Buick Century - active 3way + sub w/ nexus 7

[lithium 358]

ugh, hit backspace and lost some stuff..

 

Some questions for you guys.

 

1. Should i be concerned with stretching vinyl over these kick pods? specifically the transition between mid and tweet.
2. Is horizontal alignment of the tweet and mid something i should avoid? There's a reason why 2way monitors are vertical, right? Lobing at xover frequency? 
3. Speaking of alignments/aiming what are some other variations i should try? currently I've aimed each at roughly the location of the headunit in the dash. 
4. What should I be listening for exactly when comparing different alignments/aiming (is there a better way to describe this)?
5. Should i target a sealed enclosure volume? should i worry about matched left and right volumes?  Quentin's build has my interest peaked in ported, worth trying? I dont think i have the same output requirement he seems to have. 

thanks for looking guys. 

[///M5 2,833]

Horizontally you end up with nulls, but it is a car so you have to compromise on something.  Tons of people use MTM's as center speakers, while not ideal can "work".

 

As for vinyl, I'd probably build a single baffle for both the mid and tweet.  Sure it is a compromise as well, but improves the ease of aiming and cosmetically works.  This will really help your aiming questions.  Too many variables when you can move everything independently.  It will also allow you to get the tweeter really close to the mid.

 

Never hurts to try sealed, but mark the pods so that if you want to you can pop a hole in the back of them and vent them into the fender.

[lithium 358]

Horizontally you end up with nulls, but it is a car so you have to compromise on something.  Tons of people use MTM's as center speakers, while not ideal can "work".

 

As for vinyl, I'd probably build a single baffle for both the mid and tweet.  Sure it is a compromise as well, but improves the ease of aiming and cosmetically works.  This will really help your aiming questions.  Too many variables when you can move everything independently.  It will also allow you to get the tweeter really close to the mid.

 

Never hurts to try sealed, but mark the pods so that if you want to you can pop a hole in the back of them and vent them into the fender.

 

Thanks for the advice. If i vent the kicks into the fender will cutting a hole in the carpet be required as well? or can i assume the carpet is relatively transparent (acoustically).  

[///M5 2,833]

It'll be more of an aperiodic vent.  Personally I'd cut it, but you can always try without first.  May not be necessary.

[SpeakerBoy 64]

Updates?

Looks good so far

[Sencheezy 689]

update?

[lithium 358]

i'll get some updates for you guys this weekend. 

[Sencheezy 689]

sounds good. 

[jcarter1885 995]

[cobra93 47]

I feel like a stalker, lol.

 

I read your reply in your other post.

 

Thanks lithium.

[Shogen 325]

info info info... 

 

but more importantly ... PICS!!!

[lithium 358]

update time!

 

So back in October I accepted a job offer in Illinois so over the course of about 5 days I tried to do as much as possible to get things functional. I would lose access to tools and work space so finishing the FG was the biggest priority.

 

these are the pods mocked up. 

 

missed some pictures here but the "finished" product. 

 

a wide angle shot from the dome light. based on my testing i preferred the midrange drivers off axis. In the driver seat the mids are approximately the same angle off axis and the tweeters are aimed to clear obstacles/blockages like my leg and the E brake.  

 

 

I'm not too happy with how they look (performance is fine but forming that opinion will take more listening time). I jumped the gun on upholstering the pods and should have used bondo to form the pod's edges to give a more seamless transition between the pod and interior. I need more practice with vinyl as you can see... those tight corners are a real pain. 

 

Some additional info on the pods. There are some holes cut in the back side of the pods to vent the enclosures into the carpet/through a hole which goes to the frame. I might cut the carpet at some point. The pods are also stuffed with polyfil. 

 

Moving on to the big ass holes in my doors.

 

 

skip a few steps....

 

And that's as far as they went before I left. Assuming I'm happy with the midbass running IB in the doors I'll move ahead and finish these up in the spring. Otherwise ported door enclosures  will be next

 

I still have some work to do with deadening the doors. A few small rattles will need to taken care of. Something I tried but didn't take pictures of was adding about 5lbs of ductseal to the rear side each door trim panel. In the pic below (not my actual door panel) I circled the areas where the ductseal was applied. 

 

 

once the weather warms up I'm planning to do some more sound deadening. MLV from firewall to rear seats and rear doors, thinsulate acoustic in the headliner, and the other stuff i mentioned above concerning the front doors. 

 

Till then i've got a few problems to sort out. 

1. turn off pop due to the usb dac turning off before the amps
2. scratchy sound from mids/tweets (not sure which yet) in cold temps (<20 degrees F).
3. rear view mirror rattle

If you have any suggestions let me know.   

Edited January 17, 2015 by lithium

[cobra93 47]

Thanks for the update.

I know what you mean about the "I wish I'd of  done this different" .

 

Keep the updates comin when you get to them.

 

I've read about getting rid of turn on/off pops, I'm sure you'll sort that out.

[lithium 358]

i'm going to try adding a cap across the power pins on the dac. should give me some delay

[///M5 2,833]

Minidsp delay circuit is cheap outside of shipping and works too.

[lithium 358]

Minidsp delay circuit is cheap outside of shipping and works too.

 

have one, i'll have to take a look at how everything is wired up. between the minidc, a relay powering the tablet, and amp turn-on there's probably something i can do. 

[///M5 2,833]

It solved the problem for me on my boat completely. If the USB D/A starting up is longer than the delay though that could be the problem.

A relay adding "ghost" power when you unlock the doors on everything but the amps could help too. Of course that will shut off once you wait too long, but if it is added in parallel it could solve your problem for $5 MOST of the time.

[///M5 2,833]

It would also help boot times btw.

[lithium 358]

interesting idea. no problems with boot time right now. Turn-on time from suspend is pretty much instant. would be an interesting option for a carpc though!

[///M5 2,833]

Yep, I don't want to wait even 2 seconds lol and my carpc resumes to playing in less than 5.

[lithium 358]

well, got a small update. lots of little things still need completed but i'm getting there. 

 

I took a week off and went to visit my parent and figured why not gut the car and install some more sound treatments. Prior to this install I have treated the front doors, roof, and rear deck and now i've address the remaining areas (floor and rear doors). 

 

 

Sorry I didn't take too many pictures. 

 

I started by gutting the car, removing some factory dampening material and then applying cdl tiles, foam, and mlv. 

 

interesting pic of the factory treatments. there is 3"+ of foam under the carpet in the foot wells. 

 

the majority of the factory dampener wasn't sticking the metal. 

 

1/8" CCF used to decouple the barrier. doubled up in the foor wells. 

mlv installed. all seems sealed with vinyl cement. 

 

moving on the rear doors. 

 

oem vibration solutions are kind of interesting to me. the big styrofoam block in the door seems to add some rigidity to the door skin. I almost left it in... 

 

cdl tiles and butyl rope installed. 

 

forget to take pictures of mlv and ccf install

 

 

 

 

 

after this, I put the car back together and continued on with the other major project that I need to complete which was the kick panels and door trim 

 

I wasn't happy with the fit of the kick panels I made previously so I taped of the foot well and used bondo glass to fill in the gaps between the interior and the pods. 

 

 

similarly the doors 

 

final results fit much better. 

 

I didn't have time to finish the upholstery before leaving.  

Edited August 9, 2015 by lithium

[lithium 358]

Im really happy with the performance of SDS's products though I have some whistling from a bad window/door seal which is ruining my evaluation. Vibration through the feet/legs is down considerably. 

[Lee Carter 150]

Just reread the thread to refresh my mind- looks great! bet it sounds awesome!

[lithium 358]

Just reread the thread to refresh my mind- looks great! bet it sounds awesome!

 

wish I could say that. having an issue with with one of the minidsp's i think. 

[Fi 4 life 0]

Which one? Sub bass midbass or midrage trebble? (If thats how you have them set up...)