DD-1 First time use questions

[PositiveCrew]

Hello all, I've been dabbling in car audio for a couple years now, and have always set my gains using DMM for the subwoofer amplifier, and just never knew about distortion in head units, so I would play those to max volume or near it in most of my systems.

After seeing a lot of people recommend the DD-1, I went out and purchased one. Tonight I used it on two of the systems in my family, and have questions about a couple things.

1st system:

1999 Trailblazer, stock battery, stock alternator (105A)

JVC KD-A605 HU

4x Kenwood KFC-1665S door speakers (30W RMS each)

Pioneer GM-D9601 amp (1200W @ 1 ohm)

Soundcubed HDC3.118 subwoofer (1500W RMS, dual 2 ohm wired to 1 ohm total). (in a sealed 6ft^3 enclosure, not sure on tuning)

The first thing I did was use the DD-1 to check the max un-distorted HU volume. By setting everything flat, using track #1, and using the DD-1 on the subwoofer amplifier, I found that the max undistorted volume was 25, out of around 50 or something. Does this seem right? 25 seems really quiet to me, and I usually ran 30-35 previously.

If 25 is normal and correct, how can I get more volume out of the system? New head unit? additional amplifier for door speakers? (currently running the door speakers just on the HU, as I've never used an amplifier for door speakers before.)

Then, knowing 25 is the top end un-distorted volume, I went to set up the subwoofer. I dialed in the gains on the amplifier until just before distortion. Now, however, the subwoofer barely even moves. You can hear some bass, but when viewing the subwoofer the excursion is close to nill. Should this be the case running 1200W RMS to a 1500W subwoofer? (I set the gain first with track #3, then #5, and finally #7). Even on #7 (-15dB) it still doesn't move very much compared to when I had it set with the DMM.

Could it be correct that the subwoofer excursion with the DD-1 settings are close to nill, as opposed to a ton of excursion when set with a multimeter?

2nd system:

2004 GMC Yukon Denali, stock battery, stock alternator (130A)

stock HU

stock door speakers

Hifonics Brutus BRX1100.1D (1100W @ 1 ohm)

2x SoundCubed HDS312 subwoofers (1200W RMS, dual 4 ohm, wired to 1 ohm total) in a custom ported box (not sure on tuning)

For this setup, the DD-1 told me that the stock HU could be turned 100% of the way up without distortion. Pretty cool!

Then I went onto the subwoofer amplifier gain setting. Using track #5 (-10dB) I could set the gain level on the amp all the way up without distortion, same with track #7 (-15dB)

I just got this system, so while the excursion of the subs seems minimal, I'm guessing it's because I'm running 1100W RMS instead of the 2400W RMS they are rated for.

My question with this system is, does it make sense that the amplifier gain could be set 100% of the way up without distortion?

I think that's about it for now.

If you made it this far in the reading, thank you so much. Any and all advice is greatly appreciated!

[RooTxBeeR]

I will start with the 2nd car first, easier to answer. Every piece of gear, and set up, are all different. And honestly, they can change. My undistorted limit used to be 58, now it's 60, same everything. So yeah, being able to go up 100% is very possible, as well as being only able to go up 10% is possible as well based on the gear.

To the first one, Having half can happen, and you saying it sounds quieter, makes me want to say that before it was set higher, without properly being set. Also, that first car, the box for the sub, what kind of box is it? Custom built? Pre fab? If it is a pre fab, that will make a world of different, in output.

[Jessica]

first car, are the mids runnig off the deck power? Check the speaker outs with the dd-1 and start there.

After that, turn headunit to that volume, set sub output to distort at the same as speaker out distort level.

Set amp gain with -10 track

profit

[PositiveCrew]

I will start with the 2nd car first, easier to answer. Every piece of gear, and set up, are all different. And honestly, they can change. My undistorted limit used to be 58, now it's 60, same everything. So yeah, being able to go up 100% is very possible, as well as being only able to go up 10% is possible as well based on the gear.

To the first one, Having half can happen, and you saying it sounds quieter, makes me want to say that before it was set higher, without properly being set. Also, that first car, the box for the sub, what kind of box is it? Custom built? Pre fab? If it is a pre fab, that will make a world of different, in output.

The HDC3.118 is in a seald 6ft cubed box, made by the guy I purchased it from. It looks very professional to me, but I haven't started getting into box building yet so I really don't know much about it.

Here's a video if it when it was tuned with the DMM and I was playing at a volume level which I now know shows distortion (30):

first car, are the mids runnig off the deck power? Check the speaker outs with the dd-1 and start there.

After that, turn headunit to that volume, set sub output to distort at the same as speaker out distort level.

Set amp gain with -10 track

profit

Yeah the only thing running off of the amplifier is the subwoofer. Why should I use the speaker out's instead of checking from the amplifier like it recommends in the DD-1 manual?

And how do you decide -10 dB is the proper place to be at? I suppose it depends a lot on the type of music I listen to (both genre and quality of the files themselves), but I don't want to risk blowing anything.

Thank you both for taking the time to read and give your advice! Much appreciated.

Also if I can only turn up the gain 25% on the 1200W Pioneer amp (Blazer), but 100% on the 1100W Hifonics Amp (Denali), would it be best to swap the two amps to get more output out of the 18" in the blazer? Basically, is the non-distorted point on the amp the same regardless of which vehicle it's in and what other electronics are running?

Or is it specially that the Hifonics (Denali) can do 100% when in that system and it would do the 25% in the Trailblazer like the other amp? I guess I could test that out personally and see what I find.

[Jessica]

well pre outs tend to distort way after the crappy 12w internal amp on most headunits. So set your gain at volume whatever and your mids are gonna be distorted to hell and back.

That is why i said to do it that way.

[PositiveCrew]

well pre outs tend to distort way after the crappy 12w internal amp on most headunits. So set your gain at volume whatever and your mids are gonna be distorted to hell and back.

That is why i said to do it that way.

I'm trying to understand this, but I haven't ever installed an aftermarket HU myself. (the vehicle was purchased with it).

You're saying the outputs directly on the back of the HU distort after (at a higher volume?) than the internal amp of the HU? So by using the DD-1 directly on the amplifier instead of the pre-outs, I'm allowing more distortion?

This is confusing to me, sorry, and thanks for trying to help.

[RooTxBeeR]

You can set a amp and sub set up, to get to max power at any headunit click. So doing it at half head unit or full it can sound the same, just where you set it. You said it was tuned before by a DMM, did you do it? Did you do the test tone and measured a voltage and did the math for what wattage it puts out?

[PositiveCrew]

You can set a amp and sub set up, to get to max power at any headunit click. So doing it at half head unit or full it can sound the same, just where you set it. You said it was tuned before by a DMM, did you do it? Did you do the test tone and measured a voltage and did the math for what wattage it puts out?

Yeah previously I would set it by DMM and ohm's law. 1200W @ 1 ohm for the HDC 18, sqrt(1200 * 1) = 34V (I usually went 32-33V to be safe). I would play a 50hz and 40hz test tone, adjust the gain until AC volts on the DMM read near that number, then proceed.

[RooTxBeeR]

You can set a amp and sub set up, to get to max power at any headunit click. So doing it at half head unit or full it can sound the same, just where you set it. You said it was tuned before by a DMM, did you do it? Did you do the test tone and measured a voltage and did the math for what wattage it puts out?

Yeah previously I would set it by DMM and ohm's law. 1200W @ 1 ohm for the HDC 18, sqrt(1200 * 1) = 34V (I usually went 32-33V to be safe). I would play a 50hz and 40hz test tone, adjust the gain until AC volts on the DMM read near that number, then proceed.

I have had times with my own gear and seen someone have it happen. When they tune with DD-1, it sounds a bit quieter, because they where past the distortion point when doing by DMM. Where did you get that test tone you used to set up with the DMM. Maybe try and do the DMM tune again but with one of the SMD test tones, the 40 hz 0db one, and see if it sounds similar?

[Wehan]

First, grab something like this guy for the first vehicle. http://www.rockfordfosgate.com/products/details/r250x4

As for vehicle #2 are you running a LOC or does that amp have high level inputs? basically how are you getting the speaker lever output into your amp.