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Discussion Starter #1
I recently built a new sq system in my 4th gen firebird and am unhappy about my soundstaging and could use some guidance. Yes, I know that firebirds/camaros are not the easiest cars for sq, but I'm ok with that.

Details: I am using Alpine's newest Type X ring radiators mounted in the a-pillars facing the inside of the opposite seat (so, they are aimed crossing each other in the middle of the car). The tweeters are temp mounted inside of plastic cups (like a paint can cap) with a swivel mount attached so I can aim them. The cups are mounted as far back against the windshield as possible to minimize PLD from the door mids.

As of this moment, the system is horribly bright and soundstaging/imaging is completely nonexistent. The sound seems locked to the nearest side tweeter. I thought I was on the right track with my idea (I read on this forum how ring radiators are commonly crossed in the middle of the car, the PLD between woofer and tweeter is less then 2" and PLD between driver and passenger is only 12" for the tw and 14" for the woofer - which is just over 1ms. I'm using the included x-overs with the proper alpine suggested phase modules and I have a DSP. I have read about tweeters sounding better mounted in spheres, and tried to come close by using the plastic tops from spray paint cans.).

In my last system, an older alpine type x with silk dome tweeters in the a-pillars facing each other imaged a lot better and were nowhere near as bright.

So, I am wondering where I should start to fix my issues? I would like to know your thoughts on what could be causing the MOST problems - I know the acreage of plastic and glass isn't helping, but the problems weren't this bad with the last tweeters. Are the cups causing more problems then they are helping? Should I carpet my dash pad first? Should I aim the tweeters differently first? Any other thoughts or suggestions?

Much appreciated!
 

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I'd look at the reflections first. I've read that one of the main pro's to a sail panel install is reduction of reflective surfaces near the tweet.

Can you post some pics of where they are located on your dash? This will help is visualizing what ya got going on. If you had better luck with your last location, did you try the new tweets there as well?
 

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Discussion Starter #3
Here are pics of my temp install (sorry I can't link the images - I haven't posted enough yet - so just copy and paste these into your browser)

i213.photobucket.com/albums/cc216/shudson105/IMG_0230.jpg

i213.photobucket.com/albums/cc216/shudson105/IMG_0229.jpg

I have not tried to install them in the previous location mainly because I am trying to keep the tweeters as on-axis as possible and the old locations are way off axis. However, you can see in the pictures the big hole in the a-pillars right next to my tweeters - that is my old tweeter location.

After thinking overnight about it, I'm thinking my biggest problems with this current install are two things. One, my tweeters are in thin plastic spray can tops, and even though I put dynamat on the insides of the cups, the thin plastic is probably still resonating like crazy and the flat sides are probably spreading the sound in unhelpful ways. And two, the sound waves are reflecting off my dash in almost perpendicular waves straight at me and causing the brightness. The old tweeters fired into the windshield in such a way that the reflections were much more scattered.

What do you think?
 

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I'll post them up for ya.



I'm no expert, but I think that it's more intensity than Pl's with tweets. Depending on where they are crossed anyway. They seem to be pretty close to the dash and windshield, making it like a horn. Did they sound good to you there before you installed them?

If your wanting that location, I'd at least do a dash cover, and on your finished pods, try some way to limit it from reflecting off the glass.

What other locations and orientations have you tried with the new set?
 

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Discussion Starter #5
Thank you for posting my pics!

The last tweeters were in those big holes in my a-pillars that you see in the pics. The last tweeters were facing each other and off-axis from the listener. While I did like them there, they required lots of EQ to tone down the harshness and sibilance. I have tried putting a beach towel on my dash yesterday and noticed an immediate decrease in harshness and sibilance, but the sound is still anchored to the tweeter pods with no imaging.

And now that you mention it, it sure does look like my dash and windshield are almost horn loading my tweeters. I'm going to have to look into that....
 

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No problem. Lol
Sounds like you just need to get that dash cover, and then work on your aiming till your satisfied with the imaging.
Maybe a little more off axis than you have them now, see how it sounds. Also try different angles. If you can't get it nailed down like you would like, you might have to try a different location.
 

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What kind of DSP do you have? You may be able to actively cross the speakers to give you invidual gain control. I agree that you would likely benefit from a dashmat, but also being able to lower the gain on the driver side tweet should help. You could also try changing the tweeter module on the driver side to -3db (I think the Alpine's can do this), it would be a simple way to see if the reduced amplitude makes an improvement.
 

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Discussion Starter #8
I have an alpine H701 processor and I do plan on doing some adjustments with that, but I'm not doing all active crossovers since I am using the passive alpine crossovers that came with my speaker set.

I have been reading forums for many days now trying to see what people commonly do with ring radiator tweeters like mine. I know every different car and owner is going to have a different preference, but it seems my tweeters are generally 'intense' when on-axis with the listener and cars with large amounts of glass (like mine) affect this type of tweeter more so then normal.

I started this post thinking I could think everything out first and it would sound pretty good on my first try. Ha! I can see that I am going to just have to start playing with tweeter positions and blue-tack and cover my dash pad and apillars with some ultrasuede :)

I don't want to make another thread just for this question, but perhaps I should for the benefit of everyone else: does dampening the underside of the dash pad make a difference in the sound that is reflected or absorbed?
 

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I recently built a new sq system in my 4th gen firebird and am unhappy about my soundstaging and could use some guidance. Yes, I know that firebirds/camaros are not the easiest cars for sq, but I'm ok with that.

Details: I am using Alpine's newest Type X ring radiators mounted in the a-pillars facing the inside of the opposite seat (so, they are aimed crossing each other in the middle of the car). The tweeters are temp mounted inside of plastic cups (like a paint can cap) with a swivel mount attached so I can aim them. The cups are mounted as far back against the windshield as possible to minimize PLD from the door mids.

As of this moment, the system is horribly bright and soundstaging/imaging is completely nonexistent. The sound seems locked to the nearest side tweeter. I thought I was on the right track with my idea (I read on this forum how ring radiators are commonly crossed in the middle of the car, the PLD between woofer and tweeter is less then 2" and PLD between driver and passenger is only 12" for the tw and 14" for the woofer - which is just over 1ms. I'm using the included x-overs with the proper alpine suggested phase modules and I have a DSP. I have read about tweeters sounding better mounted in spheres, and tried to come close by using the plastic tops from spray paint cans.).

In my last system, an older alpine type x with silk dome tweeters in the a-pillars facing each other imaged a lot better and were nowhere near as bright.

So, I am wondering where I should start to fix my issues? I would like to know your thoughts on what could be causing the MOST problems - I know the acreage of plastic and glass isn't helping, but the problems weren't this bad with the last tweeters. Are the cups causing more problems then they are helping? Should I carpet my dash pad first? Should I aim the tweeters differently first? Any other thoughts or suggestions?

Much appreciated!
Ok... Been reading the manual a bit and can give you a suggestion regarding your system since you've provided some good infos already - the pics helped too...

Driver's passive try:
- Phase module #1
- ON axis TW & OFF axis WF
- TW's polarity out of phase
- TW slope ON
- Off-axis ON
- Presence control ON
- Impedance compensation OFF
- TW level -4.5dB

Passenger's passive try:
- Phase module #1
- ON axis TW & ON axis WF
- TW's polarity out of phase
- TW slope ON
- Off-axis OFF
- Presence control ON
- Impedance compensation ON
- TW level -1.5dB

Tell me if it helps and what you like, don't like - then we can work from there...
Dashmat is also a good idea ;)

Kelvin
 

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Discussion Starter #10
Thanks for replying Subwoofery - I appreciate the time you spent researching the Alpine settings. However, the settings and phase modules work a little different then you have described. Each phase module adjusts those settings as a group. For example, Phase module 1 has the tweeters with reverse polarity, TW slope ON, Off-Axis ON, Presence and Impedance OFF, while Module 2 has TW polarity in-phase, TW slope ON, Off-axis OFF, Presence and Impedance correction ON. So, I can only change the Modules and use the one that most closely matches my install.

That being said, using modules 2 on the driver side and module 5 on the passenger side is what I have been using. I started experimenting today with using the different modules and will probably stick with using module 2 on both sides.

With this install, I am trying hard to tune for 2 seat listening. I am willing to compromise on the drivers side to get the passenger side better. Right now, only concerning myself with the woofers, I have been experimenting with trying to get a decent central image for both seats. I was actually quite surprised when I reversed the phase on the passenger woofer and the driver side vocals snapped into focus in the center of the car and the passenger vocals where centered directly in front of the passenger seat. This is a HUGE improvement from having both drivers in phase. Understandably, some other frequencies sound funny now.

My new question for you guys is this: should I continue tweaking the system with the passenger woofer out-of-phase knowing that I'm going to have problems with other frequencies? I'm usually a sucker for accuracy, but I don't what to continue this way if I'm never going to be able to get it sound right tonally. I do have the Alpine H701 processor, so I've got great control over everything.

What do you think?
 

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Thanks for replying Subwoofery - I appreciate the time you spent researching the Alpine settings. However, the settings and phase modules work a little different then you have described. Each phase module adjusts those settings as a group. For example, Phase module 1 has the tweeters with reverse polarity, TW slope ON, Off-Axis ON, Presence and Impedance OFF, while Module 2 has TW polarity in-phase, TW slope ON, Off-axis OFF, Presence and Impedance correction ON. So, I can only change the Modules and use the one that most closely matches my install. Ok, got ya :D
Now that I know how it really works, passenger's side is surely #2.
Now, suggest you try #1 for the driver's side and also try #5. #1 should do it but you never know.
Driver's passive try:
- TW level -4.5dB

Passenger's passive try:
- TW level -1.5dB

That being said, using modules 2 on the driver side and module 5 on the passenger side is what I have been using. I started experimenting today with using the different modules and will probably stick with using module 2 on both sides.

With this install, I am trying hard to tune for 2 seat listening. I am willing to compromise on the drivers side to get the passenger side better. Right now, only concerning myself with the woofers, I have been experimenting with trying to get a decent central image for both seats. I was actually quite surprised when I reversed the phase on the passenger woofer and the driver side vocals snapped into focus in the center of the car and the passenger vocals where centered directly in front of the passenger seat. This is a HUGE improvement from having both drivers in phase. Understandably, some other frequencies sound funny now.

My new question for you guys is this: should I continue tweaking the system with the passenger woofer out-of-phase knowing that I'm going to have problems with other frequencies? I'm usually a sucker for accuracy, but I don't what to continue this way if I'm never going to be able to get it sound right tonally. I do have the Alpine H701 processor, so I've got great control over everything. Try to find the best module first and maximize your system for the driver's side first.
When you feel that your system sounds good, reverse the whole passenger's side (INPUT on your Xover).
Since you're tuning for 2 seats, below might be more appropriate:
Driver's passive try:
- TW level -3.0dB

Passenger's passive try:
- TW level -1.5dB (also try -3.0dB)

What do you think?
Kelvin
 

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Discussion Starter #12
I have spent the last three days attempting to tune my system and I getting frustrated :( My system is acting very inconsistent - it's almost as if my system needs time to settle in-between changes. On Wednesday, I made some changes and got a pretty good centered image in 200-500 hz range and when I came back Thursday, the image wasn't centered anymore, yet my settings haven't changed. Today, it almost seemed like my processor (Alpine H701) would only take the first change I made to it and would ignore any other changes for a few hours, e.g. I would set some freq to -4 and get a reading of 76 db...I bring it up to -2 and still get 76db......and an hour later I would get 78db like I wanted. Has anyone seen or heard of this happening before? I called my local shop this afternoon and they never heard of this before (I heard them ask several other shop members too).

The only thing I can think of might be the weather - ambient temp outside is only about 30* - my garage gets to about 50* with heaters; but I don't know what temp my processor box is since it's buried in my trunk.

Any thoughts? I've got three weeks off since college is out and I'd like to use them, but I can't tune with the situation like this :(
 
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