Bi-amp or Standard Crossover??

[Deeznutz]

Ok, here is the situation. (I always like to give a back ground story, but if it's too much, just scroll down to the end of the thread).

I have a second cousin in Peru (For you geographically challenged bassheads, it's in South America. j.k.) that finally finished the complete restoration of his VW Beetle. It's his pride and joy. Having a car in a 3rd world country is a very big deal so you know how he feels about his ride. We have all felt that way about one of our cars thorough the years. VW Beetles are super popular in S.A.

Looking at the pics he sent me, I see he has a Cheap Walmart quality Sony CD player and A series Pioneer 6X9 in the back. (I'm cringing!)

Car Audio is finally making it's way down to South America. Ofcourse they sorta have a different idea of what car audio is....... It's alittle more like showing off. Doors and hatches stay open.

Well, he is family and I have a few things laying around that he could really use so he can experience we all have. A decent sound system!! So here we go. To keep my cost next to nothing, I am trying to mix and match.

1.JL XR X-overs

2.Image Dynamics IDQ 12 NIB!!!

3.Crossfire CFA302

4.Pioneer DEH-P5000UB

5.RF 4 G wiring, rca's etc.

6.***Need a 2nd amp to complete the system and send!

On to my question.....

I have a set of JL Audio XR650 X-overs as well as a set of Eclipse 8062 6.75 mids and X-overs.

I needed some tweets so I ran to the junk yard and after 3 hrs of wandering around the import section I stumbled on to an Audi. Looked stock,no rims, no suspension, no tented windows, etc......for shits and giggles I ripped the stock tweeter covers to discover these JL Audio TR tweeters.

They were glued into the stock Audi tweeter pods. JL sells them for $99.....I paid $.6.00!

I played around with the Eclipse mids, X-overs, and the JL tweets. Played different tracks, Rock, rap, pop, etc. Sounded decent. Tweeter sounded warm, and not harsh like the Infinity Reference aluminum tweets I have.

Next I tried the JL Audio XR X-overs and WOW , HUGE DIFFERENCE. Tweets were alittle louder, still warm and no harshness at all. The tweets stood out more than the Eclipse X-overs. The Eclipse mids also seemed to balance better with JL tweet using the XR X-over.

Comparing the X-overs, they are way different.

I am using an old school Crossfire CFA302 75W x 2 amp to push the mids and highs.

Now for the question!

Looking at the JL XR X-over, I am debating using the Bi-amp feature on the X-over.

I have to purchase a second amp for the system to be complete.

I can purchase a Crossfire CFA354. 35W x 4 and use the Bi-amp feature

......OR.....

K.I.S.S. (Keep it simple stupid) and just buy another CFA302 2 channel 75W x 2 and run it simple?????

SO BI-AMP OR KEEP IT SIMPLE??? I would like to buy either the 354 or the 302 A.S.A.P. The amp choice will complete the system. There's a POWER DIFFERENCE, but there's increased flexibility.

35W to the mids, 35W to the tweets................Vs. ..................75W split between the mids and tweets????

So I need your input based on experience with Bi-amplification.

The CFA302 will run the I.D. IDQ12!

Thanks for your time!

-Frank

[never knows best]

bi-amp for the cool factor, flexibility, and room for upgrades-

down the line he could go active and add more mids and highs....

edit: when you say bi-amp you do mean one amp right channel, one amp left channel???

[Deeznutz]

Bi amp, using a 4 channel Crossfire CFA354 , channel a&b for the tweets, channel c&d for the mids. 35W to the tweets x's 2 , 35W to the mids x's 2.

Right now the mids/tweet combo are dividing the 75W amongst the 2. I just wonder if the power is split down the middle or a 60/40, 70/30 split favoring the mid's magnet size vs. the tweet magnet size. That's the thing. I do not want to give the mid less watts going 35W. Get what I am asking??

-Frank

[jk13]

If this is to truly "complete the system" use the more powerful two channel, just be careful because the TRs are 50 watt max. The amp puts out 75 watts from 20-20kHz and the passive crossover determines which frequencies go to which driver. So both the woofer and tweeter will see 75 watts.

Note--the JL web site lists those tweeters as 8 ohm so that would actually work really well--. Measure the impedance to be sure. Should be just over 6 ohms.

Edit: Normally I do recommend bi-amping a mismatched set of components when you can just for separate level control, but not at the expense of more than half your power.

[Deeznutz]

Yes, both read 5.9-6.0 Ohm. Just like you said!

I wonder if that is reason the TR's sound better with the Xr vs. Eclipse??

The original Eclipse tweeter meaures 3.2 Ohms and blended nicely with the mid and it's original X-over, but only having one working tweeter, it was hard to match.

Since I found the TR tweeters and just happen to have the XR's laying around, saving them came in handy!

Guess the Ohm makes a difference in the tweeter output, or how the crossover points work? I am just now sorta understanding this stuff.

When looking at tweeters, a few forums mentioned 4, 6, 8 Ohm regarding their applications. Guess it makes a difference.

-Frank

[Wicks]

Yeah you'll want to match the speaker impedance with the impedance the crossover was designed for.

Otherwise your crossover points could change.

I'd say keep it simple with one amp.

Bi-amping is great for going active but with passive crossovers I'd probly keep it simple.

[MrSkippyJ]

so we are talking about 150 vs 140 watts total here? Power wise you won't hear a difference. Funny things start happening when you mess with the impedance of a passive crossover as far as crossover levels go. If I were you, I would not use the passive crossovers at all (bi-amped or not) and just go active so you know exactly where your crossover points are. Either that or use crossovers designed for the speakers you want to use.

But as far as power goes, either set up will end up with about the same.

[Deeznutz]

Cool guys. I will buy another CFA302 and avoid the bi amp feature for now.

-Frank

[Deeznutz]

Ok so good news, I purchased another Crossfire CFA302 on Ebay, just waiting on it to arrive.

MOre good news, looking at the original 3/4" Eclipse tweeters again, I wanted to see if it could be rebuilt since one had low output.

I was able to remove the tweeters from their front mounts.

From there I was able to remove the cloth diaphragm from the magnet itself. They both looked the same as far as the voice coils.

They both read the same also.

When I pressed the magnet onto the v.c. I noticed the same low output. I wondered what if I pulled back the magnet a mere 1mm or so.

BAM, the low output tweeter sounded just like the good one. I guess the magnet was pressing on the voice coil keeping it from playing

properly. Possibly a manufacturer's defect????? Tomorrow a.m. I will be epoxying the magnet as it sits to get the tweet to work.

Once the amp arrives, I can send all the stuff to Peru.

His front stage will be all Eclipse components.
CAN'T WAIT!!!

-Frank