Graphic equalizer/ crossover help and suggestions?

[hysteria]

So I have some Boston Acoustics Pro series speakers, which are notoriously bright, with no hopes of making them sound better with the included crossovers. I would like to purchase a long band, say 30 band or so, equalizer so that I can fine tune them. Anyone have any experience with good equalizers? Any advice?

Do you usually throw out the crossovers that came with the speakers if you are using an equalizer like this? As it stands I have the ability to modify the signal like 3 times, which seems a bit ridiculous. And none of those modifications are good enough to give me the results I want.

Why has this not been discussed before? I would think this would be in car audio 101.

[EW]

You must use some kind of passive crossovers unless you are going to run an actively crossed over system which will require separate channels(or amps) for the tweeters, mids, and subs. For a crossover, the Audio control 6XS is nice but many people use Alpine's 701 or Audio Control's DQXS which would be awesome. What kind of amp are you using?

[hysteria]

I was using a jl audio 300/4 amp, but it was stolen along with my head unit. They weren't smart or crafty enough to get my speakers out, so I was considering upgrading my amp and head unit. I definitely would want some better control over the sound, more so for the tweeters than the mid bass, but I'm sure both could be improved.

So the passive crossovers that came with the system must stay intact. I think I understand why with the positioning of the crossovers and amp configuration, but could you maybe explain a bit just so I'm sure?

Also, any other info you could write in here for crossover workings and signal filtering would be cool. I feel like this is something many people need to read more about - or maybe I'm the only one that doesn't know enough. Anyway give me input!

[hysteria]

I looked at the wiring diagram for the DQXS

http://www.mobileaudiocontrol....26063

My crossovers work between the amplifier output and the speakers (passive) unlike the way they have their system set up in the diagram. The crossovers for BA speakers offer minimal adjustment (I guess because they are passive?) and simply split the signal between the mid and high components.

So would removing this BA factory passive crossovers be something worth doing if I were to upgrade to the DQXS, or would I still need to leave it intact? Thanks again!
Modified by hysteria at 4:21 PM 8/13/2008

[hysteria]

scratch that last question - the answer was in my question, and now I understand the issue.

I would still need the passive crossovers in order to split the signal after the amp, before they reach the speakers because an equalizer's output will not be separated going into the amp and then to the speakers. The DQXS contains an active crossover, which would not help with splitting up the signal going to each individual speaker unless each speaker (or each type of speaker) had it's own amp.

So is using a passive crossover the only way to make sure each speaker gets only a certain range of the frequencies? Would the application of active crossovers be splitting the signal and amplifying each component of the signal?

[EW]

scratch that last question - the answer was in my question, and now I understand the issue.

I would still need the passive crossovers in order to split the signal after the amp, before they reach the speakers because an equalizer's output will not be separated going into the amp and then to the speakers. The DQXS contains an active crossover, which would not help with splitting up the signal going to each individual speaker unless each speaker (or each type of speaker) had it's own amp.

Yep

So is using a passive crossover the only way to make sure each speaker gets only a certain range of the frequencies?

There are two crossovers-Active which are in or before the amp and passive which are after the amp. Active requires a separate amp (or channel) for each frequency range.

Would the application of active crossovers be splitting the signal and amplifying each component of the signal?

Splitting the signal-yes, amplifying the signal-No.Sounds like you need an EQ more than an active system. Most passive crossovers do not offer much adjustment for the mid or tweeter.

[hysteria]

Splitting the signal-yes, amplifying the signal-No.Sounds like you need an EQ more than an active system. Most passive crossovers do not offer much adjustment for the mid or tweeter.

Thanks! That's what I meant to say I just didn't articulate it correctly.

I saw the Audio Control EQS on that same site - would you recommend this as a decent EQ? I really have no experience with EQ's, aside from the normal EQ's included or incorporated into a head unit.

I was thinking something a little more precise, like maybe 1/3 octave. That gives me like 30 bands of control!!! Do you think that is excessive? And have you had any experience with Pheonix Gold products? they make a 1/3 octave EQ.
Modified by hysteria at 11:41 PM 8/15/2008

[the converted]

Typically I try to amp the mid and the tweeter independently for this reason. As far as crossovers go 30 band is a little overkill for toning down tweeters. I would probably go with audio control over PG but that's just a personal opinion, both make good stuff.

[Looneybomber]

Ok, so why is this speaker "bright"? Is the 2-6khz area too loud? 4-6k? 3-10k? 6-20k?

A simple L-pad circuit with the tweeter may pad it down enough for you and will only cost a couple bucks with resistors bought at radioshack or somewhere else.

http://www.bcae1.com/lpad.htm

This will bring down the level of the tweeter by however many db you select. It's also possible to incorporate notch filters if you have problem area's/ranges like from 3-6khz, instead of reducing the output of the tweeter over it's entire operating range.

I like trying the cheaper routes first, instead of wasting money on things beyond what I need...for example a 31band eq. I would say I'm cheap in general, but I did just purchase a $305.00 tweeter for testing/auditioning purposes before buying more.

[hysteria]

hey thanks, that may actually be better for what I am trying to do. You are correct that they are not just bright overall, but rather have problem areas that I would like to improve. They are overly loud in certain high frequency areas that are annoying or offensive, and not loud enough in others (such as a snare drum, etc). I will investigate, because I definitely am on the cheap side as well!

[Looneybomber]

If you want to go the passive route, as in modifying your existing crossover, you'll need to 1) Figure out the impedence or DCR of your tweeter2) Figure out what frequencies you want to work on and what you want done with those frequencies.

For example, if you don't know what the impedence is of your tweeter, the crossover components you would use for an 8ohm tweeter will not be the same as one for a 4ohm tweeter and thus will effect different frequencies.

Also, if you don't know what frequencies are "offensive" (it's typically the 3-6k area), you may end up tweeking the wrong frequencies and making things worse.

So what part of the snare drum do you want more of? A spectral analysis of a snare drum shows lots of energy throughout a lot of the human's frequency range. Is it at the upper most part part of the range, say 8+khz?

...more on this later. I need to go mow.

[hysteria]

Yes, the upper part of the range. This is more of the reason I was thinking my options were pretty much limited to an equalizer- I figured I was not going to easily be able to tell which frequencies I wanted to modify, and the eq would give me the freedom to play around with it to see what I like. Most of the eq's I came across are 2 channel which is fine as the fronts are more of what I am concerned about. But then I would have to buy another eq if I wanted to control the rear at all. Anyway I can get all of the specs about my speakers pretty easily. Like you said before, since it is so cheap playing around with a couple of bucks worth of resistors to see if it helps any is probably a good place to start as opposed to spending a couple of hundred for an eq.

[Looneybomber]

So just to clarify, you're wanting more output above 8khz and less below that? Or whatever frequency you choose. To test this, if you have a mic, a laptop, and USB soundcard, you can get an RTA (Real Time Analysis) of your frequency response. If you don't have that, you can try a CD burning program like Nero that has an EQ built in. -Burn off a song you like, then burn it again after playing with the EQ a bit. -Burn it again and adjust your EQ a bit differently. -Write down the changes you make with each track. -Pick the one that sounds best to you and then setup your XO modification accordingly.

(For example, burn off a song, and set the EQ with 2db of cut from 2-4khz, then from 2-6khz, then 2-8khz. Repeat but with 4db of cut. Also, burn off some 20-20khz sweeps so you can kind'a hear peaks and offensive area's)

One of the good testing CD's I have is Bass Mekanic audio tool box (or whatever it's called) It has multiple test tones and sweeps with a reference to what frequency is what second ect...

Doing it passively is much harder, much more time consuming, but cheaper.

Once you find out what you need to do, you could use the -0db outputs for your tweeter (or -2db's if you don't want that much twinkle) and then set up a shelf filter to drop everything below 8khz by 1, 2, 3, ect... db's. Or whatever frequency you chose.

EQ's are much easier to work with obviously, but can also be used for both the front and rear speakers! If it has two inputs and two outputs, either split the outputs into four, or use the "pass through" outputs of your first amp to send the signal to your second amp. Wait, do you have external amps? The down side is they add noise and, if low quality, will distort the signal before it even reaches the speakers.

[Simmsled]

You're a good man Looney.