Thread: eclipse

Speaker write up eh? System design is very dependent on the available speakers and preference for equipment or install.

Matt comes from a different perspective of audio than me but he definitely knows a thing or two. I would suggest maybe putting together a specific system for our vehicles based on the science of audio that would actually be beneficial for members. eg. buy this that and the other, put it in as described, use said settings for tuning and you're golden. Downside is you'll have to do exactly as the write up says.

The bottom line is that your system is only as intelligent as the application of knowledge. You can give a monkey the best shop in the world with some high dollar engineering plans and it still won't amount to anything special. Sorry, not trying to put the community down but I've seen some nasty installs, including my own.

My approach was "screw installation" and I'll fix everything with processing. I was right and wrong. It was good enough for everybody else, just not me. I'm going to go back through and possibly refab for a very good installation. But DESIGN IS KEY!!!!

You can't design unless you set monetary goals and decide how deep you really wanna dive into the matter. On a side note, we have one of the worst interiors I've seen for car audio. Our subs are so far back in the vehicle that we only really experience a little of the lower frequencies. Transparency is a word thrown around without much understanding. A good transparent sub allows you to stand next it but still not be able to realize the sound is coming from the speaker. That's pretty tough to accomplish guys. That's why mid bass and speaker selection can be such a big deal.

When was the last time you sat in person's vehicle and it sounded like the sub was in front of you somewhere? The drummer is in front of you...not behind you.

Good luck with the install and figure out your audio goals vs monetary goals. We'll give you better answers.

Sorry if I seemed so negative

Really!!...give us some goals money wise. I just ran across what seems to be some very nice seas tweeters. They're ~$30 a piece! Great sounding audio isn't about spending a lot of money. An old saying is 10% of cost goes into hardware, the other 90% is installation.

If you install yourself you can save quite a bit

See post below

What Matt is pointing out with his photo is path length distance and the peculiarities of having speakers face each other. PLD is very important. However, throwing in reflections is an entire different ball game. Reflections cause cancellations all over the place. They also change the stage in huge ways. Proper speaker placement allows you to pin point the setup of a band or singers. It's also dependent on the recording though.

Anyways, PLD is a huge issue in cars since the drivers aren't equidistant or even sharing a common axis in line wtih our ears. Our dashboards pick up a lot of information and act as wave guides too. Almost unanimously, installers will tell you that kick panels are the #1 choice when optimizing PLD. But that doesn't fix all your problems, it's just one aspect. You also have diffraction too. Also, different frequencies interact differently with all the materials that surround them.

You can fight reflections, or try to work with them. A general rule says keep about 6 inches free in all directions of a speaker. There's actually an equation that helps explain frequency interaction with nearby obstacles and how much space is necessary. Anyways, that's where Home Audio and Car Audio go different directions. Home Audio is trying to limit the interaction of the speakers + environment and create an optimal space for the speaker to operate. Car Audio says there's no chance for that. So techniques arise that are at odds with everything Home Audio represents. eg. pointing R-tweeter 6" in front of the drivers nose and vice versa with the L-tweeter and passenger.

Therefore, Car Audio is basically trial and error instigated by theory and concepts others have used.

...Where Home Audio uses EQ to draw curves, Car Audio uses EQ to fight or enhance reflections in order to raise stage height, move a singer's voice, etc. Does CA still try to draw curves?...yes. What's most important tho?...your ears. That's where HA and CA find common ground. They share a single purpose but their strategies are worlds apart.

Now let's get back to the purpose of "stereo". Stereo is L, R, and C. C is found in R and L channels. C = center stage. R and L are obvious. The purpose of stereo is to recreate the stage that is being recorded. So no matter where your speakers are installed they're trying to replicate a stage. So where is the stage in your car?

Do you want your stage in front of you?...yes. Then install speakers in the front. Do you want your stage behind you?...no. Especially if that stage is competing with the one being created up front. So no rear speakers; unless you're instigating "rear fill"

****I'll provide a link later; for now...FORGET REAR FILL!!!!*****

Moving on. In car audio you want your speakers to work efficiently. Also, symmetry is paramount. 6x9's could work well but typically don't because of lacking design. I refuse to have anything to do with them. Some people like them but we're not talking about speakers in the rear for a good reason right now. Stick with a good pair of 5-1/4" or preferably 6-1/2" speakers if you can. Typically a mid is either good at mid-range or mid-bass but not both. Since most people don't have a trained ear I would stick with a mid that's better at mid-bass.

I'll leave speaker selection to Matt. He knows much more than I. However, I say don't spend more than $200 on retail products. Hugely diminishing returns above that imo.

If you can find some PPI 355cs for under $100 shipped I think it's a huge step in the right direction though.

Well I'm gonna finish for now but I think that explains the disposition Matt's model represented. You're definitely asking good questions and you'd be amazed at what only $500 turns into when you're finished with the product.

Quick picks would be:

$250 Alpine CDA-9887
~$100 PPI 355cs speakers
$79 US Acoustics USB4085 amplifier http://cgi.ebay.com/US-Acoustics-USB...3%3A1|294%3A50



Sub and box are another story but they can be fairly cheap too.

A few things to chew on....




Rear Fill: Grand Prixs Of North America • View topic - How to: Proper Rear Fill (needs DSP)



Speaker Loads: Grand Prixs Of North America • View topic - How much power do you need? 8ohm vs 4ohm



Sub choices: Grand Prixs Of North America • View topic - "When does a $50 sub sound like a $600 sub?"

Bottom line with subs. You can make up for lacking quality by utilizing 2, 3, or 4 cheap subs.

Headroom = less clipping = less damage to your ears

Most people looking at these threads won't notice a difference between Ohm loads. But it is worth noting that higher ohms are easier on the amps for long term use. I don't think 3 decibels is worth it

Check out that amp I linked...it's pretty good on bang for buck. It's just so big

Originally Posted by I800C0LLECT

Most people looking at these threads won't notice a difference between Ohm loads. But it is worth noting that higher ohms are easier on the amps for long term use. I don't think 3 decibels is worth it

Check out that amp I linked...it's pretty good on bang for buck. It's just so big

yeah but as long as your amp can handle it you'll probably be safe. just don't try to put a 1 ohm load on a 2 ohm amp or else

If you read the link it's implying that 8ohm is an all around better load to maintain for your amplifiers vs 1ohm and in some instances could sound better; but that's placating theory more than real world application.

3db really isn't noticed by majority and I would argue that it's better to stay with 4ohm than 2ohm if the difference is just 3db. Then again, majority of people aren't pulling that much power from their amps as their volume typically sits around 100db to 105db when playing "loud" for a 5 or 10min drive. Ear fatigue can play a big role too. If I can find the link there was a gentleman who measured the average his mid received during "cranked" music. I believe it ended up being somewhere around 16 or 20 watts? In that instance, it doesn't matter if you're 2ohm or 4ohm but, long term, 4ohm is better.