How do I bi-amp componets?

Ah, I totally misunderstood you then.  I'm sorry about that.  When you said midbass, I though you were going to use one in conjunction with a midrange which is typicaly the case. 

Metal coned tweeters can be fine because on a good tweeter the resonances are above the audible spectrum.  My comments were mainly for midranges.  My link points to an online magazine where my boss answers different user questions.  Here's a copy of the important parts:

Hobbes26 asked: How do you match tweeters to a given midrange woofer, and vice versa? What main parameters and characteristics must be taken into account? And how does this affect the crossover you build for them?

Looking at the CDT speaker, there are some things that concern me.  They say they use stainless steel for their top plate and backplate, which is extremely high carbon steel and has very poor magnetic properties.  In speakers you want softer, low carbon steel.  I tried going to their website to check the parameters to see what the Qes and BL are, but for some reason their website must be down right now.  Here are some other things I notice about it:

"flat spider-allows a consistently linear cone excursion"  Actually you normally don't get a linear response with a flat spider.  Progressive spiders are what provide a linear response.

"frequency response 65Hz-7kHz flat(6.5-octave response)" They don't specify how flat.  I'd really like to see a response curve of that. 

"Sensitivity 92.00 dB (2.83V)"  Note that this is not a 1 watt measurement.  It kind of bugs me when companies rate their speakers like that.

And now the ID mid.  I checked ID's site and unfortunately couldn't find parameters for it there.  However they did give some good information.  One thing to note is that their RE is up at 1.8 ohms, which would make this driver closer to a 3 ohm nominal impedance rather than the rated 2 ohms.  The phase plug might help it have a smoother upper response, but unfortunately they don't provide a response curve. 

Steven Kephart

Adire Audio

That doesn't come across very positive for the CDT... huh.  I've read a bunch of message boards.. lotsa word-of-mouth stuff about their HD series of componets.  Out of this world, supposedly.  What is your sense of CDT?  When I learned about the company from my internet travelings, I was delighted to learn they make their speakers in a town I lived in out California ways.  Made me instantly partial.. ya understand.

Yea that response curve claim does seem really odd, especially with what all hamfist discusses above.  I'm still trying to get a sense for what a typical range is for tweeters and midbasses/midranges..  

What is a 2.83v measurement mean? What is it comparable to? I've seen other companies rate thier stuff like that.. I've seen JBL stuff rated like that.  I guess somewhere along the line I figured it was another way of saying 1w/1m but I dunno how to ohms-law 2.83v... since I don't have an amp measurement.

The ID mid looks okay huh?  After I grab that EQX from hamfist I was really thinking of that ID mid and the ID NX30 silk dome tweet for my front end.  That stuff looks wicked to me. The only thing that I was worried about was the lower xover point on the mid than we've been discussing here... I'm *really* paranoid of bright speakers.. I've always been kinda sensitive to that and I've read when you have more sounds coming from your mids that frequently contributes to speakers sounding ...'warmer'... if you will.  From what all you and hamfist have said here, that's a load of crap huh?  Why do *so many* componet sets sound so bright to me?  With an EQ like that AudioControl I'd be able to edit that out nicely anyway though? 

hamfist:

Well lemmie ask ya this then... why come so many competition cars I've seen coming out of the two local performance shops always stack speakers next to each other.. like this:

What is that?  I've seen like 3 custom fiberglass jobs that look *just* like this.  What about the dash mounted tweeters along with it?

From what ur saying that is completely retarded?  Why do they do that? Do they just spend hours with an RTA and an EQ to perfect the reponse b/c it would natively be so peaky? 

Don't get me wrong, it might be a great driver.  I was just commenting on what I noticed on that sales page.  Those are things I would check on to see what is actually going on. 

Usually you don't want to run a 6.5" driver above around 3k because that's where beaming becomes an issue.  Of course the install will make a huge impact on this.  5.25" speakers can go a little higher though.  Tweeter bandwidth depends on the size and type of diaphragm.  Larger tweeters can usually play lower, but might start to beam within the audible range, or their response might not naturally extend all the way up.  If you try to run a tweeter too low, you will limit it's peak output capabilities.  One way around this is to use steeper slopes. 

2.83 volts supplied to an 8 ohm driver would be 1 watt.  However that same voltage applied to a 4 ohm driver would actually be 2 watts.  It's a way some car audio companies fudge the numbers to give their products inflated sensitivities. 

Actually that is true.  Your ears are most sensitive to the midrange frequencies.  And when a speaker system has a boost in this area the speakers will sound more "warm". 

It's either because that's how they were voiced, or because of the install.  As an example, our components use a metal tweeter that is very smooth because it was voiced that way.  However if you install the tweeter on-axis it becomes very bright and harsh.  It's because they were desiged to be installed off axis in the bottom of the doors.  The idea of using the EQ when going active is so you can "voice" the speakers yourself. 

I think those are examples of when form over-rule function.  They care more about how "pretty" the install is rather than how it sounds.  In the top one if both mids actually play the same bandwidth, then you would have nasty comb filtering issues.  The bottom one probably wouldn't be as bad if they used proper processing to fix the lobing issues that would develop.  However depending on how far in the tweeter is mounted, their soundstage would most likely be limited to that width. 

Steven Kephart

Adire Audio

Those doors look like a modified MTM D'Appolito configuration to me.  A gimick in a car door for sure.  The JL super tweeter may have a function as described above, but again more likely it's a show car gimick.  Show cars are always FULL of gimicks gadgets and gee-gas with little or no actual function.  I once saw a car (forget what kind) that had ten or twelve mids in each door.  The door panel was literally full of drivers.  Looked cool.  The problem was only one was actually hooked to an amplifier so it would create acceptable sound quality.  The rest were there for show.  :)

One other comment: the only place I've ever heard a metal-dome tweet and liked the sound was in a car.  Sometimes they can be a perfect solution for the horrible acoustic environment and road noise intrusion of a car.  So try it before you rule it out, if you can.

My boss wanted to take apart an SACD player and modify it to work in his vehicle.  I thought that would be fun to hear. 

Steven Kephart

Adire Audio