Hi peoples I am at the stage of doing the boot build out and I am making a few decisions as wether to go fully active with my amplification or stick with the 4 channel I have.

Headunit: IVA310E
Fronts: Dynaudio 340 3 ways
Front Amp: Alpine PDX 4.150
Sub Amp: Alpine PDX 1.1000
Sub: DD Audio 9112

My dillemna is now that I added the monoblock sub I have only the front stage running off the amp (birth certificate 187wrms x 4) to run the dyns

Will I be better off buying a PDX 2.150 to run the mid bass drivers seperately and then run the midrange + tweeters of the 4 channels of the PDX 4.150 or would I not notice the difference over running the PDX 4.150 in bridged mode to produce approx 350wrms per dynaudio crossover???

From all accounts, active with Dyns is definitely the way to go. In fact, I dont know of a single stock passive setup with Dyns that does sound very good. Although my knowledge is largely of CAAVIC only, even the few Dyn setups in QLD that I know of, are active (e.g. TUN35, Phat Devil)

As for the other people who have gone active: Shiny, Pyro, Amfibius... just to name a few. Some rather nice sounding cars in there, that have had success in CAASQ VIC. And I believe Phat Devil and TUN35 both won their respective classes this year (I think?)

Ideally get a loan of a PDX-2.150 and actually try it. It wouldnt be a whole lot of work for the piece of mind it gives. At least then you wont be left wondering.

)

what of bruces car then???(cyberpunky


IMO, the best stereo image and stage iv ever heard, ever



going active will yield two thing: a little bit more power to your speakers, enough to notice, maybe!?

and the loss of the impedance correction network...

the dyn passives are superior to many stock passives, and are very well designed and thought through...

The idea of a impedance correction network is to ensure the passive crossovers Crossover points do not
fluctuate severely.

Since impedance rises/drops have no effect on the active crossover point, the only advantage of the impedance correction is to reduce stress on the amplifier, however most amplifiers can handle regular speaker loads without flinching, and actually produce more dynamic power without impedance correction.

in any which case, adding a zoble network to any speaker power line, isn't exactly rocket science.

In regards to the main query,

avoid bridging the pdx amp to drive midbasses, the loss in damping factor isn't worth it,
the PDX Amps already suffer less than average bass control performance, (subject to a 61 damping factor) and bridging it up
will only amplify that problem.

While Damping factor is less important when running quality passives, due to the impedance correction,
running active without impedance correction when a low damping factor is present can lead to less than exciting bass
performance.

Juls

It is probably the install and fine tuning that accounts for the imaging and stage.

And dyn passives are decent, but I would hardly be praising them, dyn's running on a custom passive crossover (done properly) are quite a different story though (like what aat are doing in perth), then you enter the whole debate of any speaker running custom passive crossovers.

Ram's car (2006 National Pro Street champion) runs fully active Morel speakers
I now have the Dyn MW162 Midbasses, and will be running fully active with MD140/2 dyn mids, and 'other' tweeters.
AFAIK all the top competitors in 2006 ran fully active systems.

the thing you'll notice about running 3-ways active is how difficult it can be to get is all working right. speaker placement is still the most important factor.

There is no problem with what you have suggested to do - with the extra amp, but be ready for a lot of bother to get the 3-ways set up correctly.

also, how do you plan to drive the extra amp channels?

remember you'll need a 4-way crossover (3-way+sub)

I thought Bruce's was active? My mistake...

Although, as Hens said, I wouldnt be praising the Dyns crossovers. I think you lose most of the damping factor your amps have through it anyway. Most people have said the most noticeable difference was a big increase in midbass.

i to am tossing up betwwen active or passive, for my bostons.....pro60s.....

i figure that alot of work has gone into the xovers..so why waste them......

If the stock crossovers are bi wireable, and they have a Zoble networks onboard, then I'd probably inclined to use the stock passive via the active crossover, so you can have the separated volume, time alignment and EQ Control. I think this will probably be easier and sound nicer than going completely active.

however if the crossover cannot be bi wired, then it may be worth considering fully active or custom passive.

Juls

Dyn passives are considered one of the more inferior crossovers around, not saying they are bad but in the world of high end gear the Dyn crossovers are considered one of the least well designed or thought out. But they still sound good so you can't complain, its just they could have achieved a lot more in that area.

Anyway back to the question if you have the time and money to set up 3 way active,go for it, it will take awhile to set up correctly but the end results should be worth it. If I had the experience, time and money to go active with my 3 ways I would be.

juls, yeah the boston xovers are bi wirable, and i was thinking of doing exactkly that. prbably getting the DD C4a, and having the option there bridged passive, giving each side 350wrms in total, biwired, giving each driver 100wrms thru the xover or fully active...

I wouldnt bridge it, the extra power just isnt worth the impact on the sound

I've previously run my front stage active, and am now running my rainbow components using the supplied passive crossovers.

I think it's easy to get caught up in complexity for complexity's sake. Sure it brings a lot more adjustability, but there are a lot more points at which things can go wrong.

At the moment, I see little, if any, benefit from ditching the passives to go active. The makers of reasonable high end speakers have a clue what they're doing, and I feel I would really struggle to do significantly better.

This is just my personal opinion, from experience with reasonably decent speakers. I prefer simplicity. I'm sure there are other who have experienced very similar situations to me and will have the complete opposite stance.

even $10k speakers can have less-than-optimal crossovers - I have heard many.

I think crossovers are at least as important as the drivers, and companies should put as much effort into the crossover component quality as they do into the speakers themselves.
so many good speaker sets still have electrolytic capacitors and iron or ferrite core inductors in the crossover design - to save space. This is just rediculous and defeats the purpose of having good speakers, good source units and good amps.

^^ I fully agree with Pulse_R.

DynAudio crossovers are better then most other units around the same price point, but are still the limiting factor with those sets. Going active will remove a lot of problems that you didnt know existed with the Xovers themselves, but introduce a complexity that not many people fully understand. It is a lot harder to get a decent sound from an active system if you do not understand the consequences of your changes, and active will lose all warmth that the Dynaudios have.

However, I have found that the midbass does indeed increase its performance on an active system. Even I run my midbass active, and Im a solid passive man. The benefits far outway the negatives once you know what you are doing, in reference to the stocks.

Also, you would be amazed at how much the Dynaudios change in terms of sound by doubling or tripling the power being fed to them. They turn into a different unit altogether. I personally believe they are one of the few speaker sets on the market that audibly change their response with a mighty increase in power. However, like Juls has stated, bridging that PDX will lower the damping factor audibly, and you will lose some of your power-punch that you just gained by bridging.

OK so if I choose to go active with the PDX 4.150 + PDX 2.150, each channel should be recieving between 150 - 200 WRMS per channel.

Surely this is enough power @ 4 ohms

Was considering if going active the use of a PXA H701 to control all the tuning what are your thoughts on that particular setup?

active is fun. it expands your ability to tune(if ur gear can do it) also adds more "cool points" to your install and ego. do it do it!!!

Enough Power? Not in my opinion. I am running 175W RMS to my midbass, and it isnt even close to enough! The tweeters and the mids dont need much, for sure, but those midbasses are power hungry. Im looking around the 300-400W RMS now, because Ive heard them with this power and they are really quite good. In the end, its your choice though. Give it a try maybe, and upgrade if you dont like it. If you do, you have found what you a looking for.

Using the PXA to control the tuning is a great idea, and if you know how to use it, can be quite a powerful tool.

In terms of being enough power,
really depends on the amplifiers dynamic capability.

having more power than you need means, less distortion when the speaker is dynamically asking for more than it's rated power, since the amplifier is easily able to supply the dynamically required signal requirements.

Generally speaking,
speakers will potentially be able to momentarily use up to 2-3 times there rated power.
It doesn't mean that they need that power available, but it does mean if your amp can't dynamically produce it as required that speaker performance may be inhibited.

It's important to realise todays amps generally just produce what they say they do,
especially D Class Amps and nothing more.

Unlike the old days with A Class and A/B Class amps, where dynamically they could produce up to 4 or even 8 times there rated RMS power.

Juls

hmmm I have read a few posts and I think that active with the PXA should make a considerable difference to the overall system performance

yes
most definitely