Best Position for Mids and Tweets, SQ

[kmbkk]

Well, I'm finally getting the remaining parts of my system together and am starting to do the layout. I'm going with a PHD 3-way active component setup in the front, no rear fill, and 2 8's in the trunk. Right now I'm trying to decide the best speaker positioning for the mids and highs. I'll put the 6's in the door. I have a 4 and tweeter to fit in the dash. However I'm trying to decide if I want to build a speaker pod in place of the dash location or mount the tweeter in the A-pillar and the 4 in the dash. I'm running an MS-8 for processing, so I have a little forgiveness on location, but want to put the speakers in the optimal location.

Any thoughts are greatly appreciated!

[ean611]

Originally Posted by kmbkk

Well, I'm finally getting the remaining parts of my system together and am starting to do the layout. I'm going with a PHD 3-way active component setup in the front, no rear fill, and 2 8's in the trunk. Right now I'm trying to decide the best speaker positioning for the mids and highs. I'll put the 6's in the door. I have a 4 and tweeter to fit in the dash. However I'm trying to decide if I want to build a speaker pod in place of the dash location or mount the tweeter in the A-pillar and the 4 in the dash. I'm running an MS-8 for processing, so I have a little forgiveness on location, but want to put the speakers in the optimal location.

Any thoughts are greatly appreciated!

If you're asking here: use stock locations. You'll see people say to build pods and other exotic stuff. All they'll do is block your visibility for little gain. The MS8 will do a very good job with aligning everything.

Also, the A-pillars have air bags in them. Yeah, don't screw with those. You could get quite hurt if someone smashes into you.

Finally, if you really like having 8 channels of amplification with no rears, cool. However, the main benefit of fully active is that people place their drivers apart, such as the doors to the dash. However with the tweets and the mid range on the same axis and in the same position, you will have around zero benefit running the mid to the tweet active. (Unless you don't have a passive crossover for that, then there is a benefit). I'm running 3 way in my car, Hybrid L6 in door, L3v2 and L1v2 in dash. My doors are one set of channels, and I have an L2x crossover for the mid range to the tweeter.

I mention this, as given the space (or lack thereof), amp space is at a premium. Oh, and for time alignment? From my seating position, the speakers actually line up very nicely, meaning if you measure the time delay, you'd find that all L drivers and all R drivers are very close to the same distance from your ear, and that delaying the L channels by around 1.2-1.3ms, L and R are in phase.

Oh, also, looking at the PHD speaker images, I noticed the lack of a phase plug for the woofers. Just an FYI, phase plug in speaker construction really helps with off-axis response. The doors, specifically, the left door, needs excellent off axis response, as the angle to your head is terrible. Just a recommendation if you're not married to the PHD set, or if they have a different model than what Google image search turned up.

EDIT: I noticed you're going with no rear fill. A lot of the competition systems do this, and if you're listening with the car off not moving and for the IASCA and MECA CD, maybe there are some small benefits, but with the car running and exterior noise, those are often diminished. I'm running Hybrid Audio L3 woofers for the rear fill. (no tweeter, 160-10,000Hz response) Correctly setup, this can expand your stereo image and make the sound fuller and more alive, as there is no hall or room effect in our small little couples to create this for us (as would happen in your home with a nice set of home speakers). The effect you can achieve is that the L and R channel come outside of the dashboard while still being completely front stage. Also, to compete with road noise and your nice turbo sound, you need to move more air, as you can't fight physics. Having another set of drivers will more more air. Just like you want 2 8's (overkill, but if it's worth doing, it's worth over doing ), you will benefit with a high end set of 3.5 inch drivers in the rear.

[Zippy]

If you are going to do pods take a look at the sticky builds at the top of the sub forum and look at cruisinbill's build. In my opinion that's how pods should be built. The best way to decide if you want to mount the tweets somewhere else is to hold them where you are thinking of putting them and power them. Hear for yourself where they sound the best and look to build a pod there or put them in stock based upon what you hear. A lot of people have opinion. It all comes down to where do they sound the best to you. Your the one that has to live with the choice.

[kmbkk]

Thanks for the inputs guys. I already have the comps, so no going back there. I'm not sure if the 4" will fit in the dash without some modification, which is why I was thinking of making some pods. I've done A-pillars before, so it's not a big deal. I actually have a spare pair of them to work with. I know there are airbags and would be very cognizant of their location. Here's a pic of @koteman's dash pods he built, which is what I was thinking about doing:

[simplicityinsound]

I have a different opinion here Eit

1. having used 20 MS8s (back when virtually no other processors was avaiable), i think it does a decent job of getting you about 80 percent of the way there, but to get it to really sound to its full potential, it is almost impossible because you cannot establish a baseline. also i feel the system works best with a center channel (whcih it does properly) and rear fill. but once the other tune your own processors became available, i stopped using it all together.

2.i also think pods and pillars do improve sound if done properly, the stock location on the top of the dash for the FTs are not bad, but the tweeter location to me is definitely not ideal and i pretty much refuse to use it. tweeter reflecting off the glass, despite being early reflection, and that far in board, is not the way to go if doing a three way system. it is more a thing down to compromise, cosmetics/cost/sq

3. tweeters in airbags is a big misunderstanding. airbags do NOT blow the tweeter cover off as some imagine. virtually all cars basically have the airblag blow down through the weather stripping, and down into the door opening area, the pillar either bends or simply gets moved out of the way. i have spoken to several automotive engineers of the years on this, and they all say, a tweeter there is not going to have an issue.

here is a youtube video of the FT, pay attention to the slow mo interior shots, look what happens to the pillar, and now imagine a few oz of tweeter at the base of the pillar, and see if you think it will make a difference

[ame="http://www.youtube.com/watch?v=Z3H7o4EZRsI"]2013 Scion FR-S side IIHS crash test - YouTube[/ame]

3. in my time competing, you actually would want ideally to have the mid and tweeter in the same axis. powering things actively will help a lot more than just phasing, it allows you tune out things that are present in each individual driver (for example, a weird cone break up at the crossoverpoint etc), that you cannot do when they are on a common channel. not to mention xover point, gain, time alignment etc etc

there are a few other points, but too busy to type them out.

its just my opinion of things, but i feel i need to chime in on this thread since its about front stage...and having done 8 of these cars now with 7 being fully active with dsp, trying out different locations...i feel i got a decent handle on things.

Originally Posted by ean611

If you're asking here: use stock locations. You'll see people say to build pods and other exotic stuff. All they'll do is block your visibility for little gain. The MS8 will do a very good job with aligning everything.

Also, the A-pillars have air bags in them. Yeah, don't screw with those. You could get quite hurt if someone smashes into you.

Finally, if you really like having 8 channels of amplification with no rears, cool. However, the main benefit of fully active is that people place their drivers apart, such as the doors to the dash. However with the tweets and the mid range on the same axis and in the same position, you will have around zero benefit running the mid to the tweet active. (Unless you don't have a passive crossover for that, then there is a benefit). I'm running 3 way in my car, Hybrid L6 in door, L3v2 and L1v2 in dash. My doors are one set of channels, and I have an L2x crossover for the mid range to the tweeter.

I mention this, as given the space (or lack thereof), amp space is at a premium. Oh, and for time alignment? From my seating position, the speakers actually line up very nicely, meaning if you measure the time delay, you'd find that all L drivers and all R drivers are very close to the same distance from your ear, and that delaying the L channels by around 1.2-1.3ms, L and R are in phase.

Oh, also, looking at the PHD speaker images, I noticed the lack of a phase plug for the woofers. Just an FYI, phase plug in speaker construction really helps with off-axis response. The doors, specifically, the left door, needs excellent off axis response, as the angle to your head is terrible. Just a recommendation if you're not married to the PHD set, or if they have a different model than what Google image search turned up.

EDIT: I noticed you're going with no rear fill. A lot of the competition systems do this, and if you're listening with the car off not moving and for the IASCA and MECA CD, maybe there are some small benefits, but with the car running and exterior noise, those are often diminished. I'm running Hybrid Audio L3 woofers for the rear fill. (no tweeter, 160-10,000Hz response) Correctly setup, this can expand your stereo image and make the sound fuller and more alive, as there is no hall or room effect in our small little couples to create this for us (as would happen in your home with a nice set of home speakers). The effect you can achieve is that the L and R channel come outside of the dashboard while still being completely front stage. Also, to compete with road noise and your nice turbo sound, you need to move more air, as you can't fight physics. Having another set of drivers will more more air. Just like you want 2 8's (overkill, but if it's worth doing, it's worth over doing ), you will benefit with a high end set of 3.5 inch drivers in the rear.

[ean611]

Originally Posted by simplicityinsound

I have a different opinion here Eit

1. having used 20 MS8s (back when virtually no other processors was avaiable), i think it does a decent job of getting you about 80 percent of the way there, but to get it to really sound to its full potential, it is almost impossible because you cannot establish a baseline. also i feel the system works best with a center channel (whcih it does properly) and rear fill. but once the other tune your own processors became available, i stopped using it all together.

2.i also think pods and pillars do improve sound if done properly, the stock location on the top of the dash for the FTs are not bad, but the tweeter location to me is definitely not ideal and i pretty much refuse to use it. tweeter reflecting off the glass, despite being early reflection, and that far in board, is not the way to go if doing a three way system. it is more a thing down to compromise, cosmetics/cost/sq

3. tweeters in airbags is a big misunderstanding. airbags do NOT blow the tweeter cover off as some imagine. virtually all cars basically have the airblag blow down through the weather stripping, and down into the door opening area, the pillar either bends or simply gets moved out of the way. i have spoken to several automotive engineers of the years on this, and they all say, a tweeter there is not going to have an issue.

here is a youtube video of the FT, pay attention to the slow mo interior shots, look what happens to the pillar, and now imagine a few oz of tweeter at the base of the pillar, and see if you think it will make a difference

3. in my time competing, you actually would want ideally to have the mid and tweeter in the same axis. powering things actively will help a lot more than just phasing, it allows you tune out things that are present in each individual driver (for example, a weird cone break up at the crossoverpoint etc), that you cannot do when they are on a common channel. not to mention xover point, gain, time alignment etc etc

there are a few other points, but too busy to type them out.

its just my opinion of things, but i feel i need to chime in on this thread since its about front stage...and having done 8 of these cars now with 7 being fully active with dsp, trying out different locations...i feel i got a decent handle on things.

More great info. I'd have to disagree on the on/off axis though. Again, this is a lot of setup and preference, but I'd rather have EVERYTHING on axis. In a car, this is typically impossible with woofer to tweeter, as they're often in different locations with different off-axis positioning. Active is great for adjusting the phase of the off axis tweet compared to the midrange, but given the interference patterns generated, spacial locality is a great thing to take advantage of.

With my L1v2 tweeters in stock location and running on a HPF around 5.7KHz, and most importantly, tuned with EQ, the highs are crisp, clear and concise. The blend with my L3v2 is damn near perfect.

Where this comes down to is personal preference. Building lots of pods can be fun, and if you enjoy that, and don't mind having a non-stock look, go for it. These days, I don't have time to build that, and I I want my car to look bone stock. After a bit of tweaking, I've got some great results with bone stock locations. Remember, the OEM (Subaru and Toyota) has a lot more development time than you do. They spent a lot of time setting up their locations for drivers. Their in house audio guys are excellent. Then they run into the fact that this is a $25,000 car, and put cheap drivers, a cheap amp, and middling head unit in the setup. But based on my impulse response measurements, there are properties that the stock locations have that I would find hard to believe are not designed.

The one thing you MUST do if you don't use pure stock location is to make sure you have a sealed enclosure for the mid range driver. That will fix one of the biggest SQ weaknesses in the vehicle. With that, and a good mid range driver (I'm not very familiar with the one in this thread), you can run your dash down to around 250Hz without projecting sound into the lower dashboard.

That being said, a 4th order filter around 500Hz also cures this without the extra work and effort of building pods. I look at a lot of this as cost/benefit. From pure sound standpoint, you do not need pods if you tune/setup correctly for the mids. However, if you enjoy building them and want the challenge, it's a fun project.

[simplicityinsound]

quick question though:

what do you define as "on axis"

like take your left and right speaker, how would you aim them to be defined as on axis? i find that a lot of people differ on this particular subject and what it means exactly.

[WolfSongX]

A lot of good info here. Thanks to everyone for sharing their thoughts.

Bing, I've been toying with using the MS-8 as well since I wanted to keep the stock head unit and was looking for something that was going to be relatively easy to tune and set up. Is there something else I should be looking at processor-wise that offers similar features like time alignment and could be tuned by a well-meaning amature who knows enough about audiophile grade sound to be dangerous, but by no means an expert.

Thanks

[ean611]

Originally Posted by simplicityinsound

quick question though:

what do you define as "on axis"

like take your left and right speaker, how would you aim them to be defined as on axis? i find that a lot of people differ on this particular subject and what it means exactly.

Speakers are directional at higher frequencies. So first, you want a line of sight from the driver to your ear unobstructed. This is particularly difficult with our left door. Second, the dash, both those speakers are on the same axis as they're pointed in the same direction. If you used A-pillar mounts for your tweets (often ugly, Bing has done great work to make them look not ugly, but I'd personally rather not, again taste) the tweeter is pointed at you, which is "correct", but is no on a different axis than the midrange, as it's pointed at you, while the midrange is not.

There are two issues. As the tweeter is now further from the midrange driver, there are both interference pattern issues, as well as the difference in axis. This is mainly an issue for the crossover between the two drivers.

Honestly, this is fighting the last 1% of difference, (as you know, it's always that last 1% that kills you time wise). I use the stock locations and tune as while I'm very picky, I can get great results with the stock locations for significantly less fabrication. My view is if you enjoy the fabrication, or have another reason for wanting pods of some type, go for it. However, my belief is that unless you're in love with the IASCA or MECA competition CD, and want that to sound "perfect" from the competition standpoint, fabrication isn't needed. Stock locations (with rears) properly tuned, and you will have the stereo singing.

Finally, one of the biggest reasons that there is such a focus on a-pillar pods for both Tweeter and Midrange in competition is that they love having a high sound stage. That is, all the sound appears to be coming out of your windshield, like you're in the pit of a concert of a poorly designed theater. I say poorly designed, as in a real sound environment, different sound will have different point sources, as well as interesting house effects. In addition, depending on where you sit, you end up with higher or lower stage effects. Finally, for non-analog concerts (rock, etc), you often have the bass divorced from the rest of the sound. Bass speakers on the ground with mids / highs in the air. So if you want an awesome concert experience, you can still get it without having a perfect MECA/IASCA ideal setup fabrication wise.

Honestly. the most important piece of all of this is drivers. If you're not spending thousands on speakers, don't bother with hugely expensive installs. A more better speaker in stock location tuned correctly will often be better than a cheaper one in a custom built device.

Finally, there are a lot of people with BRZ/FR-S now. Find a meet, go check out stuff. Your ears are different than mine. See what you like. Sound is about making you happy with your stereo, not someone else. The best answer is find what level makes you happy with it, and go with it.

[ean611]

Originally Posted by WolfSongX

A lot of good info here. Thanks to everyone for sharing their thoughts.

Bing, I've been toying with using the MS-8 as well since I wanted to keep the stock head unit and was looking for something that was going to be relatively easy to tune and set up. Is there something else I should be looking at processor-wise that offers similar features like time alignment and could be tuned by a well-meaning amature who knows enough about audiophile grade sound to be dangerous, but by no means an expert.

Thanks

I'm not Bing, but the Mosconi 6-8 or Rockford 3Sixty.3 could be tuned by you if you pick up a good RTA mic, Phantom powered preamp (with USB) and your PC with Room EQ Wizard. It's a lot of fun, and you'll learn a lot.

[WolfSongX]

Originally Posted by ean611

I'm not Bing, but the Mosconi 6-8 or Rockford 3Sixty.3 could be tuned by you if you pick up a good RTA mic, Phantom powered preamp (with USB) and your PC with Room EQ Wizard. It's a lot of fun, and you'll learn a lot.

Well Bing had mentioned that he'd stopped using the MS-8 entirely, which is why I directed the question towards him. That being said, thanks for the input, ean611.

I will definitely need time-alignment and the ability to do a fully active system. I have an old set of uninstalled Alpine Type X Ref 6.5 components that I damaged the passive crossovers on and so I was hoping to use these in Phase II of my build.
Phase I is going to consist of adding a 5 channel amp and a sub, but only utilizing the sub channel for the time being. Phase 2 will concentrate on sound deadening the rest of the cockpit, wiring for the speakers and adding the sound processor so I can do an active setup on the speakers.

I'd love to turn the build into a 3 way if I could find some mid drivers that would integrate well with the Alpines.

Oh... and the budget's tight and I have less than $1K to spend on the amp, processor and speakers.

[Zippy]

Let's not forget some manufacturers design speakers to be off axis as well. Focal is one of the few that shows you their measurement chart on-axis, 30 degrees off, and 60 degrees off. The question of doing pods or not is partially what sounds better to you and partially what is the speaker designed for.

[simplicityinsound]

Originally Posted by WolfSongX

A lot of good info here. Thanks to everyone for sharing their thoughts.

Bing, I've been toying with using the MS-8 as well since I wanted to keep the stock head unit and was looking for something that was going to be relatively easy to tune and set up. Is there something else I should be looking at processor-wise that offers similar features like time alignment and could be tuned by a well-meaning amature who knows enough about audiophile grade sound to be dangerous, but by no means an expert.

Thanks

i personally prefer the mosconi ones, having done 25 or so of them. for me, what is most important to a processor is reliability, someting that doenst give me issues since i do this for a living.

the ms8 expereince, for me, was a big up and down. while it is nice that in 5 mins, you can get it to be 80 percent of the way there, if you desire more, there is simply no way to get it. there are also otehr issues with it such as the midbass tracking of the subwoofer, and other minor glitches.

over all those ms8s i have done, there were very few installs that if i had to do over again with the processors available to me now, i wouldnt make a switch

again, i dont think its bad and if you dont have a local person to help you tune, the ms8 would surely beat a standard tune your own unit, but for me, i prefer using something else.

b

[simplicityinsound]

Originally Posted by Zippy

Let's not forget some manufacturers design speakers to be off axis as well. Focal is one of the few that shows you their measurement chart on-axis, 30 degrees off, and 60 degrees off. The question of doing pods or not is partially what sounds better to you and partially what is the speaker designed for.

thats a good, though IMO those charts, which have no real standard and are measured in a room, doesnt have a ton of bearing in a car environment. In general, a lot of tweeters which are harsh on axis, should be and can be tamed a bit by going off axis. and in most cases in many cars, there are certain things you gain and loose by going on and off axis. a lot of it also depends on if you value tonality or imaging more.

but keep in mind one thing, the stock location of the FT is NOT what you would call off axis, with where it is, it is early reflection, semi on axis with a different dispersion pattern and a phase change.

but my issue with the stock wlocation is more to do with the tweeter being so far inboard and having such a tiny grille opening, than how its angled or aimed