Woofer Distortion

[kzaas]

Question for all of you audiophiles out there. I have been an Electronics tech for thirty years now but never really got into the effect on sound and sizes of speaker wire.

I wired my display speakers with wire that I had left over after wiring my lights and if I remember correctly the left channel may have been wired with 22AWG and the right with 18AWG. Midway through the season I noticed distortion on the left channel and just thought that due to the fact that these were not outdoor speakers and I was hitting them with some pretty good bass(TSO-WIW) that I probably blew the woofer in the cabinette.

I had to use these speakers in my garage with 14AWG wire and they sound fine now, no distortion. Could the distortion have been caused by the undersized wire? BTW the distance from stereo to speakers was approx. 50 feet.

[George Simmons]

Yes, very likely.

[KenL_MCSE]

Have you ever seen the monster cables they use on Sub woofers....

There is a lot of power through woofer and driver speakers. My guitar amps use some pretty thick cables between the amp the and speaker boxes

My 2 cents is yes - 22 gage is too small to drive your speakers

[gizmomkr]

I agree with all the above.

I have used cat 5 in the past, but my speakers are small (bookshelf style) and I split the pairs in half and end up with 2 bundles of 4 wires each. Its still not recomended.

The average speaker should have around 16 Awg wire. the longer the distance, the larger the cable size should be.

Your 18 awg is probably OK, but the 22 has got-to-go

[kzaas]

I totally agree the 22AWG has to go, but I was just curious as to weather this was the source of the distortion. I think maybe just to satisfy my curiosity, even though I plan on running at 16AWG to the speakers this year, if I have some time this weekend I will run some tests with different wire sizes and see how it goes.

[Steven]

This is why a commercial system uses a Constant voltage speaker system. In these systems, transformers are used to increase the impedance, meaning lower current and higher voltage, which can be sent over longer distances with smaller wire.

You can buy a reasonably-priced pair of speakers at OutDoorSpeakerStore.com, although I haven't tried those myself. I built my own system using transformers I bought on eBay, and a 3-watt audio amplifier. I ran it over an unused pair on the LOR network CAT5 cable.

[ErnieHorning]

Most definitely the cause. 22AWG wire has a resistance of .0190
ohms per foot. Multiply that by 100 both ways and you have 1.9 ohms in series with your 8 ohm speakers. If you were cranking it a bit, you probably noticed that the distortion got worse the longer the bass notes were playing. This would be the wire warming up a bit and increasing the resistance further.

[Max-Paul]

never mind

[Steven]

Max-Paul wrote:

But when did standard copper wire increase its resistance when it was heated up.

According to All About Circuits, the resistance of most conductors change as a linear function of temperature, which is specified as α (alpha).

They state that for metals, α is a positive number, meaning the resistance increases as temperature rises. They also mention that α for carbon, silicon, and germanium is negative.

For copper, α is 0.004041 Ω/°C, meaning that if the temperature goes from freezing to boiling, its resistance will increase by 40%! In the 22AWG, 200ft example, its resistance would go from 1.9Ω to 2.66Ω.

Not that you'll ever put 100 feet of cable in a pot of boiling water, but you get the idea.

[kzaas]

Steven wrote:

This is why a commercial system uses a Constant voltage speaker system. In these systems, transformers are used to increase the impedance, meaning lower current and higher voltage, which can be sent over longer distances with smaller wire.

You can buy a reasonably-priced pair of speakers at OutDoorSpeakerStore.com, although I haven't tried those myself. I built my own system using transformers I bought on eBay, and a 3-watt audio amplifier. I ran it over an unused pair on the LOR network CAT5 cable.

Is that the type of systems they use at places like theme parks? I know the 70 volt system we have here at work, although it works well, doesn't have the best audio quality. I am transmitting over FM for those who like to sit in their cars, but I get alot of pedestrians since I'm right next to a park, so I want to give them very good if not excellant audio quality.

[Max-Paul]

Dang! tried to make the retraction before someone saw it, Steven.

Right after making my post I went and looked it up. As I also stated it has been some 34 yrs sence I was in tech school. So, I saw just what you posted Steven. Came back and made an edit but you caught me. Dang, just dang, not fast enough.

[kzaas]

So I went into the garage to setup my BBQ for tonights dinner and while I was waiting for it to heat up I started looking at the wiring that I still have in place for the speakers and discovered that I made a mistake in this thread. The wiring I am using to both speakers is 18AWG. Now what? I am currently using the speakers in the garage for entertainment with 14AWG and they sound great.

I guess the next thing to check is to play the TSO - Wizards In Winter song that I was playing in my show and see if there is any distortion. Maybe its the files.There was other songs too but that one was the worst.

BTW the daily play the speakers are getting now are from sound sources such as Sirius radio and FM radio. I haven't tried them with the PC source since the season.

[George Simmons]

Max-Paul wrote:

Dang! tried to make the retraction before someone saw it, Steven.

Right after making my post I went and looked it up. As I also stated it has been some 34 yrs sence I was in tech school. So, I saw just what you posted Steven. Came back and made an edit but you caught me. Dang, just dang, not fast enough.

Think twice... type once...

[ErnieHorning]

George Simmons wrote:

Think twice... type once...

It seems that after a certain age, thinking once is hard enough.

Excuse me, I have to go think. This could be awhile...:?

[Max-Paul]

ErnieHorning wrote:

George Simmons wrote:

Think twice... type once...

It seems that after a certain age, thinking once is hard enough.

Excuse me, I have to go think. This could be awhile...:?

roger on the thinking once is hard enough. And for me it part of that, I know this stuff and in reality I know this stuff but someone rewrote the text books. Who did that when I was not looking. :? And then there are the pups who want to work outside of the box. Thats fine up to a point that they dont kill themselves or burn down mom and dads house.

I'll remember you George. Your day is coming. :cool:

[Mike Manzara]

There is one other possibility and that is you may be over modulating especially if you are broadcasting with an FM transmitter. You may have to use Audacity to bring the recording level down or reduce the volume going into the transmitter.

[Max-Paul]

Just some fun facts, not meant to bust anyone's chops.

Modulate is what is done to the RF signal when broadcasting an A.M. signal. Which is to include sideband of any flavor.
Deviate is what is done to the R.F. signal when broadcasting an F.M. signal.

And I am not going to get into all of the other forms of modulation or deviation of a carrier signal. (PSK, FSK and so on)

[kzaas]

I confused a little bit. I never said it was distorted on the radio, it's only distorted coming out of the left speaker. So is that what you are talking about when you are saying "over modulating", you are talking about my radio broadcast?

[kzaas]

Max-Paul wrote:

Just some fun facts, not meant to bust anyone's chops.

Modulate is what is done to the RF signal when broadcasting an A.M. signal. Which is to include sideband of any flavor.
Deviate is what is done to the R.F. signal when broadcasting an F.M. signal.

And I am not going to get into all of the other forms of modulation or deviation of a carrier signal. (PSK, FSK and so on)

Just to have some fun I feel like busting some chops .

Do you know what the "M" stands for in "AM" and "FM"?

It's "F"requency "M"odulation and "A"mplitude "M"odulation.

OK funs been had . Time for me to get back to work on my Win 7 and PS3 Media Streaming problems.

[terrypowerz]

I know some other terms for AM and FM...

But to keep this PG 13 I will refrain from mentioning them... or my saying for the resistor color code... :cool:

To stay on topic... I think checking the sound files is a great idea... things that sound OK on a basic set of computer speakers or transmitted to an average car radio, may sound much worse when going through a better quality sound system or speakers.
(Sound files that were passable with a Belkin TX sounded like a$$ with my EDM!)
:shock: