so confused smd distortion detector?

[CHEMMINS 10+ year member]

I think it is based off of the clip lights on amps. Based on the circuitry from them anyway. His "detector" would do the same thing as a lot of bass knobs do.

 

[optimusprime 10+ year member]

isnt a bass knob just a remote gain controller?

 

[thegreatestpenn 5,000+ posts]

the device can be very useful if the user knows how to use it. SAME AS AN OSCOPE. The only advantage to the SMD is it lights up so u don't have to worry about lighting to do your settings (i have yet to see a backlit handhelp oscope).

I do think the price of the smd ***** balls, if they can get the price down to $50 it'll sell much better

 

[optimusprime 10+ year member]

after alot of reading im thinking its more similar to a guitar tuner that lights up if your tone distorts from a note like a 49 hz g note im not gonna lie im impressed that he thought of it and surprised that no one else did.

 

[Pborcich 10+ year member]

oscope cant be that hard to operate and hell i just found one for 119 bucks

lol spend 119 on an oscope and i gaurentee youll set your amp will be set to clipping

cheap oscopes dont catch very small amounts of distortion the wave will look perfect but its not...

A good oscope shouldnt cost less than 1k

an oscope is going to let you pull more than the SMD but the SMD has some of the aspects of oscope detection that just make it plain really easy.

 

[VWBobby 10+ year member]

As far as I can tell, it must be a comparator circuit. It compares the tone at 40hz and 1khz to the track being played (40hz or 1khz). If there is any deviation, it would be detected as distortion. Sine wave test tones should have very sharp transitions on the peaks and valleys.

Guitar tuners are not distortion detectors. They detect a deviation of TONE (frequency) centered around "A" (440hz). If you are tuning for A, and you're at 445hz, then you know you need to loosen the string a little to bring it down to 440hz and the light will turn green when you're on. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[optimusprime 10+ year member]

so a guitar tuner test for frequency so it couldnt be used to test if 40hz was actually playing at 40hz?im pretty new to all this so im trying to understand it youll have to forgive my newness to all the concepts. i thought 40 hz was the frequency and the idea was to get a clear 40hz as loud as you can and when it stops being 40hz then that means its distorting?

 

[Phoenix Risen 10+ year member]

it may be a nice little tool to have, hopefully twisted can step in and say a few words since he has one.

 

[optimusprime 10+ year member]

i just want to restate i am in no way hating on steve meade or this device im only trying to understand how and why it works seems like it should be simple i can only say that its most likely not super high tech since he from what i understand didnt have the assistance of any large corporations and came out with this in a relatively short time.

 

[vaiboy 10+ year member]

I don't see how this is going to work if you follow the instructions and "disconnect the speakers". There is no way to set the gains properly with that device without accounting for the final load. The SMD device triggers at 1% THD, so using it per the instructions you are finding the point the amp reaches 1% THD with no load. So, for example, if your amp was rated at .5% THD of course the output will increase but you will be sending a dirtier signal too. Now the gains are cranked beyond rated with no load, and you connect your subs, good luck with that. Say your amp was rated at 850W@4Ω, 1700W@2Ω, and 2400W@1Ω. After using the SMD device your output voltage is 65VAC, instead of the 58VAC (4Ω,2Ω) or 48VAC (1Ω) if you had used a DMM. You might get away with a 4Ω or 2Ω load, but that output with a 1Ω load could easily damage your amp. Especially if the 1Ω rating was limited due to current, 65 amps running through a circuit that was designed for 50 is never a good thing. Using this thing with an amp like the JL Slash series with the speakers disconnected would never work, the amp is rated to do the same wattage from 4Ω-1.5Ω. The voltage output at 1%THD to a 4Ω load is going to be far different that the voltage at 1.5Ω. The SMD device isn't magic, it certainly isn't going to get you the cleanest signal possible, and it doesn't seem to be the best way to set the gains especially without a load on the amp.

 

[thegreatestpenn 5,000+ posts]

I don't see how this is going to work if you follow the instructions and "disconnect the speakers". There is no way to set the gains properly with that device without accounting for the final load. The SMD device triggers at 1% THD, so using it per the instructions you are finding the point the amp reaches 1% THD with no load. So, for example, if your amp was rated at .5% THD of course the output will increase but you will be sending a dirtier signal too. Now the gains are cranked beyond rated with no load, and you connect your subs, good luck with that. Say your amp was rated at 850W@4Ω, 1700W@2Ω, and 2400W@1Ω. After using the SMD device your output voltage is 65VAC, instead of the 58VAC (4Ω,2Ω) or 48VAC (1Ω) if you had used a DMM. You might get away with a 4Ω or 2Ω load, but that output with a 1Ω load could easily damage your amp. Especially if the 1Ω rating was limited due to current, 65 amps running through a circuit that was designed for 50 is never a good thing. Using this thing with an amp like the JL Slash series with the speakers disconnected would never work, the amp is rated to do the same wattage from 4Ω-1.5Ω. The voltage output at 1%THD to a 4Ω load is going to be far different that the voltage at 1.5Ω. The SMD device isn't magic, it certainly isn't going to get you the cleanest signal possible, and it doesn't seem to be the best way to set the gains especially without a load on the amp.

it may have something inside to present a dumby load.

 

[subzero 5,000+ posts]

it may have something inside to present a dumby load.

jizz, ?

 

[optimusprime 10+ year member]

maybe i should just stick to setting by ear?

 

[optimusprime 10+ year member]

it may have something inside to present a dumby load.

lol you said load

 

[vaiboy 10+ year member]

it may have something inside to present a dumby load.

How does the device know what the final load will be? Even if there is a dummy load, if the load inside the device is different than the final load, the gain setting will be off it's that simple. Like I said with the JL Slash amp the gain setting is not going to be in the same place when the load changes. 1000W@4Ω = 63.2VAC, 1000W@2Ω = 44.7VAC, and 1000W@1.5Ω = 38.7VAC the SMD device has no way to compensate for that. If you follow the instructions it will not end well. The amp needs to have a load present to use an o-scope or this SMD device. Even using the SMD with a load present in many cases you are only gaining output by sending a dirtier signal than rated. I fail to see the advantage to using it. Buy an amp with plenty of headroom to overpower your speakers then set the gains with a DMM so that you limit the output of the amp to match the speakers. You will have a cleaner signal and maximum output without spending $150 on this thing.