Maximum interconnect lengths?

math wizard

I just purchased an amplifier for my rear speakers. I would like to place it on the side of the room where the speakers are. To do this would require running two 35-45 ft interconnect cables from the AVR pre-out to the amplifier. Is this too long of a run? If the amplifier is placed near the AVR, shorter cables can be used, but it will require approx. 40 ft of speaker wire from the amp to the speakers. Is there any advantage/disadvantage to either senario?


Thanks

Pauly

Better off running the long speaker wire run and i would use a 14g wire. The IC runs will cost you ALOT more.

Good Luck

Pauly

CoolJazz

math wizard wrote: »

Is there any advantage/disadvantage to either senario? Thanks

Yes!

With longer interconnects the biggest issue is the cable capacitance. The more the capacitance adds up, the more the high frequency roll off there is. It takes some level though before it even gets into the audible range. The issue involves how low the driving impedance is along with the loading value of the input along with the cable values.

With longer speaker wires, the first and foremost issue is adding resistance which lowers the dampening factor. The loosens the tightness of the bass and causes the amplifier to have less "control" over the cone.

Which way to go depends on not only the quality and parameters of the equipment but also your personal preferences for sonic quality.

IMHO, the interconnect cable coming closer to exhibiting roll off is likely to be less of sonic effect than the speaker cable. Many feel differently than I do though! You are proposing a pretty darn long run! For rear channel, you're talking surround sound movie stuff and not music after all! Even if you get too much capacitance in the cable and have some slight rolloff, let's say above 15 or 16khz, that's tough to be very noticable and it's a very gentle sweeping roll off. While dampening factor control will have slight effects into the midband energy that would tend to have an audible effect on everything!

That's some of the issues...

CoolJazz

pitdogg2

CoolJazz wrote: »

Yes!

With longer interconnects the biggest issue is the cable capacitance. The more the capacitance adds up, the more the high frequency roll off there is. It takes some level though before it even gets into the audible range. The issue involves how low the driving impedance is along with the loading value of the input along with the cable values.

With longer speaker wires, the first and foremost issue is adding resistance which lowers the dampening factor. The loosens the tightness of the bass and causes the amplifier to have less "control" over the cone.

Which way to go depends on not only the quality and parameters of the equipment but also your personal preferences for sonic quality.

IMHO, the interconnect cable coming closer to exhibiting roll off is likely to be less of sonic effect than the speaker cable. Many feel differently than I do though! You are proposing a pretty darn long run! For rear channel, you're talking surround sound movie stuff and not music after all! Even if you get too much capacitance in the cable and have some slight rolloff, let's say above 15 or 16khz, that's tough to be very noticable and it's a very gentle sweeping roll off. While dampening factor control will have slight effects into the midband energy that would tend to have an audible effect on everything!

That's some of the issues...

CoolJazz

While i agree with the above I found that in some cases long in runs of component cables for instance some A/V equiptment have a hard pushing signal though a very long length. Plain old speaker cable say Dayton Audio 10ga. copper will handle long rungs just fine. I even use it myself for short runs just so all my wire is the same.

CoolJazz

xcapri79 wrote: »

+3 Keep your RCA interconnects as short as you can to minimize interference and low level signal loss.

Can you explain this "low level signal loss" thing to me? What happens exactly? Does it just get lost and goes back the wrong direction in the wire...or fall off the wire behind the rack and get stuck in the dust bunnies? Where does it go? Should we sweep them up from time to time or something...??

CoolJazz

quadzilla

What's hard to understand about it? In fact, your question would seem, at first glance, to be intentionally obtuse and argumentative. You have a very low level signal, so it's very sensitive to loss, and loss/distortions at that level will get amplified along with the rest of the signal when the power is finally applied. So unless you can afford very high end cables, both resistance and capacitance will be affecting the signal a fair amount. Even with high end ICs, runs that long are going to be subject to at least some loss. Also, it should be noted that the roll off starts down closer to 2 KHz, not above 16. Even if it didn't start until 16 KHz, that would still mean that your sacrificing all your higher order harmonics, whereas the few milliohms of resistance that a decent speaker cable adds over that distance will have much less effect than you'll find in most interconnects due to the greater capacitance in the dielectric used in common cable types, especially the budget cables. You're again more concerned with capacitance and the roll off of the high end, causing the sound to lose harmonics and sound dull and lifeless.

CoolJazz

Easy Zilla! It was a very light hearted question. Maybe I should have used a few smilies to illustrate...

But I'd take even greater issue with your response. This low level loss thing is just about a none issue. It's a simple first order low pass filter that forms the long cabling issue. And the dielectric effects are probably more of an issue at higher levels than lower levels. Certainly, the roll off doesn't start at 2k!! I'm not even sure what your trying to say there.

But overall, I was really trying to drive at some clarity for more of the newbie's benefit on this low level loss issue. It's an often bandied about term that just becomes thrown out there like you have to have enough overall signal level to push through the signal or something. You have to understand that "low level signals" are routed for great distances on copper wire! That's how phone calls used to be routed for thousands of miles. Oh...and network programming too that was wide bandwidth, high fidelity...not to mention network video in the days before satellite.

CoolJazz

math wizard

thanks to all who replied.