Wiring speakers from crossover

[J0N8]

Hello, I am currently using a 6.5 inch JL audio C-5 component set in the front of my car. The woofers in the doors and the tweeters in the corners of the dash. I am powering them with a JL audio slash 300v3/4 4channel amplifier. this amp will supply 75 W to each speaker regardless of voltage or ohm load it gets (R.I.P.S) technology

My car is a Kia soul, it did not come with the centre speaker. However, I put in a 6.5 inch JL audio VR component woofer there. I am sending the audio signal to the centre speaker using the positive + from the left crossover woofer output and the negative - from the right crossover woofer output. My question is: what is the ohm load that my amp is seeing? All of the woofers are for rated for 75 watts/4 ohm . I was also wondering if it’s taking away power from the woofers in the doors.

Any advice would be appreciated. Thanks, Jon

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[CarAudio.com - Hal AI Bots]

Hello, I am currently using a 6.5 inch JL audio C-5 component set in the front of my car. The woofers in the doors and the tweeters in the corners of the dash. I am powering them with a JL audio slash 300v3/4 4channel amplifier. this amp will supply 75 W to each speaker regardless of voltage or ohm load it gets (R.I.P.S) technology

My car is a Kia soul, it did not come with the centre speaker. However, I put in a 6.5 inch JL audio VR component woofer there. I am sending the audio signal to the centre speaker using the positive + from the left crossover woofer output and the negative - from the right crossover woofer output. My question is: what is the ohm load that my amp is seeing? All of the woofers are for rated for 75 watts/4 ohm . I was also wondering if it’s taking away power from the woofers in the doors.

Any advice would be appreciated. Thanks, Jon

I'm here to help with car audio and automotive related questions.

 

[1aespinoza 10+ year member]

I am sending the audio signal to the centre speaker using the positive + from the left crossover woofer output and the negative - from the right crossover woofer output. My question is:

Out of curiosity; have you tried sweeping the balance to see if that speaker is truly center? I want to know if the Grounds are common. If they are common, then the speaker should only work when swept left.

 

[highfigh]

Hello, I am currently using a 6.5 inch JL audio C-5 component set in the front of my car. The woofers in the doors and the tweeters in the corners of the dash. I am powering them with a JL audio slash 300v3/4 4channel amplifier. this amp will supply 75 W to each speaker regardless of voltage or ohm load it gets (R.I.P.S) technology

My car is a Kia soul, it did not come with the centre speaker. However, I put in a 6.5 inch JL audio VR component woofer there. I am sending the audio signal to the centre speaker using the positive + from the left crossover woofer output and the negative - from the right crossover woofer output. My question is: what is the ohm load that my amp is seeing? All of the woofers are for rated for 75 watts/4 ohm . I was also wondering if it’s taking away power from the woofers in the doors.

Any advice would be appreciated. Thanks, Jon

Call JL- using that wiring, the channels, which ARE NOT common grounded, may have problems with the load of 4 Ohms between channels. If the amp was common grounded between channels, it would be low power and the load would be too low for most of thsose, which really don't like it to be <4 Ohms.

L+/R- is usually used when the amplifier is in bridged mode and if you're not using that, it may have a problem.

Power is a calculated value, so Voltage and Resistance at the amplifier's output definitely DO matter but RIPS isn't about output power with various speaker loads, it's about the car's battery/charging voltage range, as the link shows-

""Regulated" means that the power supply adjusts its operation so as to maintain the amplifier's rated power output and low distortion operation over a wide range of vehicle voltages (11V-14.5 V). This contrasts with conventional, unregulated power supplies, which allow rail voltages to sag in direct proportion to drops in the supply voltage. This can result in significant power losses when battery voltage decreases, even if those voltage dips are short in duration. This manifests itself audibly as increased distortion. With a JL Audio R.I.P.S.-equipped amplifier, the rail voltage and clean power output remain completely stable in real-world systems, resulting in superior fidelity and stability."

https://jlaudio.zendesk.com/hc/en-us/articles/204987504-Regulated-Intelligent-Power-Supply-R-I-P-S

 

[Jimi77 5,000+ posts]

Technically, you've bridged the amp and you're sending ~2x power to the center speaker. Addtionally, this wiring presents a 1.333 ohm load to the bridged channel, which is below the rated load for the amp.

 

[1aespinoza 10+ year member]

L+/R- is usually used when the amplifier is in bridged mode and if you're not using that, it may have a problem.

Technically, you've bridged the amp

Dang. I totally forgot about bridging.

If the amp was common grounded between channels, it would be low power and the load would be too low for most of thsose,

I recall when a 2 channel used as a 3 channel was a special feature.

 

[J0N8]

Call JL- using that wiring, the channels, which ARE NOT common grounded, may have problems with the load of 4 Ohms between channels. If the amp was common grounded between channels, it would be low power and the load would be too low for most of thsose, which really don't like it to be <4 Ohms.

L+/R- is usually used when the amplifier is in bridged mode and if you're not using that, it may have a problem.

Power is a calculated value, so Voltage and Resistance at the amplifier's output definitely DO matter but RIPS isn't about output power with various speaker loads, it's about the car's battery/charging voltage range, as the link shows-

""Regulated" means that the power supply adjusts its operation so as to maintain the amplifier's rated power output and low distortion operation over a wide range of vehicle voltages (11V-14.5 V). This contrasts with conventional, unregulated power supplies, which allow rail voltages to sag in direct proportion to drops in the supply voltage. This can result in significant power losses when battery voltage decreases, even if those voltage dips are short in duration. This manifests itself audibly as increased distortion. With a JL Audio R.I.P.S.-equipped amplifier, the rail voltage and clean power output remain completely stable in real-world systems, resulting in superior fidelity and stability."

https://jlaudio.zendesk.com/hc/en-us/articles/204987504-Regulated-Intelligent-Power-Supply-R-I-P-S

 

[J0N8]

As you can see regardless of the voltage or the ohms, this particular JL Slash amplifier is similar to the HD lineup of amplifiers they have currently have the same rips technology.

The speaker sounds fine. I noticed the difference if I tapped into the power output vs the woofer output Of the crossovers, then it sent full range signal to the center speaker . At first, I had put a coaxial 5 1/4 JL that I had from before but was too bright up front

I have the JL C3-6.5 inch components in the rear doors and a JLTW3 12 inch in a box specifically made for it from JL and I’m quite happy with it.

Thanks for the advice, my thoughts are if I were to try a different amp without the rips technology it may not work correctly.

 

[J0N8]

As you can see regardless of the voltage or the ohms, this particular JL Slash amplifier is similar to the HD lineup of amplifiers they have currently have the same rips technology.

The speaker sounds fine. I noticed the difference if I tapped into the power output vs the woofer output Of the crossovers, then it sent full range signal to the center speaker . At first, I had put a coaxial 5 1/4 JL that I had from before but was too bright up front

I have the JL C3-6.5 inch components in the rear doors and a JLTW3 12 inch in a box specifically made for it from JL and I’m quite happy with it.

Thanks for the advice, my thoughts are if I were to try a different amp without the rips technology it may not work correctly.

Subwoofer is Tw3-12 inch 4ohm. Wired down to 2 ohm load and powered by JL audio RD500/1.

 

[Jimi77 5,000+ posts]

Dang. I totally forgot about bridging.

I recall when a 2 channel used as a 3 channel was a special feature.

This how we powered subs back in the day - when $1+ per watt was the norm.

 

[1aespinoza 10+ year member]

Thanks for the advice, my thoughts are if I were to try a different amp without the rips technology it may not work correctly

TBH I think no one in the forum has tried your technique. Some of us have done a similar thing but with a sub and choke coils.

 

[highfigh]

Dang. I totally forgot about bridging.

I recall when a 2 channel used as a 3 channel was a special feature.

That was for amps which were designed for it and usually, it was called 'tri-mode', IIRC. It used a coil to cross the sub over and a cap for each High Pass speaker/component. That prevents a direct connection across the whole bandwidth and prevents the impedance dropping because the frequency bands don't/shouldn't overlap.

Speakers, especially woofers, have a complex impedance curve and on top of that is what's called 'phase angle'. The latter is where some ams run into trouble because as a speaker's impedance decreases with frequency going up, it's in the capacitive phase and as the impedance increases as the frequency goes up, it's in the inductive phase. If the slope of the curve is too steep, amplifiers can oscillate, some won't provide full output power and some will just puke. When I was still doing car audio in the late-'90s, Rockford-Fosgate training included the explanation of this, as well as the test results using the 'Power Cube' system- this showed power output with straight resistance, as well as the capacitive and inductive phases- their amps were very consistent across the range, many amps were almost useless when the inductance was high- if I still have the info, I'll post photos of the results.

IIRC, one of the reasons the Rockford-Fosgate amps did well is because their power supplies weren't highly regulated, so they can also provide a lot more dynamic power output.

 

[highfigh]

Power supply is everything when amplifiers are concerned and if it can provide 75W with 12.5VDC or 14.4VDC, it means the power supply has more/larger capacitors than an amp which can't provide equal output at different supply voltage but the speaker impedance you're providing isn't on their chart, which is the reason I recommended contacting JL.

As the impedance drops, the Current through the output devices increases, their temperature increases and if they and their heat sinks can't shed this heat, they cook.

Power is a calculated value and Voltage, Current & Resistance can be used to derive this and other values, depending on what is known. Since 75W is known, Current (I) can be derived by using any resistance (pure resistance, since Impedance is the resistance at specific frequencies).

The current @75W increases drastically as the resistance goes down, so for 4 Ohms, 2 Ohms and 1.33 Ohms:

square root of 75 W/4 Ohms= 4.33A
............................75W/2 Ohms = 6.12A
............................75W/2 Ohms = 7.51A

If the outputs can handle it, maybe it's fine, but I would check with JL and find out if you can minimize any harm by adding a cap to each midbass and a coil to the woofers.


The diagram may help-

 

[RobGMN 5,000+ posts]

Using L-, R+ (or vice versa) was an old school trick for getting a center channel without an additional amp. It worked best on music that had hard-centered vocals, and you usually used a resistor to drop the level to match the mains.

I tried it, but only did it with a tweeter (Boston Acoustics "wedge"), so no clue on if it would affect power output on L&R.

 

[highfigh]

Using L-, R+ (or vice versa) was an old school trick for getting a center channel without an additional amp. It worked best on music that had hard-centered vocals, and you usually used a resistor to drop the level to match the mains.

I tried it, but only did it with a tweeter (Boston Acoustics "wedge"), so no clue on if it would affect power output on L&R.

It's not meant to be wired this way with tweeters, it's used for subwoofers because they need and benefit from more power. Tweeters receive the least power in the system and connecting them to a bridged amplifier is a good way to kill them.

When an amplifier is bridged, the speaker(s) connects to two channels, typically at th L+ and R- terminals. Some work this way, others need to have a switch moved to the Bridged position and those usually don't work in stereo mode after that. What's actually happening when the switch is moved- the signal that would go to one of the channels is inverted and the result is higher voltage from the output.

If you want a center channel, use a low powered amplifier (with common grounded speaker output) for the speaker (full range, not just a tweeter) and use the L+/R- terminals. This has been done for more than 65 years in stereo systems for the home.

 

[RobGMN 5,000+ posts]

It's not meant to be wired this way with tweeters, it's used for subwoofers because they need and benefit from more power. Tweeters receive the least power in the system and connecting them to a bridged amplifier is a good way to kill them.

When an amplifier is bridged, the speaker(s) connects to two channels, typically at th L+ and R- terminals. Some work this way, others need to have a switch moved to the Bridged position and those usually don't work in stereo mode after that. What's actually happening when the switch is moved- the signal that would go to one of the channels is inverted and the result is higher voltage from the output.

If you want a center channel, use a low powered amplifier (with common grounded speaker output) for the speaker (full range, not just a tweeter) and use the L+/R- terminals. This has been done for more than 65 years in stereo systems for the home.

Yeah, but isn't he using it as a front center channel with a 6.5" speaker, not as a bridging method to get more power for a sub?

The whole L-, R+ (or vice-versa) idea to power a center is old school.

Hafler actually patented some versions of the concept back in the 60's to get a center channel form a stereo amp setup, and Dynaco made a special outboard box to do it: https://web.archive.org/web/20120617074926/http://www.the-planet.org/dynaco/Misc/Quadaptor.pdf

I'm sure that's where the idea came from when they tried it in cars in the 80's/90's (when power was more expensive and options for amps were limited).