Thread: Getting new subs want opinons.

Originally Posted by MrTube

matt : what does that mean exactly?

You have speakers that add delay them selves or something?



and on the storage space note, to alot of people storage is just as important and often more important then sound. My car is not a show car, its a work car. And the trunk will remain 80% empty even after I do work to it for sound.

He's poking at your speaker selection

My opinion is that you need two or three cheap subs or one to two nicely designed subs. Personally, I like my trunk space. I'm going to be fabricating one day so that I can gain some of that back. I don't like a box + 2 speakers taking up space the way they do.

Yea, hard to get the mids and tweeters as far from you as the subs in the trunk tho. A simple DSP would work but does anyone offer one? Id have to assume yes

I800 : yes, I know he was. However it was not my car when it happened, it was my best friends. And again, UNDER $500 for an entire system that was sooo much better then stock.

I had a $4500 system in my truck, if you check retail A/D/S/ prices from the late 90s + the $600 eclipse head.


BTW I800 check your PM'S

Turning to the SQ side! Need suggestions - Page 2 - DIY Mobile Audio


OP!!!!

Read the above I won't get into what they're speaking about but you can definitely research the site to find out more concerning speaker specs. In the end, you gotta be the fisherman.

After I finish a few things in my own project I'll be looking to go ported with my R12's. My DSP is built into my cda-9887. Check my links and you can see photos of my alpine MrTube. It's only designed for 3-way. Pioneer plans on releasing a 1k h/u from their Premier replacement line. It is 4-way w/30band R/L EQ I need the 4-way for my rear fill implementation. They also moved the jog dial for the iPod to the remote. It's a beautiful deck. You can buy the Japan version for ~1200 and it contains a 6 channel 50w amp. The Euro version doesn't have the amp.

Oh ya...tweeters aren't that big of a deal when it comes to path length distance. I'd say shoot for 15 or 20 degrees off axis(depending on tweet, but reflections make tweets go crazy). They respond much better to attenuation while mids respond better to time alignement. I'm thinking of going with kicks for mids and tweets on the upper door towards the a-pillar; about head level for me. Subs don't need t/a because their wave lengths are typically larger than the vehicles cabin.

I'd also like to point out that passive cross overs tend to vary in response due to temperatures and load values. Active DSP cross overs = gewd times and much more consistant. Some of the best speakers maintain passive x-overs but they're dealing with home audio. The correct way to build a passive in a vehicle MUST be based on specific cabin design in relationship to speaker placement too. Europeans have a thing for starting out active during tuning and building passives based on the parameters they finalize. It helps with k.i.s.s.

hrmmm.

Here we go again

Originally Posted by matt5112

Thats retarded. How you can you claim the BIGGEST waves of them all would be least affected by phase? They'd be the most likely to create MASSIVE dead spots due to cancellation.

Maybe you read into that differently than I had hoped? What I'm saying is that the frequencies your mid produces react very well to T/A. Your sub does not. When tuning to bring about a transparency between the mid-woofer and sub-woofer the stage can become confusing if your mids aren't tuned properly. Although a double kick is pronounced in the sub-range the roll off is as high as 800hz. In this instance if your mid isn't tuned properly then localization will be prevalent and the mid will not pick up where the sub left off.

The cancellation would be attributed to installation and x-over points. How about this...is it easier to manuever two cars next to each other at the same time or one at a time? Leave the sub alone. T/A mids to match distances. Attenuate and EQ for transparency.




Why? If all the speakers are the same distance from the LP, then you win.

Learn how to design a nearfield speaker and you'll see why this whole "OMG PUT THEM FAR AWAY" idea is a load of crap.

This has nothing to do with speaker design or near field presence. The relationship of this installation practice is proportionate to the actual wave lengths. Tweeters will not benefit from kicks; only the frequency range I specified which is found in your mid.



do you think they do when they make studio monitors? Cry since they're nearfield speakers and compromise the design so they'll work placed far away where no one will place them since their own intended use is for nearfield?

There you go taking experience from home audio again



And the "pros" claim they actually use the window to reflect sound properly...

Not all of them. Most of them talk a lot of trash and play mind games because they don't want psychoacoustics to ruin their scores. When they're making those claims they're referring to an installation that is designed around the issue of reflections. Instead of fighting them, they try to work with them instead.


I'll take a look at the rest when i get off work...

Originally Posted by MrTube

btw. Besides the delay another problem i've noticed with all setups including the pricey a/d/s/ one was trying to get the subs in phase with all drivers. This obviously gets even worse if you have rear-fill.


btw,

you guys think maybe we should take this to our own thread? We can call it the mrtube,I800collect and Matt thread,

Might keep this one a little cleaner... go for it

The cancellation would be attributed to installation and x-over points.

Sorry did I see you say install speakers so that their phase is naturally in line?

Read further back at my suggested setup... tell me that a midwoofer will be easy to time align when it goes down to 50 Hz and the sub won't be?

Tell me why all home audio receivers have the "distance" option for all the speakers INCLUDING the subwoofer.

This has nothing to do with speaker design or near field presence. The relationship of this installation practice is proportionate to the actual wave lengths. Tweeters will not benefit from kicks; only the frequency range I specified which is found in your mid.

Source/reasoning?

My counter argument is this:



Lets take a look at the manual...

http://www.krksys.com/manuals/rpg2_manual.pdf

Installing Your Monitors
The close-field monitor, by definition, reduces room interaction. This can be compared to the conventional stereo configuration or the large monitor arrangement in a recording studio where sounds emanating from the monitor or reflecting off ceilings, walls, and floors greatly affect the sound quality. By shortening the path to the ear, the close-field monitor offers a tremendous amount of flexibility, allowing the sound to become less susceptible to differing room conditions. The ability to adjust the high frequency characteristics is equally important to help compensate for room irregularities and achieve the best performance.

Close-Field Configuration – In a control room situation, the monitors are often times placed on the meter bridge or in a close-field listening position. Initial placement starts by measuring out a simple equilateral triangle (all three sides equal in length) with the apex at the center of the listening position (as shown in Figure 1) as an “overlay” for the stereo installation. In this configuration, the Left and Right monitors are each placed at a 60° angle, equidistant from the listening position.

Mid-Field Configuration – This configuration is similar to the Close-Field configuration. It is normally used with larger monitors or when the monitors are too large or heavy to be placed on the work surface. This set up has the potential for a larger sweet spot and better spatial imaging. Make sure that the monitor is high enough so that the woofer is not obscured by your mixing surface or studio furniture (refer to Figure 2).

So which one is more easily achievable in a car and more worth while?

Not all of them. Most of them talk a lot of trash and play mind games because they don't want psychoacoustics to ruin their scores. When they're making those claims they're referring to an installation that is designed around the issue of reflections. Instead of fighting them, they try to work with them instead.

You do of course realize that the resulting sound dispersion pattern would be hell on wheels right?

Show me an analysis of the predicted dispersion pattern or did they even think that far ahead?

Originally Posted by MrTube

btw. Besides the delay another problem i've noticed with all setups including the pricey a/d/s/ one was trying to get the subs in phase with all drivers. This obviously gets even worse if you have rear-fill.

Adjust the phase? Its not that difficult.

You have to do the exact same thing when setting up your sound system in your home. Only difference is, most of the time you can get away with having the sub in front of you.

Originally Posted by I800C0LLECT

Turning to the SQ side! Need suggestions - Page 2 - DIY Mobile Audio

Yeah... sub size is basically, go as large as you can get away with. There is no logical reason to go for a sub with less surface area since it will have to move further to produce the same SPL and thus do it with more distortion.

Oh ya...tweeters aren't that big of a deal when it comes to path length distance.

But height is a major concern.

I'd say shoot for 15 or 20 degrees off axis(depending on tweet, but reflections make tweets go crazy).

I'm not sure what you're suggesting... but tweets sound best when on axis... If you suggest anything other than that, you have no place in audio.

They respond much better to attenuation while mids respond better to time alignment.

Perhaps working a little magic you could minimize the use of both?

I'm thinking of going with kicks for mids and tweets on the upper door towards the a-pillar; about head level for me.

So you're going to put your mids where they'll be blocked by your own legs and/or any passengers you may/may not have? I see... Perhaps I should put my speakers underneath my seat.

Subs don't need t/a because their wave lengths are typically larger than the vehicles cabin.

So the phase difference at the sub/midwoofer crossover doesnt matter? I think you'll find that you can have MANY issues with that crossover if you get it wrong. This sort of thinking is why 99% of people have ****ty mid-bass.

I'd also like to point out that passive cross overs tend to vary in response due to temperatures and load values.

Passive x-overs are for those who are too cheap to buy more amps or those who are too afraid of being able to change your crossover at the touch of a button.

OR....... if you sell speakers and you wanna make sure your customer doesnt ruin them or have to set them up properly.

In otherwords, the ignorant (and i don't mean that in a negative sense) and the acoustically/electrically-retarded.

Active DSP cross overs = gewd times and much more consistant.

IFF you're using completely digital controls, none of this pot controlling the frequency business.

Some of the best speakers maintain passive x-overs but they're dealing with home audio.

They only do that because they don't want the customer to have to setup the speaker.

Coils inductance won't change much in a house since the temperatures are fairly consistent, unlike a car where it changes all the time.

That means your low pass filters will change based on the coils temperature.

Also the drivers position relative to each other doesnt change in a home audio situation unlike car audio.

The correct way to build a passive in a vehicle MUST be based on specific cabin design in relationship to speaker placement too.

And temperature?

Europeans have a thing for starting out active during tuning and building passives based on the parameters they finalize.

And that's pointless because you've already invested in the superior system and then you turn around and waste money on most likely over-priced passive x-over components.

It helps with k.i.s.s.

Honesyly I could care less if you post in this thread, i'm learning as you guys are arguing. Lol

Fine debate... Got another question while i'm posting, Where do you figure the "optimal" placing for my tweetes are. I have them cut into the mesh grille's and it just doesn't sound right. So where would you suggest?

T/A is more than just phase :/ Reflections act as speakers themselves too. This is where an RTA can really help people identify issues due to all the reflective surfaces in a vehicle. Sometimes a 1db decrease from the speaker results in much more because of the reflective areas.

That's when you bring out the math and start measuring distances between objects vs. speakers in correlation with LP and HP frequencies. Reality: Have I done it? nope. Have I read about it?...yes. Have I witnessed a conceivable difference w/installatino practices?...haven't tried

I have some pioneer tweets on the way...

FS:Alpine SPX-177A mids + old school PRS tweeters - DIY Mobile Audio