Car Subwoofer - Cuts out at certain/high volume?

[DomBruv]

First of all sorry if this is in the wrong section


wondered if any of you guys had any ideas or experience on this.


My subwoofer cuts out at a certain volume which seems not to be very high.

So no matter how its set up on the amp itself or the headset it doesn't make a difference and will cut out.

I have checked all wires, earth and live seem fine and the wires to the subwoofer from the amp itself seem fine.


I am i right in thinking even though i don't see any effect of a bad battery this will be the case?

The car starts up straight away even in the freezing cold but I literally can't think of anything else.

Go to halfords for free battery check or is there anything else i could check before doing so?

Thanks guys

 

[Psycho Sonny]

the amp is not powerful enough to power the sub. unless it's an active sub.

you have not given us enough detail. and no it's not the battery.

 

[lucid]

the amp is not powerful enough to power the sub. unless it's an active sub.

you have not given us enough detail. and no it's not the battery.

This ^

Given the limited amount of info in the OP, then the chances are that the amp is hitting its thermal or current limit. IOW, the rated power from the advert/box side/instructions is a bit of a work of fiction based on some dodgy maths and taking liberties with some definitions. That's pretty common with a lot of "digital" amps.

The other common issue is misunderstanding how impedance (Ohms*) and wattage works. There's a mistaken belief that a lower speaker impedance makes the amp produce more power for 'free'. Car subs with dual voice calls can be wired in single connection (typically 4 Ohms), or in series (8 Ohms which means it draws less current from the amp), or wired in parallel (2 Ohms) which makes it look like the amp delivers more wattage, but the speaker then draws a lot more current too. Hence why an under-performing amp cuts out at low volumes. If you have a dual voice coil sub and it's wired in parallel, try switching the wiring to a single voice coil only until you can get an amp that actually delivers the claimed power.


* Impedance is more than just Ohms. It's also induction, capacitance and phase response too.

 

[Psycho Sonny]

This ^

Given the limited amount of info in the OP, then the chances are that the amp is hitting its thermal or current limit. IOW, the rated power from the advert/box side/instructions is a bit of a work of fiction based on some dodgy maths and taking liberties with some definitions. That's pretty common with a lot of "digital" amps.

The other common issue is misunderstanding how impedance (Ohms*) and wattage works. There's a mistaken belief that a lower speaker impedance makes the amp produce more power for 'free'. Car subs with dual voice calls can be wired in single connection (typically 4 Ohms), or in series (8 Ohms which means it draws less current from the amp), or wired in parallel (2 Ohms) which makes it look like the amp delivers more wattage, but the speaker then draws a lot more current too. Hence why an under-performing amp cuts out at low volumes. If you have a dual voice coil sub and it's wired in parallel, try switching the wiring to a single voice coil only until you can get an amp that actually delivers the claimed power.


* Impedance is more than just Ohms. It's also induction, capacitance and phase response too.

sorry to hijack was wondering if you could help me.

i have this amp

https://www.alpine.co.uk/p/Products/SingleView/PDX-V9

and the DSP carver system

http://www.zpost.com/forums/showthread.php?t=63030

info above and below

https://z4-forum.com/forum/viewtopic.php?f=2&t=41138

called top-hi-fi in some places or premium audio



is there a more powerful amp that suits my system? in my head unit it goes fine up until about 35 then starts to clip. however 15 is loud enough for residential and 25-27 for motorway with the roof down. i did find something funny goes on with the subs when i start to go over 28 and by 35ish starts to clip.

i keep it 27-28 at max now which is loud but was wondering if there is a more powerful amp. i couldn't find one which does all the speakers i have.

 

[lucid]

I'm no expert on where to source the right car amps, so unless I spent a load of time trawling the web I can't say which brand has the right configuration for your needs. Have you tried the car audio forum sites?

Looking at the specs of the Top Hi-Fi amp, the power output doesn't appear to change going from 4 Ohm down to 2 Ohm. If this was a Hi-Fi amp then it would suggest that the lowest speaker impedance should be 4 Ohm and nothing lower or no parallel wiring to lower the effective impedance.

It may be that you should consider a separate power amp just to run the sub. That will lighten the load on the main 5 channel amp as it would only be running four channels (mid/woofers and tweeters) instead of the far more current hungry sub as well.

 

[Psycho Sonny]

i've had experts look at the car and it's just a pain to do. i would have been better off getting rid of all the speakers and puttin whole new different system in.

the car has 4 subwoofers. they are just a pain to drive. i followed the gear someone else used as it was the only amp that could drive everything.

before i used an aftermarket amp it was 1 amp driving everything. but the OEM head unit was a relic. i wanted a modern one with Bluetooth, etc. so I was forced to do an overhaul. cost me like 2K so I don't really want to spend any more. it's really good. just that i know i'm pushing the amp when i go over 30.

i keep it at 27/28 to prevent risk of damaging speakers

 

[Kei]

Most headunits actually clip on their outputs at or very near their maximum volume. Easiest test would be to turn the gain down to absolute minimum on the amps and see if it still does it. If you had an oscilloscope you could test it directly by using a test tone, like a 1KHz 0dB level sine wave and see what volume level you can get to on the headunit before the peaks start to flatten.