gonzopancho
SILVER Star
Really looking for radio delete plate with 2.1 (80+80+100) and a MIC in for hands free. Then mount the mic on the column and boom.
For Sale Bluetooth Stereo 100% Hidden, only takes up the space of a dash knob! (Custom knob included) (1 Viewer)
- Thread starter thecrazygreek
- Start date
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bmoonhajjar
GOLD Star
@thecrazygreek Angelo, I bet you never thought you would end up a car stereo salesman.
thecrazygreek
A.K.A. TheCraftyGreek
- Thread starter
- #203
You got that right!!!
‘what in thee hell!
any ETA on bluetooth devices ordered in November?
@thecrazygreek if I'm looking to do 4 speakers... do they need to all be the same impedance or can I have a 2ohm and a 4ohm on the same channel? I'd do them in series and not parallel.
gonzopancho
SILVER Star
You can make this work, unless you’re using coaxials or anything else with a crossover. If you use something with a crossover, the crossover will likely interfere with what you want to hear from any speaker past the one(2) with the crossover.
I was just going to run a POS wire to the first speaker and then run a POS from the first speaker to the second speaker POS. Same for the NEG side.
gonzopancho
SILVER Star
Sounds like wiring them in parallel.
@gonzopancho You are right... One diagram I saw had you connecting the two speakers POS to each other, and the NEG to each other with the POS and NEG wire from the radio going to the first speaker only. With your diagram I see this is actually parallel since each speaker effectively has its own ground back to the stereo.
Thanks for the clarity!
Thanks for the clarity!
thecrazygreek
A.K.A. TheCraftyGreek
- Thread starter
- #210
Quick update for folks who have already purchased a unit, or are looking at buying.
‘These units are rated for 5 to 24 volts. If you want to take advantage of the max power and get the loudest output you should up the input voltage
If you already have a 24v rig then your all set. If you’re like most people @12 volts then you should look into a step up converter that provides 24v.
They are super easy to instal. If you feed the unit 24 volts and are running 4ohm speakers, you will see the full 50 or100watts per channel depending on which unit you bought.
Amazon sells these units for under $20.00. Just search 12v step up converter.
Most people that are running this unit are more than happy with the sound volume. But a couple folks inquired about getting even louder.
‘This up converter is the best way to accomplish that.
And don’t forget about the OHM rating for the speakers. 4 OHMS is best! if you have 8 ohm speakers then you will see 72watts per channel for the 200 watt version.
I hope this information will help!
Angelo
‘These units are rated for 5 to 24 volts. If you want to take advantage of the max power and get the loudest output you should up the input voltage
If you already have a 24v rig then your all set. If you’re like most people @12 volts then you should look into a step up converter that provides 24v.
They are super easy to instal. If you feed the unit 24 volts and are running 4ohm speakers, you will see the full 50 or100watts per channel depending on which unit you bought.
Amazon sells these units for under $20.00. Just search 12v step up converter.
Most people that are running this unit are more than happy with the sound volume. But a couple folks inquired about getting even louder.
‘This up converter is the best way to accomplish that.
And don’t forget about the OHM rating for the speakers. 4 OHMS is best! if you have 8 ohm speakers then you will see 72watts per channel for the 200 watt version.
I hope this information will help!
Angelo
@thecrazygreek when you say 4ohms is ideal, then that means I would want to do 4 2-ohm speakers (so therefore 4ohms per channel and 8ohms total) when wired in parallel?
Or am I not understanding how ohms are 'read' by the amp.
Thanks again! Going to try to have mine setup in the next few weeks!
Edit: did some reading... So what is the ideal ohms at the amp? I see that two 4ohm speakers in series equals 8ohms at the amp, while two 4ohm in parallel will be 2ohm at the amp. When you say 4ohms is ideal, do you mean at the amp? If so, then either two 8ohm speakers in parallel or two 2ohm speakers in series would be ideal?
Or am I not understanding how ohms are 'read' by the amp.
Thanks again! Going to try to have mine setup in the next few weeks!
Edit: did some reading... So what is the ideal ohms at the amp? I see that two 4ohm speakers in series equals 8ohms at the amp, while two 4ohm in parallel will be 2ohm at the amp. When you say 4ohms is ideal, do you mean at the amp? If so, then either two 8ohm speakers in parallel or two 2ohm speakers in series would be ideal?
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gonzopancho
SILVER Star
If all the speakers in parallel have the same impedance, divide the impedance by the number of speakers in parallel.
Two 4 ohms speakers in parallel: 4 divided by 2 = 2 ohms.
If you have speakers with different impedance then the general formula is 1/x, where x is the sum of the inverses of the impedance of each speaker in parallel. x = 1/a + 1/b + 1/c + …
This form can be used for the simple case:
Two 4 ohms speakers in parallel:
1/(1/4 + 1/4)
= 1/(1/2)
= 2
Edit: you asked about how ohms are read by an amp. They aren’t. The amp has to work harder to produce the voltage required to make a given volume of audio when the speaker circuit has more resistance. Most common automotive amps produce 60V peak-to-peak (+30v, -30v both in reference to the truck’s chassis ground.)
If you double the resistance you (roughly) have to double the amperage consumed to keep these voltage levels.
As you push the amp harder, more distortion results. Beyond a given point, the distortion becomes decidedly non-linear with additional increase.
Two 4 ohms speakers in parallel: 4 divided by 2 = 2 ohms.
If you have speakers with different impedance then the general formula is 1/x, where x is the sum of the inverses of the impedance of each speaker in parallel. x = 1/a + 1/b + 1/c + …
This form can be used for the simple case:
Two 4 ohms speakers in parallel:
1/(1/4 + 1/4)
= 1/(1/2)
= 2
Edit: you asked about how ohms are read by an amp. They aren’t. The amp has to work harder to produce the voltage required to make a given volume of audio when the speaker circuit has more resistance. Most common automotive amps produce 60V peak-to-peak (+30v, -30v both in reference to the truck’s chassis ground.)
If you double the resistance you (roughly) have to double the amperage consumed to keep these voltage levels.
As you push the amp harder, more distortion results. Beyond a given point, the distortion becomes decidedly non-linear with additional increase.
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thecrazygreek
A.K.A. TheCraftyGreek
- Thread starter
- #213
Great info/\
As far as I understand it, the above explanation is valid.
Also, some have asked about 2ohm speakers. Mathematically it would give you more power, but the amp would not be happy. Overheating may occur etc..
As far as I understand it, the above explanation is valid.
Also, some have asked about 2ohm speakers. Mathematically it would give you more power, but the amp would not be happy. Overheating may occur etc..
So if 2 ohms is overheating but loud, and 4 ohms is good balance, then 8 ohms would be quieter, but even less strain on the amp?
thecrazygreek
A.K.A. TheCraftyGreek
- Thread starter
- #215
As I understand it yes.
The specs on the amp with a 8 ohm speaker is (144w) 72watts per channel. (200 watt unit)
gonzopancho
SILVER Star
OK, I really didn’t want to turn this into an audio engineering tutorial.
V = IR is just half of it. P = IV is the other half.
See attached.
Voltage is basically fixed for any impedance… sort of. It may be slightly lower in voltage gain with lower impedance and higher current, but it's basically fixed.
Because voltage (V) is the same, with more impedance (R), the current (I) goes down, and the power (P) goes down. Too much current will make the magic smoke come out of your amp. When you let the smoke out, the circuit ceases to work.
As an example: 6 ohm home receivers happened because the standard "8 ohm" home speakers kept going down in actual impedance, (because: loudness) and amps that were at the limit with 8 ohms were being over driven. Speaker manufacturers do this to get higher power into a speaker for high sound presume levels (SPL, aka how loud a speaker plays) versus the competition.
The resistance of a speaker is actually a function of frequency, not one value. For example, an 8 ohm speaker may have resistance as low as 6 ohms in the mid-range, and as high as 100 ohms at the resonant peak. This allows for a certain … “creativity” in creating speaker impedance specifications. The marketing department will have its way.
Attached is an example (from Wikipedia) of an actual speaker's resistance versus frequency... note that the resistance goes off the chart at the higher frequencies, and peaks at well over 30 ohms at resonance.
TL;DR: drop the speaker impedance too low and you stand a chance of over-driving the amplifier.
V = IR is just half of it. P = IV is the other half.
See attached.
Voltage is basically fixed for any impedance… sort of. It may be slightly lower in voltage gain with lower impedance and higher current, but it's basically fixed.
Because voltage (V) is the same, with more impedance (R), the current (I) goes down, and the power (P) goes down. Too much current will make the magic smoke come out of your amp. When you let the smoke out, the circuit ceases to work.
As an example: 6 ohm home receivers happened because the standard "8 ohm" home speakers kept going down in actual impedance, (because: loudness) and amps that were at the limit with 8 ohms were being over driven. Speaker manufacturers do this to get higher power into a speaker for high sound presume levels (SPL, aka how loud a speaker plays) versus the competition.
The resistance of a speaker is actually a function of frequency, not one value. For example, an 8 ohm speaker may have resistance as low as 6 ohms in the mid-range, and as high as 100 ohms at the resonant peak. This allows for a certain … “creativity” in creating speaker impedance specifications. The marketing department will have its way.
Attached is an example (from Wikipedia) of an actual speaker's resistance versus frequency... note that the resistance goes off the chart at the higher frequencies, and peaks at well over 30 ohms at resonance.
TL;DR: drop the speaker impedance too low and you stand a chance of over-driving the amplifier.
It's this all testable?
gonzopancho
SILVER Star
Yes, but it’s easier to just stay inside the rating of the amp.
thecrazygreek
A.K.A. TheCraftyGreek
- Thread starter
- #220
Thank you for the nice words! I hope you enjoy!Received two units down under today. Blown away by the quality of the knob. Nice work Angelo and thanks again
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