Audio experts help Decibel output.

Yeah its just a basic cheapo mini amp for a car system. The speakers are all identical. I figure I'll try it as I planned, and if it actually is quieter I guess I'll just have to get a more powerful amp.

Thanks

Al, just a simple electronics question. I would think that a speaker has its own electronic attributes of resistance, reactance and inductance. So . . . would the characteristics of the signal coming off the amp be changed as it passes through the first speaker into the second? In other words, hooking two four ohms nominal rated speakers up in series isn't as simple as 2 times 4 equals 8. If it was, why not just stick a high power 4 ohm resister in series with just one speaker? Last point - a 30 watt amp is a pretty low power amp. If the OP winds up overdriving the amp, it may clip.

Would the characteristics of the signal coming off the amp be changed as it passes through the first speaker into the second? In other words, hooking two four ohms nominal rated speakers up in series isn't as simple as 2 times 4 equals 8.

Hi Bruce,

Yes, the signal seen by one speaker will be affected by the presence of the other speaker. However, if the two speakers are identical models, as I indicated they should be, their impedance vs. frequency characteristics will presumably match very closely. Given that, the effect will simply be that each of them will at any instant of time see a voltage equal to the output voltage of the amplifier at that instant divided by 2, which in turn will cause the amount of current flowing through them to also be divided by 2, relative to what it would have been without the other speaker being present. Since for a given load power is proportional to voltage x current, the two factors of 2 result in a four-fold reduction in the amount of power delivered to each speaker, as I had indicated.

Another consideration is the effect of the series connection on damping factor. Although it seems counter-intuitive, that is not an issue, as explained in this paper, which I must credit A'gon member Kijanki for calling to my attention a couple of years ago.

Why not just stick a high power 4 ohm resister in series with just one speaker?

That would waste half of the power being put out by the amp, since all of the power consumed by the resistor would be converted into heat, rather than some of it being converted into sound.

Last point - a 30 watt amp is a pretty low power amp. If the OP winds up overdriving the amp, it may clip.

Good point, especially of course if the speakers are relatively inefficient.

Best regards,
-- Al

Thanks Al. If I understand your post, presumably, the FR of each speaker hooked up in series will NOT change. Instead, the resistance at any particular frequency will double. I guess I'm still a bit confused because if, for example, a speaker's phase angle suggests that the speaker is presenting a reactive load at a particular range of frequencies, it's hard for me to understand how that attribute doesn't affect what the next speaker downstream will see. What would happen if the speakers were hooked up in parallel? Thanks for the electroncis lesson.

If each speaker has 1/4 power when they are wired in series, being that they are 50 watt speakers does that mean I need an amp that is 200 watts per channel to fully power them?