Should I move tweeters?

I have focal access components with the 6.5" located in the door and the tweet in the stock 3.5" speaker  location(top of dash).  Would inside of the side mirrors sound better?  And I don't want to modify my door so installing by the mid is not an option.

ack. Either one isn't good. I'd think twice about modifying your door. The closer to the mid the better.

I'd probably keep it in the dash at this point.

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New Project: 2003 Pathfinder

I would keep it where you have it know, if your not happy with it try some kick panels,

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is it true that when installing components speakers you wan t the tweeter closer to the driver?? i thought the tweeter should be closer the ear, but maybe i'm totally wrong?

hightek wrote:

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is it true that when installing components speakers you wan t the tweeter closer to the driver?? i thought the tweeter should be closer the ear, but maybe i'm totally wrong?

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You are wrong. The tweeter and the midrange should be as close to the SAME distance away from your ear as possible AND as close to eachother as possible.

See page 106 of The Loudspeaker Design Cookbook by Vance Dickason, one of the leading books and authors on loudspeaker design:

c]ombining output from two radiating sources will produce complex interference patters, with areas of reinforcement (hot spots) and cancellation (dead spots). The further apart you place the two [drivers], the more complex the interference pattern will become.... the most uniform radiation patten ... occurs when you separate the two drivers by a distance equal to, or less than, the [lowest] wavelength [the high frequency driver] will produce. For practical purposes, that distance is equal to one wavelength at the crossover frequency."
Vance then lists on page 107 the frequency to distance chart. For a 3000hz crossover point the recommended distance is no more than 4.5" inches. On page 107 he also includes pictures of the radiation pattern when the tweeter is located four wavelengths away (your tweeter in dash is located even further!!!) and the resulting radiation pattern looks very bad indeed.
Anyway, you can fix some of this by using higher order crossovers. By using higher order (24db/octave)+ crossovers the reduce driver overlap is reduced and the resulting interference pattern becomes less pronounced and complex. Also, this isn't even touching on what placing the tweeter closer to or further away from the ear does to time alignment and phase. However, the same 'steep crossover fix' helps here some too. I hope you see that the easiest way to ensure quality sound out of off-the-shelf components is to locate the tweeters as close to the midrange drivers as possible. Frankly, by choosing to leave the tweeters in the dash w/ the original xo, you'd probably be better off just selling the components and buying some quality coax speakers instead.

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New Project: 2003 Pathfinder

so basically i should quit looking at components and look more at coax? i guess in my case, where i'm not really going to get into all the specifics of imaging and stuff like that, then coax would fit the bill?

There are some components out there that allow you to mount the tweeter in the coax position. That is the main reason I bought the components I did - at the time I didn't want to mess around w/ cutting my doors. Image Dynamics also makes some... there are others.

Having said that, I think a well done coax will beat many low cost component sets. Eclipse makes some excellent coax drivers. Their point-source coax drivers are nice. Again, there are others.




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New Project: 2003 Pathfinder

Look for a high order crossover of 12 db/octave with coaxials.  Most have a 1st order 6 db/octave slope that muddies the sound and sends errant lower freqs to the tweeter, which can cause early failure.  https://www.memphiscaraudio.com/products/details.asp?id=16 is a coaxial that allows for tweeter rotation and has a 12 db crossover.

great post, as usual, kfr01. I love that book! It is where I started with almost "everything speaker" What he is referring to is "sound power". The interference of one wave-front with another. Imagine dropping two stones in a pool of water next to each other - one big (the woofer) and one small (the tweeter) Each stone will make very diferent size waves. The same applies with speakers. The waves will constructively (additive)and destructively (subtractive) interfere with each other in the pool. The sound waves do the same from two different speakers. When you are on-axis (in front of), the waves will be less destructive or constructive to each other, as they are coming off the speaker cone at the same angle and speed, in addition to being the same distance from your ear. When off-axis, the destuctive component is stronger in the pattern, but not at every frequency - just even harmonics. What this causes is "filtering" as you move your head through space - some places one frequency will be "hotter", while 3 inches away from that point, it will be "colder".

As a final point to what stevdart said, and at the expense of another amp, you could always bi-amp, but yes, always a steeper slope is good!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."