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headshothills

Alpine CDE-HD149BT.. Not what you'd expect with DD-1

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End Result...

Purchased another 149 at local shop, tested before purchase, went to 26 volume at 27 it distorted.. went back, got it all hooked up, max volume now 30, set gains accordingly, Subwoofer at -10db 40hz, gains are about 3/4... -5 db 1kHZ on full range, gains about 1/3.. much better...

Here is what is REALLY ODD... So Alpine has the Power IC which is the internal amp for running speakers off the HU.. If I leave this on, granted there are NO Speakers hooked up, sound out the RCA's is much better, no distortion.. IF I turn OFF the Power IC, the RCA's put out a Distorted Signal.. Really odd.. I set the gain with the DD-1 with the Power IC On, out of curiosity, after setting, left DD-1 connected, no distortion, turn off the power IC and the Distortion light immediately comes on...

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I have been having these same problems on my 148 as well. Very frustrating to say the least.

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I have been having these same problems on my 148 as well. Very frustrating to say the least.

It's worth testing with Power IC on.. I bet you get a cleaner and louder signal out the RCA's at least that's what I found.. It took me going through 3 different 149's before I found one that was acceptable...

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Was told to post this here by keep_hope_alive. If you don't know who he look him up.


My SPL to SQ Build Log

Vehicle:
1997 Dodge Dakota Ext Cab 4x4 2009 Dodge Journey SXT
5.2L V8 Magnum 3.5L V6
Stock Alt

Equipment:

Headunit- Alpine CDE-147BT

Mids/Highs Amp- JL Audio G6600 Class AB 6 Channel

Sub Amp- Hifonics BRZ1700.1D @ 2 Ohms Taramps DSP3000.1D

Sub- Hertz Hi Energy 12" HX300D SounDrive SDA3 12

Tweeters- Rockford Fosgate Power Series Silk Domes Hertz Hi-Energy

Mids- Dayton Audio Reference 4" Full Range Drivers 

Midbass- Silver Flute 6.5" Hertz Hi-Energy 6.5"

Processor- MiniDSP 2x4

RCA- 6 channels of SounDrive HF series

Wire- EB Flex 2/0

 

-Member of Team SounDrive

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Was told to post this here by keep_hope_alive. If you don't know who he look him up.

LMFAO... Idiot light... Hilarious... This proves nothing other than lack of clipping at full volume. We never said anything about clipping, we referred to the Idiot light as Distortion greater than 1%. I can run mine at full volume, thats not the issue, the issue is the signal is dirty at full volume. I think its been proven by the other video with the $1300 Alpine HU, that you dont need it to clip in order to get distortion. With that said, hook that pig up to the idiot light on the decks RCA's, and lets see what the idiot light says, I guarantee the signal is dirty... Not Clipped, but dirty.. Now magnify that dirty signal through your amp and into your speakers, guaranteed it will sound like shit. Which is exactly what was happening to me on 2 different 149's, which is why I went to a local shop and tested his, found his to be clean up to 27 before it went dirty, bought it, sent the others back. I want to be clear on what it is we are checking. An O-Scope doesnt test for a dirty signal, it only checks for a clipped signal. a DD-1 will check for a dirty signal AND a clipped signal, both of these will result in the "Idiot Light" illuminating. This is why there is benefit with the DD-1 over the O-Scope. Steve has proven this in numerous videos. Im not saying you cant set your system up with an O-Scope, but lets be clear on what each unit is capable of accomplishing and telling you.

Again, the sub RCA's out, were clean at full volume, -15db/-10db/-5db 40hz and 4.0v measured on RCA's. No Distortion, no clipping. So if your only goal is to SPL, Alpine is good to go there. In terms of SQ, this is where you have to find where the RCA's for Front/Rear get dirty(Distorted), not clipped, distorted. Avg the 2 and go from there....

Edited by headshothills

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I'll see if he will post on here but I doubt someone that competes purely in SQ is going to accept a dirty signal. If there is it is so minimal that it won't be picked up. I'll just let him talk if he come in.


My SPL to SQ Build Log

Vehicle:
1997 Dodge Dakota Ext Cab 4x4 2009 Dodge Journey SXT
5.2L V8 Magnum 3.5L V6
Stock Alt

Equipment:

Headunit- Alpine CDE-147BT

Mids/Highs Amp- JL Audio G6600 Class AB 6 Channel

Sub Amp- Hifonics BRZ1700.1D @ 2 Ohms Taramps DSP3000.1D

Sub- Hertz Hi Energy 12" HX300D SounDrive SDA3 12

Tweeters- Rockford Fosgate Power Series Silk Domes Hertz Hi-Energy

Mids- Dayton Audio Reference 4" Full Range Drivers 

Midbass- Silver Flute 6.5" Hertz Hi-Energy 6.5"

Processor- MiniDSP 2x4

RCA- 6 channels of SounDrive HF series

Wire- EB Flex 2/0

 

-Member of Team SounDrive

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Was told to post this here by keep_hope_alive. If you don't know who he look him up.

LMFAO... Idiot light... Hilarious... This proves nothing other than lack of clipping at full volume. We never said anything about clipping, we referred to the Idiot light as Distortion greater than 1%. I can run mine at full volume, thats not the issue, the issue is the signal is dirty at full volume. I think its been proven by the other video with the $1300 Alpine HU, that you dont need it to clip in order to get distortion. With that said, hook that pig up to the idiot light on the decks RCA's, and lets see what the idiot light says, I guarantee the signal is dirty... Not Clipped, but dirty.. Now magnify that dirty signal through your amp and into your speakers, guaranteed it will sound like shit. Which is exactly what was happening to me on 2 different 149's, which is why I went to a local shop and tested his, found his to be clean up to 27 before it went dirty, bought it, sent the others back. I want to be clear on what it is we are checking. An O-Scope doesnt test for a dirty signal, it only checks for a clipped signal. a DD-1 will check for a dirty signal AND a clipped signal, both of these will result in the "Idiot Light" illuminating. This is why there is benefit with the DD-1 over the O-Scope. Steve has proven this in numerous videos. Im not saying you cant set your system up with an O-Scope, but lets be clear on what each unit is capable of accomplishing and telling you.

Again, the sub RCA's out, were clean at full volume, -15db/-10db/-5db 40hz and 4.0v measured on RCA's. No Distortion, no clipping. So if your only goal is to SPL, Alpine is good to go there. In terms of SQ, this is where you have to find where the RCA's for Front/Rear get dirty(Distorted), not clipped, distorted. Avg the 2 and go from there....

So your "technical" response is that the light turned on, so it must be so. Any light that provides zero information as to why it illuminated is an idiot light. That's not a dig against the DD-1, it's how it is with lights. We've had them in cars for decades, and now we have them in car audio. Idiot lights are there to tell people to take their thing to someone who knows what they are doing. If the DD-1 provided an actual calculation of THD, then we would have a different discussion.

I'm not saying the light doesn't illuminate. I'm saying there are many reasons why it illuminates despite the lack of >1%THD. The DD-1 is a tool with limitations, just as any other tool has limitations. One of it's main limitations is that it's designed around two test frequencies. As an analog circuit, it cannot perform calculations on THD. In the 1kHz test it expects to see fundamental and harmonics of 1kHz tones. Anything else is considered unwanted and thus distortion. Any noise elsewhere in the system can be confused for signal distortion. Anything in the output that shows up as any signal other than what is expected, is taken as distortion. Many HU's have been known to have a slight hiss above 3/4 volume. That hiss would be confused with distortion in the DD-1.

The concern with this thread was that because the DD-1 light turned on, even though the output wasn't clipped, the OP couldn't use the HU as-is. I shared a video taking that exact head unit, running it to full volume, and not being offended by the distortion produced by the system (HU, amp, speakers ran full range). LMAO all you want, but running the HU up isn't going to hurt anything, especially with a non-SQ system. The system is 8 by-nines and four 15's... on a boat. Why are you even talking about THD? No distortion will be audible if the boat is moving anyway.

No one in this thread can comment on how much distortion is being measured, because all you are reacting to is a light on a box. You are making the assumption that a distorted waveform is being measured. I suspect there is something in the output that the DD-1 thinks is distortion. This is supported by the claims that changing the IC power status changes the result. It's also possible that a head unit will want a 14VDC input to reach full volume, cleanly. You always want to note system voltage during the test and many power supplies are not 14.4VDC.

While many make the point that the DD-1 isn't measuring clipping, but distortion, SMD's own video compares the DD-1 against a PC-based THD analyzer and uses a clipped signal to prove the function.

Another useful method for measuring distortion is an RTA. You can run the RCA outputs into a soundcard (with adequate input range or with a LOC on amp outputs) and look for distortion harmonics. You will see a clean fundamental and harmonics associated with the test tone, then anything else that crops up is distortion. A scope will show this as sine-wave distortion, but depending on the thickness of the scope trace, you may not identify HF noise.

Cheers.

Edited by keep_hope_alive

Electrical Engineer/Acoustics Engineer/car audio hobbyist

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So your "technical" response is that the light turned on, so it must be so. Any light that provides zero information as to why it illuminated is an idiot light. That's not a dig against the DD-1, it's how it is with lights. We've had them in cars for decades, and now we have them in car audio. Idiot lights are there to tell people to take their thing to someone who knows what they are doing. If the DD-1 provided an actual calculation of THD, then we would have a different discussion.

It is not an "idiot light" it is an indicator light. The dd-1 doesn't need to give you an actual calculation of THD. It just needs to tell you it is seeing 1%. This way you can set your gains properly and also adjust your overlaps. It's a simple, quick, painless way to set the gains properly with a few choices (of overlap) that have been STANDARD (with an O-scope) for years. They have been teaching what we do, with a scope (and now with a DD-1), the same way we do it forever. As long as a gain has been on an amp. While you may only have a choice of 3 or 4 overlaps, you can still turn it DOWN to your taste, by ear once you establish your limits. The AMAZING DD-1+ allows you to adjust gain overlaps by .1 increments therefore you can actually see exactly where you are at.

I'm not saying the light doesn't illuminate. I'm saying there are many reasons why it illuminates despite the lack of >1%THD. The DD-1 is a tool with limitations, just as any other tool has limitations. One of it's main limitations is that it's designed around two test frequencies.

As taught in every class i have ever taken and is still being taught in every class. 1khz and 40hz isn't something we chose to be different. It's almost exactly the same procedure as using a scope but easier, faster, more convenient and more accurate.

As an analog circuit, it cannot perform calculations on THD. In the 1kHz test it expects to see fundamental and harmonics of 1kHz tones. Anything else is considered unwanted and thus distortion. Any noise elsewhere in the system can be confused for signal distortion. Anything in the output that shows up as any signal other than what is expected, is taken as distortion. Many HU's have been known to have a slight hiss above 3/4 volume. That hiss would be confused with distortion in the DD-1.

Exactly. Thank you! you finally get it now! :)

The concern with this thread was that because the DD-1 light turned on, even though the output wasn't clipped, the OP couldn't use the HU as-is. I shared a video taking that exact head unit, running it to full volume, and not being offended by the distortion produced by the system (HU, amp, speakers ran full range). LMAO all you want, but running the HU up isn't going to hurt anything, especially with a non-SQ system. The system is 8 by-nines and four 15's... on a boat. Why are you even talking about THD? No distortion will be audible if the boat is moving anyway.

Running a HU up too high and not having your gains set properly (matched to the source output) and knowing your limits can cause your amp to go into hard clipping, sending a lot more power (and dirty power) to the speakers than they can handle. This can damage speakers. Distortion itself won't damage speakers. It sounds bad. It's the side effects of going into clipping (like explained). But you already know that right?

No one in this thread can comment on how much distortion is being measured,

1% That was easy.

because all you are reacting to is a light on a box.

the light indicates 1% hence the reaction.

You are making the assumption that a distorted waveform is being measured.

Actually, if you look real close at a HIGH resolution O-scope screen, you can see the waveform is actually distorted. Even ever so slightly it would not even be noticeable on one of those cheap hand helds. That is why the DD-1 is superior to a handheld all day long. And i LIKE handhelds. I own a few.

I suspect there is something in the output that the DD-1 thinks is distortion. This is supported by the claims that changing the IC power status changes the result. It's also possible that a head unit will want a 14VDC input to reach full volume, cleanly. You always want to note system voltage during the test and many power supplies are not 14.4VDC.

You are welcome to read up on our US Patent we were just granted and learn all about how it works. Want me to dig up the link?

While many make the point that the DD-1 isn't measuring clipping, but distortion, SMD's own video compares the DD-1 against a PC-based THD analyzer and uses a clipped signal to prove the function.

I did that just to show that the product works and is accurate up against even a $5,000+ Analyzer. And it was a pretty clear demonstration i thought.

Another useful method for measuring distortion is an RTA. You can run the RCA outputs into a soundcard (with adequate input range or with a LOC on amp outputs) and look for distortion harmonics. You will see a clean fundamental and harmonics associated with the test tone, then anything else that crops up is distortion. A scope will show this as sine-wave distortion, but depending on the thickness of the scope trace, you may not identify HF noise.

Sounds like a lot of work. Of course there is more than one way to skin a cat....but I would rather use a DD-1 or DD-1 Plus and be done in under 5 minutes and accurately at that. (Available at http://www.wcCarAudio.com , Amazon, Ebay and more!) thanks! (free plug for me yay!) :P

Cheers.

cheers! :)

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"My reason for having a negative DD-1 comment is that I am unimpressed with the greed associated with the product... a product that was copied from the clipping detection circuit inherent in pro audio amps for decades. $10 in parts shouldn't carry that high of a price tag. the reason I believe it to be inaccurate for full range signals is how the circuit expects clipping harmonics to appear. harmonics are natural for any tone, and it takes more sophistication (not necessarily money) to prevent false positives. as an electrical engineer, I understand what the shortcomings are. I use a scope because that is the correct tool professionals use for accuracy. cheers."

oh wow, saw the video...dude you are the only "idiot light" in this entire thread. SMH

Where is the "greed"? we spent thousands and thousands and THOUSANDS of dollars (and hours) developing our products and are just now starting to recoup. Our patent alone was close to $15,000 alone. You have no idea what it takes to bring a product to market. You have no idea what it takes to run a business. Ya bro, just getting rich over here, you know because uncle Sam and the government lets us keep everything we make too right? WRONG. Oh and $10 dollars in parts is laughable. That is just down right silly, like your post. If you think so, build one. Build the "DD-1 killer" for $10 bucks like the last guy that tried and dissipated without a trace. You are a so called "electrical engineer", than do it. Your budget can be $100. It can't be a breadboard in a project-box. It has to be a very nice, quality, presentable product. What do you want your deadline to be? Want till 2017?

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Highest OFFICIAL SPL scores (at shows, on the TermLab)

DBDRAG - 156.5

Usaci - 157.4

Usaci Streetbeat - 155.2

 

 

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oh and just an FYI to stay on topic. SOME Alpines, in fact most Alpines i have tested, have no distortion at full volume. If one does, it might be a design issue or maybe a bad unit. But for the most part Alpine has been one of the cleaner brands.




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Highest OFFICIAL SPL scores (at shows, on the TermLab)

DBDRAG - 156.5

Usaci - 157.4

Usaci Streetbeat - 155.2

 

 

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