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View Full Version : how to set RMS for your component set



JoshC
12-13-2011, 08:01 PM
I currently just have my gain sitting at like 1-2oclock slightly below 2v(my alpines preouts are 2v). My question is if i wanted to set the gain using a DMM could i just check the wires running to the amp for impedance or is there a different way to figure the ohm so i can calculate a voltage. Thanks


For clarification, the wires run to a crossover which powers my herts mids and DD tweeters. Thats why im wondering if theres a specific way

kramer_212
12-13-2011, 08:05 PM
i would just do it right at the amp terminals.

J31Rob
12-13-2011, 08:07 PM
I can't believe people still ask these questions like the search feature just doesn't exist.

JoshC
12-13-2011, 08:08 PM
i would just do it right at the amp terminals.

thats what i meant by wires that run to the amp, so i can just hit it with the DMM there and use that impedance to get my voltage?

Also my mids have a RMS of 100 and my tweeters 80, im giving the crossover 90 right now and they sound great. But my rear 6.5's are on my HU so i have 2 available channels. Would it be better to put my rears on the amp OR give my fonts the full 180rms each. Since my 4ch can do 220x2 @ 4

dumple
12-13-2011, 08:12 PM
you should get a better headunit and run active

J31Rob
12-13-2011, 08:15 PM
you should get a better headunit and run active

I second this. Buy my 9887.

dumple
12-13-2011, 08:18 PM
I second this. Buy my 9887.

i second this the 9887 is amazing

J31Rob
12-13-2011, 08:20 PM
..but the Eclipse MKii7200 I've got my eye on is better. :sneaky:

dumple
12-13-2011, 08:22 PM
..but the Eclipse MKii7200 I've got my eye on is better. :sneaky:

im going to custom fab a copper case for the 9887 and then itll be very similar

JoshC
12-13-2011, 08:22 PM
couldnt i also just get an external crossover? although a differnt HU would prob be easyer, so i just read threw on the stickie on active vs passive. So basically theres not point in even using HPF on my HU or my amp if you running a passive crossover before your speaker/tweeter? Thats what i got from it, your yall r suggesting that i get a Head unit that has adjustable crossovers built into it for mids and highs then use my 4ch to power each individual speaker correct?

J31Rob
12-13-2011, 08:22 PM
I can't lie.. 9887 is the best unit I've ever owned up to this point. I hope the 7200 tops it.

dumple
12-13-2011, 08:25 PM
yes using the headunit to tell the amplifier what frequency and what not to play thru speakers

J31Rob
12-13-2011, 08:27 PM
I've done active setups w/crossovers, headunits & external processors.. the 9887 makes it cake for sure.

JoshC
12-13-2011, 08:32 PM
i could also just add the alpine imprint system to my CDA105 and run active that way.

But still havnt answered one question, is there even a point in using the HPF on my HU for my mids/highs or should i turn it off since im running passive
(My high amp is on full pass since i have the HPF set to 80Hz on my HU)

JoshC
12-13-2011, 08:36 PM
What other HU models are good for running active?


NVM i found a list

BnGRacing
12-13-2011, 11:07 PM
If you're using a DMM to guestimate the power your sending to your speakers in hopes you can match the sticker on the woofer's magnet - you'll be in a world of hurt when you go active.

Going active and doing it right is anything but easy. Don't expect good sound from a HU's DSP either.

In short; do not worry about how much power you're sending your interior speakers. You're not going to hear a difference between 60w & 80w and the 'ratings' speakers have are bogus numbers since no one really knows what they mean. Is it RMS for a second? Minute? Pink noise? 1kHz size wave? Music? Who knows...