# Combining different speakers to one channel

Hi!

I have this more or less closed-set subwoofer with integrated amp and two sattelites on one channel. Now i got two sets of speakers for free.

Speakers and technical details

https://i.snag.gy/dkvLME.jpg

From what I know and worked with I would connect in series:

• 16-24 Ω
(amp.L - A.L) — (A.R - B.L) — (B.R - C.L) — (C.R - amp.R)

or would it be a good idea to combine series and parallel connections like

• 10-12 Ω
(amp.L - A.L & C.L) — (A.R & C.R - B.L) — (B.R - amp.R)

Are those calculations right and is this even a proper idea for a setup?

I know the speakers are very different and the soundophile might disapprove. I liked the sound of my other build though, where I combined 6 different non-set speakers in 8 Ω series to two channels on a proper amp (4 Ω stable) with some fine-tuning

Any hint is very much appreciated:)

I am no expert (and lack some technical terminology), but as far as I know it all depends on the impedance of your amp (or rather, the outlet for each speaker) and the impedance of your loudspeakers. The best thing is to match the impedance, but the rule is that it is safe to have more impedance on the loudspeaker side of things than on the outlet. So, if you have a 4 ohm outlet (this depends on the make and model of your amp) and you put two 4 ohm speakers in series, it equals 8 ohms, so it is safe, but they will play at half the volume compared to only wiring one speaker to the outlet. If you have two 4 ohm loudspeakers in parallel, the resulting impedance will be 1/(1/4+1/4)=2 ohm, which is of course lower than your 4 ohm outlet and therefore you risk blowing the amp. It is possible to make two parallel connections in series and achieve a result of 4 ohms, however I'm not really sure how such a configuration would look like, I just asked my buddy who knows his stuff.

Edit: and it has to be so-called real impedance, (I have no clue what non-real impedance is), otherwise you'll get a phase change.

I had the balls and just tried it out in series with two of the speakers connected in parallel

Works like a charm and feels very very diverse, like it covers three time the audio spectrum that the stock satellites (C) did.

Looks good, too:D

Still open to suggestions, maybe someone did/does something similar.
I'll keep tinkering, maybe another combination is even more worthwhile.

Okay, keep in mind my profession is in large audio applications. That being said, You really want to choose series OR parallel
Do you know your internal amps' Ohm rating? It is less important in small amps, however, dropping below what your amp is rated at can damage the amp. what happens with impedance too low is like cutting an artery, too much flow for the amp to handle. so you need to figure out what the lowest Ohm rating is for your amp.

Okay, keep in mind my profession is in large audio applications. That being said, You really want to choose series OR parallel

Why is that?
I used this article as my main ressource. They are describing series-parallel connection of speakers as one standard beside the individual two.
Is there any downside to that setup that I missed?

Do you know your internal amps' Ohm rating?

Unfortunately no. It's a closed-set kind of package, the manufacturer didn't feel the need to put that information anywhere on or in the subwoofer (which includes the amp) or in any publically available manual. I feel that I don't need that information, though.
The stock satellites are rated at 4-8 Ω so I calculate for 4 Ω minimum.

The current setup has ~6,7 - 12 Ω:
* 4 - 8 Ω from speaker A in series
* with the parallel speakers B and C
::1/4-8Ω + 1/8Ω = 1/Ωrating
-> from 4 Ω + 2,7 Ω to 8 Ω + 4 Ω

Please correct me if that calculation is wrong

If it was indeed 2 Ω stable, I could get some more power out of that thing right?
I don't need that, it's loud enough long before it heats up^^

If the amp can handle 4 Ohms, You're golden. If it can't, it may be giving up the magic smoke in the future. The way these systems are made assume certain conditions.

Namely that it is most commonly used in guitar cabs where the drivers are in one container so they don't have a nest of wires on the outside of the enclosure. Unless your speakers have options to do this, you either have to open the back of the enclosure, and solder to the driver, or, cut back speaker wire and create a T-Tap . That is going to create a massive spider web of wires no matter where you tap from.

I think I don't understand what you're saying
The first picture in Post #3 shows that the wiring is already done, more or less hassle-free.
Each set has their internal cables fixated on the speakers and a luster terminal that connects a long copper cable with banana plugs to connect to an amp. Pretty neat, as long as I don't want to separate and individually move them around a lot :D

Is it just the 'massive spider web of wires' that you are concerned about when mixing parallel and in-series connections?

Mixing parallel- and serial -connections is fine. It's something that is commonly done in big line-array PA-applications in order to suit the impedance to get maximum power output from the amplifiers, as well as in multi-element speakers.

Impedance is actually so much more than just a single number, for one it varies wildly with frequency, but it is a complex number on top of that, meaning there's an phase angle attached to it and it does matter for the amplifier/speaker interaction.

As far amplifiers go, disregarding tube amplifiers, the output impedance of functioning amplifier is very, very close to 0, as this is ideal and easily realized in transistor amplifiers. There is no reason for it to be anything other than 0 really. What matters here is the current and voltage capability of an amplifier, amplifier cannot give more voltage than the supply rails provide and it can only give out certain current depending on the power supply, output transistors ratings etc.
The most practical way to figure these out is to look at the manufacturers power ratings at given impedance.

Further complication is that the phase angle of the current vs voltage plays a big role on this too, and it dependent on the speaker in question. For this, it's pretty hard to figure out unless you have background in electronics/acoustics, so just play around and see if the magic smoke comes out. It's all part of the fun, right? :)

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