Connecting an HK 635 to Klipsch 100W 4 Ohm speakers

[devphreak]

Hi,

New here to the forums. I've been reading around (great articles btw!) to find the answer and although everything I've read points to yes, I still wanted to make a post to get some feedback from some pros, just to be sure.

I was recently given an HK 635 receiver and a set of Klipsch 5.1 speakers. All five of the Klipsch speakers are 100W (not sure how the sub ratings go). The center speaker is 8 Ohm, while the satellites are 4 Ohm. The receiver operates at 8 Ohm. Do you think this will be an issue? What types of concerns should I be aware of?

A totally unrelated question. The original owner of the receiver lost the power cable. The connection is exactly like a computer power supply cable, only missing the third pin. I plugged in a computer cable and it fits just fine but I didn't plug it into an outlet yet. Is there anything I should be concerned about with plugging this into the outlet?

Thanks a ton for any advice!

 

[rnatalli]

HK amp sections are pretty robust so it's likely your 635 will handle the load.

 

[devphreak]

Thanks for the reply rnatalli! Any ideas on the power cord question? I called HK and they said I should be okay, but I'm not sure if the guy I spoke to really understood my question because he didn't speak English that well

 

[rnatalli]

Don't know about the power cord. The third pin is only a ground so probably isn't a problem. Hopefully someone else chimes in here.

 

[bigbassdave]

I used an HK 635 for years. I drove the 4ohm axioms in my sig without any issues whatsoever. That is a pretty powerful receiver. You won't have any issues in that regard as long as you give it room to breath.

 

[PENG]

Thanks for the reply rnatalli! Any ideas on the power cord question? I called HK and they said I should be okay, but I'm not sure if the guy I spoke to really understood my question because he didn't speak English that well

The HK 630 had lab measured power output for both 8 and 4 ohm loads about 20% (approx only as I am going by memory edit:actually more like 30% lower for 5ch driven and 40 to 50% lower for 2 ch driven) or so lower than that of my then Denon 3805. The 635 had similar if not exactly the same specs and weight so it should be powerful enough to handle the typically highly sensitive Klipsch speakers despite the 4 ohm impedance. Still to be sure, you have to consider your room acoustics including the size and how loud you like to listen to your music/movies.

Regarding the power cord, my 3805 one is 14 AWG. Computer cords typically are 16 AWG so I suggest you go and buy a 14 AWG power cord. 16 AWG is okay and perfectly legal for that AVR based on its draw; and technically appropriate for such a short run based on voltage drop considerations, but 14 AWG is better though there may not be any audible effect.

 

[devphreak]

Thank you everyone for your replies! I called HK up and they said that the AWG of the cable they sell for that receiver is 8 - 10 AWG so I'm just going to bite the bullet and order one directly from them for 17.94 (ouch!).

What AWG speaker wire would any of you recommend for this setup? Also, do brands matter with speaker wire? When I called HK, they recommended 14-16 AWG, but still I wanted to check with the pros here to be sure

 

[M Code]

The HK 630 had lab measured power output for both 8 and 4 ohm loads about 20% (approx only as I am going by memory edit:actually more like 30% lower for 5ch driven and 40 to 50% lower for 2 ch driven) or so lower than that of my then Denon 3805. The 635 had similar if not exactly the same specs and weight so it should be powerful enough to handle the typically highly sensitive Klipsch speakers despite the 4 ohm impedance. Still to be sure, you have to consider your room acoustics including the size and how loud you like to listen to your music/movies.

Regarding the power cord, my 3805 one is 14 AWG. Computer cords typically are 16 AWG so I suggest you go and buy a 14 AWG power cord. 16 AWG is okay and perfectly legal for that AVR based on its draw; and technically appropriate for such a short run based on voltage drop considerations, but 14 AWG is better though there may not be any audible effect.

I lifted these from archives.
These measurements are about 6 years old for the AVR630 using an Audio Precision System 2, they should answer your questions:

1. Power output into 8 Ohms 7 channels driven 81W x7, 20Hz-20kHz @ 0.04% THD
2. Power output into 4 Ohms 7 channels driven 103W x 7,20Hz-20kHz @ 0.072% THD
3. Power output into 8 Ohms 2 channels driven 105W x 2, 20Hz-20kHz, @ 0.43% THD
4. Power output into 4 Ohms 2 channels driven, 123W x 2, 20Hz-20kHz, @ 0.067% THD

The AVR630 was a very robust AVR, heavy duty dual power supplies and high-current amplifiers.

Just my $0.02..

 

[its phillip]

Thank you everyone for your replies! I called HK up and they said that the AWG of the cable they sell for that receiver is 8 - 10 AWG so I'm just going to bite the bullet and order one directly from them for 17.94 (ouch!).

What AWG speaker wire would any of you recommend for this setup? Also, do brands matter with speaker wire? When I called HK, they recommended 14-16 AWG, but still I wanted to check with the pros here to be sure

For the required gauge, check here:
http://www.roger-russell.com/wire/wire.htm

Just get cable from monoprice.com

 

[devphreak]

If the power output into 4 Ohms 7 channels driven is 103W and I'm only going to be using 5 channels (plus the sub which I have no idea of the watts and ohms), should I be worried if my Klipsch are only 100W speakers?

 

[its phillip]

You'll be fine. You'll probably only be pushing a handful of watts to your speakers 99% of the time...and having more power available is always better than not having enough.

 

[PENG]

I lifted these from archives.
These measurements are about 6 years old for the AVR630 using an Audio Precision System 2, they should answer your questions:

1. Power output into 8 Ohms 7 channels driven 81W x7, 20Hz-20kHz @ 0.04% THD
2. Power output into 4 Ohms 7 channels driven 103W x 7,20Hz-20kHz @ 0.072% THD
3. Power output into 8 Ohms 2 channels driven 105W x 2, 20Hz-20kHz, @ 0.43% THD
4. Power output into 4 Ohms 2 channels driven, 123W x 2, 20Hz-20kHz, @ 0.067% THD

The AVR630 was a very robust AVR, heavy duty dual power supplies and high-current amplifiers.

Just my $0.02..

Thanks, but difference source different method/instruments/person may yield different results, in my post I referred specifically to two HT lab measurements as part of the reviews by the same person back in 2004:

HT Labs Measures: Harman/Kardon AVR 630
Five channels driven into 8-ohm loads: 0.1% distortion at 79.7 watts; 1% distortion at 93.3 watts

This graph shows that the AVR 630's left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 84.6 watts and 1% distortion at 100.6 watts. Into 4 ohms, the amplifier reaches 0.1%distortion at 146.9 watts and 1% distortion at 170.8 watts.

The above, compared to a Denon of the day in the same price bracket (1299 for the HK and 1199 for the Denon):

HT Labs Measures: Denon AVR-3805
Five channels driven into 8-ohm loads: 0.1% distortion at 114.9 watts; 1% distortion at 125.0 watts

This graph shows that the AVR-3805's left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 132.2 watts and 1% distortion at 162.3 watts. Into 4 ohms, the amplifier reaches 0.1%distortion at 218.4 watts and 1% distortion at 243.0 watts.

The HK should be quite capable of driving 4 ohm speakers under certain conditions, but I included a comparison here just to once again demo how all of them, HK, NAD, Sony, all play their marketing game, using loosely defined or undefined terminologies such as high current, continuous rating, all channel driven, dynamic power blablablabla... You pay the price, you get the power, HK or not you pay enough for it you can drive 4 ohm load, though in some cases you have to add an external amp.

 

[Alex2507]

... compared to a Denon of the day in the same price bracket (1299 for the HK and 1199 for the Denon):

The MSRP of the H/K is not even close to what they sell for in the real world.
I understand the market in Canada is different in this regard.

Having said that I have driven a 635 hard enough into low impedance speakers to make it turn itself off. The speakers dipped close to 2 Ohms and I was cranking the piss out of the rec'r in a critical analysis of Money for Nothing ... okay, fine ... I was just cranking the piss out of it because it didn't belong to me.

 

[M Code]

Thanks, but difference source different method/instruments/person may yield different results, in my post I referred specifically to two HT lab measurements as part of the reviews by the same person back in 2004:

HT Labs Measures: Harman/Kardon AVR 630
Five channels driven into 8-ohm loads: 0.1% distortion at 79.7 watts; 1% distortion at 93.3 watts

This graph shows that the AVR 630's left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 84.6 watts and 1% distortion at 100.6 watts. Into 4 ohms, the amplifier reaches 0.1%distortion at 146.9 watts and 1% distortion at 170.8 watts.

The above, compared to a Denon of the day in the same price bracket (1299 for the HK and 1199 for the Denon):

HT Labs Measures: Denon AVR-3805
Five channels driven into 8-ohm loads: 0.1% distortion at 114.9 watts; 1% distortion at 125.0 watts

This graph shows that the AVR-3805's left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 132.2 watts and 1% distortion at 162.3 watts. Into 4 ohms, the amplifier reaches 0.1%distortion at 218.4 watts and 1% distortion at 243.0 watts.

The HK should be quite capable of driving 4 ohm speakers under certain conditions, but I included a comparison here just to once again demo how all of them, HK, NAD, Sony, all play their marketing game, using loosely defined or undefined terminologies such as high current, continuous rating, all channel driven, dynamic power blablablabla... You pay the price, you get the power, HK or not you pay enough for it you can drive 4 ohm load, though in some cases you have to add an external amp.

HK has demonstrated and delivered over the years AVRs that did fine with 4 Ohm loudspeakers. One of the primary reasons is that their brand Infinity were typically 4 Ohms not 8 Ohms... To a large extent most of the power output specs are created by the marketing/advertising boys not the design engineers. Thats why one can often see big differences in specs between USA and Euro models, as the local guys will do whatever is necesasry to make the AVR an easier sell.

The other thing to be careful about is the timing, comparing AVR power output specs of 5 years ago and models of today is not valid. Today's power output specs are hyped beyond believeability due to the weak economy and fight for marketshare..
I know of some examples where the actual output specs came from their customers (big box seller) telling the brand what the disclosed spec should be rather than the design engineer..

Just my $0.02..

 

[PENG]

The other thing to be careful about is the timing, comparing AVR power output specs of 5 years ago and models of today is not valid.

I fully agree with you on this but I compared the 630 to 3805, same vintage. I did not compare the 635 to 3805 but even if I did it would still be valid, 630 to 635 would be like 3805 to 3806, not much different on the power side.

Today's power output specs are hyped beyond believeability due to the weak economy and fight for marketshare..
I know of some examples where the actual output specs came from their customers (big box seller) telling the brand what the disclosed spec should be rather than the design engineer..

Just my $0.02..

I can agree partially and agree to disagree partially. I can find examples for both. For example, the seemingly robust Denon 4810 weighs over 42 lbs, draws about 10A indicating it might have a P/S transformer same size as that in the EMO XPA-5, yet they rated it 140W per channel, certainly not overblown. Now it was bench tested to trip (protection cicuit) at around 50W under HTM's ACD test. That kind of ACD test is ridiculous and meaningless because it may mislead the non technical public to think the 4810 (just as an example) is much less powerful than the 4310 when the real reason is their different protective circuit design. Sorry I digress, just could stop and I am trying to make the point that today's apparent weaker performance in HTM/S&V kind of bench tests could also be due to the more aggressive protective systems that were not employed in the much older models. Your suggested reasons about the weak economy and manufacturers/distributers try to survive could also be real.

 

[Alex2507]

I am trying to make the point that today's apparent weaker performance in HTM/S&V kind of bench tests could also be due to the more aggressive protective systems that were not employed in the much older models.

I think I get it. The power supply is being monitored and the ACD thing trips it up but the ACD thing is never a consideration with H/T or music. This keeps up for much longer and I will be the guy who knew too much.

Oh yeah ... 50 H/K watts are better than any number of Denon watts.
... tried resisting but failed.

 

[PENG]

I think I get it. The power supply is being monitored and the ACD thing trips it up but the ACD thing is never a consideration with H/T or music. This keeps up for much longer and I will be the guy who knew too much.

Oh yeah ... 50 H/K watts are better than any number of Denon watts.
... tried resisting but failed.

Yep, I have never fired the first shot but if I see those honest watt better than any Yammy/Denon/Onkyo watt posts I would simply counter by firing back, well to put in gently let's say I would simply offer the other side of the story. I would have been a happy HK AVR owner myself if it wasn't those ridiculous Canadian pricing, but that won't stop me from telling the other side of the truth.

 

[Alex2507]

I would have been a happy HK AVR owner myself ...

That's unlikely. They are always like a day late and a dollar short on their features which keeps 'us' away while their price is high. The good thing is that with their reliability issues you can wait 6 months to a year and pick up their factory refurbs with full warranty for like half of the MSRP at which point they are suddenly quite desirable price/feature/power wise.

Don't get me wrong. My H/k has served me well enough but I have also had a couple of issues. It not playing loud enough has not been one of my issues though. Actually one of the things it use to do is just start turning itself all the way up all by itself. Let me tell ya ... that gets your attention but quick.

I want a 4310.

 

[PENG]

That's unlikely. They are always like a day late and a dollar short on their features which keeps 'us' away while their price is high. The good thing is that with their reliability issues you can wait 6 months to a year and pick up their factory refurbs with full warranty for like half of the MSRP at which point they are suddenly quite desirable price/feature/power wise.

Don't get me wrong. My H/k has served me well enough but I have also had a couple of issues. It not playing loud enough has not been one of my issues though. Actually one of the things it use to do is just start turning itself all the way up all by itself. Let me tell ya ... that gets your attention but quick.

I want a 4310.

If I were to stick with practical reality I would have got myself the 4310 or 4311 and be done with it. If I were truly me yet patent (that I am not), I would have waited for the 4811, grab it and be done with it. Now I ended up with the AV7005 that won't make any sound hence the MM8003. Go figure!

I wish I were smart enough to simply go with the 4310. What are you waiting for?

 

[Alex2507]

What are you waiting for?

A better economy.
These have been like the worst 2 or 3 years of my life financially.
Yet the speaker/amplifier/rec'r lust burns strong ... my love will never die.