[HELP] Subwoofer is too silent

[Pavel Horniak]

Hi. I have car audio system with stock 4x25W speakers (8ohm), and i have active subwoofer.

Subwoofer has two stereo inputs, high input and low input. I have searched, that high input is speaker input, so i connected subwoofer parallel to rear speakers. Now i hear subwoofer, but on maximum volume is too silent.

I can unsolder and change resistor to lower value on high input when needed.

Should i use low input when i have it connected parallel to speakers? is it safe to try low input on speaker output? or how i can connect it to have both speakers and subwoofer loud?


Thanx.

 

[sizzling]

Do you mean parallel? A sub needs its own Amp output, you cant connect it in parallel to other speakers. A subwoofer will need an Amp, you cant drive it off the head unit.

 

[Pavel Horniak]

Do you mean parallel? A sub needs its own Amp output, you cant connect it in parallel to other speakers. A subwoofer will need an Amp, you cant drive it off the head unit.

I have Amplifier for this subwoofer, but my radio does not have rca output, so i need connect that Amplifier parallel to two speakers (two because amp has left and right chanel input, it is probably mixed in circuit). Amplifier have two input types. High (speaker level) and Low (normal) impedance input. On high impedance input conected parallel to 25W speaker is my subwoofer too silent when amplifier is on maximum volume. and i dont know if is safe to connect low impedance input parallel to that 25W speaker.

 

[jsmithepa]

IF HU provides low level output (LINE OUT) you should use that instead, but if not you don't have a choice do ya. Don't hook up to rears, hook up front, which is typically louder.

 

[Pavel Horniak]

IF HU provides low level output (LINE OUT) you should use that instead, but if not you don't have a choice do ya. Don't hook up to rears, hook up front, which is typically louder.

I have tryed front speakers too. but same results. i can balance volume between front and rear speakers. and they are same. 25W 8ohm.

And Head Unit does not have LINE OUT. it is ford focus mk1 stock radio.

I think that High Input have big impedadance and it cause problem when is connected parallel with speaker.
Maybe i can change that resistor on amp to smaller one. but i dont know what values will be acceptable. I have 8 ohm speaker and i think that now is 1k or 10k resistor in amp.

I need to know what is lowest value of resistor that i can change in my amp.

EDIT: I will try tomorrow disconnecting rear speakers and have connected only front speakers and subwoofer

 

[jsmithepa]

Not familiar with this, but If I was in your shoes, I open up the sub and see if it's a simple resistor in-series, and if so replace it with one 1/4 its value. Why 1/4? am thinking your sub is looking at a 4V (newer) line signal vs older 1V signal.

 

[Pavel Horniak]

Not familiar with this, but If I was in your shoes, I open up the sub and see if it's a simple resistor in-series, and if so replace it with one 1/4 its value. Why 1/4? am thinking your sub is looking at a 4V (newer) line signal vs older 1V signal.

OK, that is exactly what i was looking for. So i will firs test it without stock speaker connected, if it will work, i will replace the resistors.

Thanx.

 

[sizzling]

Without a proper sub output I cant see this ever working properly as normally the head unit will include a crossover so only low frequency notes are passed to the sub. I think the most likely to work is as suggested and that's removing the rear speakers completely but this is still a bodge solution.

 

[Pavel Horniak]

Without a proper sub output I cant see this ever working properly as normally the head unit will include a crossover so only low frequency notes are passed to the sub. I think the most likely to work is as suggested and that's removing the rear speakers completely but this is still a bodge solution.

Problem is in subwoofer amp. because it is silent on high output when i disconnected other speakers too.
And subwoofer amp has its adustable low-pass filter. (80-180Hz). Subwoofer is working, and playng only low frequencies, but its is silent. My speakers are playng low frequencies (bass) too, but it is not enought for me, i want it louder. Subwoofer is silent when i have it connected paralell to reaar speakers, but when i disconnect rear speakers, subwoofer is silent too. it is probably problem in high output, it is not compatible with my radio.

 

[TommyP030]

Hi. I have car audio system with stock 4x25W speakers (8ohm), and i have active subwoofer.

Subwoofer has two stereo inputs, high input and low input. I have searched, that high input is speaker input, so i connected subwoofer parallel to rear speakers. Now i hear subwoofer, but on maximum volume is too silent.

I can unsolder and change resistor to lower value on high input when needed.

Should i use low input when i have it connected parallel to speakers? is it safe to try low input on speaker output? or how i can connect it to have both speakers and subwoofer loud?


Thanx.

Which subwoofer are you using? If changing the gear is an option, I would recommend the Alpine Type-R. It's go a lot of power and comes quite cheap.