# Use your subwoofer to get better midbass



## ErinH (Feb 14, 2007)

In this video I discuss why I recommend using your subwoofer to improve midbass response. Get your pitchforks ready!... I’m suggesting to run your sub higher than 30hz! 

This isn’t truly a shocking revelation. Plenty of people already do what I suggest. It just goes against intuition and against some beliefs in the car audio community that a subwoofer should not play too high in frequency because it can cause the bass to be localized behind you.

The reason why is due to one MAJOR issue in car audio: the “Nearside Null”. This is the large dip in response of the driver’s side midbass speaker that occurs typically in the 70-90hz region. This doesn't occur in every car; there are certainly exceptions to the more extreme car installs.


It is an acoustical null caused by the relationship of the listener’s location relative to the midbass location and generally caused by the width of the vehicle. If you play a track with bass guitar it’s very prevalent; you get a localization to the nearside midbass speaker when the midbass speaker is crossed lower than the frequency where the null occurs. 

Generally speaking, the lower your crossover point between midbass and subwoofer, the more noticeable this occurrence is. Unfortunately, this isn’t something you can simply “EQ out”, either. Throwing +6dB at this null may only result in 1dB of actual gain; that means you’re wasting a LOT of power and risking damage to your speaker for no acoustical gain. Some of you may even think to yourselves “seems like you’re not getting much by crossing the midbass low. Maybe there’s not as much benefit as I thought in doing that”. That’s a logical assumption and a lot of times that’s actually true. Crossing the midbass too low can actually result in more “bass behind you”! And you can also take some of the strain off your midbass by crossing them at or above the null. Ironically, we in car audio tend to cross midbass low to get the “up front” bass we so much desire. BUT, IN FACT, the majority of the time you have bass that pulls to the rear is BECAUSE of the midbass nulls. I know that sounds counteractive. But it’s the truth. Standing waves are problematic and this is one symptom of them; whether in home or car audio.

Contrary to popular belief, raising the subwoofer crossover in to the region that this null occurs can actually HELP the sound to stay focused and achieve “up front” bass. If you can move your subwoofer to a location where it is null-free through a frequency above the Nearside Null then you can likely improve midbass without negatively impacting the “up front bass” effect that so many are after. And you can also take some of the strain off your midbass by crossing them at or above the null frequency. Not all have the luxury of space to move the subwoofer around much but experimentation is key here; you may be surprised at the difference subwoofer placement in the trunk can make.

And one important conclusion here is that placing the rear mounted subwoofer on the opposite side of the listening position often results in better response!


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## I800C0LLECT (Jan 26, 2009)

I've always been a big fan of this approach. When I first arrived at this site I tried going active and crossing my mids low. I noticed that it impacted my mid-range and the happy spot seemed to be steep slopes around 80hz to 90hz. 

In the end, I found that a passenger rear trunk sub gave me the best performance overall. I couldn't ever make enough sense of my logic to post though. I really appreciate all the work you put in to the site.

Matter of fact, this thought process almost led me to try and replace my mids with stereo subs in my rear deck for a 3-way setup 

Sent from my Pixel 4 XL using Tapatalk


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## ErinH (Feb 14, 2007)

I800C0LLECT said:


> I really appreciate all the work you put in to the site.


Thanks. I'm working on getting my test setup going again. I am also going to be testing loudspeakers and doing reviews on them as well in the same format. But I plan to keep trying to do these "educational" type videos as often as I can to help people who struggled with the same stuff I did for years.


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## I800C0LLECT (Jan 26, 2009)

These videos are great. It took me a long time to fully comprehend some of the concepts and I'm still learning a lot. I think that's one of the reasons diyma gets a bad wrap. A lot of this information is hard to communicate. 

These threads should by sticky'd! Let's keep donating to Erin too guys 

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## F150Man (Apr 14, 2017)

The last video, I found myself thinking of how I have always tuned like that, just didn't realize WHY I like it that way !


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## eficalibrator (Aug 25, 2005)

So what happens when you move the front midbass crossover point higher? e.g: going from 60Hz high pass up to something like 100Hz high pass? Would using a second order slope improve things if the filtered band is now 180* out of phase? A shallower slope starting from a higher crossover point should still leave a significant amount of energy going to the midbass at 80Hz, but still have enough effect on cone control at low frequencies.

I've been fighting this for a while in my C6 Corvette. Sub placement had a big impact on bass presence due to cancellation from the cabin geometry. I found the best answer was to move the sub(s) from the rear corner(s) of the hatch forward to right behind the driver/passenger shoulders, but I still have a relatively soft midbass response considering the power and speaker selection. Door speaker locations are not up for change, so finding other ways to minimize losses like this sounds good.


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## garysummers (Oct 25, 2010)

Thanks for posting this video. Since I put my subwoofer up front it has given me the ability to do, with much success, exactly what you are talking about. My car has the exact left side dip you reference. It is at 75hz and is about 6db.
Moving the sub crossover from 50hz to [email protected] and shifting the mid bass HP from 80hz to [email protected] has totaly center the bass in the car. It hits hard and center, no pulling left. Also raised the LP on the mid basses which has also improved the impact and clarity of the system.


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## lucas569 (Apr 17, 2007)

Erin, Any input on which way the sub faces? When I place facing the back obviously I get more impact. But when faced towards front the bass seems better and easier to blend but the impact goes way way down.


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## dumdum (Feb 27, 2007)

lucas569 said:


> Erin, Any input on which way the sub faces? When I place facing the back obviously I get more impact. But when faced towards front the bass seems better and easier to blend but the impact goes way way down.


Sub loading will change the response of the sub a little, it’s normally one way or the other sounds better 👍🏼


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## dumdum (Feb 27, 2007)

To further illustrate this point about phase and doors...










that is a phase measurement in smaart with 1/12 smoothing, if you see the green line and how it wraps around at 80hz you can’t possibly cross that to a sub at 80hz and get phase coherence due to the massive room mode influence at the listening position

then to show a different mounting, this is my hybrid u69v2 in the floor nestled just under the front edge of my seat IB










that is what you want phase to look like, even with the small blip at 160 and 220 on opposing sides you can see that the phase (And timing also) is largely identical so I get 6db of summation and perfect phase coherence for the most part 👍🏼 It also includes the almost perfect transition to my mids from the midbass where the phase matches perfectly to over 1k where there is a slight wrinkle and then on up...


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## jaya07 (Aug 31, 2019)

dumdum said:


> To further illustrate this point about phase and doors...
> 
> View attachment 275917
> 
> ...


Hi, i've tried to use Smaart V8 to check phase alignment but im not able to get the measurements like yours. Mine only shows straight lines on the transfer function window. Im using behringer ecm8000 mic and um2 and connected to my helix dsp pro mk2 via rca inputs.


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## dumdum (Feb 27, 2007)

jaya07 said:


> Hi, i've tried to use Smaart V8 to check phase alignment but im not able to get the measurements like yours. Mine only shows straight lines on the transfer function window. Im using behringer ecm8000 mic and um2 and connected to my helix dsp pro mk2 via rca inputs.


Post pics on a fresh thread and I’ll see if I can help 👍🏼


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## captainbuff (Mar 11, 2017)

dumdum said:


> Post pics on a fresh thread and I’ll see if I can help 👍🏼


Good man...good to see people wanting to help others out 👍


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## Jaloosk (Jan 13, 2010)

I took your advice. I had my door speakers crossed at 60Hz/24db and sub crossed at 90Hz/24db because I wanted more midbass, but was never happy with it. Sounded sloppy. Changed them both to 80Hz/24db and the whole thing came alive! Thanks!!


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## Stycker (Jan 31, 2018)

now move the sub low pass down to 60Hz. That should clean things up even further and will also allow the accoustical crossover to stay close to 80Hz when you turn the volume up.


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## claydbal (Dec 1, 2020)

great thread mr OP! im subscribing! next thing you will talk about is attenuating into the mid and building some bass trap(s).


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## ILX Cheeta (Feb 23, 2020)

Jaloosk said:


> I took your advice. I had my door speakers crossed at 60Hz/24db and sub crossed at 90Hz/24db because I wanted more midbass, but was never happy with it. Sounded sloppy. Changed them both to 80Hz/24db and the whole thing came alive! Thanks!!


Shop has mine set at. Sub at 80htz. Mids at 70 htz. I need to look at changing mine getting some real
Odd sounds at certain frequencies. Perhaps that is why.


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## Jaloosk (Jan 13, 2010)

Stycker said:


> now move the sub low pass down to 60Hz. That should clean things up even further and will also allow the accoustical crossover to stay close to 80Hz when you turn the volume up.


What do you mean by acoustical crossover?


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## dumdum (Feb 27, 2007)

Jaloosk said:


> What do you mean by acoustical crossover?


Where they actually crossover... the number in the dsp is not relevant to real life due to the level of the sub being higher... the audiofrog guide does provide a good explanation for this with pictures of responses to demonstrate what is being referred to 👍🏼


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## ErinH (Feb 14, 2007)

Stycker said:


> now move the sub low pass down to 60Hz. That should clean things up even further and will also allow the accoustical crossover to stay close to 80Hz when you turn the volume up.


Careful... That _could _also defeat the entire purpose of my initial suggestion and may leave him with a "hole" in the response. You can try it. Just don't expect that it will absolutely work. That's just part of this hobby. Lots of variables. But try and see.


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## Holmz (Jul 12, 2017)

^Lowering the subwoofers frequency^ seems like a reverse psychology approach to the spirit of, "Use your subwoofer to get better midbass"?


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## Ablakesurf77 (May 19, 2021)

Just wanted to say thanks for putting this on here. I was wondering where the midbass went in my car. Crossed it back at 80htz and sloped it at 24db. It's back and I love it. 

I now have a bit of a transition problem where I can tell where the sub is kicking in more instead of it all blending. The punch is stronger now than when I used a 12db slope. Wondering if this is a trade off.


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## AudioBob (May 21, 2007)

Nice video and thanks for taking the time to make it. I was always taught to crossover the sub as high as it could be crossed and then work on the mid bass crossover next. Every car and install can be so different based on so many factors that there is no one size fits all and experimenting always seemed to yield the best results for me. It's always best to let the sub do what it does best, and even at that experimenting with box configurations, placement and phasing takes time to get it just right. Sometimes I will build two or more boxes before I arrive at one that seems to work the best.

I find that letting the sub play loud within it's intended design lets me cross the mid bass speakers higher and allows them to play cleaner and louder and makes the system much more dynamic and enjoyable. I have started builds that have taken over a year to sound decent to me and even at that, I have had some that I have never been happy with. It is the rabbit hole that is high end car audio.


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## llebcire (Nov 17, 2016)

Great topic - thanks for the post and video @ErinH ! I missed this thread last year as I wasn't actively working on a system.

I've been on the struggle bus getting solid mid-bass up front on the 2 Accord Coupes I've owned in the last 7 years. Before the first one in 2014 I owned a GX470 with the Mark Levinson system that had 3-way in the doors with 6x9 woofers with good impact - I never really got the bass I was looking for out of Morel 6.5s after moving to the Accord. Traded that Coupe for an Infiniti G37x that used 10s in the doors for the Bose system - again an impressive output from the front doors.

For my current Accord Coupe, using the same Morels, I started experimenting (great part of DIY) with crossover frequencies - part of this was reading online the markings from the amplifier manufacturer are often not visually correct for the built in crossover frequencies - where I thought I had previously been crossing over around 80 Hz was closer to 55 Hz.

I'm planning on downloading REW soon to use and look for the null you mention in the 50-80Hz range and adjust accordingly. After running 6x9s and 10s in the doors I was convinced I would never have the same output from 6.5s - after moving the crossover frequency (both to 80) and watching this video I have some more work to do!

-Eric


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## Elektra (Feb 4, 2013)

Would you ever have a situation whereby you cross your midbass say at 60hz if not lower and cross your sub higher? 

If you have a set of 8’s as midbass you don’t want to really cross your midbass higher as there would be no point to a 8” midbass driver 


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## lithium (Oct 29, 2008)

Typically you don't need to overlap. So the sub would just play the bottom octave (<60). If you dont have a null issue from the midbass location and they have enough output then you shouldn't need the sub to play the midbass pass band.


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## Patrick Bateman (Sep 11, 2006)

I always overlap my subs and my midbasses, and something I've found helpful is to mess with the delays of ONE driver.

For instance, when my two subs and my two midbasses are running with no delay, I have a whopper of a peak at 60Hz, something like ten dB. Obviously, this is a room mode, the four drivers are hitting a room mode.

The "normal" way of fixing this would be to use EQ, which I tried. And it wasn't satisfactory; when you're using a "cut" of ten decibels, it's just going to sound weird, that's a lot of EQ.

So here's what I did instead:

1) 60Hz is 567 centimeters long. 
2) Sound travels 34 centimeters in one millisecond
3) 567 divided by 34 is 16.67

So I delayed ONE subwoofer by 4.34 milliseconds.

What this does, is it puts one of the four drivers ninety degrees out of phase with the other three. If it was a "full" 180 degrees out of phase, you would get a perfect null. By delaying it by just 90 degrees, the one of four drivers is about fifty percent out-of-phase, but not 100% out of phase.

The net effect?

*The peak at 60Hz disappeared. *In other words, a delay of just 90 degrees on one of four drivers was enough constructive interference to completely nullify a peak in the overall response.

I imagine you could do something similar to fill in a null. IE, if you have four drivers playing at 60Hz and you have a dip, you could make one of them 90 degrees out of phase to 'fill in' the dip.

I wouldn't do this 'delay' trick with midbasses, because they cover a wider spectrum. My subs are lowpassed at around 80hz, so the delay that I introduced doesn't have much of an impact at high frequencies. But if I had delayed my midbassed by 4.34 milliseconds, instead of my subs, then there's a possibility that the delay would introduce peaks and dips ABOVE 80hz. For instance, a delay of 90 degrees at 60Hz is a delay of 180 degrees at 120Hz, and that would introduce a null.

I know this post is kinda confusing, and as always, I recommend trial and error and a lot of measurements. My main point is that overlapping your midbasses and your subwoofer can give you some tools that are not available otherwise. For instance, if you only have two drivers playing at 60Hz (your subwoofers) then this trick I describe is not as effective.

One way to visualize the tricks that I am describing, is to learn how cardioid subwoofer arrays work:









Dave Rat's End-Fire Adjustable Arc Subwoofer Array Explained


During my interview with Dave he explained a subwoofer array that he developed during a Blink182 tour. Here’s what it looks like. Here’s where Dave explains it in the interview, starting at 45 minutes. This came out of the sub testing that I did, primarily on the Blink 182 tour and then finished...




www.sounddesignlive.com







https://www.merlijnvanveen.nl/en/calculators/28-sad-subwoofer-array-designer-en


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## Elektra (Feb 4, 2013)

Patrick Bateman said:


> I always overlap my subs and my midbasses, and something I've found helpful is to mess with the delays of ONE driver.
> 
> For instance, when my two subs and my two midbasses are running with no delay, I have a whopper of a peak at 60Hz, something like ten dB. Obviously, this is a room mode, the four drivers are hitting a room mode.
> 
> ...


So you run your subs at 80hz and midbass at 60hz? 


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## thecrestedibis (Nov 13, 2021)

Hi, I'm new here, but I have a decent understanding of acoustics.

I plan to run sealed subs under my front seats of my SUV because I have 10" of vertical clearance.

The idea is to slot load them with two 8" subs under either seat for a total of 4 subs.

I can build the box so that I can alter the slot to any position.

Since stumbling across this post, I wonder if I should design the boxes so that the frequency lying between the box peak and F3 point hits squarely at the midbass null. Effectively this would function as a midbass array targeting the near side null frequency.

Thoughts?


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## lithium (Oct 29, 2008)

Underseats might not have the null at the same position as the door. All vehicles are different, you'll have to measure it.


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## Old rocker (Jan 3, 2021)

Hello from Canada, .first off a shout out to Erin for sharing the video and to those who have shared their views. Last night I was reading this thread and found it very intriguing as I have various frequency challenges with my Midbass installed in the factory location in the lower door of my gen 4 Ram truck. My issues are slightly different as my Right side driver is the typical 70 - 90Hz dip not my drivers side left. Then the Left I have a dip at 140 - 200hz and my Right side has a peak at the same frequency so in both cases they are opposite but when played together are flat. The issue as discussed in this tread is the peeks and dips are drawing the low notes to one side or the other. My doors are very well dampened with Kilmat and Noico Closed Cell PE Foam. I was crediting the lul's to so many reflections like the center console as I have tried swapping out my Morel Hybrid MW6 with a Hertz 6x9 but get similar issues measured on REW with my Audiofrog UNI-1 Mic. Note I am running a 3 way active front.
The first graph is hertz 6x9 with green as left and purple as right. The second REW measurements are the Morel MW6 with Blue as the left and green as the right. 
My Midbass are running active from 70hz to 500hz powered by 210 watts of my Mosconi Zero 4.
Below are my measurements with flat EQ Crossed at 70hz 24db LR to 500Hz 12db LR as suggested by More powered by 210w of my Mosconi Zero 4.

















As you can see from the graphs above I also have a left side peak from 200 - 400hz and a roll off of the same frequency for the right channel. To help with the 200+ frequency I have purchased new front speakers to replace my Morel's. I am expecting my Audio Frogg GB10, GB25 and GS690 to arrive this week. The main reason for my change is my Morel CDM600 mids have a FS of 480hz so I have to cross them at 500hz in my 3 way active setup where as the GB25 Mids have a FS of 170hz so I can cross these at 250 - 300 so I can move my stage up higher to the mids which are located in pods with my tweeters in my A Trim location.









With all the expertise on this thread did I make the right decision on the AF GB25 to allow a lower cut off for my mids in the A Pillar and what about bringing my Xover to 80hz between my Midbass and subs or will that not make a huge difference?
I am running 2 - 12" Morel Primo's and Hertz MLK 165.3 as rear fill at 12DB LR 300 - 4000hz.
Any advice is always appreciated.


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## therapture (Jan 31, 2013)

I have had some success with this methodology.

I was running subs at 60hz, midbass at 80-400hz, and widebands from 400+ all on 24db LR filters.

I moved the sub up to 80 -still at 24db- and the midbass to 100-600 12db and the widebands 600+ 12db. After a bit of TA to blend the sub back in it is sounding great.

I decided to try it since I just got a new enclosure and two 8" VD8's.


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## hidehide (Aug 27, 2021)

Thank you for making this thread. I originally crossed my sub and mid bass at 60 and 80 with LR24. No matter how I EQ, I still couldn’t get the punch I was looking for. Yesterday I tried to switch the crossover point to 75 and 100. Immediately, I got so much punch that I even feel being suffocated. I’m going to RTA and fine tune the EQ to minimize the punch. I initially lowered the 85hz -3 with a Q of 4, I’m already getting much better result.


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## Nineteen69Mach1 (May 30, 2017)

Been a fan of running like this for some time.
Midbass in the doors are crossed at 120hz and the sub plays up to 90hz. GREAT midbass and the bass is all upfront.


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## hidehide (Aug 27, 2021)

Nineteen69Mach1 said:


> Been a fan of running like this for some time.
> Midbass in the doors are crossed at 120hz and the sub plays up to 90hz. GREAT midbass and the bass is all upfront.


Yea. There is a null around 80hz from the door panel in most car, plus mine is just 6.5” although the spec of the driver says it’s down to 55hz. It’s better to let the subwoofer do what it is good at.


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## Elektra (Feb 4, 2013)

What happens if you don’t use a high pass on your midbass and use a low pass on your sub? 

Assuming your midbass can handle no high pass would you not get better integration? 

Reason I asked is that I have the Focal 8WMs and they handle anything I have given them so far and no rattles whatsoever they go very low pretty easily so what happens if I let them play as low as possible and add a sub to play upto 50hz? 


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## MrHarris (Feb 3, 2011)

^ I want to know the answer to this question too


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## dumdum (Feb 27, 2007)

I wouldn’t use no high pass on midbass… I have 9.5” front underseat midbass and although I can get them to play to 30, I get much better response, less distortion and effortless midbass if I play them to 50hz and the sub from 57hz down… it makes for a rough crossover of 50hz and gives me very nice low end and a good amount of midbass so the 15’s don’t overpower the midbass nor do the midbass fail to keep up 👍🏼

Just because something can do something doesn’t mean it should

As for getting a better blend… that’s down to phase and getting that bang on in, having overlap or under lap is zero use if you can’t get the phase lined up… phase is the key down low!


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## Selkec (Nov 18, 2018)

I agree. Under and overlap don’t really mean anything anyways. People get that confused. You could play a sub to 100hz and midbass to 60hz (overlap) but if the sub is a lot lower spl have a 80hz crossover 

and visa versa sub to 40 and 6-12db louder than I’d ass and midbass to 100hz and have 80hz crossover.


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## captainobvious (Mar 11, 2006)

I never saw this thread @ErinH but I remember us having a conversation about this a long time ago. I see this in many of the cars I tune. Listening position and geometry of the cabin affecting midbass response and creating nulls that are difficult to deal with.
Even IF you are fortunate enough to not have that big null (Thankfully, I don't in the van with my listening position- I got lucky!), you can often still gain in other ways from a little higher crossover point. Specifically, with increased impact, utilizing the increased cone area from sub(s) and often higher sensitivity in that frequency range (50-80hz).

Good stuff brother! This is very helpful info (and well explained) for those who struggle with achieving "up front bass".

One more consideration regarding achieving that (and unrelated to crossovers) is resonance and tactile feedback. Both of those are non-tuning issues that are also critical as part of the process of achieving this.


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## bertholomey (Dec 27, 2007)

captainobvious said:


> I never saw this thread @ErinH but I remember us having a conversation about this a long time ago. I see this in many of the cars I tune. Listening position and geometry of the cabin affecting midbass response and creating nulls that are difficult to deal with.
> Even IF you are fortunate enough to not have that big null (Thankfully, I don't in the van with my listening position- I got lucky!), you can often still gain in other ways from a little higher crossover point. Specifically, with increased impact, utilizing the increased cone area from sub(s) and often higher sensitivity in that frequency range (50-80hz).
> 
> Good stuff brother! This is very helpful info (and well explained) for those who struggle with achieving "up front bass".
> ...


And regarding that last bit…..if one has a sub mounted in the front of the vehicle, but at higher volumes, there is vibration in the back of the seat that makes some perceive the bass coming from the rear of the car, have you guys found remedies for that? Other than telling a judge to not turn it up 


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## SloVic (Oct 1, 2016)

I've read that some people have taken their seats apart and built them up to be a dense as possible.


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## bbfoto (Aug 28, 2005)

bertholomey said:


> And regarding that last bit…..if one has a sub mounted in the front of the vehicle, but at higher volumes, there is vibration in the back of the seat that makes some perceive the bass coming from the rear of the car, have you guys found remedies for that? Other than telling a judge to not turn it up


Having too much bass is a terrible problem to have!  Bass "waves" are obviously Pressure Waves, and it's really hard to isolate the seats from these massive pressure waves.  The seats are just a "membrane" that gets in the way of their propogation. I have that same problem, along with the steering wheel & column vibrating in one of my installs. 

Jason, just an experiment, but try hanging a 20lb-30lb barbell or dumbell weight from the headrest upright posts and down the back of the seat with a heavy rope or leather belt, etc, as a makeshift "damper".



SloVic said:


> I've read that some people have taken their seats apart and built them up to be a dense as possible.


I'm not positive, but I think that Steven Head "mass loaded" the front seats in his Blazer when they were reupholstered. And the seat rails were also extended so the seats slide back further and the rails were repositioned so that both front seats are closer to the center of the vehicle.

Also notice where his subwoofers are located in the Blazer. They aren't in the far rear corners or back of the vehicle where you'd most likely achieve more output due to boundary loading and cabin gain. I think he _might have_ opted to sacrifice a bit of overall SPL output for smoother modal response in the front listening seat positions. Just a guess tho'.


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## oabeieo (Feb 22, 2015)

ErinH said:


> In this video I discuss why I recommend using your subwoofer to improve midbass response. Get your pitchforks ready!... I’m suggesting to run your sub higher than 30hz!
> 
> This isn’t truly a shocking revelation. Plenty of people already do what I suggest. It just goes against intuition and against some beliefs in the car audio community that a subwoofer should not play too high in frequency because it can cause the bass to be localized behind you.
> 
> ...


saw this repost , and love it!!

this Is so true….

anyone that Heard- my car can attest this is fact

my sub has a 6db filter at 52hz and plays audible to 200. And it fills and reinforces the midbass big time and sounds excellent…

The low order filter is also phase friendly and easy peasy to snap to the midbass and the midbas doesn’t need a huge tilt!

i Play my midbass flat mostly with midrange and highs and let sub make the tilt…..

I love this thread. Thanks Erin (even tho it looks about two years late)


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## bbfoto (Aug 28, 2005)

oabeieo said:


> saw this repost , and love it!!
> 
> this Is so true….
> 
> ...


Andy, I have to agree with your findings regarding using 6dB/octave filters on the subwoofers to integrate them with the midbass. In two different systems I also use 6dB/octave filters on the subwoofers, around ~47Hz-55Hz as well.

One setup uses Two 15" sealed subwoofers, and the other is Four 8" sealed subwoofers. As with any system, you've got to eliminate all of the resonances and rattles that you can to keep that upfront bass illusion alive. I've got some issues in one of the vehicles that has proved difficult to remedy.  I mentioned it in my post above.


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## oabeieo (Feb 22, 2015)

bbfoto said:


> Andy, I have to agree with your findings regarding using 6dB/octave filters on the subwoofers to integrate them with the midbass. In two different systems I also use 6dB/octave filters on the subwoofers, around ~47Hz-55Hz as well.
> 
> One setup uses Two 15" sealed subwoofers, and the other is Four 8" sealed subwoofers. As with any system, you've got to eliminate all of the resonances and rattles that you can to keep that upfront bass illusion alive. I've got some issues in one of the vehicles that has proved difficult to remedy.  I mentioned it in my post above.



I bet two 15s was awesome…… not all subs can do what we’re doing tho . It’s like past 75hz some subs (cough kicker) have no fidelity. The higher efficiency less damped higher Q system is strongly preffered here….
like qtc .8 or .9….. and a sub with a shorting path or low inductance just shines


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## Picassotheimpaler (Sep 21, 2014)

Elektra said:


> What happens if you don’t use a high pass on your midbass and use a low pass on your sub?
> 
> Assuming your midbass can handle no high pass would you not get better integration?
> 
> ...


How are they mounted? In door? I just did some experimenting by building a test kick panel box for my gb60s, and the boundary loading alone gave roughly a 15db boost over the door location at 100hz starting at 175hz. 
If that's the case, than it probably wouldn't be an issue if you gave them some sort of xo above resonance


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## Picassotheimpaler (Sep 21, 2014)

oabeieo said:


> saw this repost , and love it!!
> 
> this Is so true….
> 
> ...


Don't you end up with some phase issues between the midbass and subs when using a 6db xo on the sub that would make the integration difficult?


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## oabeieo (Feb 22, 2015)

Picassotheimpaler said:


> Don't you end up with some phase issues between the midbass and subs when using a 6db xo on the sub that would make the integration difficult?


nope ! Makes it a breeze….

even if I did use minimum phase crossovers it would be easy….. but with linear phase crossover, I can choose a 7db slope or 9db slope and even with overlap it’s always in phase at all frequencies….

but let’s say I used minimum phase crossovers…

a 6db crossover would have minimal phase shift, the only phase change would be from the 1st room dip, then back to normal

so a simple alignment to where the phase is on midbass using plain old delay would get my in the transition…. In that instance I would choose to be centered in the transition…. It would not have phase tracking, I might even go for a 6db filter on midbass…. Which at low frequencies a6db can be quite steep

It’s Definitely not a proper crossover at all , in that sense, but with 6db there’s so little phase it’s a slam dunk to align with midbass….Could practically do it by ear


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## mzmtg (Dec 8, 2009)

bbfoto said:


> Also notice where his subwoofers are located in the Blazer. They aren't in the far rear corners or back of the vehicle where you'd most likely achieve more output due to boundary loading and cabin gain. I think he _might have_ opted to sacrifice a bit of overall SPL output for smoother modal response in the front listening seat positions. Just a guess tho'.


I made this change and it helped quite a bit. I have always pushed my sub way back in the corner to maximize cabin gain. Now that I have a setup where output is not an issue, I moved it. I moved it from all the way in the back of my CX-9 to the back of the middle row, facing the rear.

With the sub a couple of feet closer, it blends much better with the midbass. I have a hunch that since my MS-8 doesn't do any time alignment of the sub, it's always going to sound better being closer to the other speakers.


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## lithium (Oct 29, 2008)

mzmtg said:


> I made this change and it helped quite a bit. I have always pushed my sub way back in the corner to maximize cabin gain. Now that I have a setup where output is not an issue, I moved it. I moved it from all the way in the back of my CX-9 to the back of the middle row, facing the rear.
> 
> With the sub a couple of feet closer, it blends much better with the midbass. I have a hunch that since my MS-8 doesn't do any time alignment of the sub, it's always going to sound better being closer to the other speakers.


Curious how the ms8 handles the TA. Maybe jbl just assumed the sub is furthest away from the driver seat, which would result in zero delay need.


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## mzmtg (Dec 8, 2009)

lithium said:


> Curious how the ms8 handles the TA. Maybe jbl just assumed the sub is furthest away from the driver seat, which would result in zero delay need.


According to Andy, the long wavelengths of the subbass make TA unnecessary as long as the crossover and levels are correct. I know that's controversial on diyma, but that was supposed to have been the thinking behind that design decision.

As for the other channels, the MS8 uses impulse response to calculate TA.

Personally, I have heard the benefits of TA on the sub, but I also know that the MS8 does a great job of bass integration without it.


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## lithium (Oct 29, 2008)

mzmtg said:


> According to Andy, the long wavelengths of the subbass make TA unnecessary as long as the crossover and levels are correct. I know that's controversial on diyma, but that was supposed to have been the thinking behind that design decision.
> 
> As for the other channels, the MS8 uses impulse response to calculate TA.
> 
> Personally, I have heard the benefits of TA on the sub, but I also know that the MS8 does a great job of bass integration without it.


Gotcha, interesting..


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## Picassotheimpaler (Sep 21, 2014)

mzmtg said:


> According to Andy, the long wavelengths of the subbass make TA unnecessary as long as the crossover and levels are correct. I know that's controversial on diyma, but that was supposed to have been the thinking behind that design decision.
> 
> As for the other channels, the MS8 uses impulse response to calculate TA.
> 
> Personally, I have heard the benefits of TA on the sub, but I also know that the MS8 does a great job of bass integration without it.


Typically your sub is the furthest speaker from you. So with that mentality it doesn't need ta, because everything else is delayed to match it. And if for whatever reason the sub isn't the furthest, it's going to be very close to the furthest. And in that case the long wavelength will completely gloss over the small difference in time....
I believe that's the mindset atleast


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## oabeieo (Feb 22, 2015)

Picassotheimpaler said:


> Typically your sub is the furthest speaker from you. So with that mentality it doesn't need ta, because everything else is delayed to match it. And if for whatever reason the sub isn't the furthest, it's going to be very close to the furthest. And in that case the long wavelength will completely gloss over the small difference in time....
> I believe that's the mindset atleast


That is exactly right

and the GD from the crossover adds a few ms also, and the sub(being the first in the chain) won’t have a speaker under it to have GD so you can use delay to eliminate it


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## Eatmore Bacon (Dec 17, 2020)

I prefer punchy bass myself. My system is really well balanced with the single sub XO point to mid bass at 60Hz however the punch is missing. Moved it up to 70Hz and the punch is there but the bass has moved to the back somewhat so I am still playing with it.


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## gijoe (Mar 25, 2008)

Eatmore Bacon said:


> I prefer punchy bass myself. My system is really well balanced with the single sub XO point to mid bass at 60Hz however the punch is missing. Moved it up to 70Hz and the punch is there but the bass has moved to the back somewhat so I am still playing with it.


You should be able to play your subs up to 100hz, or even 120hz without sounding like the bass is behind you. Most of the time it's panel resonance, or some other noise that draws the bass backwards, 70hz shouldn't put the bass behind you. 

The "punch" that people look for, and a huge point of this thread, is that it's the integration of the subwoofer and midbass that produces great midbass, you don't necessarily need 10" midbass speakers and 500 watts for strong punchy bass, you need a subwoofer that is integrated well with the midbass speakers.


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## oabeieo (Feb 22, 2015)

Yeah gijoe is right.

and bass in front of you is only possible as it transitions between 70-150hz

Below 70 (50-60 in some cars) you absolutely can not tell the direction the bass is coming from…. It just isn’t possible. So any illusions of bass upfront would be hassing off the midbass 
Which works, but really revealing the distortion when hassing….. not a good idea 

I think bass up front is over rated….. I would rather have a solid response then screwing up the time domain to achieve a “effect” that should not be


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## Picassotheimpaler (Sep 21, 2014)

oabeieo said:


> Yeah gijoe is right.
> 
> and bass in front of you is only possible as it transitions between 70-150hz
> 
> ...


Well the "effect" of up front bass is less an effect as in an artifact and more of using the way humans perceive sound to get sound localized to where it should be in a song.
I know it drives me nuts, just like when imaging drags all over the front of the car.


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## Eatmore Bacon (Dec 17, 2020)

gijoe said:


> You should be able to play your subs up to 100hz, or even 120hz without sounding like the bass is behind you. Most of the time it's panel resonance, or some other noise that draws the bass backwards, 70hz shouldn't put the bass behind you.
> 
> The "punch" that people look for, and a huge point of this thread, is that it's the integration of the subwoofer and midbass that produces great midbass, you don't necessarily need 10" midbass speakers and 500 watts for strong punchy bass, you need a subwoofer that is integrated well with the midbass speakers.


I kept playing with the crossover point and found the sweet spot. 65Hz. At 70 it sounded like the bass wasn’t integrated with the front stage as well. I have an F250 so it’s limited on just how precise it can be anyway. At least from what I have read


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## Picassotheimpaler (Sep 21, 2014)

Eatmore Bacon said:


> I kept playing with the crossover point and found the sweet spot. 65Hz. At 70 it sounded like the bass wasn’t integrated with the front stage as well. I have an F250 so it’s limited on just how precise it can be anyway. At least from what I have read


You probably have some phase mess going on between the 2. There's no reason you shouldn't be able to get up front bass imo. Can you take some phase traces with REW?


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## Eatmore Bacon (Dec 17, 2020)

Picassotheimpaler said:


> You probably have some phase mess going on between the 2. There's no reason you shouldn't be able to get up front bass imo. Can you take some phase traces with REW?


Unfortunately, no. I just had it tuned and it sounds excellent. I just wanted the bass to be a little more snappy/punchy. I may play with it more tomorrow. It’s at a happy medium right now at 65.


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## oabeieo (Feb 22, 2015)

Picassotheimpaler said:


> Well the "effect" of up front bass is less an effect as in an artifact and more of using the way humans perceive sound to get sound localized to where it should be in a song.
> I know it drives me nuts, just like when imaging drags all over the front of the car.


I know what your talking about now, yes, knowing your in a car effect… yeah it’s annoying sometimes…

I don’t go out of my way to do any trickery to make frequencies image from somewhere else

If phase measures proper and has a fast step and no dips , to me that sounds better and any good imaging cues down low are a bonus…

The trickery is usually destructive to the time domain in my experience..(purposely changing delay and frequency to achieve a effect) although not always a bad thing…. I think I saw a video by earl geddes that said we can’t hear the first 100 some odd cycles of bass anyway….. that’s a lot of wiggle room for trickery

idk….. I’m not the jury on this……


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## oabeieo (Feb 22, 2015)

I will add cars that have a big natural peak at 70-80 (cough cough, full-size trucks) crossing at 65 probably nets a smooth response at 80 I would guess……

cars that have the big dip at 80 (small cars) you need full power going to sub…..

I think it’s a question of reinforcement vs. preference honestly and I think it suggests we all like the same thing and go about it different based on our acoustics


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## Selkec (Nov 18, 2018)

Eatmore Bacon said:


> Unfortunately, no. I just had it tuned and it sounds excellent. I just wanted the bass to be a little more snappy/punchy. I may play with it more tomorrow. It’s at a happy medium right now at 65.


That does not mean it’s perfect by any means. Have you tried time aligning your entire front stage against the sub?


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## SloVic (Oct 1, 2016)

bbfoto said:


> Having too much bass is a terrible problem to have!  Bass "waves" are obviously Pressure Waves, and it's really hard to isolate the seats from these massive pressure waves.  The seats are just a "membrane" that gets in the way of their propogation. I have that same problem, along with the steering wheel & column vibrating in one of my installs.
> 
> Jason, just an experiment, but try hanging a 20lb-30lb barbell or dumbell weight from the headrest upright posts and down the back of the seat with a heavy rope or leather belt, etc, as a makeshift "damper".
> 
> ...


Pretty cool build. His Aspen build looks very nice as well. Think he's had some practice.


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## Eatmore Bacon (Dec 17, 2020)

Selkec said:


> That does not mean it’s perfect by any means. Have you tried time aligning your entire front stage against the sub?


Time alignment has been performed but I didn’t know you could align the entire front stage against one driver.


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## cathul (Jul 2, 2018)

Eatmore Bacon said:


> Time alignment has been performed but I didn’t know you could align the entire front stage against one driver.


Just link all front drivers together or add/substract the same amount of time alignment to every single front driver, done.
Substracting can only be done when all front drivers have a delay obviously and only up to the least amount delay of any front driver.


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## Speedhunter (Feb 21, 2020)

Never saw dip at 80hz, more like 110and above(small car) and who the hell LP sub at 80Hz especialy sealed box...

here is sealed 12" 63hz LP no EQ









Midbass 63hz HP door; dip at 110hz









Sum










On sum graph nothing changed with dip(dont be confused with shady EQ aplied bellow 60Hz. It can not be fixed nor moved with sub and/or midbass. Unfortunately i dont have 80Hz LP where it can be seen same scenario. Also from 80hz LP you start to hear deep voices and bass guitar coming from subwoofer....


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## Picassotheimpaler (Sep 21, 2014)

Speedhunter said:


> Never saw dip at 80hz, more like 110and above(small car) and who the hell LP sub at 80Hz especialy sealed box...
> 
> here is sealed 12" 63hz LP no EQ
> View attachment 337459
> ...


What sort of slope are you using on your subs? You also may be hearing bass guitar from your subs, but that sounds like a good thing to me. As far as deep voices, can you hear them with other drivers playing? I'm going to guess probably not.
I wouldnt want the acoustic xo of my subs any lower than 80 hz personally. Unless maybe if you're using 8in or larger midbass drivers... If I could find a good way to xo my subs to MB higher than 80 hz I would, just to get the extra vibration out of the doors.


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## oabeieo (Feb 22, 2015)

Speedhunter said:


> Never saw dip at 80hz, more like 110and above(small car) and who the hell LP sub at 80Hz especialy sealed box...
> 
> here is sealed 12" 63hz LP no EQ
> View attachment 337459
> ...


yeah 80 acoustical is pretty much a go to

although your 10db rise, can still have absolutely awesome sq with even 130hz acoustical cross with 10db

when some of us like to bump and get out subs like 20db above midbass the 80 spot really becomes a hard limit…. As the bass knob will overshoot the crossover quite a bit

And that’s where a imbalanced sum will still work somewhat. Not ideal by any means , but when you want to bump most of your ideals are trashed anyways…


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## Speedhunter (Feb 21, 2020)

For example lets take a LP filter at 80Hz(24db/oct slope) for subwoofer and listen to music at 80db(most of the times even more). Due to "angle" of the slope you can hear 200hz at 47db from subwoofer. Not to mention, subwoofer playing that frequency at that level sounds very intrusive. So I'm going to guess part of your image is muffled and coming from the trunk. Depends on midbass i use 60-50hz XO on subs.


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## Picassotheimpaler (Sep 21, 2014)

Speedhunter said:


> For example lets take a LP filter at 80Hz(24db/oct slope) for subwoofer and listen to music at 80db(most of the times even more). Due to "angle" of the slope you can hear 200hz at 47db from subwoofer. Not to mention, subwoofer playing that frequency at that level sounds very intrusive. So I'm going to guess part of your image is muffled and coming from the trunk. Depends on midbass i use 60-50hz XO on subs.


You aren't playing only the sub though. That's over 33db below the midbass/midrange playing at those frequencies...some drivers have distortion nearly that loud.


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## Speedhunter (Feb 21, 2020)

33db?!From when sub and midbass play on same level in car sq? Check again usual house curve and do the math again. 
Also for starter take mic and measure db level of trafic inside of your car, than you will learn how much is 47db.


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## Picassotheimpaler (Sep 21, 2014)

Speedhunter said:


> 33db?!From when sub and midbass play on same level in car sq? Check again usual house curve and do the math again.
> Also for starter take mic and measure db level of trafic inside of your car, than you will learn how much is 47db.


But you have another driver playing those frequency exponentially louder. Effectively covering most of the little bit that you can hear.
This is using arbitrary SPL comparisons that I pulled off of a Google search, but it should get the point across.
A regular car is somewhat loud (~70db), but if you had a helicopter going at the same distance (~100db..or 30db louder) you wouldn't be able to hear the car at all.


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## oabeieo (Feb 22, 2015)

Speedhunter said:


> 33db?!From when sub and midbass play on same level in car sq? Check again usual house curve and do the math again.
> Also for starter take mic and measure db level of trafic inside of your car, than you will learn how much is 47db.


how loud is your bass…. My goodness…

i mean , I like to bump but not that much

47 db isn’t much, but in contrast to a full set of highs playing 90/93db is pretty quiet 
but still interacting


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## Speedhunter (Feb 21, 2020)

Evaluate in your car what you just googled and please bypass me with written stuff. Sit in the car and adjust subwoofer and midbass playing same point but with 20db-30db difference.


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## Speedhunter (Feb 21, 2020)

oabeieo said:


> how loud is your bass…. My goodness…
> 
> i mean , I like to bump but not that much


I see you also blah blah much but i cant see any constructive knowledge from you too. No wonder you stuck on sub-midbass integration.

Edit: where you take 93db from high where i set that sub plays 80db. WTF is happening to this forum.


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## oabeieo (Feb 22, 2015)

Go run a 300hz tone through your sub

you’ll hear it (whimsically)
But it definitely adds …… 

blah blah blah …. ? Haha no thanks


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## Speedhunter (Feb 21, 2020)

oabeieo said:


> Go run a 300hz tone through your sub
> 
> you’ll hear it (whimsically)
> But it definitely adds ……
> ...


Actualy did it but with 200hz.


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## cathul (Jul 2, 2018)

Speedhunter said:


> 33db?!From when sub and midbass play on same level in car sq? Check again usual house curve and do the math again.
> Also for starter take mic and measure db level of trafic inside of your car, than you will learn how much is 47db.


I'm not doing the math, but looking at my measurements.
When all drivers are leveled to my housecurve my sub is approx. 40dB less volume at 200Hz than my front speakers and approx. 35dB lower than my midbass drivers.
All with 24dB slopes and 70Hz acoustic crossover.


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## Speedhunter (Feb 21, 2020)

cathul said:


> I'm not doing the math, but looking at my measurements.
> When all drivers are leveled to my housecurve my sub is approx. 40dB less volume at 200Hz than my front speakers and approx. 35dB lower than my midbass drivers.
> All with 24dB slopes and 70Hz acoustic crossover.


Similar what i have in my curent car and thats okey. I put numbers just for explanatory purposes.

Problem arise when sub starts to dive in midbass region and that can easily occure with 80hz LP crossover or more. It starts to sound intrusive and easy to localise(beaming,rattle). Some folks can't achieve that surround bass feeling so they raise subwoofer crossover thinking they are going to cover their poor midbass or integration subwoofer-midbass.


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## oabeieo (Feb 22, 2015)

Speedhunter said:


> Actualy did it but with 200hz.


 So try with 300 
200 would still be pretty loud


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## LBaudio (Jan 9, 2009)




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## oabeieo (Feb 22, 2015)

LBaudio said:


> View attachment 337605


😁😁😁


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