Imaging or Soundstage in Ford F-150

Noisy in NC

Hello,
A first time poster on this forum and I need advice or suggestions.
My system is installed in a 2008 F-150 Pickup. The speakers consist
of 2 sets of DB571 5"x7" coaxials mounted in the stock locations in
the front and rear doors and a DB 1040 sub in a sealed cabinet in the
middle of the rear of the cab. The main problem I'm having is with the
imaging or soundstage. It seems that I'm "looking down" on the music.
Any suggestions on how to pull the image "up" towards the windshield
so it will be more "out front". I've considered several things to try.

1. Would removing the tweeters from the coaxials and mounting them
on or in the dash help ? I know you probably think I'm nuts for even
suggesting this but I have done crazier things. Also if I did do this
would I get better results mounting the tweeters flat in the dash and
bouncing them off the windshield or something like on the pillars
and aiming them more directly.
2. Adding a set of tweeters (db1001?) and mounting them in one of the
configurations above.
3. Switching to components and mounting the tweeters as above.

Just looking for ideas / suggestions before I get too far in this.
Thanks in advance.

MacLeod

The best option is to switch to components and dump the rear speakers. If you can afford them, get the new MM components. Mount the midrange in the stock door location and mount the tweeters either in the dash or in the A pillars. Firing them from the dash up into the windshield can work but you can have an awful lot of reflection problems and if you dont have a pretty flexible EQ then its gonna be hard to work them out.

Generally the best place to mount the tweeters is in the A pillars a couple inches higher than the highest point on the dash. Try to aim them to the opposite head rest.

Noisy in NC

Thanks for the advice. I had considered dumping the rear speakers. I think
looking at the components may be the best alternative. Can you give me
any more input on the reflection problems. I'm currently running a 5 band
parametric eq. Also have considered going to 6.5" drivers for the components.
The 5x7's just don't seem to have the oomph in the lower midrange.
The doors will need to be modifed slightly but a little creativity will solve that.
Does anyone know if polk releases the Thiele-Small parameters for their speakers
or are they designed to run in free air.

tk421

i would keep the rear. but still manage the front. go comps.. angles are important.

rear speakers fire into the back of your seat... loss of imaging is minor. but keeping the reas will help rear listeners a lot.

MacLeod

Rear speakers not only pull your stage to the rear and possibly down some depending on where theyre located, but worst of all they cause cancellation and phase issues. They do this because theyre playing pretty much the same frequencies that the front speakers are playing but since theyre at different distances they hit your ears at different times so this can cause cancellation of certain frequencies. And since theyll be different sizes, theyll have different frequency responses which can "smear" your detail.

Now if you just want some tunes to listen to while driving to work or haul people around a lot and just want sound everywhere, then rear speakers are fine. But if youre worried about proper stage placement then youre a more discerning listener and so I recommend against rears.

Hard to say about the reflection from the windshield. It will be different from car to car. Once you get them, Id test them out by just laying them up there for a listen then tape them to the a pillars and see what you think. You can also try them on the sail panel but this always seemed to make the left tweeter just scream at me.

Polk speakers work best in free air.

Noisy in NC

Thanks MacLeod. Your advice has been dead on so far. I disconnected the rear speakers and the difference was dramatic. The image pulled forward a great deal.
A benefit that I hadn't suspected also surfaced. The front speakers seem to have
a fuller sound and a funky curve I was getting around the sub/ speaker crossover
point is a lot better. Seems like the rears were causing cancellation with the fronts
as well as the sub around the crossover point. I will certainly won't reconnect the
rears. I think I'll listen to it a couple of days in the present configuration and look at
the MM series for the front. The 5 1/4" models will fit very easy in the doors but I
would really like the 6 1/2" even if they are more work. Have you had a chance to
listen to the sizes in comparison and would the extra work be worth the trouble
from a sound standpoint. I guess the thing with the rears reminded me of the old
adage "less is more sometimes" anyway thanks for the advice.

MacLeod

Generally, the 5.25 will have better midrange and detail and the 6.5 will have better midbass response and go lower into the sub bass region. I used to prefer the 5.25 due to the more natural sound but have flip flopped now because the added oomph in the low end from the 6.5's outweigh pro's with the 5.25's.

However a good set of 5.25's can still sound quite excellent and if theyre an easier fit then you should have no reservations about using them but if you dont mind doing some twisting and bending to get the 6.5's to fit I suggest going that route.

Also, try one thing with the rear speakers. If youre running a 4 channel amp hook the rears back up but turn the gain on them down to about half as much as the fronts. This can still cause some issues with staging but it could add some nice rear fill and a little ambience that you may like more. I prefer no rear speakers as I would rather have my stage in front and high but you might want to try it and see which way you like best.

Noisy in NC

Well the mm6501's arrived today. I guess I'll get them installed over the holidays.
I decided to try to Dynamat the doors at the same time. I was kinda amazed at
how light the mids were for a 6.5 . The neo magnets must be much more powerful
pound for pound than ceramic magnets. I guess the true test will be how it sounds.
I'll post again after I find out.

Noisy in NC

Well the mm6501's are installed. I just finished this morning. I'll have to live with
them a week or two and see how I like them. The installation wasn't too much of a
hassle. I just made some MDF rings to fir on the doors and cover the original 5"x7"
holes. Luckily I didn't have to cut the metal on the doors at all. The tweeters are in the sail panels. I looked at mounting them on the pillars but it would have taken a
week of geometry review to cut the compound (confounded ?) angles on any kind
of mount that wouls have looked decent. I also did the dynamat on both doors.
The first thing was to definetly turn down the tweeters to the -3db position. I guess
over the next few weeks I'll get it tweaked out.

MacLeod

Yup. Now the fun part - dialing it all in. Its worth it tho and to me the tuning is all the fun.