Active vs Passive on my Polks...

[flogger11]

Ok guys, I have now purchased a ZX-350 and am debating how I am going to integrate it into my system. I am leaning towards the more traditional install with my ZX-450 bridged, one channel on each voicecoil of my Treo TSX 12" dvc giving it an honest 500 watts, exactly what this baby needs. That would let me put 100 watts on each Polk, a very nice match in my opinion. OR I could try something totally new to me and run my subs voicecoils in parallel to my ZX-350, putting a very real 400+ watts on my Treo, while I run my ZX-450 active to my Polk SR-6500's, two channels for the tweets and two for the mids! What do you guys think? I have to make a decision by my install date of June 24th, so I am open for input until then. I am thinking I may just go the traditional route as in the long run I will probably put 8" mid-bass drivers in my doors with the ZX-450 running them along w/ my polks. That would leave my ZX-350 raging on my single Treo 12 (which at that point would probably be traded for a Treo TSX 15 dvc!). I am open for some input everyone, thanks so much! Mike

[fuzzysnuggleduck]

What kind of processor/xover do you have to run the components active? How easy it is to play with different settings might come into play. I am considering an AX-406A to do an active setup, but RNETs are annoying to build in proper increments and you'd need quite a few and a lot of switching to get it right, a pain really.

If you're looking for big power and strength from the front-stage then by all means put the ZX450 on 'em and let 'em rip. But, if you're a big bass kind of guy the ZX450 will be happier running then sub than that ZX350 would and provide just a tad more headroom. Of course, you're going to be reducing your font-stage presence in that scenario.

Let me just wander for a bit and describe how my stereo is setup and how I feel the blending of sub/component power is working out for me.

I have my M44 bridged to RSd6 components and an M100 running at 2ohms stereo with two RSd12D subs. Thus, technically speaking I'm running 105W x 2 to the components (assuming a % of passive xover loss and a true 4 ohm load) and 230W x 2 into the subs. The blend is excellent. I get a very powerful front stage with excellent reinforcement from the subs. I don't have earth shattering subs but they definitely have strong presence when I'm feeling loose with the volume knob and LPL.

I don't know how far the curve would remain constant, but it appears to me that with complimentarily efficient speakers/tweets/woofers, you can run double the power to your subs as your front stage and be very well off. I don't know how much cabin gain is affecting my subs since I have a large single airspace for all drivers (SUV) but that might factor in more than I've considered.

I've really been contemplating going active recently but I think that may just be an itch to do something different, not because I feel there is a particular deficiency in the current setup that I need to address. Although, many people here swear by running active as you're not letting a passive cross over rob your power and you get minute control with the right processor. You decide if being able to (and perhaps constantly desiring to) play with xover settings is appealing to you or not.

[stipud]

Well, you never really know what's right until you try. Personally I would take your ZX450... run it bridged to your components for awhile. Then run it active afterwards, and see if you prefer it. You can leave the sub running on the ZX350, to avoid having to swap things around when you get your 8" drivers.

[Bfowler]

I would go with the zx350 on sub duty also.

then in the future you could run your components active, you could run them passive on the front channels and the 8's on the rear channels....all kinds of possibilities!

[flogger11]

Thanks for all the input guys! I think I am going to lump everyones ideas into one and do the following: I am going to run the ZX-350 on my Treo, while I will be running my tweeters off one side of my ZX-450, using the internal crossover set to 10x. Meanwhile I will be using the other side to run my polk mids. Is it okay not to have a bandpass on the mids, leaving them running full range up top? I dont believe they roll off the highs on the mids w/ the original polk passive crossovers. The biggest reason I am going to run it this configuration is that I will be able to try a little higher crossover point on the tweets (which seems to be all the rage) AND it will be much easier to add my mid-bass drivers when I decide to. My sub has two 4 ohm dvc's, so it will be runnning a bridged two ohm load just like one side of my ZX-450 is now. It tends to run a bit hot and imagine it will still do so on the 350, so I will be adding additional cooling fans when I do my final amp install. Thanks for all the advice guys, dont hesitate to drop anymore on this subject before my install on June 24th. Mike

[stipud]

No need to run your mids full range! The ZX450 can be run in three-way mode, meaning it can bandpass the channels to your polk mids.

Run your RCA to the FRONT input of the amp.

- R.FEED BYPASS = XOVER (this will make your rear channels take the lowpass from your front channels)
- F.AMP SOURCE = XOVER (this will make sure your tweets get highpassed)
- FRONT MODE = NORM (ditto)
- F. XVR FREQ = set to your tastes... start high, and turn it down until your mid and tweet blend.
- FREQ MULT = X10 (ensures you get a high enough HPF freq for the tweets)

- R.AMP SOURCE = XOVER (takes lowpass from front channels)
- XOVER SELECT = HP/LP (want to highpass the signal again to make bandpass for mids)
- R.XVR FREQ = set to your tastes... start low, and turn it up until your sub and mids blend right.
- REAR SOURCE = Front (takes the front signal output)

Now if you really want to be savvy, run a short RCA from the external output to your ZX350. This will be the lowpassed signal left over from your mids, so basically just the subbass. Set your ZX350 to BYPASS the crossover. If you have an LPL, install it in the ZX450 -- it will control the bass volume of the ZX350! Now your whole stereo runs fully crossed over off of a single RCA feed!

[flogger11]

I am also very excited to play w/ the active setup, I was hoping I would be happy without mid-bass drivers, we shall see. On the 24th I am going from the Polks mounted coaxial in the doors to a full $400 custom door install w/ the dynamat extreme included. I think I am goint to have a HUGE improvement in sound with this new setup, especially with the Imprint ability to time delay the mids and tweeters seperately. MAN, IS IT THE 24TH YET?? LOL!

[flogger11]

No need to run your mids full range! The ZX450 can be run in three-way mode, meaning it can bandpass the channels to your polk mids.

Run your RCA to the FRONT input of the amp.

- R.FEED BYPASS = XOVER (this will make your rear channels take the lowpass from your front channels)
- F.AMP SOURCE = XOVER (this will make sure your tweets get highpassed)
- FRONT MODE = NORM (ditto)
- F. XVR FREQ = set to your tastes... start high, and turn it down until your mid and tweet blend.
- FREQ MULT = X10 (ensures you get a high enough HPF freq for the tweets)

- R.AMP SOURCE = XOVER (takes lowpass from front channels)
- XOVER SELECT = HP/LP (want to highpass the signal again to make bandpass for mids)
- R.XVR FREQ = set to your tastes... start low, and turn it up until your sub and mids blend right.
- REAR SOURCE = Front (takes the front signal output)

Now if you really want to be savvy, run a short RCA from the external output to your ZX350. This will be the lowpassed signal left over from your mids, so basically just the subbass. Set your ZX350 to BYPASS the crossover. If you have an LPL, install it in the ZX450 -- it will control the bass volume of the ZX350! Now your whole stereo runs fully crossed over off of a single RCA feed!

I am going to use all three outputs from my deck as they are all 4 volt and can be controlled by the Imprint in my alpine deck. If you are not familiar w/ the Imprint technology, check it out on alpines site. It controls time delay and phasing on each individual channel, controls crossover points if desired (two or three way) AND it eq's the system at 500 different points, filling in the holes and rounding off the peaks! This is one awesome system and is THE reason I purchased the Alpine over the Eclipse CD7200 mkII, despite the latters 8 volt pre-outs. Ya, it takes an Alpine dealer to set it up ($25 here) OR a $250 mic/processor setup available from alpine, but it sure can take a system to the next level w/ littly hassle!