# Signal shape close mic, then eq. Is it worth it?



## pdxrealtor (Jun 30, 2013)

I have four subs all in their own enclosure, and all on their own channel. I'm wondering if it's worth it to shape the signal of each enclosure using close mic measurements, then place for best response and EQ as normal. 


OR just place for best response and EQ. I think a lot of the ID companies shape the signal via DSP. This what made me think to ask the question.


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## jtalden (Mar 12, 2009)

Mono bass? There is no need to EQ the SWs near field individually before applying general EQ for the room installation. 

That would likely just resulting in using significantly more filters than needed to do the job. Although, I don't think it would actually hurt anything other than that. 

With 4 subs spread around the room the room modes will be smoothed significantly so there is a good chance that a few modest filters will do the job.


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## pdxrealtor (Jun 30, 2013)

jtalden said:


> Mono bass? There is no need to EQ the SWs near field individually before applying general EQ for the room installation.
> 
> That would likely just resulting in using significantly more filters than needed to do the job. Although, I don't think it would actually hurt anything other than that.
> 
> With 4 subs spread around the room the room modes will be smoothed significantly so there is a good chance that a few modest filters will do the job.



Yep - mono. 

As I said, ID companies add EQ to their products before shipping, then we get them and add EQ again. I can only assume the companies add the EQ to get the driver/box combo response that is best for the setup. 

It must be of _some_ value otherwise they wouldn't do it, nor would the amps they use have the function built in to make it possible. 

You do raise an excellent point about possibly adding more filters. As I'm re-reading some info on the mini-dsp and head room right now, it's definitely a valid concern. 

But I still can't help but wonder if it's worth it based on the fact it's done by manufactures of sub systems.


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## Wayne A. Pflughaupt (Apr 13, 2006)

pdxrealtor said:


> But I still can't help but wonder if it's worth it based on the fact it's done by manufactures of sub systems.


They’re doing it to maximize the performance of _the system;_ for example to improve extension of a driver used in a smallish sealed box. That has nothing to do with anything an installation might require. 

From what I’ve been told by people who have tried it, it’s an exercise in futility to try to individually equalize multiple subs. They say that they’ll get response looking good for each individual sub, but when they take a combined measurement it’s a mess. Basically, since the bass is omnidirectional, you’re hearing all the subs as a single source anyway, so it makes sense to equalize them the same way. 

The only exception that makes sense to me might be if perhaps one of the subs had a big peak that none of the others have. Something like that might make sense to deal with, rather than “correct” all the other subs that don’t have a problem at that frequency.

Regards,
Wayne


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## pdxrealtor (Jun 30, 2013)

Wayne A. Pflughaupt said:


> They’re doing it to maximize the performance of the system; for example to improve extension of a driver used in a smallish sealed box. That has nothing to do with anything an installation might require. From what I’ve been told by people who have tried it, it’s an exercise in futility to try to individually equalize multiple subs. They say that they’ll get response looking good for each individual sub, but when they take a combined measurement it’s a mess. Basically, since the bass is omnidirectional, you’re hearing all the subs as a single source anyway, so it makes sense to equalize them the same way. The only exception that makes sense to me might be if perhaps one of the subs had a big peak that none of the others have. Something like that might make sense to deal with, rather than “correct” all the other subs that don’t have a problem at that frequency. Regards, Wayne



Thats exactly what i was thinking. For example the drivers I just got and built enclosures for have been known to be peaky. They are also in their minimum recommended enclosure size of 4 cubic ft. 

Having eq on the input and output bank I potentially could flatten out the close mic response before placing them in the room and EQing as one. 

The question is is it really worth it?


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## Wayne A. Pflughaupt (Apr 13, 2006)

Ah, so you basically want to do the same thing the manufacturers do – wasn’t picking that up from your opening post. 

Is it worth it? Hard to say. What you might do is go ahead and take the close-mic measurements for reference. If that peaky thing is showing up both there and with the in-room measurements, then it certainly might be worthwhile to take care of the problem at source. But whether or not that would be an audible improvement over a more traditional approach (i.e. simply EQing room response) – again, hard to say. You’d have to be the judge of that.

Regards,
Wayne


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## pdxrealtor (Jun 30, 2013)

Wayne A. Pflughaupt said:


> Ah, so you basically want to do the same thing the manufacturers do – wasn’t picking that up from your opening post.
> 
> Is it worth it? Hard to say. What you might do is go ahead and take the close-mic measurements for reference. If that peaky thing is showing up both there and with the in-room measurements, then it certainly might be worthwhile to take care of the problem at source. But whether or not that would be an audible improvement over a more traditional approach (i.e. simply EQing room response) – again, hard to say. You’d have to be the judge of that.
> 
> ...


Ya...... I was definitely thinking about doing something like the manufactures do. 

I think I'm more curious than anything. I mean, if they do it and I have the capability to do the same why wouldn't I? 

I don't know........ just a thought I had since I have four separate enclosures being run off four channels. 

My last setup had four drivers off one channel, another two drivers off of one channel. It wasn't really realistic with that configuration.


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