiFi Heaven.

Got it. I won't do the fuses.

 

Hopefully distortion should not be a problem for me.

I was thinking more about over powering the speakers.

 

Thanks for the help, I tend to overthink things a bit. lol.

[winglet]

7 hours ago, MKAZ said:

Thank you again HiFi Heaven.

Got it. I won't do the fuses.

 

Hopefully distortion should not be a problem for me.

I was thinking more about over powering the speakers.

 

Thanks for the help, I tend to overthink things a bit. lol.

You said you listened at comfortable levels.  Home environment you have nothing to worry about.

 

Here's a simple spl calculator to give you an idea of how little power your speakers are actually using:

 

http://www.hometheaterengineering.com/splcalculator.html

[MKAZ]

Very cool link winglet.

So; going by the chart below the spl calculator, I listen anywhere between a vacuum cleaner (70 db) and a diesel truck (90 db).

Mostly the vacuum cleaner.

According to the calculator my RMS db spl can be approximately 118.9db (not including my sub).

[HiFi Heaven]

90dB is fine, requires less than one watt.  KG3.2 sensitivity is 94dB at 3 feet at 1 watt.  They will last a lifetime.

119dB is NOT OK for KG3.2's!  That level would require 250+ watts, they are rated 65 watts long term.  Poof!

 

 

[OO1]

2 hours ago, MKAZ said:

118.9db (not including my sub).

Not even close  , under 100 dB

[winglet]

8 hours ago, OO1 said:

Not even close  , under 100 dB

That 118.9 is for a pair of kg, wall loaded and at 3’ away..  

 

Not a realistic way to listen obviously, but they’ll get plenty loud in an average room on way less than 65 watts

[OO1]

 oh ok