# Midbass - band pass, or low pass?



## Darkrider (May 11, 2012)

So, I was tuning my Cruze this weekend. I have always bandpassed my front mids from 80 up to around 3k or so. I wanted more bass up front, so I thought why not lower the crossover point to allow more bass from my front? Well, I kept lowering it until I got to around 40hz, and was enjoying more low frequency output up front with each step. Then I thought, "why not just remove the low crossover point completely - just low pass them at 3k. I think it sounds great low passed. It brings a lot more bass up front and the subs seem to blend great.

Is low passing the front a terrible idea? Would it destroy my mids? 

I kept a setting for bandpass and another setting for low pass, but I think the low pass sounds/blends better. I don't leave it low passed or play it loud as I was afraid that I could damage the drivers. I mean don't the passive crossovers just low pass the mids? I understand that reducing the range that you're requiring a driver to reproduce can reduce distortion (while keeping the driver within it's most linear response range), but if the driver sounds ok, is it ok?

Thanks for indulging my ignorance.


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## minbari (Mar 3, 2011)

with no HPF on a 6.5" you will run out of xmax pretty fast with any amount of power. it is not going to hurt them as long as you are not running them past thier mechanical limits. problem is that is pretty easy to do with no protection at all. remember each octave lower requires 4x as much excursion.

I would try 60hz and go from there. a 6.5" isnt going to out shout 2 12w6 at 60 hz anyway.


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## theoldguy (Nov 17, 2009)

if your midbass is playing up to 3k, wouldnt it no longer be considered a midBASS? Sounds like a midrange to me.


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## minbari (Mar 3, 2011)

depends on how low you are playing it. where does "midbass" start and end and "midrange" start and end? you ask 50 people in audio you will get 50 different answers, lol.


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## Darkrider (May 11, 2012)

theoldguy said:


> if your midbass is playing up to 3k, wouldnt it no longer be considered a midBASS? Sounds like a midrange to me.


lol - I didn't think 3k was that high. It's just a 2 way, so what do you call the low frequency driver in a 2 way setup? Is it just a "mid" and not a midbass or midrange?

I think I'll start writing an "SQ for Dummies" book once I get my Cruze done.... if it ever gets done.


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## cajunner (Apr 13, 2007)

pretty simple, a tweeter and a woofer, in a 2 way system.

a midrange, comes between the woofer and the tweeter in a 3 way system.

a subwoofer, can has place to play alongside a woofer, no penalty.


that woofer can then be described as a mid bass, as long as it feels comfortable, 


not that there's anything wrong with that.


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## 1996blackmax (Aug 29, 2007)

Ha, Nicely put!


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## quality_sound (Dec 25, 2005)

That's how I've always worded it. 

On topic, I would NOT run a woofer LP only. I like crossovers in the 80-100Hz range. If you need more bass, turn the sub up. 

Sent from my Moto X using Tapatalk


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## FG79 (Jun 30, 2008)

With the right amp you can absolutely do this. The Mosconi should be fine (if that's how I'm reading it).

I once had to go a few months without a sub, and the front woofers playing full range up to the low pass point (actually it was only *1* woofer, as the crossover in the passenger door was not working). 

Had a surprising amount of bass. And the nice part is the no crossover helps with the coherence (no slopes here). 

It is fine so long as you don't blast the crap out of it. You have been listening long enough....you'll know when it's too loud or just about too loud. You will need to exercise more caution around rap music, and other bass heavy stuff early on.

For SQ music, you'll naturally see the most benefits. I'd say that up to a certain SPL the full range sound is better than high passing the woofer -- definitely fuller, and warmer. I noticed there was a fullness from the bass that was missing from the high pass. 

It will never be as dynamic as compared to a HP of 50-100 hz, but for certain music it's unbeatable. There's a certain sound you get with this setup, and subs/no subs doesn't make a difference here. 

A lot of what makes OEM car audio good is full range. You never see a home audio woofer high passed. 

I was running a Phoenix Gold MS1000 to a Morel Elate SW6 6.5" woofer. I had a big door so that helped.

Don't be scared to try it.

BTW, I think the sweet spot for all around "SQL" listening is an HP point between 40-60 hz for those woofers.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

That warmness is second order distortion.


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## Hanatsu (Nov 9, 2010)

Don't use mids without HP. You'll just introduce muddy distortion. If you run the mids "IB" then you'll have low physical power handling as well. With your 6,5" mids I'd not go below 60Hz, unless they are exceptional performers and/or you keep the volume down. Expect higher distortion around Fc, for a generic 6,5" in a door, this should be around 50-70Hz. 

"Fullness" = "mud". It's just distortion, don't get used to it. You WILL have a physical highpass function in ANY system dictated by T/S parameters and the transfer function of the room. The electrical filters will cascade this psychical filter and make the slope steeper, there is no SQ advantage if you're aware of the acoustic slope and tune accordingly.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

This^

And despite what anyone tries to tell you, there are no magical amplifiers that will change this.


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## FG79 (Jun 30, 2008)

TOOSTUBBORN2FAIL said:


> That warmness is second order distortion.


It's amusing when you say that to describe amplifier gear, but added bass which makes the sound warmer is suddenly distortion???

Besides, if it sounds good without DAMAGING the drivers, there is nothing wrong with it.


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## SPLEclipse (Aug 17, 2012)

FG79 said:


> added bass which makes the sound warmer is suddenly distortion???
> 
> Besides, if it sounds good without DAMAGING the drivers, there is nothing wrong with it.


Even order harmonic distortion. It happens at octave intervals, so it's not considered "offensive" to the ear, but isn't present in the signal.

I somewhat agree with the second part. If it's not hurting anything and you like the way it sounds then go for it. Chances are you're going to hurt something running no HP filter though....eventually.


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## Hanatsu (Nov 9, 2010)

Every deviation from the input signal is distortion. 

Tapaaatalk!!


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## cajunner (Apr 13, 2007)

it's perfectly fine to throw a 2-way set into the doors, and run them off an amp with full range going into the passive crossovers.

you'll expect more out of 'em, and you won't get them to play cleanly at high output levels, but it's okay to do it, because that's how manufacturers make them.

You see people having issues with the amount of mid bass coming out of the JBL MS-series, and if you look at their low end it's not as strong as some components out there, but even those, you can run full range.

there's nothing wrong with it, except that you shouldn't run the speakers into distortion, which does limit how loud you'll play them, and how long they'll continue to play before fatigue and stress from extra excursion eventually causes them to sound like crap.

The idea that people will run their components full range, is what makes manufacturers bump up the Qts, so there will be a bit of "free bass" in their response, and well... it's cheaper to make high Qts speakers.

If the expectation is that there will definitely be a subwoofer taking the lowest octaves, the manufacturer is given a bit of leeway, and can make a stronger motor, and a lighter cone, and result in higher sensitivity or decreased distortion in the mid bass on up.


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