sound stage quastion: how to avoid midbass and bass cancellation?

after installed/upgrade my sound sys (except stock HU), new front components spk, new sub, new wires and new amp. sound is very good. but awhile ago i went up little bit further, i wanted to add a good (or "ok"?) sound stage. So, i did a lot of search btw diyma and here. after sum up what i'd read, i reversed my driver side's spk polarity. ok, sound stage is acceptable now. but all midbass are cancelled.

 

my question is

 

1. how do you guys reverse your one side polarity (180 phase) at the sametime to avoid losing all midbass (220Hz and below) ?

 

2. i found, after reversing polarity, range btw 280~800Hz are extremely annoying, like "wow" effect on window media player. i already eq it individually left and right channel, but i lost lot of "ture" sound (compared with 0 phase on both channels). how do you guys treat this problem?

 

3. what would be the cheapest way to align timing without losing midbass with litmited time and budget approx $500? thanks.

 

mark

In don't think there is a way to reverse the polarity without killing the midbass without fancy electronics. It's kind of the nature of the beast.... I had one speaker out of phase in my second (I think?) car due to a bad installer, and even one out of the four identical speakers, the midbass was really messed up.

 

One could design a circuit with opamps that flipped the phase after a particular frequency range (PITA, but possible), complicated DSP, or just time align it. That or go 3-way with the midbass in phase but midrange out of phase.

 

on question 3: Used Bit1, Used JBL MS-8 (what I'm going to next), New or used Rockford Fosgate 3sixty.2 (what I have right now, soon to be for sale cheap), or Mini DSP. There are probably a few more systems out there I missed as well.

thanks utc_pyro

 

i'm thinking about RF's 3sixty.2 too, but i don't have any bluetooth device (e.g bluetooth palm, iphone, notebook..) .

 

about miniDSP, is it for home/pc audio? coz' my car doesn't have USB to power it.

 

what reason you want to go from sixty.2 to ms8?

 

and oh, is it a fact that after T/A, midbass will always be messed up, no matter what fancy electronics are used? how come those devices can reverse phase without hurting midbass like what i'm doing now? If "fancy electronics can do the job, i really don't mind to spend little money on it. beside, i don't think i'll go for 3x components setup, i really want to keep my car as stock as possible.

 

again, thank you so much, utc_pyro

Er, TA SHOULD fix the midbass as all of the sound waves will be hitting at the same time. It should also help with staging.

 

The mini DSP can run on anything from 4.5 to 24v. http://www.minidsp.com/images/documents/External%20DC.pdf Several people over on DIYMA are using them in cars, and one of the fellow EE's at work is thinking about getting three for his car.

 

I'm going to the MS-8 because I know I'll be spending WAY too much time tweaking the 3sixty.2 and my GF will be pissed . After the DAYS I put into tweaking my 24 band EQ I have dedicated to JUST the sub in my home theater, I don't think she can put up with me doing that x 7 in the car.

 

Joking aside, I think I can use to to better set up the rear staging/fill, bypass the crazy two step DSP solution I have now (KAX-x4r DSP amp is doing my mid/tweet crossing), allow on the fly profile switching, and have more free time as I'm less able to fiddle with it. I probably can do most of that with the 3sixty.2, and it's kind of sad planing to sell it before I even powered it up, but I think the MS-8 will give me more options. Particularly if I decide to put something in my GF's car, as I can use the KAC-X4R over there to do the entire thing.

 

Oh, and the 3sixty.2 has fairly good range with the bluetooth. Using a $10 USB bluetooth dongle on my old laptop I was able to do the OEM integration tune from inside my house with the car in the drive way.

what is "Er" stand for?

 

i thought doing TA on 3sixty.2 is about few clicks/dial in?? but you right, MS8 can do all calculation for you!

 

same here, for just the central image, i've spent soooo muchh time on fine tuning each notes started from 18k,14k, 12k... until now 400Hz with my 15bands each left and right channel, went back and forth my trunk and driver's seat. and hey, can you imagine how annoying it is when you close you eyes/getting ready to sleep, and those beeping sound is still appeared somewhere in your room?!

 

so, what you are saying is.. 3sixty.2 can do TA meanwhile it won't affect midbass at all?

 

thanks

"Er" is maing that sound. Used simular to "um" in this case.

 

The TA on the 3sixty.2 is easy, I had it roughed in within 5 minutes. You just need a measuring tape and a calculator. The EQ is what I'll end up putting too much time into, and messing with the KAX-X4R to play nice with the 3sixty.2.

 

If I remember correctally you're just running a 2-way passive front stage? If so, the 3sixty.2 will FIX the midbass by doing TA. It's only people that run 3-way front stages without enough processing channels that it messes up.

 

Are you running the rear channels? If so, are you doing it as rear fill or full range/full signal?

You need a three-way set-up in the front to avoid destroying your midbass to pull this trick off. Alpine Imprint or JBL MS8 will amaze with thier auto-tuning capabilites. I used to be totally against DSP in a car to fix problems, but these systems are amazing. I've been in a car with a center channel and JBL MS8 and I've never heard a better sounding system. Would love to have this processor as well. Currently I'm using an Alpine deck with Imprint (Audyssey.)

If I remember correctally you're just running a 2-way passive front stage? If so, the 3sixty.2 will FIX the midbass by doing TA. It's only people that run 3-way front stages without enough processing channels that it messes up.

 

yes, mine is 2 ways components.

 

contrary, i thought 3 ways can fix the problem, i thought the mid (180 phase) can create soundstage at the sametime the midbass (0 phase) can slightly coverup the mid by adj xover.

 

mark

You need a three-way set-up in the front to avoid destroying your midbass to pull this trick off.

 

i thought so too!

 

Alpine Imprint or JBL MS8 will amaze with thier auto-tuning capabilites. I used to be totally against DSP in a car to fix problems, but these systems are amazing.(Audyssey.)

 

how about 3sixty.2?

 

thanks,

mark

how about 3sixty.2?

 

thanks,

mark

 

3sixty.2 if you want to tune it yourself. It has quite a bit of capability and some cool features, but you can't deny what the Alpine and JBL processors can pull off in such a short amount of time. These things can do in 30 minutes what a professional with an excellent ear has to take days to do. I'd go so far to say, the one MS8 car I listened to was by a long shot the best sounding car system I've ever heard and I've been involved in the consumer electronics business and heard some top auto sound competition cars over the past 15 years.

3sixty.2 if you want to tune it yourself. It has quite a bit of capability and some cool features, but you can't deny what the Alpine and JBL processors can pull off in such a short amount of time.

 

 

thanks biz77, are you talking about alphine pxe-h660 imprint sys?

Both the 660 or PXAH100. The 660, obviously to integrate with your oem head unit.

i would have to second the 3way option.. once you do it youll never go without. so much more control/detail. night and day difference

Both the 660 or PXAH100. The 660, obviously to integrate with your oem head unit.

 

i thought both 360.2 and 660 are similar sys which integrate with oem HU?

Er, TA SHOULD fix the midbass as all of the sound waves will be hitting at the same time. It should also help with staging..

 

ok, my 360.2 is coming tmr, soon as 360.2 installed and TA. shall i switch left channel back to 180phase and right channel remain 0 phase? ( the sound is too annoying, so now i'm just leave all channel 0 phase! )

 

mark

i would have to second the 3way option.. once you do it youll never go without. so much more control/detail. night and day difference

 

 

i thought about this too, but an extra mid will need an extra xover, since i'm switching to active, i may need another 360.2? the cost will raise way far from what i'm spending now. anyway, i may change my mind in few days!

 

mark