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zeero3

100x4 Amp and 2 different drivers

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Quick search and I didn’t find an answer to this easy question so I’ll ask here:

If I go with US Acoustics Barbara Ann 100x4 @ 4 ohm amp how can I wire 2 Evil tweets and 2 Evil midbasses? I was figuring buy the tweets in 8 ohm to roughly power them w an estimated 50W from two channels active and get the midbasses in 4 ohm to roughly power them w an estimated 100W from the other two channels active. Is that how it works? Is each load independent on each channel thus getting independent power from the amplifier? This seems obvious but I’m not sure.

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Yes, it sure can, and the amp has active capable crossovers so you can control the cutoff frequencies for the tweeters and the mids as well for a truly active setup. 

The only thing you don’t get in such a setup as you’re looking to do is time alignment, unless your HU has manually adjustable time alignment for each individual output channel. If that’s the case then you’re all set for the best experience of a highs setup you could ask for short of running a DSP. 

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Thanks for the response! You’ve helped make this a little simpler for me. I plan on getting the miniDSP C-DSP 6x8 because I’ll be keeping my stock Honda head unit and I want to get the most out of the drivers (and I LOVE tuning things and this’ll be my first time using a DSP). This leads me to my next questions.

1) in using the DSP, I’m guessing just set all the amplifier crossovers at their “largest” setting to allow the most frequencies and let the DSP go to work? I say this because I believe channels 3&4 on the amp in question does not have a “full” crossover setting (and all mono amps have built in xovers).

2) if I buy a mono amp US Acoustics Mike, that delivers 1500W but have a sub (SI Mag v4 12”) that is rated by the manufacturer at about 1kW, what’s the appropriate way to safely “give less” power to the sub? Gain? DSP settings? Buy a different amp? 1500W is fine?

thanks in advance!

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3&4 have the HP setting that can be adjusted down to 15hz which easily gets the crossover out of the way. You’re correct on the mono amp though, just adjust it to the top of it’s adjustment and let the DSP do the work. 

That sub will probably handle 1500wrms without a problem, however due to the dynamic nature of music it won’t really be a concern. As a matter of fact the extra headroom from the few hundred extra watts on tap will only help prevent distortion. That will help it sound better and be easier on the sub in the long run. 

Headroom is a good thing as long as you can understand what the limitations are and act accordingly when you believe there could be a problem while it’s playing. I’m currently running a rated 300wrms a channel to a set of components that are rated 125wrms. I have a pair of Fountek FR88EX 3” full range drivers rated 15wrms being powered by 75wrms. I also ran a pair of 10” SSA DCON’s (rated 400wrms) on an Arc Audio XDi2000 that had 2.5x their rated power on tap. The only reason I had an issue with the DCON’s is because the enclosure failed and they were mechanically damaged. Those subs were fine thermally. The components and full range are running great still. The headroom on tap allows me to get incredible clean response from the speakers I’m using but I also don’t get stupid with the volume knob. Don’t get me wrong I do push things hard but I’m VERY alert to what’s going on and I have the crossover and EQ settings dialed in to allow me to get by with that kind of power headroom. For what it’s worth another forum member had the same components with 600wrms on tap for each channel. It’s just a matter of setting things up correctly and knowing you’re not using every bit of that power except on the most dynamic (powerful) musical peaks. 

There’s a thread on the forum related to headroom and the dynamics of music. It’s a great read to get a firm grasp on the subject. I’ll see if I can find a link. 

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Great choice on amp, mids, and highs.

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Quick update and quick question:

Everything is finally in! Everything sounds awesome and now it's time to tinker...

I have the Evil tweets mounted in a pod on the A pillar of a Honda Accord and the Evil mids are at the bottom of the front doors.  With that run of the mill setup, what would be your starting point when it comes to crossing the mids and tweets?  I've been playing with it but keep going back and forth and I've gotten a lot of mixed advice searching the forum.  With your obvious experience with these components, where would you say is a good starting point to work from?  Would 3kHz with steep crossover slopes fit the bill?

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9 hours ago, zeero3 said:

Quick update and quick question:

Everything is finally in! Everything sounds awesome and now it's time to tinker...

I have the Evil tweets mounted in a pod on the A pillar of a Honda Accord and the Evil mids are at the bottom of the front doors.  With that run of the mill setup, what would be your starting point when it comes to crossing the mids and tweets?  I've been playing with it but keep going back and forth and I've gotten a lot of mixed advice searching the forum.  With your obvious experience with these components, where would you say is a good starting point to work from?  Would 3kHz with steep crossover slopes fit the bill?

I would suggest starting lower around 2200hz or so and have a shallow slope between the two.

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2600 htz with a 12 dB slope (my favorite starting point). 

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