# 75w active or 200w passive?



## rodney757 (Aug 4, 2009)

I am wondering if it would be better to go active pushing 75w to each speaker or to go passive pushing 200w to each door?

I currently have pioneer prs-800 HU, Alpine Type-s 6.5" coaxials, and Kenwood exceleron x4r. Channels 3 and 4 are bridged running my hsu 12" sub. I'm going to be picking up a amp for my sub and am looking for some advice on how to run my fronts.

I'm looking for it to be louder w/o distortion then it is now pushing 75w to each door, but am also after the best sq I can get w/the equipment I have.

Thanks


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## t3sn4f2 (Jan 3, 2007)

"The Benefits of an Active Speaker Lifestyle"


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## GibTG (Mar 11, 2010)

More than likely the passive setup would win out in terms of loudness since the passive components will likely eat up only a little power. Bridging the amp will increase distortion in the amp though, it will likely still be inaudible though. 

The passive setup may also simplify the install, making for only one set of wires per door. I say you give it a try.

The active setup gives much more flexibility in tuning, but passive setups have been known for sonic accuracy for a long time.


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## rodney757 (Aug 4, 2009)

Thanks. 

The install would be easy, as all I would have to do is run a wire from the amp to the tweeters in the kick panels.

Are the alpine type-s crossovers any good. I thought I heard that they weren't very good which would lead me toward going active.


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## VWTIm (Apr 10, 2010)

I have that same amp running a set of Diamond D6 components active. Runs great and the levels are set low, plenty of power if you want to go that route.


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## MiniVanMan (Jun 28, 2005)

4 channel amps simplify an active install, but so much is wasted on the tweeter side due to the extreme differences in sensitivity. While you're trying to eke out as much power on the mid side, you're keeping gain way down on the tweeter side to maintain a good level match between the two.

So, if you put 50 watts to a tweeter at 92 db 1w/1m, what would you need on the mid side to level match an 86 db 1w/1m mid? Simple answer 200 watts. 

So, that being said, since the tweeter is already attenuated in the passive crossover, you're much better off just running the extra power to the passives. Though you lose the flexibility of going active, it's something you can pursue in the future, when you have the desire to cram more amps into your install.


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## King Nothing (Oct 10, 2005)

I think people get very hung up on running big power to their doors. I used to as well. The average person doesnt need more than 50w for a set of passive components. I have a diamond d6 set in my truck that I run passive off the front channels of an old school MTX 4320 rated at 40x4 (60x4 realistically). I had every intention of running them off that amp bridged but hooked it up unbridged to test it and it does everything I could ask of it. loud and clear. How do you intend to go active if your running coaxials anyway? or are you asking for future reference?


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## 89grand (Nov 23, 2006)

I don't know, when I ran a passive set, I used a 50w per channel amp, then I switched to a 150w per channel amp and it made a ton of difference. No longer was I clipping the amp every time I wanted that extra bit of volume.

I agree with MVM though because I ran a 4 channel 100w x 4 amp to a set of 720PRS mids and a set of a/d/s/ tweeters and while the amp was over kill for the tweeters, the mids always seemed to need more power.©


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## 8675309 (Jan 8, 2007)

In my car I am sporting this

50 x 2 on the tweeters
50 x 2 on the dome mids
160 x 2 on the midbass
160 x 2 on the front woofers. 

There is nothing wrong with having to much power. 

You just need to use it properly.


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## el_chupo_ (May 27, 2007)

The tweeter volume is a big issue. 

Have you already bought a new sub amp, or do you need more power for the sub?

If not, and you want to go active then you could pick up a low power 2 channel amp for the tweets, use the current amp for mids/sub.

I have 100w X 2 channels for my mids, and 50w X 2 channels for my tweeters, and I still have my tweets down 5 or 6db. I also think I have the gain set a bit higher on the channels for the mids, though I have not been in the amp for a few months and dont remember exactly.

And to correct GIB TG above:

Passives actually use quite a bit of power. IIRC, the generally accepted loss is ~3db, or about 1/2 the power.

Also, passives are not known for sonic accuracy. In fact, I have never heard of them referred to as sonically accurate outside of possibly marketing material.

All they do is roll off volume at a predetermined rate (6/12/18/24Db per octave, depending on design) at the predetermined frequency point.

This is not to say they wont work, or that they will sound bad in your car. but remember that everything is predetermined in the crossover from the factory, so it may not work as well.

Good luck!


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## King Nothing (Oct 10, 2005)

89grand said:


> I don't know, when I ran a passive set, I used a 50w per channel amp, then I switched to a 150w per channel amp and it made a ton of difference. No longer was I clipping the amp every time I wanted that extra bit of volume.
> 
> I agree with MVM though because I ran a 4 channel 100w x 4 amp to a set of 720PRS mids and a set of a/d/s/ tweeters and while the amp was over kill for the tweeters, the mids always seemed to need more power.©


You just convinced me to go out and bridge my amp and see if it changes the sound. even though Im happy with it now..... damn you


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## smgreen20 (Oct 13, 2006)

In a lot of research I have done on Passive Xovers, the general consensus is that for every 6dB the xover slope is, it's ~5% power wasted. 

100 watts
6dB = 95 watts
12dB = 90 watts
18dB = 85 watts
24dB = 80 watts.

Depending on the power, you might not even notice the difference in the power lost. 

Extra power is ALWAYS good, it will provide you with headroom. As said above, having more power then needed wont hurt, as long as you know how to use it. 

I ran 225 watts to each side to a set of Dyn comps (passive) and they loved it, though the xover didn't agree at times, but I then went active on them w/75w to each speaker and it was better, due to the amount of control I had over the sound. I now run actively and wouldn't change for anything. The mids did sound as if they wanted a bit more power in that set up, but I am no longer running the Dyns.


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## rodney757 (Aug 4, 2009)

el_chupo_ said:


> The tweeter volume is a big issue.
> 
> Have you already bought a new sub amp, or do you need more power for the sub?
> 
> If not, and you want to go active then you could pick up a low power 2 channel amp for the tweets, use the current amp for mids/sub.


I haven't bought a amp yet. I was thinking I should run more power to the sub since it's only getting 300w.

I could pick up a small amp for the tweeters instead. Maybe that would be a better idea.

The best option would probably get 2 more amps.

Thanks


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## kyheng (Jan 31, 2007)

You won't be needing much power for your tweeters, 10W is more than enough. 
As for passive component, I won't argue with pro-active fans much, take a capacitor as example, in the market you can see a "X" brand has different series and different tolerence level of capacitors they produced. Ideally, is best to get matched pair with lowest possible tolerence level but it will be very expensive. So some time we tend to choose not matched pair with higher tolerence level just to safe cost. And because of room acoustics, pre-made passive won't suit us most of the time. I've done with passive in my car few years back as when I finished building the passive, I will have a lot of left over components. Now I stay with active just for the sake of simplicity.


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## nineball (Jan 17, 2008)

rodney757 said:


> I am wondering if it would be better to go active pushing 75w to each speaker or to go passive pushing 200w to each door?
> 
> I currently have pioneer prs-800 HU, Alpine Type-s 6.5" coaxials, and Kenwood exceleron x4r. Channels 3 and 4 are bridged running my hsu 12" sub. I'm going to be picking up a amp for my sub and am looking for some advice on how to run my fronts.
> 
> ...



i think you all must have missed that part. the op is running coax, not components. those type-s coax are only rated at 80rms, so feeding them 200rms would not be a good idea.


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## rodney757 (Aug 4, 2009)

Shoot i just realized that I put coaxials, when I actually have components.

Also what would be a decent 2 ch amp to run the tweeters? Preferably not too expensive.


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## nineball (Jan 17, 2008)

well the same thing applies. the type-s comps are rated at 80rms. throw 200 at them and you will be buying a new set soon.


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## Candisa (Sep 15, 2007)

I didn't read the entire thread, so I don't know if this is suggested already but why don't you get a more powerfull 2ch amp to power the midwoofers and use your current 4ch to power the sub?
This way you have the same power on your sub as you have now and 2x75W, which should be more than sufficient, but more power on the midwoofers!

Isabelle


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## 89grand (Nov 23, 2006)

nineball said:


> well the same thing applies. the type-s comps are rated at 80rms. throw 200 at them and you will be buying a new set soon.


Not necessarily, the 80 watt rating is more than likely running full range. Having them high passed at around 80hz would significantly raise their power handling.

I ran 150 watts into an MB Quart 5.25" and Focal tweeter though the Focal passive crossover with no issues at all, and I'm sure they weren't rated to handle that much power.©


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## t3sn4f2 (Jan 3, 2007)

89grand said:


> *Not necessarily, the 80 watt rating is more than likely running full range. Having them high passed at around 80hz would significantly raise their power handling.*
> 
> I ran 150 watts into an MB Quart 5.25" and Focal tweeter though the Focal passive crossover with no issues at all, and I'm sure they weren't rated to handle that much power.©


For sure. I used to run an Orion 2150SX into an OZ Audio Matrix 100 CS 4" component set mounted in a 93' RX-7's Bose sealed door pod without an issue. They were high passed with a Soundstream SVX2 active crossover set at 100Hz and 12dB. 

They would take the power with any music. Gains set to clip the clip lights on the amp at 3/4 head unit volume. I would bring it up and past that point all the time when I wanted the output.


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## NOFATTYS (Jan 5, 2009)

Forgive the highjack...but I am looking at something similar. I would like to run a 3 way Zapco Competition setup, with a KT-8.25 tweeter, a ZCM-8.130 5in midrange, and a ZCM-8.165 6.5in midbass through a Audison LRx5.1k.

If I ran the tweet and 5in mid passively through channels 1/2, will this amp give me enough juice to run the speakers effectively, with channels 3/4 going to the 6.5in midbass, and channel 5 going to my sub?

The specs on the amp are

60x2 @4/ [email protected]/ [email protected]

Thanks for the help, sorry again for the highjack


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## rodney757 (Aug 4, 2009)

89grand said:


> Not necessarily, the 80 watt rating is more than likely running full range. Having them high passed at around 80hz would significantly raise their power handling.
> 
> I ran 150 watts into an MB Quart 5.25" and Focal tweeter though the Focal passive crossover with no issues at all, and I'm sure they weren't rated to handle that much power.©


Ya, I have the HP at either 80 or 100hz, so they should be able to handle the power as long as I'm not clipping the amp.

Any amp recommendations for the tweeters?


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## nineball (Jan 17, 2008)

89grand said:


> Not necessarily, the 80 watt rating is more than likely running full range. Having them high passed at around 80hz would significantly raise their power handling.
> 
> I ran 150 watts into an MB Quart 5.25" and Focal tweeter though the Focal passive crossover with no issues at all, and I'm sure they weren't rated to handle that much power.©


i am sure crossing them would help with power handling but i really can't see it helping it handle 2.5 times the rated power. who knows, maybe it will be fine. maybe it will blow. to each his own.


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## MiniVanMan (Jun 28, 2005)

nineball said:


> i am sure crossing them would help with power handling but i really can't see it helping it handle 2.5 times the rated power. who knows, maybe it will be fine. maybe it will blow. to each his own.


Test subject is a Dayton RS180-8. First graph is 75 watts. Notice Xmax limits excursion at 75 hz in this case. You'd want to cross at 75-80 hz.










Next is the woofer ran at 200 watts. Xmax limited excursion is at 100 hz. More than 2.5 times the power.










In either case, the power is dynamic and not continuous. So, the woofer would rarely see the full power in either case. What the 200 watts would allow is much more dynamic headroom for the full bandwidth of the driver. 80 hz bursts will be fine as you're still not even close to Xmech. Now, clip the amp, and throw an 80 hz sine wave on the thing, and the driver will cook really quick. But, being smart with the gains, and crossover point and you'll be fine. 

Also those graphs are essentially, IB, with a Qtc of .5. Driver excursion is barely limited by air pressure. Create a well sealed off enclosure, and you'll have even better excursion potential.


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## 89grand (Nov 23, 2006)

Can't argue with actual test data! It pretty much behaves as expected. Not only does it pretty much prove my point, it should also show some people that like to cross 6.5's at like 50hz, precisely why not to do it.©


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## rommelrommel (Apr 11, 2007)

nineball said:


> well the same thing applies. the type-s comps are rated at 80rms. throw 200 at them and you will be buying a new set soon.


I ran 175wrms to my tweeters in my last install, somehow they're still intact!


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## MiniVanMan (Jun 28, 2005)

rommelrommel said:


> I ran 175wrms to my tweeters in my last install, somehow they're still intact!


No you didn't. 

You ran an amp capable of 175 wrms to them, but I can guarantee they never saw 175 watts. First of all, musical content in the octaves covered by a tweeter use much less power than what's needed to provide dynamic output at 80 hz. 

But, that still brings up a great point. What do amplifier ratings really mean?


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## 89grand (Nov 23, 2006)

MiniVanMan said:


> No you didn't.
> 
> You ran an amp capable of 175 wrms to them, but I can guarantee they never saw 175 watts. First of all, musical content in the octaves covered by a tweeter use much less power than what's needed to provide dynamic output at 80 hz.
> 
> But, that still brings up a great point. What do amplifier ratings really mean?



Exactly. I ran a JBL GTO 75.4 II rated at 104w x 4 to run an active system made up of 720PRS mids and a/d/s/ tweeters, the front channels that the tweeters were on were just loafing along, while I pushed the rear channels hard that were running the mids, I wish I could have made that amp, 150w x 2 + 50w X 2, or may even 175w x 2 + 25w x 2. I may have had a 100w per channel rated amp on the tweeters, but they were getting no where near that.©


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## King Nothing (Oct 10, 2005)

89grand said:


> Exactly. I ran a JBL GTO 75.4 II rated at 104w x 4 to run an active system made up of 720PRS mids and a/d/s/ tweeters, the front channels that the tweeters were on were just loafing along, while I pushed the rear channels hard that were running the mids, I wish I could have made that amp, 150w x 2 + 50w X 2, or may even 175w x 2 + 25w x 2. I may have had a 100w per channel rated amp on the tweeters, but they were getting no where near that.©


I wish we could see more staggered 4 channels


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## redcalimp5 (Sep 10, 2007)

rodney757 said:


> Shoot i just realized that I put coaxials, when I actually have components.
> 
> Also what would be a decent 2 ch amp to run the tweeters? Preferably not too expensive.


I run my tweeters with an older Soundstream D100II, and it does a great job. Great build quality, it's very small, and does 50X2 at 4ohms. 

Best of all, though, it has seperate L/R gain adjustments. You can find them in good condition from $70-$100 shipped, usually.


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## naiku (May 28, 2008)

el_chupo_ said:


> If not, and you want to go active then you could pick up a low power 2 channel amp for the tweets, use the current amp for mids/sub.





Candisa said:


> I didn't read the entire thread, so I don't know if this is suggested already but why don't you get a more powerfull 2ch amp to power the midwoofers and use your current 4ch to power the sub?


Thank you both, you just gave me some more options on my install. I already have an Alpine MRV-F345 that I had previously used to run my sub off channels 3-4 bridged at 300W, and was running coax off channels 1-2.

I had been planning to pick up a mono amp to run the sub, and keep the 4 channel for mids/tweets. The suggestions to pick up a 2 channel amp instead makes a huge amount of sense, I never felt like my sub was lacking at all on 300W, so now have far more options for an amp for my mids or tweeters.


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## rodney757 (Aug 4, 2009)

Thanks for the help


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## rc10mike (Mar 27, 2008)

Im running a TRU T03 2.250 to my KRX2 comps passive. They're 2ohm so the amp should realistically push about 400w RMS per side. Is it too much? Probably, but it sure sounds crystal clear even at the highest tolerable volumes.


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## mellephants (Oct 7, 2010)

King Nothing said:


> I wish we could see more staggered 4 channels


agree

Also this thread wins so much


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## redcalimp5 (Sep 10, 2007)

tvrift said:


> Im running a TRU T03 2.250 to my KRX2 comps passive. They're 2ohm so the amp should realistically push about 400w RMS per side. Is it too much? Probably, but it sure sounds crystal clear even at the highest tolerable volumes.


I'd love to demo your setup sometime, but unfortunately we're 2,000 or so miles away.


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## subiemax (Nov 19, 2007)

If tweeters only need 10 watts, how bad would it be to run a set off of a head unit. I have about the same set up. Set of components, sub and a 4 channel amp. My Alpine 9887 is able to run active, so how bad would it be to run tweeters off the deck and mids and sub off of the amp? Eventually I will get a sub amp and run the set active off the 4 chan, but untill then I will experiment with using the deck to power the tweets and running passive to see what sounds best.


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## redcalimp5 (Sep 10, 2007)

subiemax said:


> If tweeters only need 10 watts, how bad would it be to run a set off of a head unit. I have about the same set up. Set of components, sub and a 4 channel amp. My Alpine 9887 is able to run active, so how bad would it be to run tweeters off the deck and mids and sub off of the amp? Eventually I will get a sub amp and run the set active off the 4 chan, but untill then I will experiment with using the deck to power the tweets and running passive to see what sounds best.


A lot of people on the forums run their tweeters off of HU power, so I think you should be fine. As you said, if you don't like it after a while, you can change it up down the road.


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## mellephants (Oct 7, 2010)

Has anybody tried CTX tweeters on an Alpine HU? These are from the CTX65CS component set. I think they are these: CTX-25 - Image Dynamics CTX Series 1" Silk Dome Tweeters

So they claim 50wrms handling, but what do they actually need to keep up with the woofers on 150wrms

EDIT made my own thread/poll http://www.diymobileaudio.com/forum...dvanced/90535-ctx65cs-active-amp-options.html


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## rc10mike (Mar 27, 2008)

redcalimp5 said:


> I'd love to demo your setup sometime, but unfortunately we're 2,000 or so miles away.


Ive since then switched to active with a DDs4 staggered 4ch....sounds much better IMO, but its probably due to the auto T/A, which works much better when running active.


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## Cruzer (Jul 16, 2010)

Why don't amp companies make at least some if not all active amps have 2 channels do whatever 25 watts or 50 watts then make the other 2 channels do at least 100 or more watts?

Especially being an active amp it makes sense IMO. Then could still have the channels bridge do even power for passive.

My other question is, can I run my tweets off hu power through a passive crossover if my hu isn't active capable? Or would the crossover eat most of the power?


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## SpeedEuphoria (Sep 15, 2010)

Cruzer said:


> Why don't amp companies make at least some if not all active amps have 2 channels do whatever 25 watts or 50 watts then make the other 2 channels do at least 100 or more watts?


I think then they lose some flexibility and will sell less amps and most everyone runs different power to different kind/brand of speakers.


I think most of this thread is on, the quality of components and the x-over used had a LOT to do with it though. I was thinking about this just recently and since my components/passives are not up to par splitting them up was the way to go forsure.

I just got done setting up my Eclipse budget 3-way. With the stock x-over the highs are overwhelming when running through the passives. It has tweeter attenuation but the mid is what really needs the attenuation. The midbass could use more. I switched to mid/tweet on separate channels from the midbass on my new 80x4. Let me tell you its great!! I switched the tweet back to +3db from the -3db where I was trying to lessen the mid. But yeah The mid/tweet is 1 click of gain and the midbass is full power 1/2 gain. It sounds how it should now.

I could really use one of the fancy active amps that your talking about cruzer.


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## Heath (May 3, 2009)

Passive


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## Cruzer (Jul 16, 2010)

SpeedEuphoria said:


> I think then they lose some flexibility and will sell less amps and most everyone runs different power to different kind/brand of speakers.
> 
> I could really use one of the fancy active amps that your talking about cruzer.


I got my active amp for $155, which imo isnt bad and i dont like to spend any more than i have or want to.

why do they lose flexibility?

my point is this, people claim active is usually better than passive. But if u go active and ur amp does 50x4, ur sending more power to the tweets than u really need, and ur mids regardless of rms rating could use more so long as u cross higher up.

i had a 2 channel amp that did 60x2 and i had it running components passive that were rated for 90 watts per side. so i was under powering them, and i could tell it, my mid bass was poor.

i just got my active amp and it does 160x2, and the difference in mid bass is HUGE and that was just throwing the amp in, turning the gain up to just hear it. nothing is set right or for best performance. the mids are rated for 40 watts rms, yet i have 160 for it and a 50watt rms tweeter. the mid is probably seeing around 100 watts, and it sounds good as far as mid bass.

now if i go active, sure i can set crossovers differently than the set passive, but will 50 watts do the mid justice for mid bass duties? maybe it will be good enough, but i doubt it will compare to the 100 watts or more that made them sound so good.


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## subiemax (Nov 19, 2007)

I switched from running 75x4 active, to bridging the amp and putting 250x2 to the mids. And running the tweets off the HU. So the tweeter are getting 18x2 and I have to turn them turned down to ballance with the mids. Mids sound a lot better with all the head room.


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## Cruzer (Jul 16, 2010)

subiemax said:


> I switched from running 75x4 active, to bridging the amp and putting 250x2 to the mids. And running the tweets off the HU. So the tweeter are getting 18x2 and I have to turn them turned down to ballance with the mids. Mids sound a lot better with all the head room.


how are you managing the tweets? how do they know what to play and what not to play, sry noob here


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## subiemax (Nov 19, 2007)

My HU has crossovers built in.


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## Cruzer (Jul 16, 2010)

aww active hu =/

could i run the tweeters off hu power through passive crossover? would crossover eat most of the power and it suck? anyone?


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## subiemax (Nov 19, 2007)

^^^^I tried the last option you listed, and the sound was great. But I had TA issues, tweeter in a-pods are really close on drivers side, which made me run tweets off deck until I can find another solution.


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## SpeedEuphoria (Sep 15, 2010)

Cruzer said:


> why do they lose flexibility?


I was saying if they made an amp that is 4channel, 2x150 and 2x25, this would cause soe people to not want/need it as everyone's setup is different.



subiemax said:


> I switched from running 75x4 active, to bridging the amp and putting 250x2 to the mids. And running the tweets off the HU. So the tweeter are getting 18x2 and I have to turn them turned down to ballance with the mids. Mids sound a lot better with all the head room.


Thats what I was thinking about doing but the tweet would be passive off the headunit



cajunner said:


> head unit power = suck.
> head unit power + passive crossover = more suck.
> head unit power + passive crossover + bridged 4 channel on mids = suck.
> head unit power turned off, bridged 4 channel on mids with front 2 channels running tweeters off passive crossovers = okay.


basically your saying head unit power =suck

but giving up the left/right balance and or TA on the mids is OK?? Can you better explain as I'm not really sure what


> head unit power + passive crossover + bridged 4 channel on mids


 means? and the next one is chan 3+4 bridged right?

Only prob for me is bridged to mids is a 2ohm or 8ohm load so basically not worth it


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## subiemax (Nov 19, 2007)

No we are talking about bridging two channels to the left mid and two to the right mid and either using a passive or the means for the tweets.


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## Cruzer (Jul 16, 2010)

SpeedEuphoria said:


> I was saying if they made an amp that is 4channel, 2x150 and 2x25, this would cause soe people to not want/need it as everyone's setup is different.


Like i said, dont make every amp that way, still make the usual 50x4 75x4 100x4, but u could make these as well.

ya 25x2 and 150x2 doesnt suit everyone, but neither does 50x4, what if my stuff is rated for 60 or 70, i have to settle for 50x4 or 75x4.

if u did 100x2 and 2x50, i wouldnt see why it would not sell. most tweets dont need more than 50, most mids are rated less than 100rms, so 100 is fine, or 150 for others that are rated more


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## SpeedEuphoria (Sep 15, 2010)

subiemax said:


> No we are talking about bridging two channels to the left mid and two to the right mid and either using a passive or the means for the tweets.


right so your talking 6 chan or multiple amps

no free lunch here


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## corcraft (Nov 16, 2010)

Ok, all of this is based on the tweeters being allot more efficient. Let's say that they're both rated at a 91db sensitivity and they're both about the same distance away from the listener. Still less power to the tweeters?


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## subiemax (Nov 19, 2007)

I settled on a JL 600/6. 4 channels bridged to the mids for 200x2 and 2 to the tweets for 80x2.


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## Bayboy (Dec 29, 2010)

You know I often wished amps were available with staggered power. Believe it or not around the early 90's I had one made by Pyramid. :blush: Yes, I know, but it did exist. The front channels were something like 30 watts and the rear were quite higher. Although I didn't run the rears to mid bass/ or mids it was very useful. The only choice like stated earlier is a giant a$$ 6 channel or 2 separate amps with different power. Not really fond of either setup but that's the breaks!


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