First off, I want to be clear about one thing. I'm not here to hate on SMD tools. However I am here to help people utilize cheaper and sometimes better equipment suited for the job as well as other jobs.
So let's begin with the dd-1
. I'm sure most of you know the main competitor to this an oscilloscope. But you might not know why.
The SMD dd-1 is 149.99
A Velleman HPS140I oscilliscope is 120$ (from Amazon)
Here are three ways that the oscope stands alone from the dd-1.
The dd-1 does not account for voltage drop. Let's say you set your gain with the dd-1 at 14.4 volts. Now you apply a real load and your voltage is in the 13s or lower. Now your top clean voltage has been lowered as the rails sag. So when you turn it all the way up to the max clean voltage you are now clipping since your voltage has dropped. An oscope can measure clipping in real time with a real load. So you will know even at lower voltages if you are or aren't clipping.
The dd-1 can only measure at two different frequencies; 40hz and 1khz. Now this might not be a big deal to some but it's fairly limited. An oscope can measure at any frequency that your audio system will reproduce. This also means you don't have to change your filters to accommodate the dd-1 and then switch them back.
The dd-1 can't account for rail sag due to impedance. In most class D amps the rails can put out a higher clean voltage at higher impedances. Hence why you see higher ohm ratings being higher than half of the power of the next lowest ohm rating. IE. An amp doing 2000 watts at 1 ohm but 1100 at 2 ohms. So if you are wiring low and you are rising to around 1 ohm then your rails are going to have their top end voltage cut vs no load on the amplifier. This however can be observed with an oscope in real time.
The dd-1 is a 1 use tool. That means that it is only suited for one thing. However an oscope can be used for many different tasks even outside of the audio industry. Plus if you ever want to try and fix your amplifier you will need an oscope.
As you can see from those reasons alone an oscope is not only better suited for gain setting, it is cheaper and is capable of handling other tasks as well.
Next the CC-1
. A lot of people don't know that you can do every function the cc-1 has with a cheap DMM.
The CC-1 is again 149.99$
A DMM can be as cheap as 10$ (for this use it's not important to have a fancy DMM.)
Now basically what we have here is a device that has a voltage comparing circuit. So you set it to remember a certain voltage and then if it's reading higher than it will illuminate the corresponding led and if it's reading lower then it will illuminate the corresponding led. When you hit the right voltage the middle light will light up.
I'm not going to delve into different kinds of filters as some have the same slope but a different level at the crossover frequency itself. Some are -3db and some are -6db down. But for the purpose of this we are going to assume 3db.
So let's take a 24db slope filter for example. If you want to set a high pass filter at 80hz then you need to open the filter all the way up. Measure the output voltage with a dmm at a level you know is not clipping. Then plug your voltage into the input voltage and select -3db on the level change and solve for output voltage. This calculator is pretty nifty:
dB calculator for amplification gain and damping (loss) factor of an audio amplifier calculation decibel dB ratio - sengpielaudio Sengpiel Berlin
So at 60 volts, if you are -3db down at the crossover point you are looking for 42.47 volts. Now play the tone you want your cutoff filter to be at. A common one is 80hz for mids. Now play 80hz with your filter wide open. So then you just keep turning the filter up until you hit that voltage. Congrats your high pass filter is set.
For low pass filters you do the same thing but set it wide open in the opposite direction.
Now lets say you need to gain match two amplifiers. (you want to do this before filters). Open your filters wide open on both amps. Set the first amp's gain using a scope, dd-1, dmm or whatever. Now play 60hz and measure the voltage on the set amp. Now just turn up the voltage on the second amp until it matches the first one. (you don't need a load for this).
If you want to match the xover settings to the first amp that has the xovers already set then all you need to is grab a tone above your low pass and below your high pass. For your high pass play the tone that is below like 20hz and measure the voltage on the first amp then slowly turn up the high pass on the second amp until the voltage is the same. For the low pass play a tone like 100hz and then turn down the filter until the voltage on the second amp matches the first amp.
To confirm your amps match properly just double check by playing a tone below, one not filtered and above. The output from both amps should be the same at all three frequencies.
Sure it takes a little more math and effort to use a dmm but at the cost of over 100 bucks difference I think it's well worth it. Not to mention a quality dmm can be used for WAY more things than the cc-1 can.
Now onto the IM-SG
Honestly it's a pretty nifty tool. However if you have a laptop I recommend a woofer tester 2 instead.
IM-SG is 299.99$
WT2 is 159.95$
At 140$ cheaper it can do everything the IM-SG can do and actually is easier to pull TSPs from. The one thing that is great about the IM-SG is the portability. So again... no laptop; get the IM-SG... yes laptop; get the woofer tester 2.
And finally the AMM-1
I gotta admit on this one that it is a pretty cool tool for the casual basshead trying to learn more about his setup. The best thing it's got going for it is the hall effect sensor built in so power factor isn't an issue. But I'm going to put a AC/DC clamp, True RMS meter and Oscope up against it
The AMM-1 is 359.99 on preorder right now. I believe it will be 400 ish full price
The hps140I scope is 119.99$
The Craftsmen 82369 is 59.99$
A Fluke 113 is 116.96$
The one area the AMM-1 has a good clamp setup beat is that it knows the power factor and thus can determine actual watts being sent to the loudspeaker. However as of now this isn't very useful information if you consider where we are. 99% of amplifier clamps are done with a DMM and clamp meter. So when people see the lower power they are going to wonder why it's lower than what other people have clamped. Yes in a perfect world we should all be clamping for watts. But in an industry dominated by Voltamp clamps then the true watt figure is somewhat unnecessary as of now.
Another issue is that it will stop reading upon clipping in the amp dyno. Which for competing doesn't make it any more useful than a couple of clamps when you start clipping. And 99% of people competing allow a soft clip for more power. Not to mention unless everyone is using the amm-1 at the comp then the division of power won't be fair. In this situation a video camera really helps with both methods as you can record the power and go back over it to find peak power at peak spl.
Another issue is that the amm-1 can't calculate amplifier efficiency since it doesn't have a DC clamp onboard. Granted this isn't that big of a deal but amp clamps are much better with efficiency figures as well. But with a proper clamp setup you can do this as well as clamp your alternator to see if that is doing rated power.
A plus for the AMM-1 is that it does all the math for you. But it really isn't that complex of math so you be the judge how much of a plus this is.
The rest of the things the AMM-1 can do can also be done with the clamp setup I listed. So I didn't feel they needed to be mentioned.
So I guess if knowing true power is that important to you then the AMM-1 is your tool. If you are fine with the current industry standard then the clamp setup is for you.
All together now.
If you have the complete SMD toolbox that costs 960$ as of right now.
If you grab the clamp setup and the woofer tester that costs you $457
Less than half the cost and the only thing you can't do is find true power/phase angle. However you can do a lot more with the second option for less than half the cost.
The choice is yours