Setting gains, Is an oscope the only real way?

[TheMonolith2001]

So its been extra hot around here recently, and my amp shut off a couple times due to thermal protect. I tried giving it more air and it still happened. After some research it seemed like I might be overheating due to clipping. I have been playing stuff recently that goes a lot lower which is probably why it didn't happen until now which lines up with my results. In fact DJ Paul's A Person Of Interest album was enough to do it not even halfway through the album. Haven't checked how low that actually goes but a buddy of mine told me it POUNDS BREH!!! so I figured I would give it a listen haha. Anyway...

When I initially set my gains, I used a 50hz tone. AND I used my oscope. I was thinking damn, clipping? How is this possible!? Better go into overkill mode! I get on my computer and generate some tones with sinegen (awesome program by the way, version 2.5 is the one you want) from 30hz (close to my box tuning which is 28hz) to 80hz (close enough to my lowpass which is like 83 or something) in 5hz increments. I start at the top and keep going, no clipping, no clipping, no clipping, then when I finally get to 30hz, CLIPPING!!!! Now my gain is all the way down, and im also using a lower max volume so I can hit those lows clean. Luckily It wasn't severe clipping and I never smelled anything so I probably didn't damage anything. It may have even been in the realm of what is considered acceptable clipping for SPL guys. My oscope is analogue so its hard to use it for anything other than drawing a line. I don't have any actual numerical measurements.

My point being, this seems like the ONLY way to set your gains. An oscope with multiple tones. We all know how using a DMM is only a semi accurate solution but WAY better than by ear, The DD1 seems like a useful tool (I don't own one) but is also limited to only one frequency. What sucks is oscopes are friggen expensive and not everyone knows how to use one. Maybe a DD1v2 that uses multiple tones is in order! (Was there a rumor about this? It sounds like something I have read before)

Some important points though:

If I had a higher box tuning this may have never been an issue and a DD1/DMM/1 tone oscope calibration might have been fine. Im after the lowest bass possible rather than highest volume however so for me, and possibly a lot of the SQ crowd, this is more of an issue. I guess this is another example of how SQ systems get crazy insane expensive and require a ton of work to set up properly. My subsonic filter may have been set at 32hz+ or something and then it would have been fine if I was doing a SPL build.

Higher voltage. When I play that low my voltage drops to 12 volts at its lowest, at idle. anything above I think 35hz if I remember right and its 14+ This is fine for my particular amp. However if I add a second battery/bigger alt to keep voltage up, This may not happen. BTW I am doing this eventually, don't have the cash right now though so gonna play it safe. It still drives me nuts that my amp is capable of operating up to 18v due to modifications. WHAT HAPPENS AT 18V?!!?? I am honestly not even totally sure how to run 18v in a car, I have seen 16v, but damn.

Box rise. It is certainly possible that if I changed the volume of my box this would also not happen. This is kind of a complicated subject so I will leave it at that because honestly I have had a few drinks at this point and I don't want to screw up my explanation.

Personal taste. I am a bit nuts when it comes to subwoofers. I don't care if I can't hear it at all as long as I can feel it - To an extent I guess. I enjoy finding it hard to breathe in whatever car/room I am in due to low frequency output. Not everyone is like this. Some people are but do it at higher frequencies. My next build is going to involve 12-16 18s in a 12X7.5ft room, all of which will probably be Fi Qs I might do an infinite baffle design with the IB series, and many crown rack amplifiers. Its still in the design phase and like I said I don't have extra cash right now, but yeah its going to be insane. Still researching subwoofers by other companies as well. Miami bass, I'm bringing it back! Point here is not everyone has the same goals as me. Some people don't want that low low bass and more of a punch. For them this wouldn't be an issue as well.

I went out of my way to write this section because I want to be completely clear due to the website I am on and to provide as much info as I can so others can learn. I am NOT bashing the DD1, It has its purpose and for many seems to be a very useful tool. I just don't think It would do much for me personally. Any input is greatly appreciated.

[Watch the bass]

I like it but i didn´t read it, sometimes you make very löng post´s.

[79 cutty]

I fail to understand where the question in your post really is?

Are you saying you want a DD1 but then in the same breath that you don't? Or are you asking for an actual comparison with the DD1 and a scope? Because there has now been more than a couple vids comparing the DD1 with higher priced scopes.

[TheMonolith2001]

Yeah I do. I like to try an be thorough in case anyone comes across this post from a google search or something.

TL,DR: Set your gains with an oscope with multiple test tones at everything you want to be able to play. This way is best, depending on application.

[TheMonolith2001]

I fail to understand where the question in your post really is?

Are you saying you want a DD1 but then in the same breath that you don't? Or are you asking for an actual comparison with the DD1 and a scope? Because there has now been more than a couple vids comparing the DD1 with higher priced scopes.

The reason for the question mark is more "someone prove me wrong, because I would like to know why" I am saying I personally have no need for a DD1, But I wanted to also say that it may not be the case for you and your application, and I am in no way bashing it.

I have seen the videos comparing a DD1 to an oscope and I honestly do not agree with the DD1 winning simply due to lack of information. There is very little information on how the DD1 actually works/detects distortion.

The MAIN point in the post though, Is information for others about how/when clipping can occur - its not just one frequency and all clipping is gone. The DD1 thing was honestly just a side point I figured I would mention because its the SMD forum.

[TheMonolith2001]

So I had another idea. Now that im playing those crazy lows clean, to make up for the loss of output in the 40hz+ range i should be able to just boost the eq right? Any reason why not? Ive got 16 bands to play around with! I should be able to hook the oscope back up and boost until I see clipping in all the lower bands. Then I can use my PAC1 equivalent (made/soldered my own) to adjust overall bass so its not all bass.

EDIT: Or even better, I have a 31.5hz band, I could put the gain back where it was and just back this one off.

[CstrokerV]

dd-1 doesn't detect clipping to begin with....... there's plenty of questions, comments, and answers on this site about the dd-1

[TheMonolith2001]

Are you sure? I'm pretty sure in one of the videos with Steve Meade himself I watched on youtube (there are a lot of them, forget which one) he mentions that it detects both which is why you would want to use it to set your gains. I mean I guess you would be distorting before you would be clipping so its just a safe assumption to make. Maybe that is what he was saying. It was a long time ago.

If the DD1 works the way I think it does, It is comparing a signal it is getting to a signal it expects within 1% margin of error. So both distortion and clipping would register as a mismatch anyway.

[Guest]

Are you sure? I'm pretty sure in one of the videos with Steve Meade himself I watched on youtube (there are a lot of them, forget which one) he mentions that it detects both which is why you would want to use it to set your gains. I mean I guess you would be distorting before you would be clipping so its just a safe assumption to make. Maybe that is what he was saying. It was a long time ago.

If the DD1 works the way I think it does, It is comparing a signal it is getting to a signal it expects within 1% margin of error. So both distortion and clipping would register as a mismatch anyway.

all clipping is distortion. but not all distortion is clipping.

[Karkov]

DD-1 all day. Enough said.

Plus you can easily do it yourself in almost no time whenever you want (most people don't readily have access to O-scope)