Car audio - subwoofer's lowest frequencies too loud?

Discussion in 'Audio Hardware' started by supermd, Aug 29, 2019.

  1. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    I am three weeks into trying to calibrate my car speakers so they sound warm and powerful. I am getting nowhere and need some help. I started a thread about using test tones to help me get a benchmark for my frequencies to all be at the same volume. This thread is a bit different.

    I am having trouble with my subwoofer. It seems to play the LOW frequencies (think 50Hz) well, but when it comes to higher frequencies like 150-200Hz, it's not as good. You may be screaming into your computer, "Don't put your crossover that high!!!", but I don't know of any other way to get my audio that warm and gooey. My previous car's audio system was heaven to me (and I think the crossover was 200Hz), but this one is proving to be more frustrating with every drive. There is a very noticeable gap in the frequency range in that area. I have highs and mids and LOW bass, but that other region is very lacking.

    I was just listening to some Tom Petty on my girlfriend's Alexa, and that had the PERFECT balance in that bass region, with the songs coming out warm and punchy. I use the excellent hi-res Petty remasters to check my many adjustments in my car, as I am familiar with how they should sound, and darn it if her Alexa sounds better. That should not be the case!!

    Does anyone have any idea why my high bass frequencies are so lacking, and do you have any advice on how to improve them? Would it even be possible to lower the LOW frequencies a bit? I don't even know where to start.

    Here is my new equipment:
    Front speakers: Kicker 44KSS6704 6-3/4" Component System
    Rear speakers: Kicker 44KSC6704 6-3/4" 2-way Speakers
    Sub: Pioneer TS-SW2002D2 8" flat woofer
    Amp: Alpine X-A70F 120W x 4 Car Amplifier
    Sub amp: Alpine MRV-M250 250W x 1 Subwoofer Amplifier
     
  2. PopularChuck

    PopularChuck Forum Resident

    Location:
    Bay Area
    I'd suggest posting this at DIYcaraudio or a dedicated car audio forum for more expert advice.

    That said... I'd lower the crossover frequency. 200hz is the uppermost limit of the recommended range for that sub, and your Kickers have a frequency response of 35hz to 21khz. Drop the sub to 120 or even 80 and see what happens. Yes, I know you said 200 was great in your other car. Every car and every install is different.

    Other things to consider...

    What kind of enclosure are you using for the sub? Generally speaking, sealed will give you smoother response throughout the range, while a ported box will give you better low-end. It's a bit of a simplification, but sealed boxes tend to be tighter while ported boxes tend to be boomier.

    Where is the box located? What kind of car is it? Hatchback, wagon, SUV, sedan, etc. will all have different dips and peaks in the frequency range.

    My suggestion: if possible, try moving the enclosure. Test it out in a few spots. Turn it around so it faces different directions. Take your time and go slowly. If you're still not happy, lower the sub crossover point to 80hz and slowly work up. Again, take your time. Get it as close as you can, then use the EQ in the head unit to get it the rest of the way.
     
  3. PopularChuck

    PopularChuck Forum Resident

    Location:
    Bay Area
  4. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    I think mine is ported? It is installed in the side of the trunk, in the wall, using the designated sub spot in the wall. This makes it impossible to move in my car, which limits things. I have a hatchback.

    I have fiddled with many different crossover points, and I am still not getting the sound I'm looking for. I will, of course, keep trying, but I'm getting discouraged, hence me reaching out.

    I'll try and create a thread at diymobileaudio.com.
     
  5. PopularChuck

    PopularChuck Forum Resident

    Location:
    Bay Area
    Does your head unit have an EQ feature? It so try making adjustments there
     
  6. shokhead

    shokhead Forum Resident

    Location:
    Long Beach,SoCa
    I'm a bass head but do not want home bass in my car because of the rattles that will pop up everywhere. I'll stick to my stock Bang & Olufsen.
     
    audiomixer likes this.
  7. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    Yes, it has the standard highs, mids, lows, but that does not seem to help at all.

    I don't want rattling, either. I'm not interesting in ground-shaking, earthquake rumbling that occurs in a home theater when watching a disaster movie. I want warm bass guitar in my car.

    This morning, I was listening to some Elton John DCC material on the drive to work, and all the meat has been sucked out, left with mid/high and extreme low. Those DCC masterings, these in particular, have that warm, analog sound, but it is not present here. Not only are the bass frequencies I want to hear completely absent, but it sounds like a huge part of the sound is missing. This is true for all my material.
     
  8. Uglyversal

    Uglyversal Forum Resident

    Location:
    Sydney
    I think your choice of sub may not have been the best but if you have a hatch back you probably couldn't go for better options either. Do try lowering the X-over frequency as perhaps your kickers are better at dealing with your missing frequencies. Try for a few days don't dismiss it immediately as you might need time to get adjusted and also you need the chance to listen to many songs before concluding whether it works or not. Otherwise you will need to go to a specialized installer and ask there as they will be able to tell immediately what's not right there.
     
  9. shokhead

    shokhead Forum Resident

    Location:
    Long Beach,SoCa
    Bummer, what you are missing/want is what I have. Happy enough!
     
  10. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    Seattle, WA
    Have you tried some extreme EQ to see if this gets you in the ball park? By this I mean something like 10dB down at below 50 Hz, and 10 dB up above 100 Hz? Some cars just sound bad inside. And since your sub is mounted in a hole in your trunk, there is no way to tighten the bass without a cabinet. So the sub is probably just booming uncontrolably at its resonant frequency right now. If you can manage to EQ the boom way down, then you might be able to turn-up the rest of the spectrum for the sub to get your warm bass.
     
  11. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    How would I be able to adjust "10dB down at below 50 Hz, and 10 dB up above 100 Hz" on my sub?

    What about reversing the polarity of the sub? I know home subs have the option to change it 180 degrees (or something like that).
     
  12. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    Rub it in, buddy. :unhunh:
     
  13. audiomixer

    audiomixer As Bald As The Beatles

    And keep your windows rolled up because I don’t want to hear it!
     
  14. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    I ain't one of those fools. YOU'D want to hear the music I play. :D
     
  15. audiomixer

    audiomixer As Bald As The Beatles

    Just no rap-rap-rap-rap-rap-rap!!!!
     
  16. carrick doone

    carrick doone Whhhuuuutttt????

    Location:
    Vancouver, Canada
    I am stuck with the sub's location also so I eq the heck out of it with a parametric equalizer. I am not averse to DSP even though I'm a purist at home. I find cars to be a completely different beast from a room. They are more like really big headphones. I approach them as such and don't worry about imaging as much as making sure the speakers are all doing what they need to be doing for my ears.

    Changing polarity may help as the sub may be out of phase with the front speakers. Also check the polarity of your fronts. If they are reversed to what you need that may be the problem. I agree with lowering the crossover too. If you are not getting the sound you want from the fronts it may be a problem with the fronts. Don't assume they are not the problem.

    You have some good components. Work at aligning all of them polarity wise so you know you are starting from a good base and they are all moving in the same direction at the same time. Test records or the 9 volt battery test works well. Then seriously look at adding a good equalizer in the chain. Tone controls are too broad. You don't mention any sound deadening / absorption in your list. I find it works really nicely on bass. More is better in a car and in door panels it will increase midbass. If you don't have any in the sub get some pillow stiffing in there if appropriate.

    Good luck to you in your journey.
     
    supermd likes this.
  17. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    Thanks for your reply.

    Can you recommend a cheap but quality equalizer? I'd rather not go there until I have exhausted every other avenue, though.

    I have a test track that checks for polarity, but I'm not 100% sure I'm hearing it correctly in the car. Is there some other way I can check without using the subjectivity of my ears? And can I do it for each set of speakers (front, rear, and sub)? Last week, I took my car back to the audio place that installed these and had them re-do my wiring, as they totally mucked up the locations (when I moved the imaging to the front right, I heard the left channel of the song, plus some stuff in the rear left speaker! - funky stuff). He claimed he checked all that stuff when he fixed it, but I'm not sure I trust them.

    My work has a bunch of audio absorbing foam that they are planning on throwing away, so it's all mine. Any recommendations on how to use that stuff? I currently have a wad of it in my trunk, just sitting there.
     
  18. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    Seattle, WA
    I'm talking with EQ. Doesn't your head unit have an equalizer built in?
     
  19. carrick doone

    carrick doone Whhhuuuutttt????

    Location:
    Vancouver, Canada
    Hmmm, I'm getting a picture of your install that I'm not liking.

    Let's back up. Have you checked your speakers for being out of phase? It isn't always easy to hear in a car because of all the surfaces. I once drove around for 6 months not knowing my speakers were out of phase. Once you determine that your fronts and rears are in phase to each other left to right, check that the fronts are in phase with the rears. In other words, they are all pushing and pulling the signal at the same time.

    The polarity test is important if you are wanting to be picky about the sound and it reads as if you are. But knowing that all speakers are in phase as a unit is the first step to getting the sound to a base level. Once you know your speakers are in phase and working together then change the sub's polarity to gauge impact.

    For polarity I find using a test track for polarity is hard when you have all five speakers attached. You would have to disconnect the ones you aren't listening to including the sub to be able to isolate. A small live recording like classical or the Cowboy Junkie's Trinity Session or Steely Dan is my best bet for this type of checking. Steely Dan because they used very simple equalization in recording and isolated the instruments so you get a strong purity in sound. The battery test is well known but you have to be able to see the speaker move in and out. When the 9v battery is connected to the speaker wires the cone should move outwardly in an obvious way. If it doesn't, reverse the leads and that is the correct polarity. Agree on a marking of negative and positive and work your way around all speakers one by one.

    If you have separate tweeters, the battery approach doesn't work well at all I find. But there is a whole conversation had about keeping tweeters out of phase. Make your best guess on them based on how smooth they transition from the mids. I find the sound should be stronger and individual instruments like horns and trumpets more coming toward me when my speakers are in polarity. And when in phase they sound localised. Use a Duophonic mid 60s recording to isolate that in the car.

    As to insulation in a sub. take a piece and put it in the cavity of the sub. You may notice an immediate impact. If it's too dead sounding take some or all of it out. If it's still boomy add a bit more. You are playing with some unknowable measurements so you have to experiment.

    YouTube how to use sound deadening but typically it comes in sheets with a sticky side. You take off the door panels (usually pretty easy to do with simple tools) and clean the panels with alcohol then lay in the deadening. Made a big difference in the clarity of sound from my fronts. The back deck is easier because you get into the trunk and lay it on the underside of the deck where the speakers are. The idea is to make it harder for the speakers to move the deck / doors so the vibration of then the sound only has one place to express. But sound deadening is a second step to making sure the speakers are working together and properly. Do not put loose insulation in door panels.

    I hear you on going with an equalizer last. You want to decide on what your base level is with your speakers then move on. I can't recommend a cheap equalizer but I can suggest Crutchfields for looking around. You won't pay too much these days as everything is done in the digital domain. Once you find your unit go to eBay for a second hand one if you can get it. Also search any of the car audio forums for their recommendations. Mine is built into my Pioneer unit. It's one of the reasons I bought it.

    Hope this helps.
     
    supermd likes this.
  20. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    Just high, mid, and low bands.
     
  21. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    Seattle, WA
    That's unfortunate. My Kenwood head unit has a full equalizer built in. Although it is not the easiest thing to use through the interface.
     
  22. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    You don't know the half of my installation problems...

    I have not personally checked my speakers for polarity issues. I took the word of the last guy who worked on it. I am a complete newbie with this stuff and don't know how to take my car panels off to check the polarity issue via speaker wire by itself. I'll try and search for a better polarity test track. That's the easiest method for me. Couldn't I just try my best to isolate the speakers by using the fader on my head unit when testing using a test track? As far as duophonic, I have those Beatles Capitol duophonic mixes. Will those do? How should I be using those?

    How would I go about reversing the phase of my sub?

    I forgot to mention I have an LC6i.
    LC6i | AudioControl

    Also, I'm getting confused by phase and polarity. I know they're different, but now I'm mixed up haha. My test track is called "polarity," but the man in the audio track says "in phase, out of phase."
     
  23. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    I should also note that these missing frequencies were present when I was using my stock speakers, so I don't think it's necessarily my car itself. That's why part of me believes it's the way these new ones are set up.
     
  24. carrick doone

    carrick doone Whhhuuuutttt????

    Location:
    Vancouver, Canada
    I hear you. To get to a specific sound for your car you need to know everything is working as it is designed.

    Yeah, don't get our host going on "phase" and "polarity". Actually he has a few really good threads on the difference - search polarity or phase but the details are all about home stereos. In general, phase is considered crucial for quality of sound, polarity can be subjective due to a number of factors. Phase speaks to each speaker with the same signal doing the same action, polarity speaks to all speakers doing the same action the recorded instrument is doing.

    Good point about using the faders to isolate the speakers front to back. You will also want to fade down the sub.

    The test track you have with the person speaking is probably talking about phase but you can use a mono signal or the hilarious duophonic left / right recording. I use Don't Worry Baby. It's really obvious when the sound is out of phase. The voice should be pinpoint in the centre if you are in the centre of the car - move your head to the centre. If it seems kind of like a cloud of sound go to your amp and switch either the left or right speaker wires of the fronts - just one speaker not both. Fade down the fronts and do the same process for the back.

    I don't have a good process for seeing if the rears are working with the fronts except for turning your head and using a mono track. Isolate just the right or left side for rears and front. Turn your head so your ears are on either side of the front and rear speakers. Play the mono track. If it locks in the centre of your ears your speakers are in phase all around. If it sounds out of phase (that cloudy sound) you will reverse both speaker wires of either the front or back at the amp. Assume the fronts are correct and do the rears.

    As to the sub, change the wires at the amp. But work through the phase of the speakers first. Also, before switching wires turn off your stereo. Silly suggestion I know but really worth it. For adding sound absorption, you are going to have to get behind the speaker and that may mean unscrewing some stuff.

    I once read that to get sound right, get the bass right first. It's counter intuitive in a car because you have so many parts that can't be moved around. It's better to get the main speakers right then the sub.

    Let us know how it goes for you.
     
    supermd likes this.
  25. supermd

    supermd Forum Resident Thread Starter

    Location:
    Campbell, CA
    I was only able to do some minor testing this weekend, but I used this track, streaming from my phone via bluetooth.



    The results were interesting. My car's sub went quiet when the speakers moved to LEFT or RIGHT, but perked up when it was CENTER. As for phase, the sub completely died when it went OUT OF PHASE in the video, and was audible in the IN PHASE sections. I tested this on my earbuds, nice Sennheiser headphones, and my home setup, and the bass on those did not act this way. What could be causing that? Could that be the culprit?

    Side note: The OUT OF PHASE section sounds a lot more centered (from the driver's seat, admittedly) than the IN PHASE section, but the complete lack of sub volume suggested something was wrong... Very interesting.
     

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