Do I need more amp or a higher preout voltage?

[audioholic 5,000+ posts]

AHHH, I see where we are lost. I wasn't saying that is the only time or that it had any direct relation. I didn't finish my thought that when a driver is surpassing it's physical limits then usually some mehanical noise is introduced(coil bottoming, leads slapping, etc) forthat I'm sorry I wasn't clear on that statement. I still don't believe anyone can hear a clipped signal on a sub. I have heard distortion in mids and tweeters easily when overdriving a signal, but not on a sub. I have heard mechanical noise from overdriving a sub though.

I guess we'll just have to agree to disagree. Ive heard clipped signals through a substage before, with my own ears. If what you suggested was true, the only real accuracy/noise problems we would need to worry about with subwoofers was mechanical motor or suspension noise, why do subwoofer designers worry about BL curves and all that... right? Clipping, and distortion in general, is definitely audible in a substage. Ive heard it from clipped amps, clipped signal processors, and from clipped h/u's. *shrug*
Cheers.

 

[grampi 10+ year member]

I just went out and checked the preouts right off the back of the HU with the volume maxed out at 35 and the DMM reads 0. It looks like the preouts on the HU are gone. I emailed the place I bought it from to ask them if I can send this HU back and have it replaced with a new one. They had some kind of return policy and I know it's been less than 30 days since I purchased it, so they should take it back. That could've been my problem with the low sub output, but I'm not quite sure if I still may have an amp problem or not. I won't be able to find that out until I get a HU with working preouts. Just once I'd like to do an install and not have a mountain of problems. Nothing can ever go smoothly for me :0(

 

[tcguy85 10+ year member]

Nothing can ever go smoothly for me :0(

thats really stinks! i wish you luck with it all.

 

[IamDeMan 5,000+ posts]

I guess we'll just have to agree to disagree. Ive heard clipped signals through a substage before, with my own ears. If what you suggested was true, the only real accuracy/noise problems we would need to worry about with subwoofers was mechanical motor or suspension noise, why do subwoofer designers worry about BL curves and all that... right? Clipping, and distortion in general, is definitely audible in a substage. Ive heard it from clipped amps, clipped signal processors, and from clipped h/u's. *shrug*
Cheers.

How high was the distortion level at this point though when you noticed it? Did you measure it for reference? When all is said and done, I believe we both can at least agree a DMM or O-scope is the only absolute way to be sure there is no clipped signal anywhere. Using your ears is still like sniffing dirt to predict the weather.

 

[grampi 10+ year member]

Something else I noticed shortly before the entire system went out was that the sub sounded like it was only playing bass drum notes and the very lowest bass guitar notes. It sounded like it was crossed over at like 50hz or something when it was actually crossed over at 80hz. I don't know if that also was related to the other problems I've been having, but it'll be interesting to see how this whole thing unfolds when I actually find out what's wrong with what. I'm also wondering if my HU is the problem with my imprint not working. There is A LOT of screwy, unexplainable stuff going on with this system.

 

[audioholic 5,000+ posts]

How high was the distortion level at this point though when you noticed it? Did you measure it for reference? When all is said and done, I believe we both can at least agree a DMM or O-scope is the only absolute way to be sure there is no clipped signal anywhere. Using your ears is still like sniffing dirt to predict the weather.

For subs, yes I agree to set the gain via a DMM or O-scope if possible. But setting them by ear, generally works just fine too. Midrange or tweeters can be set be ear easier however, no doubt about that.
No, I didnt measure the distortion levels, obviously. I do not have a Klippel machine. Point is, it was audible, and it is audible. Again, if what you suggested were true, subwoofer designers would only really need to worry about xmech.

 

[helotaxi 5,000+ posts]

Grampi-I've had a set of preouts go bad when the amp that they were connected to went bad. Try hooking an iPod or something similar up the to the amp's inputs and check for output. If the sub preout were bad from the beginning, it would explain the issue that you've been having all along.

 

[IamDeMan 5,000+ posts]

No, I didnt measure the distortion levels, obviously. I do not have a Klippel machine.

Then how can YOU know that the distortion you heard wasn't over 10%?
You are adding to what I said. I never said distortion wasn't audible at all in a sub. What I said is it takes a large amount of distortion before you hear it in a sub system. 2 totally different phrases.

This is why setting sub gains by ear is all but useless. If you can hear the distortion caused by clipping in a sub system, then you are more than likely FAR beyond where it should be set.

In mids, yes it is audible a lot sooner so setting by ear is more acceptable.

 

[audioholic 5,000+ posts]

Then how can YOU know that the distortion you heard wasn't over 10%?
You are adding to what I said. I never said distortion wasn't audible at all in a sub. What I said is it takes a large amount of distortion before you hear it in a sub system. 2 totally different phrases.

This is why setting sub gains by ear is all but useless. If you can hear the distortion caused by clipping in a sub system, then you are more than likely FAR beyond where it should be set.

In mids, yes it is audible a lot sooner so setting by ear is more acceptable.

You've lost sight of the topic my friend. I do not need a Klippel machine to substantiate my claim. Ive said all along that hearing distortion in a substage, while harder to hear than midrange (for example), is certainly not the difficulty that you seem to imply.
You are asking how I know the distortion Ive heard wasn't over 10%. Frankly, I don't, nor have I ever claimed to. You are the one throwing around vague generalities such as...

BS. With subs it takes a shit ton of distortion before it is audible.

So before you start demanding I use a Klippel to prove my side of the story, how about you start substantiating some of YOUR claims? You come here and claim you basically cant hear any distortion in a substage beyond that caused by physical speaker noise (motor bottoming out, suspension, etc), and then expect ME to prove otherwise with a Klippel? Lol Nice try.

 

[nismos14 5,000+ posts]

BACK ON TOPIC:

Grampi any progress?

 

[IamDeMan 5,000+ posts]

You've lost sight of the topic my friend. I do not need a Klippel machine to substantiate my claim. Ive said all along that hearing distortion in a substage, while harder to hear than midrange (for example), is certainly not the difficulty that you seem to imply.
You are asking how I know the distortion Ive heard wasn't over 10%. Frankly, I don't, nor have I ever claimed to. You are the one throwing around vague generalities such as...

So before you start demanding I use a Klippel to prove my side of the story, how about you start substantiating some of YOUR claims? You come here and claim you basically cant hear any distortion in a substage beyond that caused by physical speaker noise (motor bottoming out, suspension, etc), and then expect ME to prove otherwise with a Klippel? Lol Nice try.

My only point in the beginning that you first claimed BS on me about was distortion needing to be 10% or more to hear it in the substage. You said that you could. Now you tell me you don't know because you didn't measure. While I will admit I have never claim to have measured, I at least pulled up a test that confirms what I said. Your claim to say you can hear less than 10% distortion won't deter me from saying using your ears to set a sub gain is pissing in the wind.

Also you are putting more words in my mouth. I NEVER SAID DISTORTION BESIDES MECHANICAL CAN'T BE HEARD. Please go back and get reading comprehension. My whole point is that you can't hear a clipped signal until it is introducing A LOT of distortion. My reasoning is backed by the link I provided.

In most cases though you are more likely to overdrive the sub mechanically and get mechanical noise before you get to the point of hearing distortion introduced from the amp. That was my reasoning for ever mentioning mechanical limits. I never said distortion ONLY comes from going beyond physical limits.

 

[grampi 10+ year member]

Good news. The place I purchased my HU from told me to send it back and they'll replace it with a new one. Maybe in the meantime I can find one of my kid's portable media devices that has a line out that I can plug into my amp to see if it has a problem.

 

[nismos14 5,000+ posts]

Good idea ^

 

[audioholic 5,000+ posts]

My only point in the beginning that you first claimed BS on me about was distortion needing to be 10% or more to hear it in the substage. You said that you could. Now you tell me you don't know because you didn't measure. While I will admit I have never claim to have measured, I at least pulled up a test that confirms what I said. Your claim to say you can hear less than 10% distortion won't deter me from saying using your ears to set a sub gain is pissing in the wind.

Its funny you speak about my reading comprehension, when Ive already stated my point was about your mechanical limits comment, not about the 10% distortion. Hence why I quoted the mechanical limits comment, and not your 10% distortion comment. Since you seem to really want to talk about how this all started.
Dont flame for reading comprehension, when you yourself seem to lack it, if that's how you want to be about it. *shrug*

Also you are putting more words in my mouth. I NEVER SAID DISTORTION BESIDES MECHANICAL CAN'T BE HEARD. Please go back and get reading comprehension. My whole point is that you can't hear a clipped signal until it is introducing A LOT of distortion. My reasoning is backed by the link I provided.

Now you are just being arguementative. I quoted you saying mechanical noise was all that was of any real concern, you came back with some excuse about forgetting to finish your thought... now here you are trying to convince us you never even said such a thing. Let me refresh your memory...

You won't hear a cliped signal unless the added power of the clipped signal causes the driver to go beyond it's physical limitation ESPECIALLY WITH SUBS. You can have as high as 10% distortion in sub frequencies and still not notice it.

In most cases though you are more likely to overdrive the sub mechanically and get mechanical noise before you get to the point of hearing distortion introduced from the amp. That was my reasoning for ever mentioning mechanical limits. I never said distortion ONLY comes from going beyond physical limits.

How likely you are to 'overdrive' the sub mechanically is highly enclosure dependant. Burp a note very near tuning ina vented box, then come tell us how in 'most cases' you are likely to bottom out your sub before hearing clipping distortion. Your generalization about bottoming out the sub first ignores way too many variable to be considered logical. Power to the sub? Proper gain settings? Enclosure size/type/alignment? Frequency being played in a vented system? All of these variable will affect your ability to bottom out your sub, and your statement ignores them all.
If I were you, Id just stick with the facts you've read somewhere else and regurgitated here... that anything below 10% distortion can be difficult to hear in subbass frequencies. It seems you have trouble extrapolating anything further from that data, so I would suggest you quit trying.

Have a nice day.

 

[luvinthebass 5,000+ posts]

ImDeMan ur in ur 30's ur ears are not as sensitive to distortion in subs, plus you've prolly had some hearing loss to be albe to pick up all the slightest bit of distortion with bass...but to my ears i can tell distortion real easy in a sub stage and mids and highs cuz i have real good hearing.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif