My friend's messing around with a stereo at the moment. And he was curious to know if it's possible to have a set of 4 ways component speakers up front on a 2 ohm load and run his subs 4 ohm still. Will this effect his goal for SQ? Would it back and turn into SPL... or would it just make no sense at all? Would he require an EQ to balance s**t out? He wants to cruise his subs but have the fronts running hard. The 4 way are 1x6.5" Midbass, 2x4" Midrange and 1x1"Tweeter. The front will be getting 200WRMS on a 4 ohm load off a 4 channel amp. The subs will have around 500-600WRMS on a 4ohm load. Would this make any sense or is he wasting time? This one is out of my league to answer so any advice would be good.

No detremental effect unless the amps THD reaches audiable levels at 2ohm.


No.


Yes it does make sense provided he set's it up right - ie how ddoes he intend to achieve a 2ohm front stage?


All depends on the choice of speaker and their placement, but runnign at 2ohm qould require no more equalisation that if they were 4ohm. Just match the gains on the sub and front stage amp an he'll be all set.


Most of it makes sense except having two set of 4's.

and secondly, just cuz something doesnt sound good, doesnt automatically mean it "turns into SPL". SPL is about loudness. u can still have quiet, poor sounding stereos.

it sounds like a disaster to me.
if he needs to ask these sort of questions he shouldn't be attempting such things.

how does he intend to setup the crossover?
looks to me like he'll need a custom 3 way crossover (the midranges will be fine in parallel) but they're not cheap!
otherwise he'll need an active setup, with 6 channels of amplification and an active crossover.
unless he's talking about using 4 sets of coaxs instead of a 4 way component set...
in which case it's a bigger disaster.
he'd be much better off buying an existing 3 way set and wiring them off the standard crossovers (4ohm) the reduced frequency range per driver usually means better power handling.

If he wants his fronts to run hard then get a bigger amp!
As Mr Bob alluded to, what is this dude planning on running in terms of xover and amplification?

Custom 4 way passive or active xover? Active or passive xover with the 2x4" wired together (which would sound like bum in the passive case!)
With running off an existing 3way Xover you really couldn't do it passive - the impedence drop or rise from wiring the 4's together would stuff that up - the only way you might try is actively requiring an external Xover and a larger amp.
Running off a custom passive or active 4 way xover you are either going to need a hell of alot of amp channels (active) or a pretty large amp running 2 channels (passive).

The up side of running a custom 4way passive system is you need less amp channels and you will be able to invariably choose the impedance at which the crossover is manufactured.
The down side is that manufacturing such a unit will cost more than this dude's car.

I thought it sounded like a mind job! He was hoping on putting the lot on a 3 way passive crossover with the 2x4" mids parellel. Maybe he needs a head check!
Mr. Bob, what do you mean by an active setup? He is wanting to run an extra 4" (or a 6.5" if he can source one) off his 3 way split setup.... no coaxials.

ok, if he's got 3 ways, then he acn't just wire an extra 4" driver in parallel, this will acuse attentuation problems, but more importantly, it'll throw the xoverpoints out of whack, it'll sound horrible and potentially cause damage to the 4" drivers.

he can run teh 3way splits off the passive Xover, then run an extra 4" off a seperate amp (or seperate channels on the same amp) but it'll require Xovers that don't normally come on an amp, so an external crossover will eb required.
all in all, ti's ALOT of work, lots of custominsing to fit teh 4 ways in, extra amp channles, special Xovers, i'm sure there's a better way to achieve his results without the hassle.

an active setup is where the speakers are connected directly to the amp (no passive crossover) and the amp/hu/external acive xover filter the nasty frequencies out for you.

Well, he has a 4 channel, so can he run the 3 way crossover with the 6.5/4/1 connected in passive off one set of channels and the extra driver on the spair channels remaining on the amp? Still require major messing around, yeah?

well that's got the amplification sorted, but he'll still need crossovers.
we'll probably need to Bandpass them between 400 and 4khz, but he should really set it up to match his existing 4" crossover settings. (need to contact manufacturer)

only some amps will have Xovers that will adjust that far, but if it can HP at 400Hz, he can build a passive LP at 4Khz without too much hassle. (i'll help if needed)

how is he going to put these speakers in his car? it's going to require ALOT of messing around and custom work... if he just puts them "where they fit" it'll sound horrible and the benefits of teh extra 4" will be lost to cancellation.
it'll also be very hard to get imaging right (it's difficult enough with a 3 way setup)

He's going to customise the install (fibreglass pods)
He wants to use the Hertz 3 way crossovers and the amp he has is the MRV-1005 V12 Alpine

I just had a look at the specs on that amp. I think he can only get as far as 200Hz

Running 2 lots of midranges will cause a lot of problems. I wouldnt bother. The easiest and prolly the best solution is to bridge the 4 channel to 2 ch and then run the 3 ways off that using passive. It wont have any downside unlike running a pair of 4s per side will. As they say on Rikki Lake..."Don't go there"
peace
Cyberpunky

That's what I'm doing on MY own set-up.. but this "peanut" wants to be different.
But, out of curiosity.... would it work running an extra midbass? Like another 6.5" or being even more daring with an 8"?
Better off keeping it 3 way, yeah?

Spot On

i hop ethe hertz crossover suits his install and components properly, you can't just use any old crossover!!

if you want to run an extra 6.5" it's a bit easier...
you can't really run them as part of the passive Xover set, without re-designing it, but you can run them active, the crossover values are low enough that alot of amps are capable....
the beauty of multiple midbasses is that they aren't as location/angle dependant as your midrange..... so you can benefit from this without extreme custom work (depending upon yuor door trims)
there's little point running a 1,4,6.5 and 8" unless you're going to use the 8" as an upfront sub, and not have a sub aswell.
but you could swap the 6.5" for an 8" if it suits the crossover, that's probably the best option so far.

keep it 3 way up front

make sure you get the passives that are designed and made for the set you want. You can get away with a passive (2way passive) that comes with the 4inch and tweeter and run the midbass active without a passive x-over.

DONT use dual 4inch mids per side

if you want to be a little different run a 8inch midbass rather than a 6.5 in the same range of speakers this WILL make a big difference in the midbass capabilities.


if you asked me to choose between a home speaker with dual midranges per speaker vs single mid per speaker..i would ALWAYS choose a single mid, yes its not as loud but if the designer doesnt stuff up the x-over the single mid sounds better. Dual midbass is fine so if you want to run dual 6.5inch midbass in each door that can be done , or an extra set of tweeters (correctly setup can help with soundstage height..but i still prefer a single tweeter per side)

bottom line

if he wants to double up on something make sure its the subs or midbass units.

if you do a dual midbass setup the normal passive x-over shouldnt be used for these drivers a x-over designed for 4ohms doesnt work properly at 2ohms or 8ohms. Setup the midbass on their own channels (2 channels) and run them purely active. Use the passives that come with the 4inch and tweeter. SO doing this will require 4channels of power amp, dual 2 channel or a single 4channel with x-over settings builtin or in the headunit.

if you do go active/passive combo look at the midbass lowpass point to be from 200hz to around 150hz for a 4inch. 12db/oct would be the minimum slope.

if the guy wants to choose dual 4inch mids so that he can make his system go louder there is another option. USe under-dash HLCD horn loaded compression drivers and some midbass units. THis WILL be loud and very different. Check the s/h area

I've told him to keep them as 3 ways at the front and use the 4" midranges in line with his spare tweeters as rear fill. Run them of the HU direct with a cap to take out the distortion and so he can always fade them out easily.
The Hertz crossover I had checked out by Rob at Custom Car Sound in Reservoir (Kicker Importers for Australia). Rob's the tech. He said the specs on the crossover can suit the 3 way setup just fine. He mentioned to set the crossover to around 120Hz-140Hz on HiPass off the amp on a 4 ohm load and it should be safe.

Is he missing anything else here?

Agreed...

As far as the crossover goes, what drivers is he using? I am rather skeptical that another passive crossover will match the drivers all that well. It isn't just about crossover points and slopes, the crossover also has to match the sensitivities of the drivers, account for the impedance curve of each driver, even equalize the response in some cases etc. But who knows, it may still sound fine to your mate...

As far as high passing the splits go, I would normally start a lot lower than 120hz and slowly tune it until you find what sounds best. (obviously, you will also need to adjust the subwoofers low pass filter and make sure the subwoofer volume level is set correctly when tuning the high/low pass filters.)

That would be something I'd leave to the pros to fix. He copied my idea of a 3 way Kicker Impulse split system and he picked up some Hertz 3 way passive crossovers like my ones interstate. I haven't installed mine as yet. But he's eager to get his in. I'm still getting my wiring and subs before I even thinking of installing anything.

When I was after the optional 6.5" Midbass add-on driver kit, it took 3 months for JB HiFi to tell me Kicker stopped doing them. So that's why I tried looking for an alternative universal passive crossover to suit.

Well, I've told him all this and he's just turned around and said "I wasted my cash". He said he should've gotten his hands on the Type R 3 way splits. They still around anywhere in VIC? Anybody?

You can buy complete Hertz 3way splits already, with 6.5inch 4inch and tweeters.

Upgrade the 6.5inch woofer to the hertz 8inch woofer and it only costs $50 extra.

Then bridge the amp and power the whole setup and it will sound very good.

ALternatively Hertz also have a 3way crossver that allows a 2ohm load on the midbass channel, so you can run two 6.5inch woofers a single 4inch and tweeter.

This crossover is the same cost as the normal 4ohm one.

Could then buy the 3way HSK splits, change the crossover to teh 2ohm version and buy anotehr pair of 6.5inch woofers. However the amp would not run Bridged into a 2ohm load.

Go with the 8inch 4inch and tweeter, i've heard a set before and it sounded amazing.

Hmmm.... ideas for me now!!!
I kind of don't want to part with my kickers. As for my friend, he just flicked his 3 way splits off and just stuck to the 2 way splits .

I'm still sitting here though thinking well, I wouldn't wan't to hack into my doors as it is, as I need fibreglass just to fit the 4" in the doors with the 6.5" let alone trying to squeeze an 8". If I can find an extra 6.5" driver, either a carbon fibre jaycar response 4 ohm or something... unless somebody has a set of unwanted Kicker Impulse I6.1 splits, then I'll take the driver from there and have the 2 Midbass drivers with a single mirange/tweeter... bit better?

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