Sneaky: Build Logs

[kvndoom]

... and lastly set each 180 degrees out of phase with a switch in the crossovers..

I'm not sure I follow here, were your speakers out of phase to begin with? Just asking out of curiosity.

The rule of thumb, so I've heard, is that if the difference between:

the distance from the woofers to your ears

and

the distance from the tweeters to your ears

is too great, then putting one of the drivers 180 degrees out of phase can cause enough of a delay that the sine wave from the out-of-phase driver seems to reach your ear at the same time. It can be just a matter of milliseconds, but that's all your brain might need to process it correctly.

As an example, people with surround sound processors/receivers set the rear speaker delay in milliseconds. Doesn't seem like much but can make a huge difference in staging and making your living room sound larger or smaller.

[Yama]

Ok, so in a sense you are changing the phase to give yourself a delay. How very Laplace of you!

I would be cautious in doing this as you can create zones where the audio will completely cancel and zones where the amplitude will effectively double if the speakers out of phase are a scalar wave length from each other.

As far as rules of thumb goes, that sounds like an application of the 1 meter / millisecond rule of thumb which seems quite a bit easier to understand in a closed environment.

[kvndoom]

Phase adjustment is actually common in higher end car crossovers. The switches are built into the boxes.

http://www.precisionpower.com/Manuals/S ... onents.pdf

[Sable Wood]

I bet you both can read and understand this stuff, too...
this stuff

On a side note, have you seen this Wolfram thingy? It might come in handy in that physics class, Etter.

[kvndoom]

The rattle was the door handle. I guess the bolt holding it was coming loose some, and bass notes would make it vibrate. I fixed it tonight... tightened it, and padded the surrounding area with Damplifier. That fixed the noise, and of course the MB Quarts are still in. I'm wondering sometimes why the hell I don't just sell the Ebony's, get my 200 dollars back (they're in mint condition, so I know I can get full price) and be content. Karen says it'll just eat at the back of my mind till the day I die, if I do that. She's probably right. I do have brackets mostly ready for them, but the damn Quarts sound so good I just don't want to take them out.

While I had the door apart for the 327th time, I went ahead and sealed the outer edge of the door card with butyl rope to help seal in air better. I also ran it around the outer edge of the speaker. Can't say if it's really helping midbass or not, but it's there. I bought the shit, might as well use it, no?

At some point in the past week I had put in Speaker Tweakers that I had bought on sale some months ago. They were also supposed to help reduce door vibration.

It's so funny cause my driver's side door and passenger's side door are at different stages of sound absorption. Whenever I have an issue with just one door, I work on it, and then think "well while I have it apart, let me do this that or another." So each door has something that the other doesn't have yet.

I'd spend more time on it were it not for the damn repressive heat. Some days it really just feels like death outside.

[kvndoom]

Well now that I'm bitch-free again (why do I keep trying? UGH! ), I find myself in the sorry position of having little to do.

I did sell the Ebony's... got almost all my money back on them too, since they were mint condition. I just could not bring myself to put them in the car, for some odd reason.

I took half a day and ran 4-gauge power wire to the battery on the positive terminal, replacing the 8-gauge I had installed earlier. I also took out seats and lifted the carpet and routed both power wires underneath so it wouldn't look so sloppy.

I juggled between the DCON and the RSDC subs a little and I think I'm gonna stay with the RSDC long-term (until I change my mind again, of course! ). I do want to get a box that isn't so damn awkward though. If the Obcon box was shaped properly, it could have the same volume but leave me with a LOT more usable trunk space. As luck would have it, Elemental Designs has a custom box configurator so you can design your own box to the dimensions you need, and they will build it for you at a reasonable price. I came up with a 1.2 cubic foot wedge that would optimize my hatchback space (wide, tall, and shallow), and it will be like 140 bucks before shipping. That's a small price to pay for a perfect fit. Soon as I have the funds, I'm gonna buy it.

Speaker-wise, I haven't seen anything lately that has really made my wallet itch. There are some JBL's that have my curiosity, but I'm not sold on them. What I'd really love is a dedicated midrange for each door, somehow. 3-way is better than 2-way (in sound, as well as in sex...), but I'm not sure how I would pull it off. So it's a dream at the moment.

I do plan to go to a 2-amp system here soon. Not active, but a dedicated sub amp and a dedicated door-speaker amp. I know 100+ watts to each door speaker sounds like a lot, but it really isn't. Car speakers are VERY inefficient by nature, and suck up power like you wouldn't believe. 100 watts to my JBL speakers at home would get me evicted quick. 100 watts to the speakers in my car doors just leaves me craving more sometimes. So my plan is to eventually get a ~500 watt dedicated subwoofer amp and then bridge the Exile to get ~300 watts to each front door speaker. I won't actually USE all that power, but it will be there for program peaks. I like to play loud sometimes, and I hate hearing clipping. Ugh.

I will also at some point invest in an equalizer to rid myself of that lower-midrange door resonance once and for all. I haven't looked at any models yet. I really just want something basic, maybe a 10-band.

End rambling for today. I'm very depressed, and writing helps, but my eyes are tired now. More to come, when I get some shit done.