Pre-amp outputs

Okay, so the front and rear pre-amp outputs on my Clarion head unit have never worked, all that I will get out of my sub is a small vibration, at normal volume levels. If I crank the volume way way up it will start to pound a little, but that's way too loud for my regular speakers, so the balance has to be set to about 90% going to the sub. It pounds like it should using speaker level inputs. Basically it doesn't seem right at all.

I have already had the head unit in for warranty repair twice and they claimed the pre-amp outputs were fine so I went to the repair shop today myself. He hooked up the head unit and showed me that it did work, but this was hooked up to some small 3.5" speakers, not a subwoofer. I said that the pre-amps have never functioned properly, while the speaker level inputs do. He said that it's because speaker level inputs have a lot more power going to the amp, so the subwoofer will move a lot more.

He took my head unit to the back and hooked it up to a Kenwood sub to prove to me it was working. I realized he had the volume way up, on 24. I normally have my volume around 10 - 14, I could never put it up to 24 on my Pioneers running off of the head unit. His conclusion is that my speakers aren't good enough.

He came out to my truck while I showed him it can't play on that loud a volume. His solution was to get better speakers to be able to keep up at such high volumes, or just turn the gain on my amp up all the way. Head units should be able to play good speakers at volume 24 out of 30, according to him. I don't have a subwoofer right now, so I couldn't demonstrate it with a sub, not that it would have made any difference.

I'm pretty sure he's wrong but I want to make sure. My warranty expires in 2 months, and I think it would be nice to have a head unit with working pre-amps. My amp right now has speaker level inputs, and on any other amp I could get a LOC but I want this head unit to function correctly.

They suggested it could be my amplifier, or my connections, but I have tried a different input (MP3 player), different RCA cables, different amplifier and different subwoofers.

Any ideas anybody?

Are you sure those are pre-outs and not inputs?

I did that on my fiancee's Clarion.

are you sure you have proper gain settings?

Get a Volt Meter and turn your HU up 3/4-all the way (you can disconnect your mids and highs), turn the gain on your amp all the way down and you should get a voltage comming out of the amp just below or right around what hte Voltage out should be from your RCA's (the specs should be on the box or something usually 2-9v).

Then turn the gain up untill voltage reaches the voltage needed to produce the Amps desired power. To find this use E = sqrt R*P where E=Voltage, R= Resistance (impeadance) and P = Desiered power and sqrt means square root.

oh also check head unit settings, make sure your bass isnt turned all the way down or your mids/high not turned all the way up.

I usually have my gain around halfway, but I've tried different settings, same problem. My bass settings and everything else is set normal. I can actually play my amp off of the RCA cables and it won't do anything for the sub (unless I crank the volume, and adjust fader all the way to rear, so barely anything comes out of my 6.5"s), and then I can unplug the RCAs and plug in the speaker level input and it will pound like it should.

I'll re-read the manual to make sure I don't have some weird setting on.

if you're using a sub output from your headunit, are you sure it's even activated

if you're using a sub output from your headunit, are you sure it's even activated

I'm just using rear outputs... my head unit doesn't have a sub output, only front and rear. How would you activate an output on a head unit?

Can anybody tell me if it is true that speaker level inputs would put way more power to the amp than pre-amp outputs?

wait, so your using speaker level outputs, not sub-outs?

Ok first off one thing that I don't see that anyone has responded to is that the guy at the repair shop you took it to sounds like a complete idiot. When he hooked it up to that sub and amp and had the volume on 24 the sub would have started to severly distort and sound extremely bad. And as for him saying that you need to replace the normal speakers because they won't stand the unit being set to 24 of 30 is completely retarded. Out of all the systems I've owned, installed, built, and configured you get the optimum sound and clarity at 50% volume level when you go above that with a system the sub hits harder but the mids and highs start to distort severly. You should take the unit out and take it back to the same shop again and tell them that the pre-amp outputs are not functioning properly and when they hook it up to the sub again check the volume level. If it is set at more than 50% turn it down to the halfway point and see if their amp and sub is doing the same as yours. If it does which it prolly will see what they say about that. On any receiver hooked to an amp and sub you will get repsonse from the sub on 25%. As far as disabling and enabling outputs on a receiver that only has to do with sub outputs the front and rear out's cannot be disabled. Is the shop you're taking it to the same one you bought it from if it is then tell them that you want the unit replaced not fixed otherwise you will be taking your business and all of your friend's business elsewhere. And after all that if they still won't do anything for you then I recommend getting an Alpine head unit as they have dedicated sub outputs and have one of the highest track records for reliability. I had one for 5 years never so much as ran a lens cleaner through it and never had any problem with any part of it.

Ok first off one thing that I don't see that anyone has responded to is that the guy at the repair shop you took it to sounds like a complete idiot. When he hooked it up to that sub and amp and had the volume on 24 the sub would have started to severly distort and sound extremely bad. And as for him saying that you need to replace the normal speakers because they won't stand the unit being set to 24 of 30 is completely retarded. Out of all the systems I've owned, installed, built, and configured you get the optimum sound and clarity at 50% volume level when you go above that with a system the sub hits harder but the mids and highs start to distort severly.

Yes, he was a complete idiot, and seemed to take pleasure in proving me wrong. The only reason the sub pounded in his shop was because the volume was on 24, with no mids or highs playing, just bass.


You should take the unit out and take it back to the same shop again and tell them that the pre-amp outputs are not functioning properly and when they hook it up to the sub again check the volume level. If it is set at more than 50% turn it down to the halfway point and see if their amp and sub is doing the same as yours. If it does which it prolly will see what they say about that. On any receiver hooked to an amp and sub you will get repsonse from the sub on 25%. As far as disabling and enabling outputs on a receiver that only has to do with sub outputs the front and rear out's cannot be disabled.


The sub won't pound at 25%... not using the outputs. I know what he will say, he'll say that my speakers aren't good enough, I need speakers that can handle 75% volume, which is a lie. I get response on any volume when I hook it up on speaker level inputs, like it should.


Is the shop you're taking it to the same one you bought it from if it is then tell them that you want the unit replaced not fixed otherwise you will be taking your business and all of your friend's business elsewhere. And after all that if they still won't do anything for you then I recommend getting an Alpine head unit as they have dedicated sub outputs and have one of the highest track records for reliability. I had one for 5 years never so much as ran a lens cleaner through it and never had any problem with any part of it.

No, it's a different shop. The place I bought it from uses this repair shop, and then there's an insurance company which decides to replace/repair equipment. I will contact them but they most likely will just go with what the repair shop says. I will also talk to the store I bought it from again, it's so frustrating, most people there don't even know what outputs are. Originally they had decided to replace it, and I was going to take the money and put it towards a nice Alpine... but then they decided to repair it. I just feel kind of ripped off, since they never have worked and the warranty ends soon.

Is the part about speaker level inputs having way more power true?

Out of all the systems I've owned, installed, built, and configured you get the optimum sound and clarity at 50% volume level when you go above that with a system the sub hits harder but the mids and highs start to distort severly.

You need to learn how to properly tune system gains then. Mine usually starts distorting around 32-33 out of 35.

You need to learn how to properly tune system gains then. Mine usually starts distorting around 32-33 out of 35.

Okay... but either way, the sub itself should pound at any volume level, like it does using my speaker level inputs.

that was meant for dave92cherokee

something just occured to me ....... when you are using the preamp outputs from the cd player, are you using the low level RCA inputs on your amp or are you still using the high level inputs. If you aren't using the low level inputs, I think you know what to do now.

that was meant for dave92cherokee

something just occured to me ....... when you are using the preamp outputs from the cd player, are you using the low level RCA inputs on your amp or are you still using the high level inputs. If you aren't using the low level inputs, I think you know what to do now.

Hey, yeah I knew that was meant for dave92cherokee... but I was saying, regardless of whether or not your mids are distorting at a high volume level, it shouldn't take a super high volume level to get something out of the sub (which is what the repair shop said).

My amp only has one set of inputs:

http://www.mobileonesales.com/product_p/gm3000t.htm

It does have a low pass filter setting, which I keep on low pass.

Thanks for the suggestion.

no, there are two sets of inputs on that amp ....... high level and low level, you need to put the outputs from the deck and put them in the low level (the two small protruding circles, one on top of the other, with a small whole in the middle), One will be marked L and the other R.

Ok. Instead of saying that something is wrong with the HU, maybe something is wrong with the amp. If you can run the subs from the rear speaker outputs, which put out 50-100 watts, then the amp running 100 x 1 should pound the sub. The connection off the HU seems to be fine, but to be sure u could check it with another amp. Make sure you have the amp grounded, powered, and hooked up (remote wire) properly. If you dont get enough power to the amp your output will suck.

To make sure my amp is not what's causing this, I hooked up an MP3 player with a headphone to RCA plug converter... it works fine, but only starts to pound on 75% volume. Is this because it's only an MP3 player or could this mean it's my amp... because off the head unit pre-amp outputs it will only pound around 75% volume as well.

Johannes ... read the reply to your private msg. You may have to adjust the little screw inset into the body of the amp that is labeled "gain" or "sensitivity" or something like that

stuff like this is so hard to troubleshoot over the internet ...... if I could see it in person it would probably be an easy fix.

Yeah, that's true. If any more explaining or pictures would help which I doubt it would, let me know. Thanks for the help.

well, what's strange is that the hi level inputs are connected in parallel thru a resistor to the low level (rca) ones. That's really the only difference, so it's got to be some way you have it connected or adjusted either at the amp or CD player.

Yeah... I really should try another amp. Does the fact that it does work with the MP3 player, on higher volumes mean anything?

I still think it's something that is misadjusted

Alright, today I tried a different Pioneer amplifier and it seemed to work fine, so I guess that means it's the amp and not the head unit.

I'll probably just use the high level inputs on the amp for a little while, I'm hoping to get a DEI refurb soon. I also have a 3 year warranty on this amplifier so I may send it in for repairs. Thanks a lot for the help and suggestions.