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Discussion Starter #1
Hello Everyone,

I am having a tough time getting the tuning to sound right in my 2018 Jeep Grand Cherokee. Here is my current response for my different settings: "tuned" and "bass". The "bass" setting is highlighted in Yellow for visibility.

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  • When I have it set to "tuned", it sounds pretty linear throughout the frequency range. The sub blends with the door speakers but I can still tell the sub is in the back. However, the output is pretty much shit. It's loud but has very little power behind the music and virtually no bass response (mirrors barely vibrate).
  • When I have it set to "bass", it is not linear and the sub does not blend at all, but it has the low end power that I like (mirrors vibrate but I can still see out of them).
The problem with both tunings are neither sound right. They lack detail, definition, fullness, and most of all bass. With a different tuning (not shown) the system has amazing power, clear highs, nice snare attack, punchy bass, and tons of low end (mirrors vibrate so bad you cannot see out of any of them, roof flexes). The tuning I speak of has it's own issues though and basically drowns out all vocals, so I chose not to use it.

My questions are:
  • What may I be doing wrong? The response curve looks fantastic and flat, but the sound is not.
  • Is it possible to have the best of all worlds, good vocals, powerful bass, and full sound? Without swapping equipment?
  • Is it bad to have a 35db loss between 30hz and 200hz? Without steep cuts, the sub naturally plays that much louder.
Side notes:
  • Time alignment is set by distance. I used an Excel calculator that Andy posted to determine time.
  • Whenever I throw caution to the wind and tune by ear, it ends up sounding like garbage. For some reason I never hear the harsh frequencies until the next day.
  • My complete system components are posted in my signature.
  • Unfortunately, I am running a passive front stage.
  • Rear fill is set to -20db and has a flatish response and barely noticeable when turning them off/on.
  • With rear speakers off, the tuning still has the same crappy sound.
  • My amp gains are set based on voltage. It sounded pretty balanced between sub and door speakers so I left it there.
Thank you for your time.
 

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IME time alignment with the sub can't usually be done well with distance measurements due to all the reflections and the long sound waves. I found the following method gave me good results:

Sit in driver seat, flip the phase of the sub to reverse. Play a sine wav tone at the crossover frequency (80hz?) On only the sub and one mid. Make sure they play at the same volume. Change the distance for the sub until the tone is the quietest, or seems to disappear. Then flip the polarity back to normal.

Both of these tunes seem to have an extreme amount of bass. Whether there is an issue that is causing you to percieve less bass, or if you prefer much more bass than average, I'm not sure.

There could be a null in your seat.

Where are you placing the microphone for these measurements?

The other thing that jumps out at me is how you have a big hole between 200hz to 5kish then trails upward.

I would think a much better starting point would be a gradual slope from 100hz to where you have 10k, or even slightly above where you have 10k.

It's strange you have a huge drop off after 10k.
You should ideally be pretty flat in the upper end from 10k to at least 17k.

If you think it's harsh, try lowering around 2k.

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Discussion Starter #3
Thank you Ifixtheinternet for reminding me of that method. I assumed I could set time alignment using technology, but I believe my ears will work better in this case. I'll give it a try and re-tune flatter on the high end per your recommendation.

As for a NULL in the drivers seat, the bass is non existent in every seat so I assume there's a different issue. Maybe I have a phase cancellation between doors and sub? I do not see any cancellations in my frequency response so it's hard to tell. I set my microphone in the drivers seat, essentially right between where my ears would be, using a mic stand.

Does anyone have a link to video or document describing how to tune a car stereo using ears instead of technology?
 

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Holy smokes. You have a 20 to 30 dB bass boost at 40dB but don't hear enough bass?

My initial thought is that you are lacking midbass. I would try a 5dB boost around 150Hz to 200Hz to lessen the steep slope you have going into your lower end. You currently have a 10dB rise from 200Hz to 100Hz. This should be closer to 3 to 5 dB difference. Maybe start your bass boost at 300Hz and make a linear transition (straight line) up to 100Hz from there. Everything you have below 100Hz seems reasonable in your "TUNED" setting. Your "BASS" setting is good for when you want to get rowdy.

I hope my $0.02 helps you.

Ge0
 

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Here is an example of my current measurement - and I like a "bass heavy" sound.... This is just with an under-seat sub and 6x9 door midbass speaker (no real sub in the trunk or anything).

 

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Here is an example of my current measurement - and I like a "bass heavy" sound.... This is just with an under-seat sub and 6x9 door midbass speaker (no real sub in the trunk or anything).

Nick, look at JT's response curve. You'll see a lot more midbass presence than your current tuning(s). This is a good visual presentation of what I was talking about. If we consider 55dB your center point he is up 9dB at 200Hz and another 9dB above that at 100Hz. He is a little more extreme with his midbass than I but I'll betcha his system doesn't have much issue with bass response.

Ge0
 

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It is very unusual that you claim there's no bass with that measurement. make sure your microphone isn't defective and measure with just an RTA app on your phone to double-check it.

I also agree the midbass needs to be higher.


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Nick, look at JT's response curve. You'll see a lot more midbass presence than your current tuning(s). This is a good visual presentation of what I was talking about. If we consider 55dB your center point he is up 9dB at 200Hz and another 9dB above that at 100Hz. He is a little more extreme with his midbass than I but I'll betcha his system doesn't have much issue with bass response.

Ge0
Yeah, my system is definitely very mid-bass heavy when sitting in the car in the garage - but when I'm driving down the road, I seem to lose a lot of that midbass impact, which is why I have my system tuned the way I do - so that the bass is still very much there while actually driving the car down the road.

It's still a work in progress though - I'm still fine-tuning the overall tonal balance to my liking - but it's pretty close right now. I've also been experimenting with different crossover points between the 6x9 midbass door speakers and the dash speakers. If I go too low on the crossover, the dash speakers seem to overpower the system at higher volumes (with any dash speaker). I was using a 400hz crossover point, but I've found that using a higher crossover point between the door and dash speakers seems to "balance" sound a little better at higher volumes - so I'm experimenting with 650hz crossover points right now.

I'm still pretty new to all of this, so I'm learning as I go - so lot's of experimenting. :) My latest upgrade was to the 2" CDT Unity 8.0 widebands in the dash (no tweeters!) and the system is the best it's ever been - love those little 2" aluminum cone wideband speakers! :)
 

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Discussion Starter #9
Excellent feedback everyone and thank you. I am indeed lacking midbass and will use JTs response as a new target. Hoping to find time this weekend to tune again.
 

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Discussion Starter #10
With all of your help, I was able to get the tune I have been looking for! Thank you!

I used the polarity swap method to get my subwoofer in phase. Turns out I was 2 inches off in my measurement. Then I started my rise at 300hz instead of 120hz, which did the trick. Bass is smooth and full, sub bass is deep, vocals are phenomenal. There is still some minor tweaking to be done, but after 2 years of tuning mishaps and constant advice from all of you amazing patrons on this forum, I feel like I am ready to go it alone at this point.

Thank you!
 

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Awesome!
Glad you're happy with it.

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I’m just now starting my tune ventures any tips or tricks ? Stuff you wish you knew now that you didn’t know then? I’ve been reading reading reading and watching vids like crazy. Umik is on order. Been playing with REW and getting familiar with mini DSP
 

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I’m just now starting my tune ventures any tips or tricks ? Stuff you wish you knew now that you didn’t know then? I’ve been reading reading reading and watching vids like crazy. Umik is on order. Been playing with REW and getting familiar with mini DSP
Absolutely! Here are a few tips I learned along the way:
  • Read forums (especially diymobileaudio) about your installed products/vehicle and watch videos to learn
    • The most useful videos I found were from Pssound on YouTube
  • There are many amazing users on these forums who can answer pretty much any questions you have
  • Use a DSP with time alignment and a parametric eq (not graphical, you need to be able to pick any frequency) to dial in sound
    • If you choose JL Fix-86 like I did, you also need a Twk-88
  • Use sound treatment on your doors to fix midbass
    • This improves response, quiets the vehicle, and removes harsh midbass reverb
    • I only had to install treatment on my front doors
  • If you are using rear fill speakers, lower the output so they barely affect your sound when turning off/on
    • Rear fill is hard because it can shift your sound stage and add harsh sounds in various frequencies, especially low end and around 1khz
    • Mine are high passed at 200hz to avoid low end, output set to -6db and eq to flat
  • Look at the response curve jtrosky posted, it sounds excellent
    • Note the low end starts to rise around 300+hz, that seems to be key for balanced midbass
  • When using AutoEQ in REW, use the same target level for left front and right front speakers to balance left and right
    • Same goes for rear speakers but they will be at a much lower level then the fronts
Everyone has their own tuning method and most are better than mine, but this worked for me:
  1. Set amp crossovers: I set to max speaker range +/-10hz to protect the speaker from damage
  2. Set amp gains to voltage spec with radio volume just below clipping (around 3/4) and eq flat on radio
  3. Setup microphone in drivers seat, about where your nose would be
  4. Use a tape measure to measure the distance from the end of your microphone to the door speakers
  5. Add 3 inches to each measurement then plug them into a time alignment calculator, such as tracerite
  6. Set time alignment and crossovers (I left fronts full range) in the DSP and listen to the results without the subwoofer playing
  7. Manually adjust time alignment until the sound stage is on your dash in front of you as the driver (shouldn't take much adjusting, may be slightly right of center)
  8. Use REW to measure each speaker individually
  9. Plug the measured response into AutoEQ in REW (research this) for each individual speaker using a house curve (I used jtrosky's response as my curve, had to create the file and import into REW)
  10. Transfer the AutoEQ adjustments to your DSP for each speaker (this may be a manual process)
  11. Only turn on front left and front right speakers, measure the combined response, fix any glaring issues manually in the DSP
  12. Turn off the fronts and turn on the rear left and rear right speakers, measure the combined response, fix any glaring issues manually in the DSP
  13. Turn on all speakers (still no sub), have a listen from the drivers seat, fix any issues you hear (don't worry about low bass at this point)
  14. Turn on the subwoofer and have a listen for blend and harsh bass, if the bass is harsh, adjust your time alignment until the bass smooths out
  15. Set the microphone back up in the drivers seat and use REW to measure the full system response with subwoofer on, as well as the subwoofer by itself
  16. Use AutoEQ on the subwoofer to smooth it out, copy results to your DSP (yes, you should eq the subwoofer but try not to cut or boost too much)
  17. Have a listen to the full system, if it's close to the sound you want, use small adjustments of eq; if it does not meet your expectations, start over
Tuning can feel frustrating at times. Try messing with the EQ and Time Alignment in your DSP to see how your system will respond to help get past those moments. No one gets it right on their first attempt, so try try again. Eventually, you will reach your goal and everyone's goal is unique.
 
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