trying to use T/A

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  • catch22atplay
    catch22atplay Posts: 130
    edited May 2010
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    I only wish that vid was recorded in stereo. And thanks, i now have a humming i need to fix. EMF maybe i dunno. Never noticed this before. I did move the sub a few weeks ago. Maybe i'll just put it back to where it was. Bad enough i'm super picky about my home system. Now i'm about to reenter the car audio end. And car audio is so much more difficult to get right. In fact i'm pretty sure it's a never ending battle.

    I liked the sound from the drivers seat compared to other positions. High between the seat by the sunroof was surprisingly weak. Center low was weak as well. Here's where i think it's really important. Check at 2:56 where you're almost on top of the tweet. Hear that awesome sound of the guitar strings? You aren't getting that at the drivers seat. I'd give my left nut for sound like that while driving. I think you have a good start. But much tweeking to do yet.

    And thanks i think that vid was the most convincing for showing how much on axis the tweets really need to be before i install them in the wrong spot..
    Dodge Ram 1500 SLT Quad Cab 2007
    Pioneer DEX-P99RS, IPOD Touch 64gb, Rockford Fosgate T1000-4, T600-2 & T1500-1bd CP
    Polk Audio SR speakers, 6.5's, 5.25's, SR tweets and 2 SR124-DVC subs in 1.57cu ft sealed enclosures
  • MacLeod
    MacLeod Posts: 14,358
    edited May 2010
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    UM, I'm totally confused. I though you used TA to time align every thing so the sound from all drivers reached your ears at the same time. I want to hear all my speakers at the same time, not in a sequence. When I hear a male voice, I don't wanna hear the low part of his voice, then a gap as he switches notes, same with a female who is climbing up the scale. I know my mind receives all the sound at the same time, and all of it together at the same time is how staging is perceived.

    There really isnt a gap caused we're talking miliseconds here. Intervals that short, your brain doesnt interpret them as gaps but rather uses them in localizing the sound.

    If you delay every speaker by 3 ms and leave the sub at 0, youll hear the sub first then hear the front speakers. Your brain localizes by what it hears last and so your brain tells you that all the sound is coming from up front.

    Likewise with tweeters. Your tweeters are on the dash and your mids are in the doors but you want your soundstage up high. So you add delay so that youre hearing your tweeters last by a few tenths of a milisecond, your brain cues in on them and bingo, you hear your soundstage on top of the dash.

    Granted this wont work on all frequencies cause a tweeter wont play 250 Hz so youll have a harder time to get those to image up. Same with the sub. Anything above 63 Hz is going to pull to the subs locations simply because it overpowers your midbass drivers.
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • dudeinaroom
    dudeinaroom Posts: 3,609
    edited May 2010
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    I totally understand Mac. Just they way he said it, you want to hear subs first them mid last tweets. I thought he meant all the time. On my first read through, I did not realize he was just talking about just for setting up. I understand the time alignment. In a nut shell the end result should be having the same part of the signal reach your ears at the same time from all speakers.

    I wish I had more phase compensation for my subs than just the 0 or 180 degrees. Oh well, I'm not competing but do have some fairly clean bass.

    Sorry for the derail.
  • MacLeod
    MacLeod Posts: 14,358
    edited May 2010
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    I understand the time alignment. In a nut shell the end result should be having the same part of the signal reach your ears at the same time from all speakers.

    Yes and know. Time alignment is there for that reason and works well for 95% listeners, but for creative usage by us endless tweakers looking to move our soundstage around you wouldnt have all speakers hitting your ears at the same time.

    My TA settings from finals last year were the sub at 0, the mids were 4.65 ms (L) and 3.5 ms (R) and the tweeters were 5.05 (L) and 4.0 (R). The mids and tweeters, while being in different locations, were actually about the same distance so they should have the same delay if my goal were to get them to my ears at the same time. But since I was also wanting to raise my soundstage, I added even more delay so that extra half millisecond tricked my brain into thinking the soundstage was higher because thats where the last sound came from.
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • arun1963
    arun1963 Posts: 1,797
    edited May 2010
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    UM, I'm totally confused.

    Sorry dude didn't mean to confuse you. macs already summed up so I'll just add this.

    TA lets you hear the sound from all the drivers at the same time. For this to happen your drivers have to fire in a certain sequence. the furthest one fires first and the nearest is last. The tweets define your height as they are carrying frequencies 2khz and up. So linking the sub to the mids and then the mids to the tweets will allow your tweets to lift the entire stage. Since tweets are generally closest, you would delay them the most and hence these would fire last. Within this you can play around a bit like Mac said.


    MacLeod wrote: »

    My TA settings from finals last year were the sub at 0, the mids were 4.65 ms (L) and 3.5 ms (R) and the tweeters were 5.05 (L) and 4.0 (R). The mids and tweeters, while being in different locations, were actually about the same distance so they should have the same delay if my goal were to get them to my ears at the same time. But since I was also wanting to raise my soundstage, I added even more delay so that extra half millisecond tricked my brain into thinking the soundstage was higher because thats where the last sound came from.

    Macs settings above follows the same sequence. Since the sub is furthest its on 0 delay and fires first. Followed by the far mid. The near mid and the far tweet are set within 0.5ms of each other. This is under the haas limit, so the brain would process it as one sound.

    One way to do it is to set the near mid and far tweet to the same delay. Doing it Macs way pulls the stage further up. Without any loss. The near tweet which is closest fires last.

    While doing the TA I work on two drivers at a time based on this sequence. It's just something I've got used to. That said there different ways you can use to get to the same place :).
  • TakeTheTime
    TakeTheTime Posts: 249
    edited May 2010
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    arun1963 wrote: »
    Can you explain why that's everything I shouldn't do please? 'cause yeah, it works well!

    Then that's what counts.

    I'd still want you to say why you think it wouldn't work?
    This way the RR's aren't reflecting everywhere - they
    point so the reflection ends up in the back of the trunk...
    Pioneer P88RS-II | Polk Audio SR5250 | JL Audio 12w6v2 | 2x Genesis 3 Stereo 100 | Genesis 3 Monoblock
  • dudeinaroom
    dudeinaroom Posts: 3,609
    edited May 2010
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    I understand. All 3 of us are pretty much saying the same thing, just taking different routes to get to the same place. I'm not worried about time alignment in my current vehicle(95 Chevy Astro). I have a pair of db components, I won in a karma a while back. The mids made it into the dash, and the tweeters were removed. After installing I found out that one of the crossovers, and tweeters were toast. Oh well I paid nothing for them. I have stock drivers out of a 00 chevy Venture in the rear location(can not be heard over the fronts). Now the subs you will laugh at. I picked up a pair of PSB 40 MKII's at a garage sale. One of the tweets was junk. The bass from them is tight and punchy, but not bloated or boomy. In free space I'd say these things dig below just below 40 hz, in the van it will hit as low as I ever need it to. I have them hooked up to an old MTX RT2200, so each one is seeing about 50 watts(not sure it the subs are 4 or 8 ohm).