No Distortion with Gain at full tilt...

[b0r]

So, I bought my DD-1 pretty much when it released and have nothing but good things to say about it. I upgraded to a Fi BL 15 and Rockford Fosgate T1000-1bdCP, so I gave my old system: RE SXX 12 and JBL BP1200.1 to my friend.

His max/everything else is different when compared to my headunit, so I grabbed the trusty DD-1 and headed over to his house. His HU goes up to 50, but the comfortable listening volume is 25, so we didn't have to test for clipping from the deck, we just went straight to the woofer. I disconnected the sub, put the red lead in the + channel on the amp, grounded the DD-1 to the amp's ground with track 7 playing at 25, since this is where we want our "balls to the wall max", but most listening will occur at 20-22.

The 40hz light comes on on the DD-1 at about half way on the gain, but continuing to crank it all the way didn't give me any distortion. what? His JVC headunit only puts out like 2.5V or something, but how is there NO distortion with the gain cranked? That doesn't seem possible. Well, doesn't seem probable, anyway.

I decided to crank the gain down a 1/4 turn and head out on a drive slamming at 22-23 and do a heat check when the drive was over. The sub was HOT....not "pull your hand away now" hot, but it was definitely 105-110 degrees F or so. (No real idea on the temp, I just know it was hotter than 98.6.) The amp on the other hand was untouchable after about 2-3 seconds. It was scalding for the most part. So how can we have NO distortion with MAX gain, but the sub and amp are hot enough combined to cook an egg? (and this is with me turning the gain down a 1/4 in disbelief that it didn't distort at all)

When I had the sub and amp, I set the gain with my volume at 47/50, even though my listening volume was 32. I got enough bass to keep me happy and I don't recall my amp ever being over my body temp and my sub was certainly never "hot" to the touch. This can't be normal. Any reason for the lack of a distortion light? It's not broken, as it kinda lit up and went off like it does, but never got solid.

When we turned the head unit up to 35 instead of 25, it came on at about half way, but that's not where we want to be.

[Raptorman]

So, I bought my DD-1 pretty much when it released and have nothing but good things to say about it. I upgraded to a Fi BL 15 and Rockford Fosgate T1000-1bdCP, so I gave my old system: RE SXX 12 and JBL BP1200.1 to my friend.

His max/everything else is different when compared to my headunit, so I grabbed the trusty DD-1 and headed over to his house. His HU goes up to 50, but the comfortable listening volume is 25, so we didn't have to test for clipping from the deck, we just went straight to the woofer. I disconnected the sub, put the red lead in the + channel on the amp, grounded the DD-1 to the amp's ground with track 7 playing at 25, since this is where we want our "balls to the wall max", but most listening will occur at 20-22.

The 40hz light comes on on the DD-1 at about half way on the gain, but continuing to crank it all the way didn't give me any distortion. what? His JVC headunit only puts out like 2.5V or something, but how is there NO distortion with the gain cranked? That doesn't seem possible. Well, doesn't seem probable, anyway.

I decided to crank the gain down a 1/4 turn and head out on a drive slamming at 22-23 and do a heat check when the drive was over. The sub was HOT....not "pull your hand away now" hot, but it was definitely 105-110 degrees F or so. (No real idea on the temp, I just know it was hotter than 98.6.) The amp on the other hand was untouchable after about 2-3 seconds. It was scalding for the most part. So how can we have NO distortion with MAX gain, but the sub and amp are hot enough combined to cook an egg? (and this is with me turning the gain down a 1/4 in disbelief that it didn't distort at all)

When I had the sub and amp, I set the gain with my volume at 47/50, even though my listening volume was 32. I got enough bass to keep me happy and I don't recall my amp ever being over my body temp and my sub was certainly never "hot" to the touch. This can't be normal. Any reason for the lack of a distortion light? It's not broken, as it kinda lit up and went off like it does, but never got solid.

When we turned the head unit up to 35 instead of 25, it came on at about half way, but that's not where we want to be.

Bolded and underlined your problem.

Edit: By problem I mean the problem with you having to max out the gain.

Edited August 30, 2013 by Raptorman

[Kyblack76]

Werd.

You need to find the HU level FIRST. Not what YOU think it is.

I

[b0r]

Yep, just read another post about it. My question is, why does the HU have to be at max volume if that's not where it's going to be played?

[Kyblack76]

Yep, just read another post about it. My question is, why does the HU have to be at max volume if that's not where it's going to be played?

It doesnt have to be at max,.. YOU NEED TO FIND MAX, USING THE TOOL.....

[b0r]

And just to clarify, this isn't a complaint post, it worked for me perfectly. It's a "why is this happening" post. I understand the manual completely, but said to myself "We CAN'T listen to this system at 47/50....our ears would explode, so we will set it to where we will be listening to it"

[P4killer_]

there should be an option for finding h/u max through the amplifier no? iirc there is

[Raptorman]

If you have like .2 volts coming from the head unit since you are at 25/50 voloume, you're gonna have to crank that gain to match it. The preout voltage from the head unit increases more and more the more the volume goes up. As for your amp heating issues, i would say to check your grounds. Make sure they're clean, and proper. It's fine if equipment gets warm. If it gets hot enough as to where you cant keep your hand on there for more than 5 seconds without serious pain, then there's a cause for concern.

[sprkn_ranger]

If I'm thinking about it right, then the reason it doesn't clip at full gain is cause the head unit output voltage is so low at 25/50 volume that the gain on the amp can never get to the point of matching the headunit output voltage. I'm sure someone will correct me if I'm wrong but that's what my thinking is.

Edited August 30, 2013 by sprkn_ranger

[P4killer_]

^^^^ pretty much sums it up right derr