3-way active frontstage and sub off 880?

[gatorgrizz27 10+ year member]

I think I figured out how to run a 3-way active frontstage and sub of an 880, but I just wanted to see if anything is wrong with my idea. The highs and mids would be set up as normal, then the Low LPF (typically for the sub) would be set at 250Hz and split into 2 pairs of RCA's. One would run to my amp for the midbasses, which can be highpassed at 80Hz on the amp, and the other would run to my amp for my sub, which can be lowpassed at 80Hz. Is there anything I am overlooking that would keep this from working? Thanks.

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[kappa546 10+ year member]

i dont remember if the low output on the 880 is a mono signal or not but thats something to look into. i know it is with my 8053, otherwise you're good to go.

 

[///M5 10+ year member]

You lose time alignment between your sub and midbass other than that it is fine.

It would be my preference to split the drivers that are closest to each other. i.e. with kicks for the mids & tweets, midbass in the doors, and sub in the rear I would split the mids/tweets via the amp since you could much more easily use the same t/a for those channels if they are right next to each other.

The only other thing is, I haven't checked does the sub out actually go up to 250hz?

 

[///M5 10+ year member]

Just saw the other post pop up, you can run the sub output mono or stereo...independent eq as well for l/r!

 

[gatorgrizz27 10+ year member]

Yes it does go up to 250 hz, I would use my 4 channel for the tweets and mids, my 2 channel for midbass, and get another amp for the sub. I have heard T/A isnt really as important for the sub, so I would just T/A the midbass, and the sub would be the same. I have to split it that way because of the active settings in the h/u, there is no other way to do it. Thanks for the replies so far.

 

[adam71 5,000+ posts]

Question. If you cross it over at 250 hz what is going to stop the LOW frequencies for example 60hz and down from going to your midbass drivers??

 

[gatorgrizz27 10+ year member]

I think I figured out how to run a 3-way active frontstage and sub of an 880, but I just wanted to see if anything is wrong with my idea. The highs and mids would be set up as normal, then the Low LPF (typically for the sub) would be set at 250Hz and split into 2 pairs of RCA's. One would run to my amp for the midbasses, which can be highpassed at 80Hz on the amp, and the other would run to my amp for my sub, which can be lowpassed at 80Hz. Is there anything I am overlooking that would keep this from working? Thanks.

Boston Amps FTW

 

[Flipx99 5,000+ posts]

Works better than my plan did!

 

[helotaxi 5,000+ posts]

Like ///M5 said, split the closest drivers with the amp x-overs. It may not seem like a big deal to time align the midbasses and then use that same signal on the subs, but when you consider that the subs are probably the farthest drivers from you and everything else is delayed based on their distance, and the midbasses are the closest...

Second, once you align the midbasses for the difference between right and left and then combine that left-right signal to mono for the subs, it will be one big smear. The subs will sound like crap.

 

[gatorgrizz27 10+ year member]

The problem is the amp x-overs only adjust from 20Hz - 350Hz, so the midbasses and sub are the only speakers I can control with them. Is there any type of simple box or module that could time align my subs independantly? Just something with one pair of RCA's In - adjustable delay knob - RCA Out? Or what would I need to build something like that? Thats also a good point about combining the L/R channels into a mono, but if I were to use only the right channel (farther from me), and split it into 2 with the Y-connectors to the sub input, that would solve that problem wouldn't it?

 

[helotaxi 5,000+ posts]

It would solve the problem if all the bass information was confined to the right channel. Otherwise you're going to lose a bunch of information. Another option is to get a standalone crossover to go between the mids and tweets.

 

[Flipx99 5,000+ posts]

Here is something you can consider and it will work, I am pretty sure

1. Leave the sub alone

2. Set the HPF on the "mid" to 80hz (or whatever) @ -12 dB

3. Set the LPF on the "mid" to 1.25k @ PASS

4. Set the HPF on the "high" to 1.25k @ PASS

Split the signal from the "HIGH" to a 4 channel amp. The DD C4 has the greatest flexibility I have seen (The Sundown can too, but the DD is cheaper) You can bandpass the midrange from say....400 - 3k, and then highpass the tweeter 3k up

Get another four channel amp (like the S4 by DD) and then run the mid/sub to it. Adjust the LPF on the "mid" channel to 80 hertz and the HPF to 400 hertz.

This combo can get you the following power and frequency ranges

100 x 6; 700 x 1

For a recap, this is how I would set it up

Sub: 20 - 63 hertz

Midwoofer: 80 - 400

Midrange: 400 - 3000

Tweeter: 3000+

 

[baker001 10+ year member]

I ran into a similiar problem with the cd7000 in my jetta. It has 3 way in the front and a sub in the back. I had it wired with the highs and mids on thier own channel and the lows were split between low and midbass.I changed it last week.Since I was using T/A on the midbasses, it affected the sound of the sub. Now the highs have their own channel,mids and mid bass share,and the sub has its own channel.For the mid/midbass channel I used 500hz hp and 500hz lp FMODS and split the mid channel. For the power I use the 700.5 kicker(tweets,mid domes,sub) and punch 75.2(mid bass).

 

[Flipx99 5,000+ posts]

I have the 880 but I wonder if it has any speaker-level power when it network mode.

 

[///M5 10+ year member]

I have the 880 but I wonder if it has any speaker-level power when it network mode.

Headunit power is an oxymoron, but it if you turn on the internal amp the outputs will be crossed over at the same frequencies as you set for your RCA's.