Hi guys,

I installed a new sub and amp on Sunday, and I just would like to hear some advice/recommendations/definitions on tuning my amp. I haven't fixed it in place yet, I'm doing that today :P. I'm the first to admit I'm a car audio n00b, and I don't really know what most of the switches and dials on the back of my amp do... soooo I will chuck up a picture of the back of my amp and we can play a little game! It's called 'What does this do?'

http://i10.photobucket.com/albums/a126/BlazingMatt/13072011027.jpg


Also, I'd like to know if the amp has been wired up correctly? I was a little bit unsure whether I'd put wires in the correct places or not :P So feel free to tell me I've done it all wrong! lol. It was 2nd hand, so it has no instruction booklet - if it had one I'm sure I wouldn't need to ask these questions! hahaha

http://i10.photobucket.com/albums/a126/BlazingMatt/13072011029.jpg

Thanks in anticipation,
Matt.

lol here goes :)

You look to be bridging the rear channels into one for the sub which is fine IF you have your impedance right. Im guessing it would be stable at 2ohm and im hoping you havnt got a DVC (dual voice coil) 1 ohm sub hooked upto it. Know what impedance the coils are on your sub and if SVC or DVC?

Other then that its okay

The RCAs appear to be in the output which is wrong. Output if for going to another amp sort of daisy chaining the signal to pass it on to the next amp for it to use. The RCA should be in rear input coming from the head unit

Because you are only using the rear channels the top switches and knobs are irrelivent. So only adjust the bottom ones as you need

Gain: Think of it as a volume control but thats not what it is. It is for sensitivty RCA rating. Basically preouts on head units come at different voltages ie 2,4,8. The gain is used to match to the voltage. If you can't do that then turn up the headunit to about 90% volume and adjust till you can hear distortion. Best to lower it a little to give a bit of leeway for the amp also

Filter: This is your frequency crosover switch. What setting you put this on will depend on what the xover switch does. HP= high pass will let the HIGH frequencies through, LP=low pass will let the low frequencies through, FLAT=will basically void the xover switch. For a sub for would want this set on LP to let the sub frequncies through

xover: As explained this will decide where your xover kicks on. For instance set the filter to LP and the xover to 60 and that will ensure ONLY frequencies LOWER the 60hz get sent to the sub.

As a starting point 60hz is good for a sealed sub but play around and get it sounding how you like

Also be aware your head unit may have electronic crossovers aswell which will need to be disabled first before tuning

Hope this helps and you know where to find me if you need any help :)

The bass EQ usually bumps up the gain (vol) of the bass at a set frequency... e.g 45hz. So you will end up with one particular frequency point being elevated (artificially), if I understand correctly. You may want to avoid having this all the way up if your gains are set high!

lol here goes :)

You look to be bridging the rear channels into one for the sub which is fine IF you have your impedance right. Im guessing it would be stable at 2ohm and im hoping you havnt got a DVC (dual voice coil) 1 ohm sub hooked upto it. Know what impedance the coils are on your sub and if SVC or DVC?

Other then that its okay

The RCAs appear to be in the output which is wrong. Output if for going to another amp sort of daisy chaining the signal to pass it on to the next amp for it to use. The RCA should be in rear input coming from the head unit

Because you are only using the rear channels the top switches and knobs are irrelivent. So only adjust the bottom ones as you need

Gain: Think of it as a volume control but thats not what it is. It is for sensitivty RCA rating. Basically preouts on head units come at different voltages ie 2,4,8. The gain is used to match to the voltage. If you can't do that then turn up the headunit to about 90% volume and adjust till you can hear distortion. Best to lower it a little to give a bit of leeway for the amp also

Filter: This is your frequency crosover switch. What setting you put this on will depend on what the xover switch does. HP= high pass will let the HIGH frequencies through, LP=low pass will let the low frequencies through, FLAT=will basically void the xover switch. For a sub for would want this set on LP to let the sub frequncies through

xover: As explained this will decide where your xover kicks on. For instance set the filter to LP and the xover to 60 and that will ensure ONLY frequencies LOWER the 60hz get sent to the sub.

As a starting point 60hz is good for a sealed sub but play around and get it sounding how you like

Also be aware your head unit may have electronic crossovers aswell which will need to be disabled first before tuning

Hope this helps and you know where to find me if you need any help :)

Wow dude, what an awesome post. I'm pretty sure that helps me a lot. Let me get a can of monster and read through that again though! lol.
brb :P

You look to be bridging the rear channels into one for the sub which is fine IF you have your impedance right. Im guessing it would be stable at 2ohm and im hoping you havnt got a DVC (dual voice coil) 1 ohm sub hooked upto it. Know what impedance the coils are on your sub and if SVC or DVC?

OK, tbh I have no idea about the specs of the sub lol! All I know is the brand (DD). To find out I'd assume I need to take it out of the enclosure and look on the magnet for any writing? I shall do this soon and get back to ya!

The RCAs appear to be in the output which is wrong. Output if for going to another amp sort of daisy chaining the signal to pass it on to the next amp for it to use. The RCA should be in rear input coming from the head unit

Ahh, I had a feeling that might be wrong lol! I shall fix that up!

Because you are only using the rear channels the top switches and knobs are irrelivent. So only adjust the bottom ones as you need

excellent, cheers!

Gain: Think of it as a volume control but thats not what it is. It is for sensitivty RCA rating. Basically preouts on head units come at different voltages ie 2,4,8. The gain is used to match to the voltage. If you can't do that then turn up the headunit to about 90% volume and adjust till you can hear distortion. Best to lower it a little to give a bit of leeway for the amp also

Sweet, I think I got that!

Filter: This is your frequency crosover switch. What setting you put this on will depend on what the xover switch does. HP= high pass will let the HIGH frequencies through, LP=low pass will let the low frequencies through, FLAT=will basically void the xover switch. For a sub for would want this set on LP to let the sub frequncies through
Understood!

xover: As explained this will decide where your xover kicks on. For instance set the filter to LP and the xover to 60 and that will ensure ONLY frequencies LOWER the 60hz get sent to the sub.
Sweet, seems logical now!

Also be aware your head unit may have electronic crossovers aswell which will need to be disabled first before tuning

Is there any way to tell? Or just fiddle through the menus and find something that might resemble electronic xovers on/off :P

Hope this helps and you know where to find me if you need any help :)

Very helpful indeed! I shall use this advice and post results! Thanks heaps mate!

The most easy way to check impedence is with a multimeter. Check the resistance on each coil and tell me what it is? DD is custom made so could be anything so its vital i know this so you don't fry your amp

As for your headunit what model and make is it? I can tell you pretty quick if it has crossvers lol But yeah i forgot about the bass EQ which is a bass boost at a preset frequency on the cheaper models. Yours should be at 45 as that is the most common tuning for sealed enclosures

Cheers :)

The most easy way to check impedence is with a multimeter. Check the resistance on each coil and tell me what it is? DD is custom made so could be anything so its vital i know this so you don't fry your amp

As for your headunit what model and make is it? I can tell you pretty quick if it has crossvers lol But yeah i forgot about the bass EQ which is a bass boost at a preset frequency on the cheaper models. Yours should be at 45 as that is the most common tuning for sealed enclosures

Cheers :)

My headunit is a Kenwood KDC MP436U.

I just put the sub back in the box but took a few pics while it was out if that will help at all:

http://i10.photobucket.com/albums/a126/BlazingMatt/13072011030.jpg

http://i10.photobucket.com/albums/a126/BlazingMatt/13072011031.jpg



otherwise I suppose I'll pull it all apart again :P
But how exactly do I measure the resistance on the coils? Been a long long time since I've used my multimeter (if I still even have it!!)... Would I just check the resistance over the +ive and -ive terminals?

I have fiddled around with the amp and changed a few settings on the Head Unit and it is a fair bit better, but still not great.

Yeah it does have electronic crossovers. In the audio settings turn the 2 HPF filters to off and the LPF filter. At least for tuning.

Sub looks to be an old 3510 or 3512 and SVC aswell. Put the multimeter on resistance, the positive to + on sub then negative to - on sub. Whats the reading?

If you come tonight to the meet i can have a bit of a tune for you lol

Yeah it does have electronic crossovers. In the audio settings turn the 2 HPF filters to off and the LPF filter. At least for tuning.

Yeah I had a feeling that's what they may have been, I have them all set to 'through' as the other options are all 80Hz, 120Hz etc etc.

Sub looks to be an old 3510 or 3512 and SVC aswell. Put the multimeter on resistance, the positive to + on sub then negative to - on sub. Whats the reading?

Alright, will try that out if I can find my multimeter, and let you know!

If you come tonight to the meet i can have a bit of a tune for you lol

Can't make Wednesday nights anymore :(

In other revelations, there is the possibility that the sub and/or amp may be screwed (I'm leaning towards amp at this stage). My main reasoning is that the speaker cone does not move very much at all compared to other subs I've had before. It's not even really visible, but I can feel a vibration if I touch it, which I think may just be the vibration from the rear speakers resonating through the car. I have tuned the head unit (never have before lol) and I am thinking this has brought out a lot more in the stock speakers giving me the 'illusion' that the sub is working!! lollol.

I've got a mate (the one who I bought this from) coming around later tonight when I finish work and we're gonna play sub swapsies to see if the sub is working, then maybe we'll get around to amp swapsies to see if we can rule out my theories. He has no idea if they work or not either, they came uninstalled with his new car but he had his own system he wanted to put in instead haha.

I just noticed something on those pics. The wires to the subs! They should be 8ga for those subs not those tiny wires you have running off the bigger ones! like i said they are some serious subs for SPL

You talkin' bout the wires in the second lot of pics?? I thought that was a bit weird when I opened it up today!! It goes from the nice fat wire to a little skinny one after the leccy tape... So would you think that this would make such a big difference that you'd get almost nothing from the sub??

Just measured the resistance at the end of each of the tiny wires inside the enclosure and got 4.7ohms, I couldn't measure at the terminals as they had been coated in black stuff and heat shrink :P

Id say it is a 4 ohm SVC sub then, fine for that amp. Im thinking the wire will make a fair amount of difference but not as must as what you are saying. Fix it, it will only cause you problems if you dont

At the very LEAST, cut back to the thick wire and measure resistance there

Id say it is a 4 ohm SVC sub then, fine for that amp. Im thinking the wire will make a fair amount of difference but not as must as what you are saying. Fix it, it will only cause you problems if you dont

At the very LEAST, cut back to the thick wire and measure resistance there

Alright thanks a lot mate. I'll see if I can scrounge up some better wire and fix it up, and in the mean time I will measure the resistance. Might be a job for tomorrow now though! :P I wonder how long the previous owner had been running it like that... probably a fair while hahaha.

Just a thought, if I connect the thick wires straight from the amp to the thick ones on the sub, that should work fine, shouldn't it? At least I can test if it makes a difference to the sub first :P

Yeah should be fine for a test lol

Wow... what a dodgy wiring job LOL. After unravelling metres of tape..... hahaha.... Still no good. I'm looking towards to Amp now... is there a way to test if the amp is still good or not? I know it's receiving power of some sort as there is a red light that comes on on the remote bass controller. But that is my only signal hahaha :P

edit: oh, and I'm now getting pretty much dead on 5 ohms now from the sub.

Is there 2 or 4 cables coming from the sub?

Is there 2 or 4 cables coming from the sub?

2 cables :)

5ohm is a very very weird reading lol but even still the amp should not be going into protect. Turned the gain up?

5ohm is a very very weird reading lol but even still the amp should not be going into protect. Turned the gain up?

I'm pretty sure I've tried pretty much every setting :P

BUT I will double check again paying specific attention to gain. Also, I will let you know how the results go when we try different sub/amp combos! lol

It's really strange!!

Any lights on the amp itself?

Nah not that I can see anyway! lol

My other concern is if the amps grounded properly

My other concern is if the amps grounded properly

Well I've got it temporarily grounded to a bolt in the parcel shelf. I just chucked it there as it was the easiest spot to see if everything worked :P Where would you reccomend I connect the ground?

tire well, sand back the paint first though lol could be something with the amp lol just try different things

Maybe post up a Pic of the other side of your Amp..... the Supply side, so we can see the Thickness of your Cables..
Another thing you could try, is to swap your Sub wires and RCA leads to the Front Channels on the Amp.... Maybe your Rear channels are blown... Either Input or OutPut...

Maybe post up a Pic of the other side of your Amp..... the Supply side, so we can see the Thickness of your Cables..
Another thing you could try, is to swap your Sub wires and RCA leads to the Front Channels on the Amp.... Maybe your Rear channels are blown... Either Input or OutPut...

Cheers for the suggestion mate, I'll give it a go in the morning and pop up a picture of the other side of the amp as well!

http://i10.photobucket.com/albums/a126/BlazingMatt/14072011035.jpg

Here's the other side of the amp :)
'Bout to try a few things this morning, and will post back results!

My other concern is if the amps grounded properly

BAM! That was it! After all my doubting haha, it was my stupid mistake right at the end of the install to 'hurry up and finish it'. Moved the ground to a spot between a bracket and the boot floor under the carpet - and BOOM! My test song sounded suddenly more epic - WAKING THE DEMONNN!

Thanks heaps for your help troubleshooting Jamie! Now to tune the amp properly as per post 2, like I was ORIGINALLY trying to do, and put everything neatly back together and go on a celebration cruise :P

Hmm, OK, I 'almost' had it... Now the amp is coming on/off intermittently... I am assuming this may be a problem with the 12V connection. I wired it up to the 12V lighter connection (pretty sure I spliced into the correct wire anyway) which I've heard should be fine... but my connection has always been a bit funny there with my phone charger. Sometimes it will charge, other times it wont.

Just wondering if it's possible to splice into the power antenna wire? Does this receive a constant 12V while the car is on, even when it's not in radio mode on the head unit?

Cheers guys!

Wait. . you have the amps connected to the positive on the battery right???

I really hope so. . Otherwise whoever told you that needs a good punch in the head. .

Wait. . you have the amps connected to the positive on the battery right???

I really hope so. . Otherwise whoever told you that needs a good punch in the head. .

Yeah of course I do!! I'm not THAT stupid :P lol, it's just the tiny wire that's connected to the lighter.

And I've figured it out now. There must be a short or something within the wiring on the ash tray piece. I left it unplugged and it's been working fine all afternoon. Love it!! Perfect day for a drive through the hills, and that's what I did for the last hour or so... Without a problem whatsoever :D.

Good news buddy :) enjoy! DD goodness!

Good news buddy :) enjoy! DD goodness!

Oh hell yeah :P. Now I think I need to crank some dynamat around my boot... but might upgrade the 6" front door speakers first :) And maybe the rear 6x9"'s