Running speaker cables under skirting

[sxp842]

Hi all

We are getting a surround system and have sorted out all the wiring for it, except that we have just realised we need to run another cable for the subwoofer.

All the other speaker wires have been run from a media cabinet, underneath the floorboards, and then channeled up the wall.

however, it’s going to be a pain for us to now open up the floorboards again. We haven’t put our skirting board down but there is about an inch gap between the floorboards and the wall.

Could we run our speaker sub cable in this gap? And then put the skirting board on top? The subwoofer will sit on the floor so we won’t need to channel the walls.

I’ve seen mixed things online about whether you can run wires behind skirting boards, and we would be diy’ing it so we just want to make sure this is ok.

thanks

 

[Lucid]

Are we talking about the thin 'bell wire' type speaker cable for the sort of sub that comes with a DVD/Blu-ray playing main unit, or a proper coax cable for a powered sub?

As an installer, I don't have a problem with putting coax cable behind skirting, but I am mindful to avoid filling the expansion gap for laminate/solid wood floors, and I give consideration to any existing mains cable runs and fixing/nailing points.

If it is coax you're putting in, then the right cable can make the job a whole lot easier and help to avoid hum issues from interference.

There's a mini coax lead sold on Amazon that I have used in the past. It's only the same thickness as the thickness of a Pound coin yet incredibly-well shielded and very flexible.

At first sight it looks pricey compeared to the average sub lead, but it's built miles better and half the price of a similar product from QED.
I have had some of their cable too. It's much stiffer and no better despite the price.

Hum killer install cable

The seller doesn't list every size, but if you message them they will get probably get back to you with a price.

 

[Tigercubrider]

you can't really tell where a Sub is. Obviously if you mount it next to a party wall, the neighbours are likely to hear it as well.
But don't get too fixated on having it in one location.
Too many people think "hide it behind the sofa"

In theatres it's common to have the Sub onstage, or even under the stage.
You don't really know where the bass comes from.

Normally I am talking about Powered Subs, using Turbosound speakers, but the same rule applies.

 

[Lucid]

you can't really tell where a Sub is. Obviously if you mount it next to a party wall, the neighbours are likely to hear it as well.
But don't get too fixated on having it in one location.
Too many people think "hide it behind the sofa"

In theatres it's common to have the Sub onstage, or even under the stage.
You don't really know where the bass comes from.

Normally I am talking about Powered Subs, using Turbosound speakers, but the same rule applies.

The idea that the location of a sub is undetectable depends very much on the frequencies it is playing.

In a commercial cinema the speaker arrays for the front and centre channels are more likely to be large enough that they don't need the support of the LFE channel sub.

The LFE channel itself goes up to 120hz which is well within the male vocal range, but there's no dialogue or music in a proper LFE channel sound track, so we wouldn't localise the sub(s).

In a domestic home cinema system the channel arrangement is different. The front three speakers might rely quite heavily on the sub to supplement the lower frequencies of village and music. This is especially the case where the speakers are very small and have a high crossover point.

To prove this, play some dialogue and disconnect the centre and fronts. It will be possible to hear muffled talking from the sub.

The sub location being undetectable then is only true in certain circustances.

 

[sxp842]

Thank you for the response guys!

@Lucid:
This is the wire we are thinking of - https://www.amazon.co.uk/gp/product/B01D5H8GYG/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Its a subwoofer cable for a powered sub for a 5.1 surroundsound.

We just wanted to check if its possible to put Sub speaker wire in this gap.

@Tigercubrider : Yea we are not too fixated on it but we kind of want it to be hidden so we decided to have it on the side of sofa so its hidden. Putting in a sub cable in now would give us this option. Otherwise it would have to go outside the media unit.

 

[Lucid]

Thank you for the response guys!

@Lucid:
This is the wire we are thinking of - https://www.amazon.co.uk/gp/product/B01D5H8GYG/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Its a subwoofer cable for a powered sub for a 5.1 surroundsound.

We just wanted to check if its possible to put Sub speaker wire in this gap.

It's probably not what you want to hear, but my professional opinion is that it's a cheap lead dressed up to look fancy.

"Copper clad" means that it's either a steel or aluminium centre core with a bit of copper anodising rather than using a pure copper core. That's a cost-cutting measure and totally unjustified too since the centre core doesn't need to be that thick that the cost of a pure copper centre would be significant.

"Aluminium foil" is a euphemism for Mylar. That's a plastic film with an aluminised coating a bit like the stuff they make party balloons and crisp packets from. Whilst effective at blocking high frequency noise it does nothing for the sort of low frequency mains noise that often affects subs in noisy environments. You need either a foil + braid combo or the more effective double-layer high-density braid.

The other issue with just foil is it's rubbish at grounding away the energy trapped from RFI/EMI noise. This is the same for any foil, even the 100% copper foil in TV/sat coax. To carry that energy to a ground point needs a good conductor. A copper braid is the best solution.

Incidentally, any foil layer inside a cable makes it far less pliable.

The plug ends look fancy. The anodised gold layer will be a few micros thick, so more of a cosmetic finish since it will wear through pretty quickly at any contact points. They probably use solder bucket contacts for the cable joints. That means any shield integrity benefits from having a coax cable get thrown away at the plug ends.

There's not much more in a spec as such that tells us anything useful.

It's best guess how thick the cable itself is. For that reason I can't really comment on whether or not it will fit in the gaps you have. Being thicker than that other cable I mentioned, and less pliable because of the foil shield, means it won't go round tight corners without damaging the cable internally. There's something called the minimum bend radius, and if we say that the cable is 5mm thick then the min bend radius will be 30mm. Have you got any corners to go round in your planned cable path?


I think where someone doesn't have a problem with noise, and they just want a cheap sub lead that looks nice, then it'll do; hence the high proportion of positive reviews. If the sub has hum or hiss after the cable is hooked up then they can return it to Amazon for a refund. That's always easy with Amazon.

The 1-star reviews are illuminating. Cables chased in to walls that then stop working after a few months; that's not good. You pays yer money and takes yer chances. One thing's for certain, I wouldn't use something like this on my own jobs.

 

[sxp842]

@Lucid Thank you so much for your response, I really appericiate it. I am a newbie to sound system and audio in general. This is our first sound system we are getting. We recently purchased our sound system at Richer Sounds and the staff member who was helping us suggested we get a better Sub Speaker cable and said that it would be better sound quality and more durable. I didn't know if this was a sales tactic or he was being genuine. He sold us a 55 pound sub cable , this one
https://www.richersounds.com/audioquest-subwoofer-lead.html

I was going to do some research on it and see if it was better than the one I linked from Amazon. The 1 star reviews are alarming especially as we would have in under floorboards (plus we have chipwoodflooring over the floorboards so would be a pain to re route another cable)
if it is going to hum we would need to sort that because we are in a flat that would disturb the neighbours upstairs. would the richer sounds sub cable be a better fit?

I will attach some pictures which show gap where I'm thinking to put the sub speaker cable. (in the pictures below) The black lead Is the cheap sub cable as I'm still waitin on delivery for the actual RicherSounds sub cable.
The cable would be going in the same place, it has to to go around the chimney breast so it does have some corners it needs to go round. we were planning to make a small opening in the flooring/ skirting so the wire could come. Please let me know what you think of that idea otherwise we could look to route it elsewhere.

images

https://ibb.co/dgQC6PQ
https://ibb.co/BKd69dG
https://ibb.co/ZfKDnT0

thanks again for the response, it's super helpful.

 

[Lucid]

The sales person may well believe what they're telling you, but that's not the same thing as saying their information is correct.

The world of Hi-Fi cables is full of technobabble. It's easy to get swamped by it. In the forty-odd years I've been involved with Hi-Fi, AV and aerial systems I've found very few manufacturers and their agents who can back up their claims with some solid science. That's what lead me to do a lot of my own research; I'd be sat opposite a rep who would give me the company line on why this or that cable was better, but they couldn't give me anything technical to justify their views.

I've had a look at the sales blurb for that Black Labs cable. A lot of it falls in to the same trap. There's stuff they make claims for such as the long crystal stuff that's almost impossible for the average customer to prove or disprove. Other stuff is technobabble. For example, the cold welded connections; it's a fancy way of saying a crimp connection. Another one is air-filled foamed-polyethylene insulation. Yeah, my aerial cable has the same stuff.

There's one thing where I really do thing they go too far. That's this idea of a "Unique grounding cable"

This is going to get a little technical, so my apologies, but it's important. They're selling this as a special feature, but IMO it's a con. Their idea is that this special little connection will miraculously cure subwoofer hum. Here's where I think they're trying to pull the wool over your eyes.

Signal cables using RCA phono plugs have two connections: the centre pin (signal), and the outer ring which is both the return feed and the grounding connection. A ground is like a soakaway for the interference energy captured by the cable's shielding. In a previous post I mentioned how foil shields are good at blocking very high frequency interference, but that a foil is also a very poor conductor. That means the energy is trapped. It can't drain away to the ground because the foil shield is very high resistance. Cables with a foil shield need some low resistance wiring as well to act as the drain. With aerial cable its a braid that looks like fishnet stockings cross weaving. That's actually quite good because the braid acts as both a low frequency shield and as a drain for the energy to ground it. A cheaper alternative is a simple single core wire running the length of the cable.

The drain wire serves just a single purpose. It helps move the energy to ground, but it doesn't have any low frequency shielding properties.

In a cheap cable with a foil shield and with a drain wire, both will be connected to the RCA phono plug's outer ring. The ring of the RCA socket on the sub and the amp is connected to each item's metal chassis. There's no need for any additional ground connections.

What AudioQuest appear to have done is keep the foil shield and the drain wire separate. The result is that any purchaser with cable-induced hum before they bough the fancy cable will still experience the same problem until they connect the magic fly leads. Without realising it, they'll have enabled the lead to drain the stored energy properly. How it will appear though is that these little connections "did the trick". It's really just smoke and mirrors.

Hum in subs comes from one of 3 places generally. The first is bad shielding in a cable. Next, its something called a ground loop; this is where there's a relative difference in the earthing level of the mains sockets that the amp and sub are connected to. Finally, you get hum if the sub is a poorer design or broken.

Any properly designed audio cable with good shielding will do a first rate job of grounding the energy to the chassis of the amp without the need for fancy little fly leads.



Honestly, I wouldn't bother messing around or wasting any more time on other sub leads. Just get that one I linked to in the previous post.

A 4m version is under £27 delivered. A 5m version can't be much more. Message the seller. Get a price, order it and do the job with the best sub lead you'll ever buy and way cheaper than the AudioQuest product.

I pinched an image from when they were listed on Ebay.

Edit to add: The 5m version here with reviews 5m Super-thin 'hum killer' install 75 Ohm subwoofer: Amazon.co.uk: Electronics

 

[sxp842]

@Lucid Thank you for that, i ordered from your amazon store last night.

Regarding putting the wire in the slot (in the pics i linked above). Is that allowed, will it be safe to go there. We will put skirting over it.

 

[Lucid]

From what I can tell looking at the pictures, and from dealing with similar in my own installations, you might be able to put the cable in to the slot fairly easily. There could be a couple of places where shaving back the plaster might make the job easier.

The trickier areas are always the corners.

I would be tempted to use a sharp chisle to cut a little off the corner of the chipboard at a 45 degree angle so the cable doesn't have to be bent sharply. You're looking for a smooth bend as if going around the edge ofa £1 coin. You should be able to make that bit of space and still cover over with the thickness of the skirting.

If you plan to do carpet it's easier.

Have the gripper rods put down, then run the coax on the side closest to the room centre. Secure it with duct tape.

Where you need the cable to cross over the gripper rods, cut a channel through it and secure the open ends of the gripper with a couple of additional nails. Your carpet fitters can then fit as normal and bring the cable ends up from under the carpet edges.