Time Alignment and Bandpass when going Active

[wutang512 3]

Can anybody explain to me what each of these does and how can it benefit the sound I'll be reproducing in my system.

The deck I will be using will be the Alpine CDA-9887

Also do i have to or need to measure anything when I do time alignment

I wanna be able to do this right the first time and for the last time in my vehicle.

Any suggestions welcomed

Edited June 24, 2010 by wutang512

[Kanaworm$ 292]

Brad or Sean better handle this one! They are way better explaining the technical side of these subjects.

[///M5 2,833]

Right the first time isn't going to happen. There is no rule of thumb that will work.

Generically speaking you want to bandpass your mid with a HP that allows it to play as low as possible for the listening levels and music you listen to. If it ever sounds stressed you need to raise it. The LP on the mid is a bit trickier as underlap, overlap, or the same cross point can all work depending on your installation locations and personal preferences.

Typically as a rule of thumb you want to figure out how low your tweeter can play the same as with the mid, but you have to be much more careful as it is very easy to blow the tweeter.

Once you have those ranges then you have to figure out when/where they mix the best. This could take many, many hours.

Time alignment generically is used to compensate for path length differences. How to use it will depend on where your speakers are mounted, but usually you take the furthest away and adjust the rest to match.

[wutang512 3]

Right the first time isn't going to happen. There is no rule of thumb that will work.

Generically speaking you want to bandpass your mid with a HP that allows it to play as low as possible for the listening levels and music you listen to. If it ever sounds stressed you need to raise it. The LP on the mid is a bit trickier as underlap, overlap, or the same cross point can all work depending on your installation locations and personal preferences.

Typically as a rule of thumb you want to figure out how low your tweeter can play the same as with the mid, but you have to be much more careful as it is very easy to blow the tweeter.

Once you have those ranges then you have to figure out when/where they mix the best. This could take many, many hours.

Time alignment generically is used to compensate for path length differences. How to use it will depend on where your speakers are mounted, but usually you take the furthest away and adjust the rest to match.

And Bandpass does require a 4 channel amp with a Subsonic filter Correct?

[Kanaworm$ 292]

Bandpass can actually be accomplished with a 2 channel with variable low pass and a SSF. But that also depends on whether you are running a 3 way active front stage. But a 4 channel can be used for a 2 way active system.

[wutang512 3]

Bandpass can actually be accomplished with a 2 channel with variable low pass and a SSF.

Hmmm.... Explain more please

Ive been searching for about the past hr a 4-channel amp 100watts or more at 4 ohms

with a subsonic filter without going over $250 used or brand new

[Kanaworm$ 292]

The Sundown SAX-100.4D is a great amplifier for the money with a 2 way electronic crossover network along with line outs. 12 or 24db per octave selectable slopes, variable frequency adjustment, x10 switch to multiply the frequency higher to run tweeters.

Sundown Audio - SAX-100.4D

A little out of your price range.

[wutang512 3]

The Sundown SAX-100.4D is a great amplifier for the money with a 2 way electronic crossover network along with line outs. 12 or 24db per octave selectable slopes, variable frequency adjustment, x10 switch to multiply the frequency higher to run tweeters.

Sundown Audio - SAX-100.4D

A little out of your price range.

I seen DB-r has them for $290 Refurb

and When I think about it ill only be paying $100 for it since i sold my inifinity amp for $130 and opened a chase account with a coupon which they gave me a extra $100.

Might as well get it. Ive seen everybody else around here with sundown products and have heard no complaints

[wutang512 3]

you dont think sundown will revise the 100.4D Any time soon?

[stevemead08 752]

theres one used on here for $260 i believe

[wutang512 3]

theres one used on here for $260 i believe

I think i seen that one its the C revision.

whats the difference between the C and D revisions

[Kanaworm$ 292]

C to D the Crossover section was improved and iirmc the heatsink was changed to the new casing.

[wutang512 3]

yeah i definantly want the D revision then

[///M5 2,833]

Right the first time isn't going to happen. There is no rule of thumb that will work.

Generically speaking you want to bandpass your mid with a HP that allows it to play as low as possible for the listening levels and music you listen to. If it ever sounds stressed you need to raise it. The LP on the mid is a bit trickier as underlap, overlap, or the same cross point can all work depending on your installation locations and personal preferences.

Typically as a rule of thumb you want to figure out how low your tweeter can play the same as with the mid, but you have to be much more careful as it is very easy to blow the tweeter.

Once you have those ranges then you have to figure out when/where they mix the best. This could take many, many hours.

Time alignment generically is used to compensate for path length differences. How to use it will depend on where your speakers are mounted, but usually you take the furthest away and adjust the rest to match.

And Bandpass does require a 4 channel amp with a Subsonic filter Correct?

Bandpassing your mids will be done completely in the 9887.

The SSF is ONLY for your subwoofer, but with the LP of the headunit and the SSF your sub will be bandpassed as well.

[wutang512 3]

Right the first time isn't going to happen. There is no rule of thumb that will work.

Generically speaking you want to bandpass your mid with a HP that allows it to play as low as possible for the listening levels and music you listen to. If it ever sounds stressed you need to raise it. The LP on the mid is a bit trickier as underlap, overlap, or the same cross point can all work depending on your installation locations and personal preferences.

Typically as a rule of thumb you want to figure out how low your tweeter can play the same as with the mid, but you have to be much more careful as it is very easy to blow the tweeter.

Once you have those ranges then you have to figure out when/where they mix the best. This could take many, many hours.

Time alignment generically is used to compensate for path length differences. How to use it will depend on where your speakers are mounted, but usually you take the furthest away and adjust the rest to match.

And Bandpass does require a 4 channel amp with a Subsonic filter Correct?

Bandpassing your mids will be done completely in the 9887.

The SSF is ONLY for your subwoofer, but with the LP of the headunit and the SSF your sub will be bandpassed as well.

When I get the amp and deck Ill come back to this thread and ask how to set it up correctly. Im trying to work a crazy amount of overtime

[wutang512 3]

Alright Im back I have the deck installed(9887) and Im wondering as soon as I get my amp in this week how do i set it up. Do I set the crossovers on the amp to full pass or do i set them both to High pass?

[Impious 1,476]

Since you are going to be using the 9887 for all of the crossover duties, you will want to leave the crossovers on the amplifiers set to full pass.

[wutang512 3]

Since you are going to be using the 9887 for all of the crossover duties, you will want to leave the crossovers on the amplifiers set to full pass.

I also dont need to turn on the subsonic filter either since the 9887 can do bandpass

[Impious 1,476]

Depends on if the 9887 will bandpass the subwoofer or not, most of them do not. You might need the SSF if you are using your subwoofer in a ported enclosure.....otherwise you wouldn't need to use it.

[Adrian_D 520]

You don't need to worry about the front stage amplifier's crossovers, just set them to full and start playing with the ones on the head unit.

Rear channels are for mids since they have both low-pass and high-pass crossovers.

For the subwoofer you will need a subsonic filter, the 9887 only has a low-pass on the sub channels.

[wutang512 3]

Ill have the speakers in the doors and the tweeters as well. Whats the most accurate way to measure time alignment cm or inches? And how would I go about doing it?

[wutang512 3]

Just got back from San antonio after work to finish this install the 100.4D came in from UPS yesterday. Got damn this amp is huge. Its bigger than my alpine mrp-1000.

I was trying to figure out how im going to mount it behind my seats. Other than that Ill let yall know in the morning how everything goes as far as tuning.

[jcarter1885 995]

If I got the 100.4D I was gonna get a shelf board for home depot for a few dollars and attach it to both seats so you can put a large amp on it, if you have 60/40 fold seats. It also helps so now you can pull both seats down at the same time, check out my build log for an idea of what im talking about.