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

[keep_hope_alive]

The DD-1 is NOT a distortion meter. It does not measure anything.

The DD-1's main limitation is that it cannot discern between noise and distortion. It is important for people to understand what the tool can and cannot do. There are many issues with the DD-1 and certain amplifiers - which are the likely result of unexpected harmonics or noise. That does not directly translate to 1% THD.

Anyone can prove this to themselves by playing a pink noise track. You will see the distortion indicator illuminate very early. This is not because there is 1% THD in the signal, but instead the DD-1 is confused by what it sees.

If it was appropriately named the UFD-1, for Unexpected Frequency Detector, it would be more honest. You could also say that sometimes, the unexpected frequencies may correlate with distortion. You can say that under some circumstances, the DD-1 will illuminate with 1% THD on a 1kHz sine wave. But the disclaimer should be added that illumination doesn't guarantee there is 1% distortion in the signal and that noise can provide a false positive.

I had my local dealer put a BNIB Alpine CDE-HD149BT on their DD-1 and they did NOT measure distortion with a 1kHz tone up to full volume. Pink noise resulted in detector illumination around half volume, which proves my points above. The OP has be struggling with his DD-1 measuring head units with what appears to be false positives. The main issue with analog electronics is the accuracy of the components and the tolerances of the components.

Those are factual statements.

My personal opinion is as follows;

If the DD-1 has more than $10 in internal parts, your designer isn't very clever. These days, with microprocessors so cheap, you can have a more useful detector, with a wider range of input signals and usable output information... for the same price point. I feel the price of the DD-1 is greedy because it is a HUGE markup for a simple circuit with a branded sticker. We won't agree on my opinions, that's ok.

Cheers.

[ToNasty]

Keep hope alive from MAF?

[headshothills]

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.

Thanks Steve for adding to this, and to be completely honest, I even reached out and have been texting with to our good ole friend Michael Hughes (SPL2K) since Im a boater and go to Havasu.

The whole point I was trying to make by this post was, be careful what you get and double check if you do.. Let me also clarify a couple more things..

I ordered 2 149's from 2 different Amazon dealers, BOTH units did the exact same thing on the DD-1.. Distorted at volume 22. This was with the Power IC Off.. The one that was installed in the boat, was tested with Power IC ON and OFF, with same results.

Out of curiosity, headed down to a local shop and was going to test his 149, and the thing wouldnt accept CD's.. Imagine that... ERROR and kept spitting it out... Hmm But Alpine is the bomb right?? Anyway, went to another local shop, more expensive, but had the 149's. Cracked open a brand new case of them, says they install 5-6 of them a week and its the most popular unit... Cool...

Hooked it up to his display board, popped in the CD, hooked up the DD-1, Subwoofer channel clean as a whistle, which was the case on all of them... Hooked up the Front/Rear, and this unit went to 27 before distorting... Imagine that.. Wonder why, maybe the engineer building it has a little less caffeine before working on this unit.

The bottom line was I was disappointed seeing distortion at a volume of 22 out the front/rear RCA's. After all there posts about how Clean Alpines were to full vol, I was determined to find a unit that did... Ultimately, I PERSONALLY never found one, but I did find one that was clean up to 26 out of 35, which is better than the previous 2 units which were only clean to 21... So if you have a unit that is Clip Free AND Distortion free at full volume 35... Then you my friend have a Winner Winner Chicken Dinner Apline 149, and I dont...

As far as distortion in my boat, first of all, when youre doing 100+ MPH, you dont have the stereo on to begin with, cause its pointless... When youre rafted up, sitting in a cove, and youre shit is pounding at close to max volume... if you have distortion coming out your speakers, your sound system is gonna sound like the speakers have a bag over them.. So yes, distortion makes your $$$ sound system sound like dog shit, hence my reason for being so anal about keeping the distortion to a complete minimum.

And if I can by 4 new PDX amps, I can buy a DD-1... I could give 2 shits if the DD-1 was $200, its a tool, its not from Harbor Freight, so I didnt expect to get it for $19.99...

Again, the whole point of my thread was consumer awareness.. Ill stand behind my Kenwood X997 producing a much cleaner signal than the 2 Alpine 149's I had ALL DAY.

[headshothills]

I had my local dealer put a BNIB Alpine CDE-HD149BT on their DD-1 and they did NOT measure distortion with a 1kHz tone up to full volume.

The OP has be struggling with his DD-1 measuring head units with what appears to be false positives.

I guess you are the chosen one, congrats, you have a 149 that goes to full vol and doesnt distort, mine does...

The only thing I was struggling with is finding a Alpine 149 that "supposedly" goes full volume without distortion. I tested my Kenwood right after the 149, and it goes full volume 0 distortion... So lets be very clear, the struggle was with finding an Alpine 149 that could do the same... Not with the DD-1 or myself...

[TonyD'Amore]

****************************************************************************************

Class in session. Have a seat.
***************************************************************************************

The DD-1 detects harmonic distortion. It measures it, by comparing the quantity of it to the original signal. Once the harmonic distortion reaches -40dB of the original signal the DISTORTION LED is illuminated. Because 20 * LOG ( 0.01) = -40dB 0.01 = 1% . The amplifiers that have trouble being tuned on the DD-1 have either a harmonic distortion measured by the bandpass filters set for 3rd harmonic or the just happen to have *noise* at those exact frequencies. Does it matter which? Not at all. I don't want any noise at 120Hz or 3kHz. Anything that is not the original signal is a DISTORTION of the original signal, albeit not harmonic.

You saying that you can play pink noise and witness the Distortion LED illuminate removes all doubt that you have no idea how the tool works or what pink noise is. Pink noise contains all frequencies, including those frequencies that we are looking for, thus the LED will blink. Same thing if you use music. The tool isn't designed to work that way. Pink noise is not able to be analyzed for distortion as there is no reference, pink noise is random by design.

All of your assumptions are that the DD-1 was designed as a THD+N analyzer. Did you google that or something? That is not how the DD-1 works. THD+N analyzers work by removing the test signal from the received signal via a bandpass filter subtraction and calling the remainder TOTAL HARMONIC DISTORTION + NOISE.
Not how the DD-1 works at all, quite the opposite.

About building one for $10. Good luck.

Tony D'Amore

PS "FACTUAL STATEMENT" This guy doesn't understand what he is saying, at all.

The DD-1 is NOT a distortion meter. It does not measure anything.

The DD-1's main limitation is that it cannot discern between noise and distortion. It is important for people to understand what the tool can and cannot do. There are many issues with the DD-1 and certain amplifiers - which are the likely result of unexpected harmonics or noise. That does not directly translate to 1% THD.

Anyone can prove this to themselves by playing a pink noise track. You will see the distortion indicator illuminate very early. This is not because there is 1% THD in the signal, but instead the DD-1 is confused by what it sees.

If it was appropriately named the UFD-1, for Unexpected Frequency Detector, it would be more honest. You could also say that sometimes, the unexpected frequencies may correlate with distortion. You can say that under some circumstances, the DD-1 will illuminate with 1% THD on a 1kHz sine wave. But the disclaimer should be added that illumination doesn't guarantee there is 1% distortion in the signal and that noise can provide a false positive.

I had my local dealer put a BNIB Alpine CDE-HD149BT on their DD-1 and they did NOT measure distortion with a 1kHz tone up to full volume. Pink noise resulted in detector illumination around half volume, which proves my points above. The OP has be struggling with his DD-1 measuring head units with what appears to be false positives. The main issue with analog electronics is the accuracy of the components and the tolerances of the components.

Those are factual statements.

My personal opinion is as follows;

If the DD-1 has more than $10 in internal parts, your designer isn't very clever. These days, with microprocessors so cheap, you can have a more useful detector, with a wider range of input signals and usable output information... for the same price point. I feel the price of the DD-1 is greedy because it is a HUGE markup for a simple circuit with a branded sticker. We won't agree on my opinions, that's ok.

Cheers.

[Soccerballzs]

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!)

Cheers.

cheers!

Well Said!!

[headshothills]

Im half tempted to just eat the $200+ bucks to prove a point and send this friggin Alpine 149 to Steve or Tony so they can actually post EXACTLY what the distortion is and make a vid on it...

Tony would be easier, cause hes in Tempe and Im in Scottsdale... HAHAHA

[TonyD'Amore]

What point are you needing to prove

[headshothills]

What point are you needing to prove

Just wanting to show this unit distorts at 22 and show what the actual % of distortion is, thats all... Im a nobody, you're the somebody... LOL

[meade916]

****************************************************************************************

Class in session. Have a seat.

***************************************************************************************

The DD-1 detects harmonic distortion. It measures it, by comparing the quantity of it to the original signal. Once the harmonic distortion reaches -40dB of the original signal the DISTORTION LED is illuminated. Because 20 * LOG ( 0.01) = -40dB 0.01 = 1% . The amplifiers that have trouble being tuned on the DD-1 have either a harmonic distortion measured by the bandpass filters set for 3rd harmonic or the just happen to have *noise* at those exact frequencies. Does it matter which? Not at all. I don't want any noise at 120Hz or 3kHz. Anything that is not the original signal is a DISTORTION of the original signal, albeit not harmonic.

You saying that you can play pink noise and witness the Distortion LED illuminate removes all doubt that you have no idea how the tool works or what pink noise is. Pink noise contains all frequencies, including those frequencies that we are looking for, thus the LED will blink. Same thing if you use music. The tool isn't designed to work that way. Pink noise is not able to be analyzed for distortion as there is no reference, pink noise is random by design.

All of your assumptions are that the DD-1 was designed as a THD+N analyzer. Did you google that or something? That is not how the DD-1 works. THD+N analyzers work by removing the test signal from the received signal via a bandpass filter subtraction and calling the remainder TOTAL HARMONIC DISTORTION + NOISE.

Not how the DD-1 works at all, quite the opposite.

About building one for $10. Good luck.

Tony D'Amore

PS "FACTUAL STATEMENT" This guy doesn't understand what he is saying, at all.

The DD-1 is NOT a distortion meter. It does not measure anything.

The DD-1's main limitation is that it cannot discern between noise and distortion. It is important for people to understand what the tool can and cannot do. There are many issues with the DD-1 and certain amplifiers - which are the likely result of unexpected harmonics or noise. That does not directly translate to 1% THD.

Anyone can prove this to themselves by playing a pink noise track. You will see the distortion indicator illuminate very early. This is not because there is 1% THD in the signal, but instead the DD-1 is confused by what it sees.

If it was appropriately named the UFD-1, for Unexpected Frequency Detector, it would be more honest. You could also say that sometimes, the unexpected frequencies may correlate with distortion. You can say that under some circumstances, the DD-1 will illuminate with 1% THD on a 1kHz sine wave. But the disclaimer should be added that illumination doesn't guarantee there is 1% distortion in the signal and that noise can provide a false positive.

I had my local dealer put a BNIB Alpine CDE-HD149BT on their DD-1 and they did NOT measure distortion with a 1kHz tone up to full volume. Pink noise resulted in detector illumination around half volume, which proves my points above. The OP has be struggling with his DD-1 measuring head units with what appears to be false positives. The main issue with analog electronics is the accuracy of the components and the tolerances of the components.

Those are factual statements.

My personal opinion is as follows;

If the DD-1 has more than $10 in internal parts, your designer isn't very clever. These days, with microprocessors so cheap, you can have a more useful detector, with a wider range of input signals and usable output information... for the same price point. I feel the price of the DD-1 is greedy because it is a HUGE markup for a simple circuit with a branded sticker. We won't agree on my opinions, that's ok.

Cheers.

god damn the OWNAGE is strong here. There is nothing you can say to that other than grab your deflated football and go home.