DD1 and RCA issues. Someone please fill me in

[Kaleb]

I have a bmw, I'm using audio controls lc7i as a line driver and a alpine mrv-v500 amplifier. I still have stock head unit. After playing around with the dd1 for hours watching videos wondering why nothing says its distorted even when i have my output levels and all my gains cranked i just knew that couldn't be right. As i was plugging the RCA's in i think i may haver found a problem. If i connect a single LEFTR RCA to my audio control and a single RIGHT RCA to the amp it still plays music and sounds very distorted. Can someone please confirm that the left RCA should be completely separate from the right RCA? I have never seen that before and I've already went ahead and ordered the smd quad crass. My main question then  comes to be, is this why the dd-1 was not working properly? Im pretty experienced with car audio any help is appreciated and if someone cold contact me directly with a little help that would be great. Thank you ahead of time.

[Tribe Called Bass]

Plug your probes into your speaker outputs, don't use your RCA's on the DD1 unless testing headunit distortion. Make sure you have your HPF/LPF all the way up, play the proper track which is 3 I believe. If it's not picking it up your headunit cannot handle a 0db test tone, try -5db and go from there. I couldn't really understand what you're trying to ask and what the issue is so I went ahead and said what I believe might be your issue

 

Welcome to the forums, have no hesitation asking questions. You'll always have someone chime in.

[Tribe Called Bass]

Are you trying to figure out your distortion from headunit? Or amp....

[bcbrassard]

You can do both at the same time with DD-1 thru the amp. DD-1 instructions are detailed on how to do it. Any deviation will end up w/ issues like op is having. Even with the LC7 he can tun everything  thru the amp.

[Kaleb]

On 4/11/2017 at 11:43 AM, Tribe Called Bass said:

Plug your probes into your speaker outputs, don't use your RCA's on the DD1 unless testing headunit distortion. Make sure you have your HPF/LPF all the way up, play the proper track which is 3 I believe. If it's not picking it up your headunit cannot handle a 0db test tone, try -5db and go from there. I couldn't really understand what you're trying to ask and what the issue is so I went ahead and said what I believe might be your issue

 

Welcome to the forums, have no hesitation asking questions. You'll always have someone chime in.

I can do that but when testing for distortion through the amp speaker outputs the lc7 does not distort, and neither does my amplifier. It will read signal and pick up the tone but never distorts. Obviously the lc7 and amp gains should not be all the way up. Now checking for distortion through the RCA out on the lc7 lets me get distortion but it is not at the same time as the clip/maximized light does on the lc7. And just clearly judging by sound i have to trust the lc7 before the dd1.

What i was saying about the RCA cables is i can plug one RCA into my amp and the OPPOSITE RCA into mh lc7 and i get a distorted sound coming from that speaker. I don't think the signal is suppose to transfer from one RCA to the other. I have already ordered the SMD rca cables to replace them.

'

[Kaleb]

Any help? if someone could contact me that'd be great

 

[audiofanaticz]

You are probably not sending enough signal out to the amp.

You need to find max non distorted volume of the radio using the speaker wires that feed into the LC7i using the 0db tone (1khz for mids and highes, 40hz for sub) and turn that up until you see distortion and back it off until the distortion like turns off.
Once that is found, keeping that volume on the radio at the same move on to the LC7i using the 0db tone (1khz for mids and highes, 40hz for sub), and turn that up until you see distortion and back it off until the distortion like turns off.
Now move on to the Alpine amp and again turn the gain up using the 5db, 10db, 15db 40hz test tone (track 3, 5, or 7) and turn the gain up until you see distortion and back it off until the distortion like turns off.

Now as for channels being crossed, it shouldnt be that way, Im guessing the wiring diagram to get your oem wire colors may not be correct and causing that issue.
IIRC the LC7i has something called "channel summing" which takes all the input channels and combines the frequency range from all channels to give you a full pass RCA output. So the more channels you feed into the LC7i the better. Otherwise what happens is if the vehicle has passive or active crossovers built into the amplifier, or on the speakers and you only feed the high level input levels from the midrange into the LC7i for example, you wont have no tweeter or subwoofer outputs, because its not able to sum the channels together properly.
 

Another possible issue is the actual plugs on your rca cables.

Sometimes the plugs that do not have the full length outer shield exposed will not always fit into the dd-1, I know they revised the dd-1 later on down the road but without knowing which style plug on the dd-1 you have I am not sure.

The newer dd-1s with the Tiffany style connection coming out of the dd-1 with the nut wont be effected by this issue, but the older style dd-1 with the rca plug that is recessed into the housing will have this issue.

So if your RCA plugs are like this with only a bit of the shiny outer shield showing they wont fully plug into the dd-1 and wont get a signal.

 

 

You need cables with a fully exposed outer shield like this.

 

 

If this is the issue, just grab a Y cable, or a male to female rca plug so it makes contact, or wait until your new cables arrive.

I use a right angle adapter on my dd-1 when the rca plug issue is a problem.

If it is not an RCA plug issue then there is a 99.9% chance that the issue is on your side someplace with the wiring, bad rca cable, to low of input voltage, not summing the channels, or something else all together because each dd-1 and all the other SMD tools are all tested after they are built.

If you have any other questions, or need more help trouble shooting let me know!

[audiofanaticz]

On 4/13/2017 at 8:40 PM, Kaleb said:

I can do that but when testing for distortion through the amp speaker outputs the lc7 does not distort, and neither does my amplifier. It will read signal and pick up the tone but never distorts. Obviously the lc7 and amp gains should not be all the way up. Now checking for distortion through the RCA out on the lc7 lets me get distortion but it is not at the same time as the clip/maximized light does on the lc7. And just clearly judging by sound i have to trust the lc7 before the dd1.

What i was saying about the RCA cables is i can plug one RCA into my amp and the OPPOSITE RCA into mh lc7 and i get a distorted sound coming from that speaker. I don't think the signal is suppose to transfer from one RCA to the other. I have already ordered the SMD rca cables to replace them.

'

Clipping and Distortion are not the same thing.

The dd-1 will detect distortion long before the lc7i detects clipping (depending on which track you are using on the dd-1 disc)

You want 40hz/1khz 0db test tones for the headunit, and the lc7i.
For the output of the lc7i you typically will want 40hz -5 or -10db for subs, and typically 1khz -5db for the mids and highs (sometimes -10db for the mids works well to depending on the setup).

If you are saying that you can plug the left RCA cable into the amp, and plug the right RCA cable into the lc7i, and still get audible output even with the other 2 ends of the RCA cables unplugged makes me say that there is a short in your RCA cables (possibly due to screwing into the cables when putting the car back together), or your input wiring from the oem radio wires going into the lc7i are not correct (which still makes no sense period because there should be no signal if 2 opposite ends are not plugged in).

[Kaleb]

On 4/17/2017 at 1:29 AM, audiofanaticz said:

Clipping and Distortion are not the same thing.

The dd-1 will detect distortion long before the lc7i detects clipping (depending on which track you are using on the dd-1 disc)

You want 40hz/1khz 0db test tones for the headunit, and the lc7i.
For the output of the lc7i you typically will want 40hz -5 or -10db for subs, and typically 1khz -5db for the mids and highs (sometimes -10db for the mids works well to depending on the setup).

If you are saying that you can plug the left RCA cable into the amp, and plug the right RCA cable into the lc7i, and still get audible output even with the other 2 ends of the RCA cables unplugged makes me say that there is a short in your RCA cables (possibly due to screwing into the cables when putting the car back together), or your input wiring from the oem radio wires going into the lc7i are not correct (which still makes no sense period because there should be no signal if 2 opposite ends are not plugged in).

I have the RCA issue figured it out, it was simply poorly made RCA's. 

As you say the DD1 Should detect distortion before the lc7 detects clipping, that is not true with my setup. Its actually backwards the lc7 deters clipping and the dd1 doesn't detect distortion. 
if you don't mind me asking i recently ran into another issue. I tried moving up in the world from the lc7 to audio controls DM6087 DSp. With the lc7 i have a light static/humming sound when my volume is at zero. As long as my gains are as low as i can go its not bad you'd almost have to put your ear next to the speaker to hear it. When i switched to DSP that noise was twice as loud no matter how i configured it. The DSP would also not detect clipping as its suppose to but the LC7 does? Im very lost I've tried changing my grounds, i have came to the conclusion by removing the speaker level inputs my static noise disappears so i assume its in the head unit, which i cannot change. That still doesn't explain why its so much louder with the DSP compared to the LC7. Thanks for your help, as you can see i need some lol!

[Kaleb]

On 4/17/2017 at 1:20 AM, audiofanaticz said:

You are probably not sending enough signal out to the amp.

You need to find max non distorted volume of the radio using the speaker wires that feed into the LC7i using the 0db tone (1khz for mids and highes, 40hz for sub) and turn that up until you see distortion and back it off until the distortion like turns off.
Once that is found, keeping that volume on the radio at the same move on to the LC7i using the 0db tone (1khz for mids and highes, 40hz for sub), and turn that up until you see distortion and back it off until the distortion like turns off.
Now move on to the Alpine amp and again turn the gain up using the 5db, 10db, 15db 40hz test tone (track 3, 5, or 7) and turn the gain up until you see distortion and back it off until the distortion like turns off.

Now as for channels being crossed, it shouldnt be that way, Im guessing the wiring diagram to get your oem wire colors may not be correct and causing that issue.
IIRC the LC7i has something called "channel summing" which takes all the input channels and combines the frequency range from all channels to give you a full pass RCA output. So the more channels you feed into the LC7i the better. Otherwise what happens is if the vehicle has passive or active crossovers built into the amplifier, or on the speakers and you only feed the high level input levels from the midrange into the LC7i for example, you wont have no tweeter or subwoofer outputs, because its not able to sum the channels together properly.
 

Another possible issue is the actual plugs on your rca cables.

Sometimes the plugs that do not have the full length outer shield exposed will not always fit into the dd-1, I know they revised the dd-1 later on down the road but without knowing which style plug on the dd-1 you have I am not sure.

The newer dd-1s with the Tiffany style connection coming out of the dd-1 with the nut wont be effected by this issue, but the older style dd-1 with the rca plug that is recessed into the housing will have this issue.

So if your RCA plugs are like this with only a bit of the shiny outer shield showing they wont fully plug into the dd-1 and wont get a signal.

 

 

You need cables with a fully exposed outer shield like this.

 

 

If this is the issue, just grab a Y cable, or a male to female rca plug so it makes contact, or wait until your new cables arrive.

I use a right angle adapter on my dd-1 when the rca plug issue is a problem.

If it is not an RCA plug issue then there is a 99.9% chance that the issue is on your side someplace with the wiring, bad rca cable, to low of input voltage, not summing the channels, or something else all together because each dd-1 and all the other SMD tools are all tested after they are built.

If you have any other questions, or need more help trouble shooting let me know!

I do need help, thank you. And lots of it. Okay so its a bmw base stereo so theres usually only 4 mids in the car no tweeters no factory amp. The person that had the car before me had a alpine kit with a amp and tweeters, installed. All it is is a little alpine amp with a factory wire harness that would now power the front underseat, mid bass subwoofers and the front door mids along with the tweeters. 
All i did was remove the alpine amp they had installed get rid of the factory harness. Use the wires they ran which was the two mid fronts for signal and two speakers wires one for each mid-bass underseat speaker which was not signal pick ups they went straight speakers. I added extra wire for the rear speakers to reach the truck for the signals and ran new speaker wire to those two speakers. I assume bmw used a in line frequency converter for the speakers under the seats but I'm not to sure of this, i assume because the alpine amp that i took out did not have any just the speaker wire to power them, it only had a front left and right signal pickup. the tweeters are also connected to the mids using a converter in the door panels. 
When i follow the dd1 instructions or do what you said to do i get stumped as soon as i start. the signal wires going into the lc7 will not detect distortion even when the bmw stereo is at full volume. This makes no sense to me.

If someone could contact me by text message or a messenger that would be great and less time consuming on my end.
Please read my above post also.