2ohm and 4 ohm speakers wiring

[dolemon]

I got questions that i need inputs from all sifus in here. This is my system setup.


I'm using Blaupunkt GTA 480 with a specifications below :



Max. Total Power @ 4 Ohms 850 Watts
Max. Power at 4 Ohms 4 x 160 / 2 x 425 Watts
Max. Power at 2 Ohms 4 x 210 Watts
RMS Power at 4 Ohms 4 x 75 / 2 x 210 Watts
RMS Power at 2 Ohms 4 x 105 Watts
Number of channels 4/3/2
Frequency response 10 - 35,000 Hz
Signal to noise ratio > 95 dBA
Distortion factor (@ full RMS Power) < 0,03 %
Input impedance > 10 kOhm
Attenuation factor (@ 4 Ohms) > 100
Input sensitivity 0,3 - 8 V
Input sensitivity Direct Aux Input 300 mV
Stability 2 Ohms (4 Ohms bridged)
Lowpass 50 - 250 Hz (12dB/Octave)
Highpass 50 - 250 Hz (12dB/Octave)
Bass Boost 0 - 12dB @ 45 Hz
Inputs 4 x Cinch/RCA gold plated, 4 x HighLevel, 2 x Direct Aux Input via 3.5 mm phone jack
Outputs 4 x loud speakers
Dimensions (w x h x d) 352,5 x 53 x 268,5 mm


I already bought two pairs of Alpine SPR17S Type R Speakers with the specifications below (Which I did out of impulse, without thinking or doing research, since i feel that it is cheap ;()



* Sensitivity: 87 dB
* RMS Power Range : 110 Watts
* Peak Power Handling: 330 Watts
* Frequency response: 65-27000 Hz
* Diameter: 6.5 Inch
* Impedance : 4 Ohm

Now my questions is,

1) since my amplifier can only drive 75 W of RMS and 160 W Max power at 4 Ohm and the speaker can handle up to 110 W RMS and 330 W Peak at 4 Ohm, is it a matching combination? Can i use the GTA480 to drive the SPR17S?

Seems like there is not enough RMS power and the maximum power is even smaller.


2) Since the amplifier can drive 105W RMS and 210 W Max at 2 Ohm, which is i think enough to drive the speaker. Is it possible for me to wired the speakers parallel like the diagram below, so that i can use two channels to drive both pairs of speakers and still have two channels available to drive my subwoofers at bridge mode? (Refer to the diagram below). Just wanted to make sure whether this type of wiring is possible. Thanks...

***forgot to ask....what will be the effect of the tweeter on this wiring?

 

[gabantromen]

this is a gud question for us newbies...i oso wan 2 know..sifus, we need help...

 

[Zenn]

dont worry, the 75W from the amp will be enuff for the alpine speakers, they are not power hungry.. anyway the more important thing is the quality of the watts. u can try an audiophile grade amp, which cost around 3k, but only gives out 50W, i can guarantee it will sound louder and clearer than the blaupunkt. so dont worry so much on power issue.

i would definitely advise AGAINST wiring the front channels at 2ohm and then bridging mono the rear channels for the amp. running amps at 2ohms, even tho gives out more power it will be running extra hot, severely decreasing its usable age.

what i suggest is run the front components from the front 2ch, bridge the rearch for the sub, and just use your HU power for the rear components. rear speakers do not need to be loud, it will only kacau the front stage. in fact most good car audio systems do not have any rear speakers.

 

[bafukie]

agreed with zenn.... dun go 2 ohm load... u might shorten the amp's life

 

[appleyard]

Basically you cant wire 2 4 ohm comps to 2 ohm. The passive xover wont let you do that. Dont worry about your comps not getting loud. It may seems that 75w is small but actually it is plenty to get your components going. Also the type r tweets are a bit sharp and by having 2 pairs, I couldnt imagine the ear piercing sound from them.

 

[Hz_to_kHz]

My stupid opinion ( dun shoot me if i'm wrong )

Matching amplifier power supply with the speaker, it's not only look at the amplifier's RMS.
double check ur speaker manual, it's have told u about the speaker SENSITIVITY (dB/w/m)

if the speaker's SENSITIVITY is 90dB, that's mean when u give 1watts power to the speaker, the destiny 1 meter since ur speaker can get around 90dB sound pressure ( can explain to volume ).
if you need to make more +3dB, the speaker need to get double up of the power.

List like this.....
1w to speaker = 90dB
2w to speaekr = 93dB
4w to speaker = 96dB
8w.................= 99dB
16w...............= 102dB
32w...............= 105dB
64w..............= 108dB
128w............= 111dB

actually if you use 75rms to run ur speaker, u can get minimium 108db (volume) into ur car, it's really a enough loud to let you listen song already!! next time matching power to the speaker, dun only see the RMS only.


4ohm to 2ohm, the power supply from the amp with double up!!! Sure your speaker can get more of power from the amp, but ur amp Damping Factor will be drop also....Total Harmonic Distrotion will increase too. It's not good and not suggest to run parallel to ur component system.

 

[jimmylim85]

aren't is standard that most component speaker runs on 4 ohm impedance?

Usually i see subwoofer use on 2 ohm impedance to provide tighter bass.

 

[Zenn]

a sub can only go 2ohm if it comes as a 4ohm double voice coil sub. if the sub is normal 4ohm single voice coil sub it will play at 4ohm. u cant pick to play 2 ohm or 4 ohm, like flicking a switch on the amp, or something like that. its how the sub is wired, and if its capable of wiring down to 2ohm or not. amps are also not readily available to play 2 ohm. most 4ch amps will not play 2ohm bridged mono. so u have to check with amp's specs first. mono amps no problem, and some 2ch amps also can.

 

[vishnnu]

damn.......i get freaked out at times after reading the things y'all come up with.......the knowledge............and i thought i was a smartass after doin nautical studies....hahaha.......

 

[jimmylim85]

a sub can only go 2ohm if it comes as a 4ohm double voice coil sub. if the sub is normal 4ohm single voice coil sub it will play at 4ohm. u cant pick to play 2 ohm or 4 ohm, like flicking a switch on the amp, or something like that. its how the sub is wired, and if its capable of wiring down to 2ohm or not. amps are also not readily available to play 2 ohm. most 4ch amps will not play 2ohm bridged mono. so u have to check with amp's specs first. mono amps no problem, and some 2ch amps also can.

Seems like lower impedance provide tighter bass right?

I'm running 10" DVC 4ohm being powered by 4 channel amp capable of bridged 240W @ 4ohm mono.

 

[Zenn]

not necessarily lower impedance gives tighter bass. tight bass depends on box actually. lower impedance gives higher power, so if your sub was underpowered before, then yes, the increase in power would have helped in tighter bass.

by the way, your dvc sub is now either running at 2ohm (if wired in parallel) or 8ohm (if wired in series). so u are getting either 480W or 120W to your sub. if its wired in parallel at 2ohm your amp maybe running super extra hot and its life will be shortened quite a bit. check manufacturer's specs first before bridging mono 2ohm on a 4ch, usually they are not stable.

 

[jimmylim85]

not necessarily lower impedance gives tighter bass. tight bass depends on box actually. lower impedance gives higher power, so if your sub was underpowered before, then yes, the increase in power would have helped in tighter bass.

by the way, your dvc sub is now either running at 2ohm (if wired in parallel) or 8ohm (if wired in series). so u are getting either 480W or 120W to your sub. if its wired in parallel at 2ohm your amp maybe running super extra hot and its life will be shortened quite a bit. check manufacturer's specs first before bridging mono 2ohm on a 4ch, usually they are not stable.

I'm using Soundstream Xstream XTA480 4 channel to power up my Soundstream Picasso PW-10L 4ohm DVC. In which channel 3/4 bridged and connect to sub in parallel which provide 2ohm.

Is it going to be an issue?

 

[appleyard]

Seems like lower impedance provide tighter bass right?

I'm running 10" DVC 4ohm being powered by 4 channel amp capable of bridged 240W @ 4ohm mono.

Nope

Lower impedance is for power. Because it is cheaper to produce 1000w@1ohm compared to 1000w@4ohm amps.

Tighter bass is resulted in steep roll off in response. Its the ability of the driver and also box dependent.

 

[Zenn]

I'm using Soundstream Xstream XTA480 4 channel to power up my Soundstream Picasso PW-10L 4ohm DVC. In which channel 3/4 bridged and connect to sub in parallel which provide 2ohm.

Is it going to be an issue?

yes i suspect the 4ch amp is not stable down to 2ohm bridged mono. amp will run unecessarily hot and shorten its life. if played loud the amp should shutdown, unless it doesnt have a protection circuit built in.

 

[jimmylim85]

The XTA480.4 does have protection circuit to shut down incase is overheat. Yet the amp runs quite hot too even previously just being powered by my soundstream xts693 6x9 200W speaker.

 

[cacin]

The XTA480.4 does have protection circuit to shut down incase is overheat. Yet the amp runs quite hot too even previously just being powered by my soundstream xts693 6x9 200W speaker.

Hi bro,
Even if there is such protection circuitry, I still believe that what Zenn said is true. I haven't personally checked the spec for the amp, but I believe that most multi channel amp can't go to 2-ohm mono load. You're taking risk of overheating the amp.
Why not just run the sub in 8 ohm configuration?

 

[jimmylim85]

If i run on 8ohm seems to be real underpower. Like the sub is rated at 300W RMS while 8ohm bridged maybe is just 120W :(

Does Soundstream D2 D1.300 Class D monoblock able to solve the problem? Besides Class D monoblock runs cooler and less power consumption than Class AB amps.

 

[Zenn]

yes class d is more efficient, and if its a monoblock u can lower the load according to manufacturer's specs. so u can get more power and doesnt run as hot.