Chained speakers signal connected in series

oldhvymec - You are funny, thanks. I'm going to actually do some "grade school" math on a 2nd order low-pass filter. I will connect them in series first, then in parallel and the numbers should speak the truth, unless my math is bad. I will share the numbers once I'm done! Your analogy of a 103dB speaker also got a chuckle out of me. 103dB @ 1watt,1meter distance is not that loud, really. Break glass you're flat out wrong, even 1000watts, that only 133dB. Jet engines at a distance of more than 100 feet are 140dB, that doesn't break glass. 123dB @ 100watts is loud, but rock concert levels and threshold of pain are about 130dB. While I don't listen to music at those levels now, I wish I NEVER did... 

Interesting - I spent a little time to sketch the schematic. Granted the amplifier output will see 2 inductors in series, the crossover frequency of the driver is based on the L and C values. That ratio does not change whether the speakers are connected in series or parallel. My vote is that it does not change the crossover frequency. As far as the series or parallel connection of the speakers to the amplifier, the series connection does make it typically easier for the amp to drive the load. But this is only true up to about 70% of the maximum voltage capability of the amplifier. A parallel connection of the speakers will yield a 3dB increase in SPL, if your amplifier can handle the load resistance and deliver enough current. I preferred to connect them in parallel. That being said, I frown on multiple drivers in series OR parallel, especially in the midrange and tweeter frequencies. Whether they are point source of line source drivers, the sound will lose detail and become fractured and unclear. Happy listening!

Yes, OP that is basically what I said. One speaker connected to each amplifiers output will sound better than two, whether it's in series or parallel. If you connect them in parallel, if your amp can handle it, it will be about 3dB louder but NOT as clear, just like in series.
For those other Agoners that said the crossover frequency will change when connected in series, I have done the calculations and the crossover frequency DOES NOT change. I will post diagrams later, but if you want to do your own calculations, be my guest. Can we agree that Rt equals 16ohms in series? Can we agree that Lt = L1 + L2 in series? Can we agree that 1/Ct = 1/C1 + 1/C2 in series? If it's yes to the above, then simply plug those numbers into the equations. f = R/2πLQ and f = Q/2πRC. Both will come out the same with a very small error depending how many decimal points you take it out too. Happy listening to all.

rodman - That's all good info, but when I saw "geek" letter for ohms instead of Greek letter, it made me skeptical😁 The clarity thing I mentioned is from my testing, I had to prove it to myself. The theory about multiple drivers over the same frequency range is pretty well known. This is for high frequencies mostly, but also applies to the midrange in my listening tests.
esputnix - To make your listening tests more meaningful and convincing, use an SPL meter to make sure the listen levels are both the same. I would also use the same program material, speaker placement and distance from the speakers to your listing position. All things being the same, something louder will appear to "sound" better.

Even if L1 and Lvc1 are present, L2 and Lvc2 are also present. If the frequency of the crossover is say 2kHz., it will remain at 2kHz., because L1+Lvc1 equals L2+Lvc2. Is that not correct? L1 = L2 and Lvc1 = Lvc2 for each speaker. Both inductances are present whether they are used to calculate the crossover frequency or not. Correct?
Perhaps a crossover design simulator would give us a better answer, I am willing to listen to your presentation. That could save me the hassle of posting sketches. I think we are both capable since we have been working to solve the problem with likklegerry's crossovers. I will be waiting.

I will post some sketches tomorrow. If you connect the second speaker just across the woofer of the first speaker, the second speaker will see both inductors. I'll show you what I mean, but if you care to just plug some numbers into the "grade school" math equations, you will be able to see without me having to post anything... Elementary school?🤣

If Lvc1 does not equal Lvc2 in a dynamic setting, then it maybe possible to perceive a change in the crossover frequency, maybe even measure it. I’m saying in a "grade school" math equation, the data does not support this. I personally don’t ever connect speakers in a series configuration, for MORE than one reason. It just would be nice to see some actual data from some physical testing or calculations that will support the crossover frequency change. Does anyone want me to post sketches or does everyone understand the circuit? I don’t want to spend more time on this subject unless someone has proof to show me. Enjoy the music!

I think audiokinesis nailed it here! I should have mentioned this before, thank you for sharing your knowledge.