A few System Setup questions for you experts out there . . .

[bdonkersgoed 10+ year member]

Hey Guys,

I am in the process of buying all of the gear for my new system, and was hoping you experts out thecould give me some setup suggestions. Here is the gear I am working with:

GEAR:

- Alpine CDA-9835 CD/MP3 Head Unit

- Focal Utopia 165W 6.5" 2-Way Components for the front (100W RMS each side, but not sure?)

- PPI Ax400 (Art Series) Old-School Amplifier to power the Focals

- Two Resonant Engineering RE8s to mount in the rear doors (175W RMS, DVC 4-ohms, but not sure?)

- Orion HCCA 225 G4 Old-School Amplifier to power the RE8s

OK, so that is the gear I am working with. Now the question is, how do I optimally set this system up?

Specs for Orion HCCA 225 G4:

2 x 25 @ 4 Ohm

2 x 50 @ 2 Ohm

2 x 100 @ 1 Ohm

2 x 200 @ .5 Ohm

1 x 100 @ 4 Ohm

1 x 200 @ 2 Ohm

1 x 400 @ 1 Ohm

Specs for PPI Ax400:

4 x 50 @ 4 Ohm

4 x 100 @ 2 Ohm

2 x 200 @ 4 Ohm

So, on to the questions:

QUESTION #1

My Utopia Components are bi-amplifier capable. The PPI Ax400 is a 4-Channel amp that can output 4 x 50 @ 4 Ohm, or 2 x 200 @ 4 ohms. Should I use all four channels and amplify each woofer and tweeter separately (50W to each), or should I bridge the amp and give 200W to each tweeter/woofer pair? Would 50W to each tweeter and each woofer be enough power for them?

QUESTION #2

What are the advantages of using biamplification for the Focal Utopias?

QUESTION #3

If I biamplify, could I use my Alpine CDA-9835's internal crossover to independantly control the tweeters and the woofers? The internal crossover has independant lines for "Front", "Rear", and "Subs". I was thinking maybe I could put the tweeters on the "Front" line, the woofers on the "Rear" line, and the RE8s on the "sub" line. Is this possible with my gear? Or would I have to have two separate amps powering each of the Focal Woofers and Focal Tweeters to accomplish this?

QUESTION #4

If what I suggest in Question #3 is possible, are there any realy good benefits to this setup? I think this way I can control the volume of the tweeters and woofers independantly (+/- db) ? Would this also allow me to send better and more appropriate signals to each speaker?

QUESTION #5

Does anyone know with certainty what the impedance of the RE8 is? Does anyone know any of the RE8s other specs? I hear that they are DVC 4-ohms . . . is this true? If so, then I would be able to wire the two RE8s in parallel to get a 1-ohm load, and thus get 1 x 400W out of the Orion HCCA 225 G4 amplifier that is going to power them . . .

So, that about sums up all of my difficult questions. I hope someone out there can help me out, because these questions are really bugging me . . .

I appreciate any help that anyone can offer!!

Thanks!

Bryan

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[squeak9798 5,000+ posts]

QUESTION #1

My Utopia Components are bi-amplifier capable. The PPI Ax400 is a 4-Channel amp that can output 4 x 50 @ 4 Ohm, or 2 x 200 @ 4 ohms. Should I use all four channels and amplify each woofer and tweeter separately (50W to each), or should I bridge the amp and give 200W to each tweeter/woofer pair? Would 50W to each tweeter and each woofer be enough power for them?

I personally would bridge the amp and run 200w to each side, if you intend on using the passive xovers. In reality, bi-amping with 50w to each is no different then simply having a 50w x 2 amp powering them (since they would still each be getting 50w off of the 2-channel amp).

Go with more power, and lower the gain if needed.

QUESTION #2What are the advantages of using biamplification for the Focal Utopias?

Independent control of the speakers. Assuming you had the adequate amps to accomplish this; you could run more power to the mids than to the tweeters (say, 100w x 2 amp to the mids, and 50w x 2 amp on the tweeters). Then you can use the gains to somewhat level match the speakers and such.

But, see above. I personally would rather go with the 200w x 2 instead of (essentially) 50w x 2.

QUESTION #3If I biamplify, could I use my Alpine CDA-9835's internal crossover to independantly control the tweeters and the woofers?

Now you are into a whole 'nother territory; active frontstages //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif You'd essentially be ditching the passive xovers and using the Alpine's internal xover to crossover the speakers.

The main benefit of active xovers is being able to contour the xover points & slopes to better match your vehicles interior, as well as have better level matching control between the mids/tweeters.

Not a bad option if you have the patience and knowledge to tackle it.

The internal crossover has independant lines for "Front", "Rear", and "Subs". I was thinking maybe I could put the tweeters on the "Front" line, the woofers on the "Rear" line, and the RE8s on the "sub" line. Is this possible with my gear?

As long as the Ax400 has one input for each channel (i.e. 4 total inputs), then yes. That would allow you to highpass your tweets, bandpass your mids and lowpass your subs.

Or would I have to have two separate amps powering each of the Focal Woofers and Focal Tweeters to accomplish this?

See above

QUESTION #4If what I suggest in Question #3 is possible, are there any realy good benefits to this setup? I think this way I can control the volume of the tweeters and woofers independantly (+/- db) ? Would this also allow me to send better and more appropriate signals to each speaker?

See above.

Problem with passive xovers is that they are optimized for the speakers. However, toss those speakers in a car and the xovers points that are "optimized" for the speakers won't be optimized for the speakers in your car. Many times different slopes and/or xover points will be needed to maximize the speakers performance in your car. Things such as steeper slopes, underlapped xover points, different levels (as you mentioned), etc etc.

QUESTION #5Does anyone know with certainty what the impedance of the RE8 is?

DVC 4ohm, as stated on RE's website

Does anyone know any of the RE8s other specs?

http://reaudio.com/html/re_ts.htm

I hear that they are DVC 4-ohms . . . is this true?

Yes

If so, then I would be able to wire the two RE8s in parallel to get a 1-ohm load, and thus get 1 x 400W out of the Orion HCCA 225 G4 amplifier that is going to power them . . .

Yes

Hope that helped.

 

[bdonkersgoed 10+ year member]

Thanks Squeak!! That most certainly did help!! Wow, I can't believe that one person was able to answer all of my questions in such a manner that I could understand what they were saying //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif That was an awesome write-up! Now I know what people are talking about when they asy Active and Passive crossovers too . . .

A few more questions:

QUESTION #7:

Are you familiar with the Alpine CDA-9835 Head Unit? Do you think I should use it's active crossover instead of the passive crossovers that come with my Focal Utopia components? Can I only do this if I am biamplifying the Utopias?

QUESTION #8:

Can I only use the "Front", "Rear", and "Subs" crossover on my CDA-9835 to control individual volume levels on my Utopias if I bimplify?

QUESTION #9:

What would be the impedances on each individual component of my Focal Utopias (i.e. impedance for each woofer and for each tweeter)? Is it possible to wire these component speakers up so that I can get a 2-ohm load on each of the four channels? This would give me 100W x 4 using the PPI amp. It's a strech, but I thought I would at least ask

QUESTION #10:

Do you know the mounting depth of the RE8?

QUESTION #11:

I don't know if the PPI Ax400 has separate inputs, and I don't even know how to check. . . I don't have the amp yet, and don't get it until this weekend, but I believe it is the same as this one up fro sale on Ebay right now:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4950&item=5766115595&rd=1&ssPageName=WDVW

Does this amp up for sale have indendent inputs?

Thanks again for your awesome help! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Bryan

 

[squeak9798 5,000+ posts]

QUESTION #7:

Are you familiar with the Alpine CDA-9835 Head Unit?

Somewhat //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Do you think I should use it's active crossover instead of the passive crossovers that come with my Focal Utopia components?

That's a call for you to make. I'm not extremely familiar with the Utopias crossovers, but I'd assume they have some nice built in features such as zobel networks (do a search if you don't know what that is), tweeter protection, etc etc. You would loose those "features" by ditching the passives and going active. Now, to some people, that trade-off is worth it (being able to control xover points/slopes/etc when active). To others, it's not.

And like I said before, if you run them through the passives, you could do 200w RMS per side (and gain down the amp some if needed). To run active with that amp, you'd only have 50w/speaker. Depending on your listening style and preferences, that may or may not be enough power to satisfy your sonic bliss cravings.

Can I only do this if I am biamplifying the Utopias?

Yes. To run an active setup, you must have one channel for each speaker. So, to run a 2-way (one tweeter and one mid per side) frontstage, you must have 4 channels of amplification. Now, for you this isn't a problem since you have a 4-channel amp //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

QUESTION #8:Can I only use the "Front", "Rear", and "Subs" crossover on my CDA-9835 to control individual volume levels on my Utopias if I bimplify?

Not quite sure what you mean here. If you were going to run active, then you'd need to use all 3 preouts (the "front" would be the highpass to the tweeter, the "rear" would be the bandpass to the mids, and the "sub" would still be for the sub).

If you were going to use the passives, then you could just run a single RCA to the amp from the "front" output, then use a y-splitter to split that single RCA to all the inputs on the amp. Then use the sub output for the sub amp. The rear would be unused.

QUESTION #9:What would be the impedances on each individual component of my Focal Utopias (i.e. impedance for each woofer and for each tweeter)?

AFAIK all the speakers are 4ohm. But check with Focal or your dealer to verify this

Is it possible to wire these component speakers up so that I can get a 2-ohm load on each of the four channels?

No. It is not possible.

QUESTION #10:Do you know the mounting depth of the RE8?

Heh...can't answer this one. I was doing good though....9 in a row up till now //content.invisioncic.com/y282845/emoticons/moon.gif.9d317aec3339ffe7fde0638df52c628a.gif

QUESTION #11:I don't know if the PPI Ax400 has separate inputs, and I don't even know how to check. . . I don't have the amp yet, and don't get it until this weekend, but I believe it is the same as this one up fro sale on Ebay right now:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4950&item=5766115595&rd=1&ssPageName=WDVW

Does this amp up for sale have indendent inputs?

Yes, it has 4 inputs (one for each channel). Most due, but in rare cases some don't. So it's always best to check first.

 

[bdonkersgoed 10+ year member]

Thanks so much once again Sqeuak //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif I'ev learned more today than I have learned all week //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Excuse me for being a stupid newbie, but one more question . . .

AFAIK all the speakers are 4ohm. But check with Focal or your dealer to verify this

Oh wait . . . I was going to ask about wiring the tweeters in parallel and the woofers in parallel so that I get a 2-ohm load across two channels. I don't even know if this is possible, but even if it is, I guess I would lose my Left to Right? Hmmmm . . . too much thinking for me for today

Thanks again for all of your help //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Bryan

 

[squeak9798 5,000+ posts]

I guess I would lose my Left to Right?

Yes, you would lose stereo sound as well as your left-to-right balance. And, considering music is in stereo, this would be very, very bad

 

[bdonkersgoed 10+ year member]

But it probably would have worked though?? But yeah, I wanna keep the "stereo" in my system

Thanks again,

Bryan

 

[squeak9798 5,000+ posts]

Technically it would "work" (nothing would explode). But it definitely would not be a wise decision //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[sephiroth619 10+ year member]

//content.invisioncic.com/y282845/emoticons/peace.gif.2db28b618ed8d1964ebbe2f5021d2c39.gif//content.invisioncic.com/y282845/emoticons/peace.gif.2db28b618ed8d1964ebbe2f5021d2c39.gif Squeak