wiring method for 125W (per channel) speaker amp

[darekelec]

customer will be installing Sonos Amp 250W Stereo Power Amplifier MFR #AMPG1US1BLK

specs say 2 channels,

Amplifier power

125W/Ch into 8 ohms

wires will go in walls
I am unable find info in specs if it is class 2 power supply in t
What wiring method for speakers should I use?

 

[PaulMmn]

Will the customer be running the amp at full power/full volume? Or a more sedate, ear-preserving volume?
Normally speakers are wired with at least 12 gauge-- I used garden lighting zip-cord. Of course, the aficionados will require zero-oxygen copper specialty cables...
It's low voltage... normally.... would it require plenum-safe wire? Conduit would seem like overkill...

 

[darekelec]

I found this thread

Class 2 Circuits on 70V Audio System over 100W

I need some help getting clarification on what the NEC states vs what manufactures post on equipment. Code References as follows, 640.9(c), 725.121, 725.139, and Table 11A. What I'm gathering is that the amplifier output on a 70.7V system can utilize Class 2 wiring (640.9(C)) as long as the...

forums.mikeholt.com

in post #2
Doesn't matter what the wattage is, if it says Class 2 wiring may be used you can use CL2. If there is no label or nothing about a wiring requirement you automatically have to assume a Class 1 wiring method.
Whether an amp is Class 2 or not is all determined by the design and the listing

Let me continue the theoretical question ; If it does not cay Class 2 wiring method can be used on the amp, what wiring method is suitable so the sound quality is not compromised and NEC compliant?
CL2 speaker wire in emt or fmc?

 

[LarryFine]

I would choose a jacketed, in-wall rated 12 gauge speaker cable for customers.

My home theater system has 2,200 watts continuous power*; that's what I use.

*Mains: 2 x 300w/ch; center/sides/rears: 5 x 200w/ch; stereo subs, 2 x 300w/ch.

 

[hbiss]

wires will go in walls
I am unable find info in specs if it is class 2 power supply in t
What wiring method for speakers should I use?

From the user manual:
Speaker terminals- Use high-quality speaker wire to connect your speakers to Amp

The speaker wire you use should be as high in quality as that over hyped consumer junk. I wouldn't worry about it. Just use 12/2 CL2 so you can run it within the walls.

125W/channel?

-Hal

 

[ggunn]

Of course, the aficionados will require zero-oxygen copper specialty cables...

I read a review of speaker wiring in Stereo Review some years ago where they invited a bunch of golden eared audio experts in to listen to a double blind test that compared several brands of hideously expensive, oxygen free, exotically twisted, etc. speaker wires to zip cord from a hardware store. None of them could demonstrate that they could tell the difference.

 

[LarryFine]

125W/channel?

I don't get the funny.

 

[LarryFine]

I read a review of speaker wiring in Stereo Review some years ago where they invited a bunch of golden eared audio experts in to listen to a double blind test that compared several brands of hideously expensive, oxygen free, exotically twisted, etc. speaker wires to zip cord from a hardware store. None of them could demonstrate that they could tell the difference.

I read of a similar test using coat hanger wires, with similar results.

 

[hbiss]

I don't get the funny.

It's consumer stuff. Normally 125W would be measured with 400Hz in and 125W out into an 8 ohm load (31.6V) continuously before clipping and also at or below the specified distortion levels.

Betcha it doesn't come close. Kinda like a Sears 2Hp blender.

-Hal

 

[LarryFine]

So, you're saying you think it's an exaggerated rating, and more like peak instantaneous power at 1khz. That was common in the olden days before the FTC got involved in the industry.

I'm pretty sure my amps' ratings are not exaggerated (Sunfire Stereo and Sunfire Cinema Grand.) Their power ratings double with halved speaker impedance all the way down to one ohm.

My speakers are actually rated at 6 ohms nominal, not 8, so the available power level is technically greater than I said above. Plus, my front mains are bi-wired, I forgot to mention.

See: http://www.hifi-review.com/153488-sunfire-stereo-power.html

 

[hbiss]

I'm pretty sure my amps' ratings are not exaggerated (Sunfire Stereo and Sunfire Cinema Grand.) Their power ratings double with halved speaker impedance all the way down to one ohm.

Easy enough to check with an audio generator, scope, RMS volt meter and resistive load capable of the wattage... if you wanted to.

-Hal

 

[LarryFine]

Easy enough to check with an audio generator, scope, RMS volt meter and resistive load capable of the wattage... if you wanted to.

Naah. They have been tested plenty. I'm happy (watching and) listening to my system.

 

[Speedskater]

The reason 12 or 14AWG is often suggested for loudspeaker cables is. The end-to-end resistance of the cable needs to be small in relation to the impedance curve of the loudspeaker. Amplifier wattage has nothing to do with it. 25 Watt or 500 Watt amp need the same cable (pro sound systems excepted)

 

[rambojoe]

So, you're saying you think it's an exaggerated rating, and more like peak instantaneous power at 1khz. That was common in the olden days before the FTC got involved in the industry.

I'm pretty sure my amps' ratings are not exaggerated (Sunfire Stereo and Sunfire Cinema Grand.) Their power ratings double with halved speaker impedance all the way down to one ohm.

My speakers are actually rated at 6 ohms nominal, not 8, so the available power level is technically greater than I said above. Plus, my front mains are bi-wired, I forgot to mention.

See: http://www.hifi-review.com/153488-sunfire-stereo-power.html

Good idea to ohm out custom speakers always, but 8ohm always seems to ring out less than 6 and 4 around 3... good advice for op, (not larry)
14awg is more than enough, so is 16awg..

 

[rambojoe]

Naah. They have been tested plenty. I'm happy (watching and) listening to my system.

View attachment 2567031

What on earth are you listening to through that?! Do your neighbors like it?

 

[LarryFine]

Good idea to ohm out custom speakers always, but 8ohm always seems to ring out less than 6 and 4 around 3...

Of course, DC resistance of most speakers will almost always be lower than impedance, which itself varies throughout the frequency range, and typically alternating between capacitive and inductive.

 

[LarryFine]

What on earth are you listening to through that?! Do your neighbors like it?

Movies and music. I have an 8" CRT projector, with a 10' diagonal screen, about 5' by 8.5', so I wanted a sound-stage up to the task. You can see the size by the 2' ceiling-grid spacing.

I can play The Eagles or The Blue Man Group at realistic concert level. Only the bass really leaves the room to upstairs or outside, and I don't run it loud late at night, so no complaints.

 

[LarryFine]

I replaced a few components in the pics several years ago, most notably the B&K preamp/processor.

In its place now sits a Fosgate Audionics FAP-T1+.

 

[electrofelon]

I read a review of speaker wiring in Stereo Review some years ago where they invited a bunch of golden eared audio experts in to listen to a double blind test that compared several brands of hideously expensive, oxygen free, exotically twisted, etc. speaker wires to zip cord from a hardware store. None of them could demonstrate that they could tell the difference.

Unfortunately it DOES make a difference: they have done studies on the pleasure centers of the brain and found that people who THINK they are having some super expensive high end wine or chocolate do get more pleasure from it (even if it's not). I am not sure if they have done it with music, but I assume the effect is similar.

 

[ggunn]

Unfortunately it DOES make a difference: they have done studies on the pleasure centers of the brain and found that people who THINK they are having some super expensive high end wine or chocolate do get more pleasure from it (even if it's not). I am not sure if they have done it with music, but I assume the effect is similar.

Yeah, the placebo effect works to the advantage of purveyors of audiophile gear as well. Want a US$5,000.00 six foot 120VAC power cable? How about a US$450.00 wooden volume knob for your power amplifier? I have seen ads for both, and both ads promised an improvement in system sound.