sound stage, imaging in 2 seater

2)  Speakers are more like light bulbs than lasers.  They don't project their sound directly forward.  In fact they only start to beam at upper frequencies, that frequency being determined by the cone size of the driver.  Try reading my "Advanced front Speakers" thread above for more information, mainly what I write on page 2. 

3)  That depends on your definition of "quality".  I've found that peoples definition of this is greatly effected by their experiences.  If you have experienced a really good sounding system, then that is your reference point to use on your own system.  Working on your experiences and knowledge will greatly help you in building your own system.  This is a very time consuming, but will be worth it in the end.

shines wrote:

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I reread your advanced front spkrs thread, and understand the lightbulb analogy. How will only having speakers in the front of my car effect the sound quality. .

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Speakers only in the front is prefered by many people, like me.  The front sound stage is all that really matters.

I think this relates to the orginial topic...  Why is the front sound stage the only "important" part?  I couldn't figure out how to explain that to someone.

arrow12 wrote:

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I think this relates to the orginial topic...  Why is the front sound stage the only "important" part?  I couldn't figure out how to explain that to someone.

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The very basic reason is sound is supposed to come from in front of you.  Your ears face forward.  When you listen to a live performance (concert) you generally face the stage for the best sound.  The ideal way to listen to recorded sound is to face the source.  So in a car, you want the sound to appear as if it's coming from in front of you.  Since that's where the windshield lives, you have to compromise of course.    You do not want the sound to come from behind your head as this is not natural.

The Lotus are a nice driver as well.  In fact, I believe Dyohn runs them in his car stereo.  They has one or two advantages over the Extremis, but in my admitidly biased but still honest opinion, the Extremis has many more advantages.

shines wrote:

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- 2 av5's-- not sure on location-- maybe molded into the same location as the extremis 6.8's??

- a 4 channel amp

- and the grace of GOD to make this sound good without a head unit-- I'm using a dedicated computer as my media player..

Give me your thoughts; I appreciate your knowledge.

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IIRC the AV5's are no longer available.  However a quick e-mail to Adire should clear that up.  But then, I would recommend simplifying the process and just run the Extremis up to the tweeters.  They have a nice response all the way up to 5 kHz without much issue.

Here's a good tweeter: https://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=264-735  And here's it spec sheet: https://www.partsexpress.com/pdf/264-716s.pdf  It has very good extention on both ends as you can see by it's response.  I like that their measurements are at 94 dB.  Also if you notice on the waterfall plot, there aren't any bad stored energy ridges. 

shines wrote:

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I was going to use the seas lotus rt25f as my tweeter; the extremis as my mid bass; maybe the adire AV5's--I'm not sure if they fit in with the listed components; no sub.

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Doh, my bad.  I should have looked up your model number.  Unfortunately I can't find any measurements on those speakers. 

The Extremis is a wide band driver capable of delivering great midrange performance.  You really don't need to add a seperate midrange to the equation as this will make things more complex with crossover design. 

That does bring up the next question; what are you going to do about the crossover?  Keep in mind that the crossover is THE most important part of any speaker system and will determine how good your final results are.

1) Thanks!  I don't recommend that to people as there was a lot of work involved.  Hopefully some day I will finally finish it though.

2)  Well then you are going to have to ask yourself how much difficulty you are ready to face.  Read the different levels of speaker designs I list in that above sticky and decide which one you want to take on.  However if they all look too difficult for you, then I would suggest a  pre-available speaker set from one of the many manufacturers.

A passive crossover is an inline filter.  But it isn't as simple as selecting some parts and throwing them together hoping to get decent results.  Even using textbook alignments won't provide you with very ideal results.  This is because the response of the drivers in their intended locations must be taken into account. 

I was involved in quite a few crossover designs when I worked at Adire.  My boss, Dan would have me build a test enclosure and have me mount the speakers.  He would then take his computer and hardware (the expensive equipment I mention in the other thread), hook it all up to each speaker and measure their individual responses.  He would then use his computer program to design a crossover with those response curves, and try to get the best response with the fewest components.  Then he would hook up his computer again to the speakers and listen to his designed crossover.  After he is happy, he would order the parts, I would build the crossover and we would listen to the final result.

Hi there.  Yes, I used to use the Seas RT25A tweeters in my car as they are part of the Lotus Reference set.  These now live in my wife's car and I'm using a set of Eclipse comps (with Vifa drivers) in my new car.  The Seas tweeter should work well with the Extremis in a 2-way setup as it can be crossed over as low as 1700Hz since it has a low fs.  It is a great sounding tweeter (and the Extremis is a great sounding woofer!)  And I agree you really don't need a 3-way set unless you really want to try that.

Steven's comments about crossover design is right on, of course.  A text-book crossover might provide a starting point and in some cases turns out to work fine.  But for example, the Seas tweeter mentioned above has 89.5db sensitivity and the Extremis is 86db, so in addition to a simple crossover network you'll need to pad the tweeter by at least 3db.  If you have the interest and the time to tweak and get it right, crossover design is the most fun part of speaker building IMO.

shines wrote:

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Having never taken the easy way out on anything; I will stick it out, learn more about this hobby, and feel good.

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Here are some links to programs I got from others here in the forum (you've been tralking to some of them!).  Speaker Workshop is a passive crossover design program.  The other programs associated with the FRD can be picked through and chosen, and add as you can or you see fit.   At this point in my speaker-building hobby, I'm getting the enclosure down with Unibox, copying the manufacturer's response and impedance curves using SPL Tracer, and designing the crossover with Speaker Workshop.  The rest of it...I use intuition and whatever knowledge I've gained from all sources.

• https://home20.inet.tele.dk/kou/ubmodel.html
• https://www.speakerworkshop.com/
• https://www.pvconsultants.com/audio/frdgroup.htm
• https://home.twcny.rr.com/cnydga/FRDtools.html

For a bunch of calculators you can refer to often, as I certainly do, this is where you want to go.  And Rod Elliott has interesting and useful things to say here. 

shines wrote:

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So what do you guys think about center-mounted speakers

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For what?  They make great center channels...

Steven Kephart wrote:

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Hey Steve, one thing I recommend is getting at the very least a cheap RTA software program and mic to meter the speakers rather than using the manufacturers response curves.  The reason for this is those curves are taken anechoic on an IEC baffel, and usually are smoothed quite a bit.  Also the response curve of the mid might not be taken at the same output level as the tweeter which could effect the results even more. 

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Somehow I missed this post, Steven.  I'm eventually going to get to that level, but I have to take widdle baby steps to get there.  I just have to experience a catastrophic failure doing it this way first.  (...or it could be that my ears are very forgiving!)