Contour Enthusiasts Group Archives Forums Modifications Audio speaker pos and neg? how do i tell each?

the vifa has two terminals that are the same. so if i use a battery to test the speaker it can damage the speaker?

No you wont damage the speaker! Just use a small voltage battery and hold it on there only long enough for it to kick, If it kicks out from the frame you have positive. They said the same thing before... as you know.

Just a side note, about the being out of phase, kinda a question too. The only ways I can tell if they are out of phase is...
1. The left if backwards from the right or the front is backwards from the back. Due to the sound cancellation. This is easy to tell anyone can tell this something just is not right.

2. Mids and highs I can not hear if its backwards in the higher HZ, if they are both hooked up the same. Only low in hz and its the initial pulse... so the distance is what matters and that���?�s why you can hook them up backwards sometimes and they be in the right phase do to the top of the wave hitting you first, so therefore its more efficient. It changes with the frequency.
Dose this sound correct??????????

â�?��?No you wonâ�?��?�t damage the speaker! Just use a small voltage batteryâ�?�

Like 97 scort said, to not damage your speaker touch and release using a low volt battery (like 3v or 6v).

You don't want to hold the speaker leads to the battery for long periods, that's what I mean when I say be careful. You don't want to make your voice coil a heater.
Still most speakers can handle 12v to 16v.

Originally posted by 97 scort:

---

1. ... Due to the sound cancellation. This is easy to tell, anyone can tell something just is not right.

---

Yeap, that's what makes it easy.

Originally posted by 97 scort:

---

2. Mids and highs I can not hear if its backwards in the higher HZ, if they are both hooked up the same.

---

A trained ear can, as you noted it frequency dependent.
When designing crossover polarity or by speaker position you can create compounding or suck-out (destructive interference), which can be heard easily. Although its easier to see it on an RTA. Another subject I need study is called â�?��?lobingâ�?�. This will explain what Iâ�?��?�m referring to above.

Originally posted by 97 scort:

---

- low in hz and its the initial pulse... so the distance is what matters and that���?�s why you can hook them up backwards sometimes and they can be in the right phase ..., so therefore its more efficient. It changes with the frequency. Dose this sound correct??????????

---

Yeap, distance is key. My study into wave propagation is weak but here it goes. Basically you have two sources creating near identical or identical air pulses and what results are node (suck-out) and antinode (compounding) locations in space. An in-phase point in space will compound on a positive pulse (be constructive, more efficient). Near identical air pulses results in a car due to early reflections of hard surfaces in front of the speaker.

With sub frequencies you want the point in space to be the entire interior of the vehicle. That is, all air compounds on positive phase and sucks-out on negative phase. What determines at what frequency this starts to happen?, Distance across the interior listening area.
At what point can it happen and you still experience life like sound?, depends on the distance between your ears and and ear lobes size