SI Expression inputs mic/line conflicting info

Sean Muckian

Freshman
May 7, 2014
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0
0
We just got a new SI Expression 2. In the product manual it has a diagram (pg 9) showing the back of the board that reads "Recallable Mic/ Line inputs x24". Then on the soundcraft website the product description reads "the Si Expression 2 features 24 recallable mic pre amps". I have been playing with the board alot and im pretty sure that the 24 inputs are only mic inputs and that the product manual is wrong. Can anyone confirm this? I cant see a way to change any of the mic inputs to line. If someone knows how to do that please enlighten me.

Thanks
 
Re: SI Expression inputs mic/line conflicting info

Sean,
The input gain you apply to the preamp determines if you can feed them a line level signal. If your gain is low, it will take a line level signal without issues.


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Re: SI Expression inputs mic/line conflicting info

Thanks for the speedy replies!

Good to know that these can be used for lines (I am currently using 6 mic inputs as line inputs). I guess what I find confusing is that if I adjust my gain so that my levels look good on those channels then the input is really loud. I can turn the trim way down but then I dont have any visual reference on those inputs because they aren't even reading on the meter. As a total n00b when it comes to audio engineering I was always under the impression that you want your levels peaking right below unity (0db). If I turn the trim down they dont even come close to unity. Am I wrong about that?

Have either of you experimented with the 4 analog line inputs? Are they stereo or mono? I dont have the correct adapters to connect anything to them at the moment.

I am a novice regarding this type of equipment so please excuse my lack of knowledge. Thanks for the info!!
 
Re: SI Expression inputs mic/line conflicting info

If certain inputs are too loud with the gain set correctly on the input (you seems to be going down the right path) then there is a good chance that your amp is turned up to far. Contrary to popular belief, amps don't need to be turned up to 11 all the time. As for the 1/4 inputs on the back, they can be stereo or mono.


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Re: SI Expression inputs mic/line conflicting info

Thing is the amps arent turned up very far. The mic levels all look good and are a good volume. It just the line levels that are super loud. If I turn up the gain on the inputs I am using as line to match what the mic levels look like (peaking right below 0db) then those lines are very very loud. Thats why I was thinking that the mic inputs needed to be switched to line inputs because it seems the mic inputs I am using as line inputs are putting a preamp on my line levels making them very loud. Does that make sense?
 
Re: SI Expression inputs mic/line conflicting info

For example I have my computer connected to channels 21 and 22, channel 21 is panned to left and channel 22 is panned right and they are linked giving me a stereo signal. I have the gain turned all the way down to -5db (about 7 oclock) on both 21 and 22 which gives me a good volume when those channels are at unity. Now on channel 1 I have a hand held microphone with the gain at 16db (about 11 oclock) which gives me the same volume as the computer when that channels is at unity. However the mic channel has good visual levels peaking right below 0db as oppose to channel 21 and 22 where the levels aren't even registering. Its not the end of the world if I cant have visual levels on the line inputs (21 and 22) but it would be nice...
 
Re: SI Expression inputs mic/line conflicting info

For example I have my computer connected to channels 21 and 22, channel 21 is panned to left and channel 22 is panned right and they are linked giving me a stereo signal. I have the gain turned all the way down to -5db (about 7 oclock) on both 21 and 22 which gives me a good volume when those channels are at unity. Now on channel 1 I have a hand held microphone with the gain at 16db (about 11 oclock) which gives me the same volume as the computer when that channels is at unity. However the mic channel has good visual levels peaking right below 0db as oppose to channel 21 and 22 where the levels aren't even registering. Its not the end of the world if I cant have visual levels on the line inputs (21 and 22) but it would be nice...

There is no such thing as "unity", just like "normal" on the clothes dryer it's only a silk-screened pointer. Really.

But here's your problem - the meters on your Si are "0 DBFS." That reads as "zero DB, Full Scale." That translates to mean "Zero is FULL TILT BOOGIE, there ain't nothing left."

In techno-speak, it means that "0" is referenced to the maximum voltage output capability of the mixer, +22dBu in this case. IOW 0 = +22. You should have inputs peaking around -18dBu.
 
Re: SI Expression inputs mic/line conflicting info

Thanks for in input! I am just using the word unity to represent the 0 mark on that particular channel. This may be incorrect as I am not a pro audio engineer. Please excuse my ignorance. Basically what I am trying to figure out is how to use the mic inputs as line inputs and have the visual meters read "accurately". As I have mentioned in previous posts if I solo each channel and dial the gain so that each level is peaking on yellow or just below 0 then the mics sound good where as the lines are way too loud. I assume that this is because each of the inputs have a mic preamp applied to them so a line signal is getting boosted. I could be wrong. However I just found some 1/4" adapters so that I could plug my line into the line inputs and that seems to have the effect I would expect. The line meters match the mics, so now both mic and line are reaching yellow and they seem to have the same volume. This is the effect I am looking for but I was hoping to use the mic inputs because I would have a lot more connections to work with.
 
Re: SI Expression inputs mic/line conflicting info

if I solo each channel and dial the gain so that each level is peaking on yellow or just below 0 then the mics sound good where as the lines are way too loud. I assume that this is because each of the inputs have a mic preamp applied to them so a line signal is getting boosted. I could be wrong.

If the signal was being boosted you'd see that on the meter. Is it possible that you're just playing back very compressed music which sounds louder than someone talking into a mic?

Are there any options to change the metering point in the channel? If there was gain being applied after the point the meter reads that could cause this. A post preamp metering point and a compressor with a lot of output gain would be one scenario.

Chris
 
Re: SI Expression inputs mic/line conflicting info

Yea thats the one thing that seemed strange to me, because you're right the meter should show that the channel was super loud. As I was writing it I had the same thought "if the signal was boosted the meter would be boosted" but I am just not that knowledgeable so I am just trying to piece these ideas together. I don't recall a setting to change the metering but thats the next thing I will look at. Big THANK YOU to everyones help thus far. This is what happens when you put an IT guy in charge of sound, lol.
 
Re: SI Expression inputs mic/line conflicting info

Thanks for in input! I am just using the word unity to represent the 0 mark on that particular channel. This may be incorrect as I am not a pro audio engineer. Please excuse my ignorance. Basically what I am trying to figure out is how to use the mic inputs as line inputs and have the visual meters read "accurately". As I have mentioned in previous posts if I solo each channel and dial the gain so that each level is peaking on yellow or just below 0 then the mics sound good where as the lines are way too loud. I assume that this is because each of the inputs have a mic preamp applied to them so a line signal is getting boosted. I could be wrong. However I just found some 1/4" adapters so that I could plug my line into the line inputs and that seems to have the effect I would expect. The line meters match the mics, so now both mic and line are reaching yellow and they seem to have the same volume. This is the effect I am looking for but I was hoping to use the mic inputs because I would have a lot more connections to work with.

You didn't read my post, did you?
 
Re: SI Expression inputs mic/line conflicting info

I suspect he used a Mackie mixer in the past - unity setting was made up by them I think.

Tim, on your post, did you mean -18 dbfs?

To the OP, if the level seems loud, don't push the fader up so much. They don't all have to be in a line.


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Re: SI Expression inputs mic/line conflicting info

Yes I did read your post, but because I dont know a whole lot about sound it didnt really make much sense to me. I am not an audio engineer, I am a guy that has been put in a position where I need to figure out how to use a piece of equipment that I dont fully understand nor do I have the background knowledge to figure out on my own. All I know is that I have been told that each channel should peak at yellow on my meters. So I adjust gain on all inputs so that the signal peaks at yellow. Then I turn each channel up to 0 and some of the channels are louder than others. I am trying to figure out why. Thank you for your help.
 
Re: SI Expression inputs mic/line conflicting info

@rob
Thanks, thats the method I have been using but on the channels with the line signal i am only moving the fader up like a half an inch and its very loud. Now I can turn the gain way down and then I can move the fader up farther but then my meters arent even registering on those channels because the gain is so low. I guess it doesn't matter and I can adjust by ear but its difficult because im in a booth and I cant really hear the house sound very well, having any extra guides (like visual meters) are helpful. I was told that the meters should peak at yellow so thats where I have been adjusting gain to.
 
Re: SI Expression inputs mic/line conflicting info

Check you don't have a load of gain being added somewhere later in those channels, like at the compressor.

I've had a look at the editor and all the metering on that console is in dBFS. You don't want to be anywhere near 0dBFS, as said above -18 is about right. If the signal is at line level to begin with you shouldn't need to add any additional gain.

Chris
 
Re: SI Expression inputs mic/line conflicting info

I have the compressor turned off on every channel. To make things easier (on me) I turned off everything (hpf, gate, compressor, eq) on all channels to ensure there is nothing else affecting the signal. It makes sense that line would have the gain all the way down because thats where it sounds correct. Its just the visual meter that is confusing things for me. I guess my thought process is that all signals should sound that same volume if they visually match but I guess thats not how sound works...?
 
Re: SI Expression inputs mic/line conflicting info

Yes I did read your post, but because I dont know a whole lot about sound it didnt really make much sense to me. I am not an audio engineer, I am a guy that has been put in a position where I need to figure out how to use a piece of equipment that I dont fully understand nor do I have the background knowledge to figure out on my own. All I know is that I have been told that each channel should peak at yellow on my meters. So I adjust gain on all inputs so that the signal peaks at yellow. Then I turn each channel up to 0 and some of the channels are louder than others. I am trying to figure out why. Thank you for your help.

You want each channel to "peak" between -22DBFS and -18DBFS on the meter when you use the solo or PFL button. If you do this to each input, some things you want to be softer will need to be turned down by lowering the fader, which is why "unity" as a user-setting is bullshit. Believe me, if you have hi hats peaking at -18DBFS, and vocals doing the same, you won't want their faders to be in equal positions... trust me.

Don't freak out that soft signals will not give you a full meter display of level. Back in the Ye Olde Analogue Dayz, with big mechanical analog meters we couldn't "see" signals lower than -20dBu, either.

And regardless of whatever verbal advice was given by a salesman (or similar), try using the owners manual. Soundcraft has hook up drawings and relevant text to help you do things right.
 
Re: SI Expression inputs mic/line conflicting info

Is there any way to zoom in on that editor without it just zooming in to the bottom edge of the console? There aren't any scroll bars. :?~:-?~:???:

Chris
 
Re: SI Expression inputs mic/line conflicting info

Man... sound is a complex beast! Clearly this is beyond my skill set. I really appreciate everyones input! Cheers