# EQ built-in subs of L/R speakers



## tdo722 (Mar 12, 2011)

Hello,

Anyone out there EQing the built-in subs of their L/R speakers? I have a pair of martin logan spires and they are extremely bad because of my room acoustics.

First, I EQ (using FBQ2496) the right speaker sub only and only upload to right channel of FBQ2496. Then after that I ran REW with both subs from both speakers but this time using the suggested EQ filters and upload only to the left sub of the left speaker. The result is okay but not so great. I think I need to tweak a bit more.

My question is, will this degrade the quality of my L/R speakers because I just introduced the FBQ2496 to the audio chain? That's my #1 concern. Perhaps the FBQ2496 is so low-end and will create all sorts of noise and distortion. I used XLR from source to finish but still a bit iffy about the whole thing. I still have not touched the pair of Fathom F113s yet because I wanted to make sure the built-in subs of my L/R speakers perform at least decent before I move on to actually using my 2nd FBQ2496 to EQ the pair of Fathom F113s.

Let me know your thoughts on this.

Cheers


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## Kal Rubinson (Aug 3, 2006)

First, you do not have "built-in subs." You have woofers and there is no reason I can think of to EQ them with the FBQ2496. 

Second, the FBQ2496 will introduce a time delay and, if it is only in the woofer circuit, you will need to compensate for it. If it is in the circuit for the ELS, I question whether its A/D/A is sufficiently transparent.

Your response curve is pretty good, fwiw.


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## tdo722 (Mar 12, 2011)

Thank you Kal for your response. I will disconnect the spires from the FBQ then. I was afraid that the woofers of the Spires will mess things up once I introduced the 2 F113s to the audio chain due to my screwed up room acoustics. Hence it will make it so difficult to adjust the F113s because the woofers of the spires is always in the equation but has not been EQ.

So what's the correct sequence?

2 subs + L speaker 
then 2 subs + R speaker 
then finally subs + L and R speakers


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## Kal Rubinson (Aug 3, 2006)

tdo722 said:


> Thank you Kal for your response. I will disconnect the spires from the FBQ then. I was afraid that the woofers of the Spires will mess things up once I introduced the 2 F113s to the audio chain due to my screwed up room acoustics. Hence it will make it so difficult to adjust the F113s because the woofers of the spires is always in the equation but has not been EQ.
> 
> So what's the correct sequence?
> 
> ...


I am afraid that I do not understand your question.


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## tdo722 (Mar 12, 2011)

Oh I was asking about the correct EQ sequence. 2 subs + left speaker first, then 2 subs + right speaker? and then finally 2 subs + 2 speakers?

Or just EQ everything together.


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## Kal Rubinson (Aug 3, 2006)

tdo722 said:


> Oh I was asking about the correct EQ sequence. 2 subs + left speaker first, then 2 subs + right speaker? and then finally 2 subs + 2 speakers?
> 
> Or just EQ everything together.


If by subs, you mean the f113s, I guess so. There are others here with more experience using the FBQ with REW.

Kal


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## tdo722 (Mar 12, 2011)

Kal,

I just went though two hours of listening and yes, a huge mistake to connect the spires to FBQ2496. It sounds very muddy in every single music track that I played. Spires were made with music in mind or so I think.  and this is of course not what was intended. Transparency is gone.


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

tdo722 said:


> Let me know your thoughts on this.


What are we looking at there? Mains? Mains + subs?




> I just went though two hours of listening and yes, a huge mistake to connect the spires to FBQ2496. It sounds very muddy in every single music track that I played.


I don’t know why anyone would equalize $8000 speakers with a low-end equalizer. If you need or want to EQ your main channels, get a first-class EQ like the Yamaha YDG2030 or YDP2006. 

But before you go that route I’d first exhaust all the tools you have on hand. For instance, the Spires have a woofer level control that might need adjustment. And resist the temptation to run the Spires full range. Since you have subs, set the mains the small, and EQ the subs with the FBQ. This gets the best sound in the great majority of installations.

Regards,
Wayne


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## tdo722 (Mar 12, 2011)

Hi Wayne,

Thank you for your response. That graph was for main only after I EQ it with FBQ but yes bad idea to use FBQ with the spires.

I'm trying my very best to integrate the 2 subs with the spires and having a very hard time. There's always 2 dips one at the crossover and one at around 30 to 40 hz freq.


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## tdo722 (Mar 12, 2011)

This is the graph after I EQ the 2 subs with hard knee. No mains.


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## tdo722 (Mar 12, 2011)

OK, I had to remove the hard knee and do lots of manually adding filters into the FQB and finally got a decent result blending main+2 subs. No filter boosted over 6db.

Now, time to enjoy some music then some movies. 

Thank you all.


Final question, how do i pull the filter settings out of the FQB and save it on my laptop? Oh well, I might just go through it one by one and write it down. Just thought if there's a quicker way.


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## tdo722 (Mar 12, 2011)

Wayne,

Thank you for your suggestion. I think on eBay is selling a used one for under $200. I think I will grab it just in case for future since it's sub $200.


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

Well, your sub-only graph looks pretty good. Don’t know how you’re doing the equalizing, but it’s usually best to EQ dual subs as a single entity, with a single set of filters. Trying to EQ them separately, especially if they are not co-located, can be a nightmare.

That leaves the dip around the crossover. You might try staggered crossover settings, adjusting the sub’s phase control, different sub locations, etc.

Regards,
Wayne


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

tdo722 said:


> Wayne,
> 
> Thank you for your suggestion. I think on eBay is selling a used one for under $200. I think I will grab it just in case for future since it's sub $200.


If you’re talking about the YDP2006 from the seller “promusicstuff,” take a pass. It looks like it’s had a hard life. The one from “gearorphanage” looks pristine; I’d go for that one.

Basically, it’s best to get one from a permanent installation (auditorium, studio, etc.), not one that was schlepped around from gig to gig in a road rack.

Regards,
Wayne


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