Anyone running "on-axis" components up front?

[TOOSTUBBORN2FAIL]

Originally Posted by kmbkk

Very nice. I had 2 Mk IV's and traded them for a Mosconi 300.2 amp. I'm holding out for the Mk V to be released and put it in the foot well also.

I have a mkiv that will go in my wife's kia's foot well, and will put a mkv in my foot well when I get my car.

[cjd]

I'll be doing some work along these lines, though I anticipate being able to keep it all passive if that's useful (not sure the XO for the door would be worth the weight.) Should be an interesting project. Curious to see what others are doing.

[czechm8]

To the OP....I would maybe think about changing up your drivers a bit. It is always a challenge in a car environment to get good imaging and staging when the drivers are placed apart from one another. I went through many drivers in my quest to equip my Sequoia, including almost the entire CDT lineup. I'm running a two-way setup up front with the mid-base in the lower door and tweets in the sail panels.
I found that a mid-base driver that can play well in the upper ranges (5K-6K) and overlapping the x-over points with a solid tweeter, you can achieve much better imaging and a higher sound stage.


You might consider using a ring-radiator style tweeter. They will give you much better off-axis response than what you are currently using.


I ended up with Scanspeak Revelators in my doors, and a pair of impedance matched HAT Legatia SE tweeters -all on some custom built crossovers.

[Vmax911]

Thanks for the response. I have been looking into other drivers, while trying not to break the budget. I've also looked at dome-type drivers for better off axis response, as well as AMT tweeters.


My concern is even if I get better off axis drivers, will bouncing them off the windshield "smear" by hearing both the off-axis response and the on-axis reflection delayed from the windshield.

[TOOSTUBBORN2FAIL]

I would avoid ever playing a midbass up to 5-6khz, and instead find a tweeter than can be crossed at 2000hz with a 24db/oct slope.

The problem is, a 6.5" speaker will start beaming just below 2000hz, so the dispersion from the midbass and tweeter will never match up if the midbass is ran than high. That will cause frequency response problems that vary with location in the car, and will also vary as the sound bouces off different surfaces in the ca , and can't be fixed with any amount of eq. 6.5" speakers need to be low passed no higher than 2500hz, and even better at 2000hz.

[cjd]

You need controlled directivity, not wider dispersion.
Also just about required to be 3-way, there's just too much distance and off axis on the door drivers. The bounce off the glass alone isn't the issue, I'd guess there is some nulling from the shape of the glass/dash and the bouncing between surfaces that happens. The good news is that limited vertical dispersion isn't much of an issue in a car, so it is solvable.

C

[TOOSTUBBORN2FAIL]

You need the directivity of the drivers to match at the crossover point. That is impossible crossing over a 6.5" above beaming, because the tweeter will be radiating sound omnidirectionally while the woofer will have extremely narrow directivity at 5000hz. That will be impossible to fix with eq, it's just physics. What happens when a woofer beams is that the sound below beaming is still reflecting off of everything around it, and above beaming it stops reflecting off everything around it. But when you eq the system, you are eq'ing the sum of the direct and reflected sounds. Those won't match up when a speaker is beaming. The only way to correctly do controlled directivity is with waveguides and horns.

I know Scott Buwalda claims running a speaker into beaming is good, but he is the only one who has ever had success with that in real competition, and his installs and processing took extreme steps to cover for that. Everyone else uses a speaker in its pistonic and omnidirectional bandwidth.

[TOOSTUBBORN2FAIL]

I'll add this, I've heard cars tuned with Scott's "controlled directivity" approach including cars tuned by Scott himself, and I've heard cars that ensure all speakers are matched in directivity at the crossover, and the second of those two approaches has in every case, imaged and sounded better.

[cjd]

Originally Posted by TOOSTUBBORN2FAIL

I'll add this, I've heard cars tuned with Scott's "controlled directivity" approach including cars tuned by Scott himself, and I've heard cars that ensure all speakers are matched in directivity at the crossover, and the second of those two approaches has in every case, imaged and sounded better.

Both comments are spot on. By the time listening axis, distance to the listener, and distance to the dash is accounted for, 2k is a huge stretch - a 3-way should help significantly. I have three systems I've designed where I cross a 7" to a tweeter, all at 1600Hz - two 24dB/oct, one 48dB/oct, passive (cauer-ellipctic filters for the 48dB/oct slope). I'd have preferred to cross the one lower but couldn't get 1400 out of the tweeter comfortably without a waveguide (learned a few things since then, might have better luck were I to try it now...)

One of those systems has the 7" at a 45° angle to the tweeter - it presents an interesting set of problems; in this case, you can either listen on the tweeter axis, or off - but not both (phase has to be flipped on the tweeter depending on your choice.) I was shooting for 3rd order slopes to try to work around this, didn't have much luck. Very similar to what a car does, where you're almost 90 degrees off-axis to the near-door driver. Makes for a messy problem. Power response is a beast.

The other problem in this case remains the fact the dash placement will introduce reflection issues in the upper frequencies which I believe can be helped with some directivity control on the tweeter. I'll be trying a few things out, not really sure what will work at this point. It's highly probable I'll be getting the tweeter vertical. 3" or 4" mid.

First time doing a custom car install for me though, so I expect to fail a few times.

C

[labskaus]

Have a look at my thread

I am running the car in this setup (3way plus sub, activ) hardly 3 years now. In national competions I only made first places and also in the european competions I am not that bad.
My Setup:
Sub 0(flat) to 36hz (18db/oct)
MidSub 40hz (18db/oct) to 200hz (12db/oct)
Midrange 220hz (12db/oct) to 1600hz (12db/oct)
Tweeter 2000hz (12db/oct) to 20000hz (flat)

As you can see, the 4" Midrange work across the windshield, while the Tweeter is facing direct to the driver.

The only problem is the different in the angle of the midsub. left is punshing good but as no deep, the right one as a good deep but no punsh. Can the handled with the EQ,

[cjd]

Originally Posted by labskaus

Have a look at my thread

I am running the car in this setup (3way plus sub, activ) hardly 3 years now. In national competions I only made first places and also in the european competions I am not that bad.
My Setup:
Sub 0(flat) to 36hz (18db/oct)
MidSub 40hz (18db/oct) to 200hz (12db/oct)
Midrange 220hz (12db/oct) to 1600hz (12db/oct)
Tweeter 2000hz (12db/oct) to 20000hz (flat)

As you can see, the 4" Midrange work across the windshield, while the Tweeter is facing direct to the driver.

The only problem is the different in the angle of the midsub. left is punshing good but as no deep, the right one as a good deep but no punsh. Can the handled with the EQ,

Curious about your comment on the "MidSub" disparity (traditionally called a woofer...) - got any frequency sweeps demonstrating the issue?

Slick setup regardless. How big is your mid? 125mm?

I have to get in there to see just how much depth is available in the dash for a mid. Looking at the Satori MW16P-4 for the door, not sure what I can pull off in the dash. Need to keep it lightweight too.

[Vmax911]

Originally Posted by labskaus

Have a look at my thread

I am running the car in this setup (3way plus sub, activ) hardly 3 years now. In national competions I only made first places and also in the european competions I am not that bad.
My Setup:
Sub 0(flat) to 36hz (18db/oct)
MidSub 40hz (18db/oct) to 200hz (12db/oct)
Midrange 220hz (12db/oct) to 1600hz (12db/oct)
Tweeter 2000hz (12db/oct) to 20000hz (flat)

As you can see, the 4" Midrange work across the windshield, while the Tweeter is facing direct to the driver.

The only problem is the different in the angle of the midsub. left is punshing good but as no deep, the right one as a good deep but no punsh. Can the handled with the EQ,

Your setup looks great! I'm glad the midrange firing at the windshield is working for you. I may try a similar setup if I can figure out how to make some tweeter pods on a budget.