How to protect a 2.1 speaker system from power issues?

I'd reccomend series mode protection, if you want surge protection.

That said, Surge-X would be what I'd go with, with price in mind.





No, you don't need voltage regulation, no,.. the amps need no protection from brown outs.

A good dedicated circuit, ideally with an isolated ground, series mode protection ... sized so there's no current limiting. That's key here, as an improperly config'd scenarion could actually be worse.

The finest come from Torus. Their RM series is the best available, when price isn't an issue. But realistically, one must determine whatpower quality issues actually exist, and go from there.

Much depends on where you live and the severity of your power issues.

As a starting point use a power conditioner with series mode surge protection - SurgeX, ZeroSurge, Brickwall or Torus. The Torus RM include series mode surge protection as well as an isolation transformer. Great sound quality improvement and well worth it in the context of a high end system. You can also use the Torus IS series which is an isolation transformer without series mode protection. However combining the IS with a SurgeX can come out at a lower price than buying the RM series, though you have everything in the same box with the RM. As an alternative to series mode you can try to find a product that only provide surge protection using MOVs from live to neutral. There aren't many of these around, and most surge protectors have MOVs to ground, which you don't want near your AV equipment in my opinion due to ground contamination from leakage currents across the MOV. One option which you can install in the wall is the Environmental Potentials Digiplug Stationary.

From there I'd add a dedicated electrical line, whole house surge protector at the main panel and also potentially a ground filter.

If your area has frequent brownouts (extended periods with low voltage from the grid) getting something with voltage regulation is useful.

I get hammered with brown outs and I use a Panamex power conditioner. It's done what it's advertisers said it would.

Sent from my SCH-I535 using Tapatalk 2

The best surge protectors are the whole-house devices that have to be installed by an electrician.

Good luck, the Isobars stuff is likely the best of the non-series mode offerings. They will allow surges, but most gear doesn't really need any protection. I'm skeptical of anything not series mode in topology, hence the Surge-X suggestion. I'm guessing Nyal feels the same.

Yes, the Torus offerings are expensive, very expensive. But they're the finest iso/surge power components out there. That's why I said the Torus were the best, and I didn't know your budget for this item.




You're right, that's the best first step.

But I'd say "best" would be a tiered approach, begining ...like you suggested, at the meter/service, .. and ending up with a device at the point of use. A series mode device ideally.

What provisions does a series mode device have to mitigate surges that come down the cable.

You are going to power a sub with a 4000 watt RMS amp off a 15A 120V circuit?

Reality check - no special joy having a circuit appreciably larger than the main breaker in the amp. You probably want enough circuit capacity so that if a breaker goes, its the local one for your convenience in resetting it.

The amp gets away with a ca. 1800 watt breaker on a 4000 watt amp because the crest factor of music is high - absolute minimum is 2 (6 dB) or quarter power, and it can easily be 20 or 1/400 power. That presumes that you actually crank the 4000 watt monster to clipping.

Cable TV?

The only other topology I'd use close to equipment is a 'single mode' protector i.e. line to neutral. Anything else is going to cause ground contamination and potential issues with equipment interconnected via cables but on different electrical circuits.

Yes that's the right first step, but a lot of 'surges' come from within your house (switching transients caused by motors in your washing machines, tumble dryers, extractor hoods, bathroom fans, furnaces, AC compressors, etc), so optimally you have a point of use device as well.

Don't know what kind of home you live in. If it is like mine, these are all on different circuits than the AV gear. A whole-house surge protective device will reduce any surges from these devices to a safe level for the AV gear.

Now, if you have your AV gear on the same circuit as a window air conditioner, you might want that point-of-use device.

Doesn't even have to be different circuits. If a surge protective device shunts a surge to the equipment grounding conductor, two points on the conductor can vary in potential by thousands of volts.

FWIW 3-mode MOV-based surge protective devices can be used safely if you understand the implications of shunting a surge to ground, and ensure that all ports of your AV gear are protected with a surge protective device referenced to the local ground. In some cases, this may be a bit difficult to do.

Many of the whole house devices still let through quite a lot of surge voltage not only due to their MOV based design with it's intrinsic 'clamping voltage' but also because of the length of wires that connect the whole house protector to the panel. That impedance, small as it is, reduces the effectiveness of the device in terms of it's ability to deal with surges. Plenty of documentation on that on the interweb from people like Eaton. Some of the newest whole house devices plug into your panel like a breaker. A point of use device, if MOV based, is connected basically across the live and neutral with zero impedance and so can work very effectively at clamping surges to ground. A series mode device is even better from a let through voltage perspective: 0V. Net-net that's why most combine a whole house with a point of use device. Big surges are dealt with by the whole house device and the point of use reduces the let through voltage from that device to a non-damaging level as well as dealing with surges caused within the home, either on the same electrical circuit or on others in the house.

A properly selected whole-house device will reduce surges to a level safe for your AV gear. Typical CE equipment is inherently safe to 600V or more. One doesn't need zero let-through voltage.

Typical surges generated in-house, with the possible exception of sources such as you mentioned are not a problem, not because they don't exist, but because of their parameters.

Can you explain what you mean about protecting all ports of your AV gear with a SPD referenced to ground?

Hi Colm, you obviously know your stuff here.. just curious where are you getting the 600V figure from? AFAIK 330V peak (2x normal) is the IEEE Emerald Book recommendation in terms of how much to reduce the surges to.

It's worth illustrating the effect of wire length on whole house SPD performance. The official UL1449 testing that determines voltage protection rating / let through voltage is I think carried out with a 6 inch wire length. Here's some data from Eaton:



There are also the added performance benefits of using the right point of use device in addition to the protection benefits. That's why I have my two tier whole house / point of use recommendation, and that seems to be commonplace across a lot of industries including IT for example.

Martzloff and others. It has been so long now, I cannot remember all the sources. Intel had a requirement for power supplies to be used with its board designs to be able to withstand a 800V or so surge IIRC. Business computer manufacturers built to a similar standard.

I could also give you some personal annecdotes. For instance, before I installed a whole-house device, I was replacing incandescent lamps and dimmers at an excessive rate. After installing the whole-house device, the problem disappeared. It takes a 800V or greater surge to kill an incandescent lamp, 1200V or so to kill the triac in a dimmer. Yet, I have never had a failure of AV gear before or after installing the whole-house device. IOW, it seems that my AV gear was inherently immune to surges of at least 800V or more.

Interestingly, the fact that we are not replacing incandescent lamps all the time means that surges of 800V or more are rare events, this according to Martzloff.
I don't know that it is recommended to reduce surges to 330V, but that is the minimum rating that can be assigned to MOV-based surge protective devices under UL1449. And IIRC part of the definition of a surge is that it is at least twice the nominal voltage. I wouldn't put a whole lot of stock in what IT does when it comes to surge protection, even in the biggest companies. Their expertise is computer hardware, database systems, operating systems, networks, etc., not power quality. Ever see a power quality engineer in an IT department?
Edited by Colm - 3/6/13 at 12:22am

FWIW my whole-house device has a voltage protection rating (VPR) of 600V as installed. That means that it limits a 6000V, 3000A surge to somewhere between 501V and 600V. Smaller surges will have lower let-through voltages. Assuming that the statement that almost all CE devices are safe to at least 600V is accurate, looks like I am good to go without point-of-use devices because my AV gear is on a dedicated circuit and there are no obnoxious devices on the same circuit. Your mileage may differ.

You use a device which Martzloff called a surge reference equalizer. They are all around us. It is nothing more than a surge protective device that handles AC and the other conductors like coax, etc. As long as all the ports of the gear are protected by the same surge reference equalizer, surges on the equipment grounding conductor are not an issue. A good application I saw was a surge protective device for a subwoofer. It protected the AC and the coax.

There is a problem with the approach, though. Some things are essentially impossible to protect this way. HDMI is the main issue. There are no real surge protective devices for HDMI ports.

I use a tiered approach as well, but slightly differently because I live in an apartment.
In the meter room downstairs, the main apartment feed has a single MOV based DIN unit (A-E); this then feeds two sub mains, the apartment and the AV.
In the apartment there is another MOV DIN unit (A-E and N-E) at the sub board in the kitchen and upstairs in the office where the computers are is a GDT (A-E, N-E) based unit.
In the AV feed which enters the apartment via a completely different route than the main feed, is a Novaris Series unit (whole house unit rated at 40A/240V) which post the LC has a MOV (A-E, N-E). The added benefit of this unit is the LC protection is that it reduces mains noise because it has an F3 of 800Hz.

The network where I live is overhead but I'm less worried about lightning then I am by HV/LV intermix because of weather or motor vehicle accidents. The system is not how I would ideally lay it out in a house, but I have some restrictions on what I can do in common spaces, and is designed to make best protection for the most difficult to replace parts - all the custom AV and PCs and the apartment automation. A fridge damaged under a fault condition is a nuisance but can easily be replaced at a whitegoods store. The rest can not. Total cost including free installation by me (I'm licensed) should be under $200 because of some luck in picking up great deals.

I only have the cable modem to do (I have to move the point).

Ah thanks. There is still an issue with this approach (using 3 mode protection), since the operation of the shunt mode device to ground could flow over an interconnect to another piece of equipment with different ground potential. This normally happens when devices like subs or flat panels are on different electrical circuits than the rest of your gear. Though if you use a 'surge reference equalizer' on your sub, like the one you mentioned, then you are good. For HDMI if you want to use a 3 mode device then you would want to use a fiber optic HDMI cable - that will isolate the display.

Yes, No power supply, designed by a competent person, requires an external surge protector.

Nothing will protect you from a lightning strike.

These surge suppressors have MOV's in them, just like (almost) every power supply input has.