BillFitzmaurice.info

Bruce Weldy wrote: ↑Fri Jul 02, 2021 8:09 am We need to get Seth a girlfriend.......or a dog..

Oh jeez... is it that obvious? Two please. LOL

Not only can I not answer his questions.......I usually don't even understand them.

But, we need guys that dig deeper - that's where the innovation comes from. Me, I'm just a user who wants to wring out whatever I'm working with to its very best. Not to mention that whole "old dog - new tricks" thing.

Keep it coming Seth....

Even as a child, my mind tried to figure out how stuff works. My folks tell me it used to drive them nuts that they'd get me a new toy to play with and I'd take it apart to see how it worked. My mind is nearly always chipping away at something, trying to figure it out. Honestly, I enjoy it. Although a doctor or two has tried to label it ADD. I'm not entirely convinced. But, sharp as I am, I never did do too well in school (very very poorly actually. Barely slid out of High School with a diploma). So, maybe there's something to it. Don't know, don't care.

Seth wrote: ↑Sat Jul 03, 2021 9:21 am My folks tell me it used to drive them nuts that they'd get me a new toy to play with and I'd take it apart to see how it worked.

I was the same, took everything apart. My parents didn't get it, they said I broke everything I touched. By the time I was eight I could put everything together gain, by twelve I reached the stage of not only being able to fix anything but I could build things from scratch. I've never had to hire anyone to do anything, be it electrical, plumbing, carpentry, automotive, you name it. It frees up a lot of cash to do things you want to do when you never have to pay for services rendered.

i see a pattern.
After disassebling a wide variety of our household appliances my parents had the foresight to keep me suppled with broken ones.
After The Talk(tm).

tallevan wrote: ↑Sat Jul 03, 2021 12:42 pm i see a pattern.
After disassebling a wide variety of our household appliances my parents had the foresight to keep me suppled with broken ones.
After The Talk(tm).

tallevan wrote: ↑Sat Jul 03, 2021 12:42 pm i see a pattern.

Yup. Prolly why we all ended up on a DIY speaker site...

himhimself wrote: ↑Sun Jul 04, 2021 8:29 am

tallevan wrote: ↑Sat Jul 03, 2021 12:42 pm i see a pattern.

Yup. Prolly why we all ended up on a DIY speaker site...

Nah.....I'm just a cheap bastard.

Q: Assuming impedance is not a variable and is just a constant 8Ω, if a single sinewave is played through an amplifier at a constant voltage, would adding a second sinewave of different frequency yet equal amplitude as the first change the resultant power (watts) in any way? Same voltage, same impedance... one vs. two sinewaves.

A: No. In order for power to rise voltage and/or current would have to rise, which doesn't happen in this case. All that you'd get with adding the second sine wave is a complex waveform, with no increase in voltage or current. All sound content consists of complex wave forms. - Bill Fitzmaurice

That's what I figured. Thanks for the confirmation Bill

Grant Bunter wrote: ↑Fri Jul 02, 2021 5:27 pm Moot in real life because:
Impedance changes with frequency.

Hence the reason we need to look at impedance charts to determine "will this amp do the job if I have X amount of cabs per side".

Possibly moot, possibly not. It leads into part 2 of the curiosity.

Instead of two frequencies, let's say we have three frequencies that make up a complex waveform. Just for visualization, let's say 60Hz, 600Hz, and 6000Hz.

This complex waveform goes through an amplifier and into a 3 way passive crossover and onto a woofer, midrange driver, and a tweeter... each 8Ω.

Playing 1, 2, or all 3 sinewaves at identical amplitude, would there be a change in resultant power (watts) in that configuration?

Nope. The power is split 3 ways. 1+1+1 in this case equals 1. Besides, discussing sine waves doesn't really relate to discussing sound waves, which are not only complex, but the power density drops by 3dB with each octave increase in frequency. A tweeter rated for use in a 100w system will seldom see more than 5 watts, while 75% of the power is typically below 500Hz.

I'm surprised Seth is discussing sine waves; normally he's off on a tangent.

Rich4349 wrote: ↑Sun Jul 04, 2021 11:34 am I'm surprised Seth is discussing sine waves; normally he's off on a tangent.

At one point he talked about two waves, so is that cosine?

I also like your thinking Seth.
It challenges me to explore what I know, what I think I know, and what is fact.

You started with an assumption. You know, the 8ohm one.
It's a fact that impedance is frequency dependent.
Since impedance changes with frequency, so does power...

After disassembling various can openers, rotary telephones, TVs, radios... About the age of 12 I realized effectively everything has an electromagnet in it of some size or capacity. I'm envious of you guys though, who were able to reassemble said items.

For those of you who took stuff apart as a youngster and haven't seen or heard of an AvE BOLTR video, you're welcome.

(BOLTR = bored of lame tool reviews... AvE = arduino vs. everything) There's a ton of them and nearly all of them are fairly fascinating. Just search BOLTR on YouTube.

Here's one that's fairly relevant to our interests around here.





Really, just more proof that Canadians are the coolest people on the planet

Grant Bunter wrote: ↑Sun Jul 04, 2021 3:51 pm I also like your thinking Seth.
It challenges me to explore what I know, what I think I know, and what is fact.

You started with an assumption. You know, the 8ohm one.
It's a fact that impedance is frequency dependent.
Since impedance changes with frequency, so does power...

You're completely right Grant. I did say "assuming", however it wasn't a blind assumption. I intentionally ruled that out of the equation for the sake of conversation. It's intended as part of the construct of a hypothetical situation. And you're right that it's real and matters. But, it's not impossible for a 3 way system to have nearly identical impedances at some point in each drivers bandwidth.

For instance, this plot is essentially 4.5Ω at 60Hz, 600Hz, and 6000Hz.



Are you seeing the logic in my line of inquisition? It's still not making complete sense to me. I'm still in a state of quandary. Does it make sense to you?

Seth wrote: ↑Sun Jul 04, 2021 6:03 pm For those of you who took stuff apart as a youngster and haven't seen or heard of an AvE BOLTR video,[snip]

I figured you had watched his vids!.....because you had used one of his terms, in one of your posts.....can't remember which one ATM. OOPS, that may have been on TorqueTest channel. (pixie)

Seth wrote: ↑Sun Jul 04, 2021 6:03 pmReally, just more proof that Canadians are the coolest people on the planet

Thanks! hehe.