DevilDriver

Rather than edit this, there is one cautionary caveat that I failed to mention in my post above: a filter is not a brick wall. It's quite possible, even with a 3kHz xover point, that reversing polarity will have an effect on your tweeter. At 750 Hz, response is down by only 24dB (assuming a 2nd order filter) and ITD is still an issue. Sean is very good at making me jog my memory.

If the symptom is a stage that leans to the right at upper frequencies, the cause is more directly related to a frequency response issue. This, of course, depends on the frequency at which the tweeter is crossed over at. If, for example, it's crossed over a 3 kHz or higher, changing polarity of that tweeter is not likely to do anything for you at all, as the ear identifies localization cues along the horizontal axis based on Inter-Aural Level Differences. I hate to totally whore this article out, but have a read of http://www.audiojunkies.com/blog/457 It is possible that changing the polarity of one of your tweeters can make a difference if it is crossed over low enough to have an effect on Inter-Aural Time Differences, which is what we use time alignment to avoid. However, a change in polarity is usually most effective with your midrange and/or midbass, as that is where ITD is the dominant factor in horizontal localization cues.

Actually, now that I think about it, I think there's an Apple call centre in Saskatoon, where Scott lives. Maybe that's where your call routed to?

As someone who used to do quality assurance for a call centre, I thank god that he was at least nice about it. Most are, unfortunately, dicks when a customer asks them a question they haven't heard before as they feel it is unimportant. Good luck with the new iMac, as well. We just got a new computer and my girlfriend wants an iMac now, too.

Congrats! What vehicle is this in? Any pics?

Here is a response I wrote, being driven by your question. http://www.audiojunkies.com/blog/457 In your situation, I recommend option number 3 (detailed a little lower in the article). If I remember correctly, your original concern was that you were unhappy with your stage height and wanted to know if you could get better height and still have the tweeters in the kicks. The simple answer is yes. You can, but it will require careful positioning and some EQ trial and error. If you stick with the 2way design, you can move your tweeters up into the a-pillars and bring the stage up with it. You will want to cross them over as low as possible with as steep of a slope as possible, to avoid vertical localization cues coming from both the mid and the tweeter. By the way, I saw the install you were talking about with the tweeters way up high in the a-pillars: that's retarded. They should be much lower down in the a-pillars. If go the 3 way route and you do move the midbass to the door, I wouldn't recommend crossing it over any higher than 400 Hz (and even that is pushing it a bit). Ideally, I think your existing mid in the doors crossed at 300 Hz, a 3" dedicated midrange driver in the kicks handling 300 Hz to 5/6 kHz, and your tweeter taking the top end in the a-pillar.

Nah, I don't think it's necessary. It's a cool concept and I would probably still be up for a separate forum if someone else wants to come along for the ride, but I like SSA just the way it is.

http://www.canadiancaraudio.com/online/270796-post14.html

In a clipping argument for the 300th time......

Quoted for truth. There's a weird dichotomy here: either they are brainless and own garbage, or they are brainless and just pay to have something. Not enough enthusiasts, unfortunately.

Scott, what are you going to see Sean for? Business, or pleasure? Not sure what I'll be buying in the next month, but I appreciate the offer and will be sure to take you up on that if the need should present itself.

Even though I hate paying duties and such on items coming across the border, the one thing I don't expect a company to cut me slack on is shipping.

Yup. Those MJ18's should be getting sold for $50 each, shipping included. Anything else is just a rip off. But if I buy 8, I should get them shipped for $25 each.

You should keep the warning system on for us. I'd like to give a good run at getting Scott banned.

Aaron, please send me 8 navigation units for $20. And maybe some curly fries, while you're at it.

Hey, when you're at home, you've got time for verbal diarrhea.

To expand on that for a moment... The tuning frequency is a function of it's cross sectional area, it's length, and the volume of the enclosure. The port is, in fact, another speaker, but in a different form. If you look at your typical speaker, it's mass on a spring that is driven by the an oscillating voice coil in a magnetic field. In a bass-reflex enclosure, the air in side the port is the mass, the air in the enclosure is the spring, and the speaker itself is the motor. The mass in the port can easily be excited at a resonant frequency, much like a speaker is at Fs (it's resonant frequency). This resonant frequency is the "tuning frequency". When it comes to the tuning frequency, you can make a few general assumptions: 1. Tune lower and you will net greater low end extension and sacrifice some upper frequency sensitivity. 2. Tune higher and you will net greater upper frequency sensitivity, but lose some low end extension. 3. Tuning lower requires a longer port, assuming the same cross sectional area of the port and net volume of the enclosure. 30-35 Hz is a common tuning frequency in vehicles because, with music, it serves for the best compromise between low end extension and upper frequency sensitivity. If this is something you're wanting to achieve, perhaps post what products you are using now and we could help determine the best net volume of the enclosure as well as the dimensions of the port. You might find playing with programs like WinISD or UniBox to be beneficial in your understanding of the concept.

Werd. I would love 8 18" Q's, but I have no reason for it in any room in the house. If (and when?) you do go this route, be sure to post some pics here. I don't get over to see the cult very much anymore.

I didn't think PE sold the woofer tester anymore, but I could be wrong. Google it, though, and you can find it. There's other ways of testing thiele/small parameters, but it's probably the easiest route for most users.

I could not feel worse today. It hurts to look at the computer and I am terribly nautious.

Ok, getting really long. Give me an hour, or two, or a day. You've been patient enough; what's one more day?

Order the BTL, with SPL, Pole Chamfer, and 3rd magnet options.

4 Cubes sealed, 7.5 Cubes ported tuned to 28-32 Hz. I have the old recommendations memorized still. If you want the actual thiele/small parameters, use www.webarchive.org

Albert Collins :thumbup:

1. I have no idea where that is 2. I assume you're speaking of Chernobyl 3. Russia has not been abandoned Chernobyl is in the Ukraine. Chernobyl is actually seeing a surprising regrowth; a lot of animals are moving back much earlier than expected.