Re: Erin's 2006 Civic Sedan
random info...
often it's said that ILD & ITD dictate that phase doesn't matter for high frequencies. It's a notion people have inferred from light reading... and it's not entirely correct. The truth is, time alignment absolutely affects high frequency response. Now, the result isn't as dramatic as it is with midrange frequencies where you can hear the center move left and right with little adjustment between left/right t/a values. However, the time alignment allows a cohesiveness that you can't get simply by adjusting polarity of tweeters. I've often noticed in my car that cycling through T/A 3 times (roughly equivalent to 0.06ms, in 0.02ms steps) results in a full 'phase cycle'. Listen for the "s" sound ... aka: sibilance. Cycle through your T/A and listen for that sound to move out of phase and then *pop* back in phase. You may find the center moves a bit to the right or left, depending on what channel you're adjusting. But this is pretty minor unless you have your tweeters crossed really low. What you'll likely find is that you get in a cycle like I've mentioned where you can literally hear the tweeters pop in phase. Try it. Seriously. You'll notice it. Just shut everything off and leave your tweeters on.
To illustrate what I've said, here's a comparison of the tweeters in proper polarity; adjusting the left tweeter so it arrives at the same time the right does. The red is with no time alignment. The orange is with time alignment done by ear. See how the red is about 2dB lower than the orange? The orange is in phase and time delayed to match the wavefront of the right side tweeter.
http://i18.photobucket.com/albums/b1...ealignment.png
Re: Erin's 2006 Civic Sedan
ALRIGHT.....
So, all the stuff above was back in March or so. It's now August and I had changed some things since then but it's not worth really talking about. I basically hit a funk in car audio recently where I could care less. That said, I've been really just enjoying JAMMING OUT to my favorite tunes. Because of this, my focus has shifted away from competing and back on to just plain ol' enjoying the fun and playing with the science side of things.
As it stands, the updated list of gear will be somewhat the same with some changes:
- Same front stage (Kef, JL)
- Same amps
- P99 is back in the car after a brief departure
- Helix DSP
- AE SBP-15 will be going in the car (I'll explain this later)
- No more rear fill. Don't have the processing for it since I sold the RFQ (in lieu of an h800 I'm not using) and it's not a priority. It was cool. Just not something I want to chase ATM.
I'll explain some of the updates in a bit.
Re: Erin's 2006 Civic Sedan
I think that's the best place you can be. When it becomes a job, then it's time to step back a bit. Hobbies are supposed to be fun.
Re: Erin's 2006 Civic Sedan
Indeed. It became more about swapping gear to chase a single point here or there than about just plain ol' rocking. I look forward to making more GTGs next year. I'll probably still make a couple comps but I won't be chasing points to make finals. If it happens, it happens.
Re: Erin's 2006 Civic Sedan
Great thread, and enjoyable to read!
Keep it up!
Re: Erin's 2006 Civic Sedan
So, I had (2) AE IB15's. Then went to JL 13TW5's. Now I'm at a single AE SBP-15.
Why the change(s)? You thought I was content? So did I, initially. If you care enough to follow me through the reasons, here's it is in a nutshell:
The (2) IB15's didn't seem to like my trunk (Qtc was a bit higher than I'd like). That and I thought they were simply excessive. After all, they were the most attenuated speakers I had in the car.
I joined team MSE (Mark Eldridge's group) last year and since it is co-sponsored by JL I wanted to support the brand. I opted for the 13tw5's because they're slim and could go in a small enclosure. And once they were installed the impact and response was like nothing I had heard. The reason I got rid of them was really no fault of their own. It just came down to application and personal goals.
As time passed I realized I missed the low end that you have to trade off for the small box size. That's pretty much all there is to it. There are tradeoffs and this was one for the JLs; they gave up low end response for being a shallow mount sub. I started looking at IB again and decided that a single sub would suffice. Plus, it would save me a touch of weight which was nice. I wound up settling on the SBP-15 after talking to John @ AE.
I modeled up the AE vs the current JL (1 driver each) and the sim indicates the performance I'm after. The good part is even when assuming a smaller enclosure, the low end response and overall smoothness is good. The smoothness is important to me because I've got a few ideas I want to pursue. If they happen to pan out then I'll post up the results. Namely, they revolve around cabin gain.
http://i18.photobucket.com/albums/b1.../SPB15VSJL.png
Re: Erin's 2006 Civic Sedan
Quote:
Originally Posted by
WOOSEY
Great thread, and enjoyable to read!
Keep it up!
Thanks. :)
Re: Erin's 2006 Civic Sedan
Nice write up. Seeing the Cliff's version makes it easier to follow that the 300pg log on that other site :P
Just out of curiosity, have you ever run any plots and/or decays with the windows and other hard surfaces covered with something to break up reflections? I've always been curious to see what the response would look like if there was some foam egg crate stuck over the side windows.
Re: Erin's 2006 Civic Sedan
Read most of it already, been folowing it for a while...... but hadn't seen the 13's install, and the latest bits.....still read the whole thing through, great read......and thanks for posting it here! I love reading from you super techy guys about your measurements and proof of why this does that, and so on. Wish my knowledge of the science side was greater so I could jump in there and discuss/debate with ya........but its not......so I can't....Ive been forced to learn as much as I have, most by trial and error, to get to where I wanted to be .....( ie; make my ears happy happy happy). Until I'm unsatisfied again, I guess ill wallow in my ignorance of this side of the hobby........everytime I read some guru type posts, I get a lil more out of it.....at least I've gotten a better handle, and while I still struggle, at least I can follow now, if not fully comprehend!.....so once again thanks for taking the time to recompile and repost all this info.....no easy task, it is appreciated.
Re: Erin's 2006 Civic Sedan
Quote:
Originally Posted by
AL9000
Nice write up. Seeing the Cliff's version makes it easier to follow that the 300pg log on that other site :P
Just out of curiosity, have you ever run any plots and/or decays with the windows and other hard surfaces covered with something to break up reflections? I've always been curious to see what the response would look like if there was some foam egg crate stuck over the side windows.
I never really have. Honestly, as cool as it would be to see, there's not a whole lot I could do with it since I couldn't drive the car like that. And I've already go semi-anechoic measurements of my speakers so there's that.