Where have all the wired 5.1 surround systems gone?
I've had a Panasonic Bluray player with built-in 5.1 amp for over a decade. It has served me well, but over the weekend stopped booting up and it is repeatedly flashing "please wait" on its screen. So I am back to using the TV's built in speakers.
Looking at replacement options, they are very limited. Sound bars with subs seems to make up the majority of the market and the options that do have rear speakers are very expensive and wireless meaning I need additional plug sockets behind the settee which I don't have.
My Panasonic speakers are still fine, so I'm considering just finding an AMP with ARC and using my existing speakers. However, most amps seem too big for the shelf under our TV.
Any ideas? I'm actually considering looking at second hand market.
Just to be clear I don't need a blu-ray player any more I don't think I've played a Blu-ray for nearly a decade.
The idea of using the Panasonic speakers is a complete non-starter if you decide to go down the road of a proper AV receiver. Those speakers might look fine, and still have worked fine with the Panasonic, but as others have said, they're designed to work with the Panasonic and not intended to be used with AV receivers.
If you want to get into the technicalities of it, the Panasonic speakers have a much lower impedance (3 Ohms) than speakers for an AV receiver will have at 6~8 Ohms. Also, at certain frequencies they'll go a lot lower than that. The closer the impedance gets to 0 Ohms the more it looks like a dead short to an AV receiver, and the bigger the risk that the receiver will just try to dump a lot of electrical current, and it's the current that causes things to get hot > overheat > then transistors blow up.
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So how come the Panasonic amp doesn't blow up if 3-Ohm speakers are so bad?"
3-Ohm speakers aren't bad for an amp designed to run with them. It's when you mix-n-match inappropriately that you run into trouble. If you put higher Ohms speakers with that Panasonic head-unit you'd find there'd be a heck of a lot less volume. The better quality of proper Hi-Fi/AV speakers would also throw a spotlight on the sonic shortcomings of the head unit, too.
Standard AV receivers are the size they are in order to keep the magnetic fields from the transformer away from the interference-sensitive preamp circuits.
The Panasonic head-unit and ones similar to it use switch-mode power supplies and Class D power amps. It's possible to make an amp that will deliver a lot of current with circuits using very few components, so it saves space and can be done at a low cost. This is partly why entry-level DVD home cinema kits started at £99 for the head-unit plus speakers and sub whereas the entry-level AV receiver systems were £199~£249 and still needed a DVD player as an extra.
Class D amps are very good at delivering a lot of current, but not so good at creating a voltage as a music signal. For cheaper transistor amps it's the other way around. The way that speakers work, the music signal as a voltage causes the speaker to react and draw current from the amp. A speaker with lower Ohms draws more current at a lower voltage to create a Watt of power. Another way of looking at it is that for the same voltage, the lower Ohms speaker draws more current and so it looks like the system is a higher wattage.
Speakers work from a low voltage AC signal, so strictly speaking it's not right to use the DC power equations, but it keeps the maths simpler and helps show the proportional relationships.
A 6 Ohms speaker responding to a 12V signal uses 24W of power. (V squared / Ohms = Power, so (12x12) / 6 = 24).
A 3 Ohms speaker responding to a 12V signal uses 48W of power. (V squared / Ohms = Power, so (12x12) / 3 = 48).
The low Ohms system looks like it is creating more watts, but in the process it is burning through twice as much current (fuel) to do so. The calculation for current is simple. It's just Volts divided by Ohms.
12V / 6 Ohms = 2 amps
12 / 3 = 4 amps
Okay, that's enough of the background. Now let's look at how you get your system back up and running.
I think the first option you should seriously consider is a repair to the Panasonic head unit. There is nothing as slim in an aftermarket AV receiver as the 40mm / 1.5" player-amps in these kits. If 40mm is your maximum, with little or no leeway, then your hands are tied. The fact that this has started to fail rather than gone with a bang gives you some hope that the issue is bad capacitors. You can Google 'bad caps' online to see the sort of issues. Replacing the caps like-for-like (same voltage, same uF) will restore the system if it's a capacitor fault.
Where you have a bit more height to play with then there are some other options, but they won't be new. They may also will involve either a bit of ingenuity with the speaker connections or changing the speakers too.
- You could look for a replacement Panasonic head unit. This gives you the best chance of the speaker plug ends fitting directly. Personally, I would look at repairing yours before going down this road as you already know its condition and how it has been used
- A replacement head unit that will work with 3-4 Ohms speakers. This one is slightly trickier because stuff like the crossover frequency between the main speakers and the sub will have been set to work with whatever speakers that head unit was supplied with. Being set in the circuit design means that it can't be changed, and so the risk is that it's either too high or too low to match what your speakers and sub need. The result could be either too much overlap between the speakers and sub, or not enough. You'd have to do some digging on what speakers any replacement head unit came with to see if they're a close enough match to your Panasonic speakers. The second issue is fitting the plugs. It's usual to find that the speaker cable plug ends are specific to each manufacturer. You might be able to get around this by fitting boot lace ferrules to the cables after cutting off the attached plugs. Have a look at the Pioneer head-unit receiver under eBay number 126127502226
- A slimline AV receiver for 6-8 Ohm speakers. You will need to swap your speakers as well, so factor this in with the cost.
The slimline receivers from Marantz (the NR-series), Pioneer and others also use switch-mode power supplies and Class D amps, but of much better quality. These will be around 10cm / 4" tall, and they'll need another 4" of clear space above and to the sides for ventilation since they don't use the forced air flow of fan cooling.
The Marantz range gives you the best chance of an ARC connection, so any sources that need to be 4K can go straight to the TV, and then sound can be sent out in DD5.1 to the receiver. I've seen prices as low as £100 and ranging up to £300-£400 depending on whether the seller is including speakers. Some of the later NR series receiver are 4K compatible, but the prices are higher.
A lot of these receivers were supplied with set-up microphones, and the EQ wizard not only sets the speaker sizes, delays crossover frequencies etc but also measures the effect of the room's acoustics on the sound then compensates for it. It's important to make sure the receiver comes with the original set-up mic and the unit's remote control.
Some Marantz receivers for you to look at: eBay numbers
126138543855,
186118506184,
Pioneer made some DD/DTS slimline receivers too. Being older, they have none of the HDMI ARC and fancy room EQ features, but they're relatively cheap. Search eBay: "Pioneer receiver" and you should find VSX-321, VSX-C300, VSX-S310
