# Secrets to blending Mids with Sub



## tjswarbrick (Nov 27, 2013)

I finally have all my components sorted out - I think.
JL .75" tweets.
Silver Flute 6.5 mids.
Audiomobile GTS 2110 sub.

Is there anyone in the San Jose area who considers him/herself experienced and pretty good at this stuff who might give a listen and offer some pointers on tuning? Beer and Pizza or $$$ for services can be discussed via PM.

Open to all: general guidelines, helpful hits, or explicit instructions are welcomed. 

Music - like acoustic music, vocals, jazz, classical - sounds absolutely fantastic. So I know the bones are good, and the system is almost there.
Rap and Dance have lots of slam and rumble - so I know the sub is good (though it does fall off a bit from just above 30Hz.)
The biggest problem I'm having is rock music - which is probably what 60-70% of my time is spent listening to. Vocals are awesome, guitars scream, bass is powerful, and effects can shake stuff. But most of the time kick drum sounds slow, one-notey and a little soft. Turning it up oftentimes just causes the mids to max out. So I'm pretty sure it's the difficult crossover transition range causing me trouble.

Before I go looking to replace the sub with something "faster" - I know 90% of a system is the install and tune.
This is my first system with multiple amps, EQ, and DSP. So I know I need to match the gains across all my electronics. I may need to play with crossover frequencies (set around 80-90Hz right now), EQ and probably front-to-rear T/A. But whenever I do, I start changing too much at once and tend to make it worse. (It's a DIY system, bought mostly online, so I don't have an installer to fall back on - though I know there are a couple awesome ones in the area.)

I have pretty good ears, but I don't have enough musical or 12-Volt background to effectively translate what I hear, or what I want, into effective adjustments on my components.

Can you provide a step-by-step for tuning the sub-to-mid transition starting with gain-matching and going up through polarity, X-over freq, EQ and T/A?


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## kaigoss69 (Apr 2, 2008)

I am not the most knowlegeable on the subject, but I think I can help point you in the right direction.

I would start with phase. Not just sub to midbass, but also right to left midbass. Right to left phase you do by ear (plenty of info on the forum how to do it), sub to midbass you do by RTA or SPL meter (play a test tone at the exact crossover frequency, you are looking for the sub polarity that gives you the loudest response at the crossover frequency).

Then level. There is a track on Spotify from Chesky on the "Stereo Review" surround sound system test CD. It helps you set the correct level between sub and midbass, by ear.

Then T/A. Delay the front stage relative to the sub until the sub location moves to the front.

Then EQ. You need a good RTA unless you have a good ear. There are plenty of threads here on the subject. If you like a bump in response on the low end (most people do), then make sure you have a smooth transition between the plateaus. I think Andy W. recommends a smooth transition between 60 and 160Hz (or thereabouts). This helps with blending.

Perhaps a somewhat simplistic approach, but it should sound a lot better afterwards. I'm sure others with more experience will have a more detailed or perhaps a slightly different approach. Good luck!

EDIT: Forgot about the crossover frequency, and slope. Generally you want the midbass to play as low as possible. To find out where that point is it helps to disconnect the sub and trying different frequencies over a period of several days (playing your favorite music and listening for distortion or "muddyness"). You want to find the point where they still play clean and loud. It also helps to choose a crossover frequency above the driver Fs, but this is not always the case and depends on the driver and the install). For the slope, 24dB/oct always worked best for me, and many others would agree I'm sure. But every install is different and it is not as cut and dry as that, you have to try. It is a good starting point though. 



tjswarbrick said:


> I finally have all my components sorted out - I think.
> JL .75" tweets.
> Silver Flute 6.5 mids.
> Audiomobile GTS 2110 sub.
> ...


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## quietfly (Mar 23, 2011)

At first i was going to suggest having a big enough blender, but after reading Kaigoss69's summary, i find myself agreeing with him. the only thing i have to add is i find midbass response to be very tricky once i let it roam much above 100. with an Fs of 37.5 Hz you can probably safely run them from 70-120 @12db, but listen for sloppiness if you get any near that higher range either lover the xover point or steepen the slope. its a lot of hit or miss.... and trial an error...
good luck


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## tjswarbrick (Nov 27, 2013)

Thanks guys. Good stuff.

quietfly - will one of those Fruit Ninja jobbies do it? 

I've done most of the above, but not necessarily in order, and 1/2 of it was with different mids and a different sub (which I never got to blend, either.)Oh yeah, and no outboard X-Over. I probably need to reset to zero and start over.
Running wires out the window from my PC to my car for REW is lots of fun...


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## CrossFired (Jan 24, 2008)

I've got a Boston Pro 10.5 woofer. I can meet you in Sunnyvale, if you want to try it out? It's yours for $60. plus a cheap lunch(lunch non refundable).







tjswarbrick said:


> I finally have all my components sorted out - I think.
> JL .75" tweets.
> Silver Flute 6.5 mids.
> Audiomobile GTS 2110 sub.
> ...


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## theoldguy (Nov 17, 2009)

I would say most important (but definitely not the easiest with mobile audio) is location location location. If your mids are in close physical proximity to your sub(s), then it will be much easier to blend. Best sounding setup I have ever had was a 15" IB for 50hz and below, 10 sub/low mid in each front door 50-250 hz, a 4" mid in the kicks 250-1500(i think), and a tweet in the A pillar.


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## quietfly (Mar 23, 2011)

actually for me the secret to front "sounding" subs has always been TA, and Phase....


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## Justin Zazzi (May 28, 2012)

I used to live in the San Jose area, but I've relocated to Chico now. If you're willing to make the drive I'll spend all the time you want.

Fow now, study the last few posts in my build log. I go over exactly what is needed to blend midbass/sub together. It's all about the *acoustic* crossover slopes, not the electronic or processing slopes. I put a bunch of links and photos in those last few posts to make it as user-friendly as I can. I hope it helps! (link is is my signature below). Keep in mind the time alignment *and* frequency response will effect the relative phase between the mid/sub near their crossover frequency. You must adjust both, and this is where it gets tricky.

For tuning, start with setting amplifier and all equipment gains so that every component clips at the same time, and don't touch the gains after this (an oscilliscope helps tremendously). Then you can move to a rough level matching between speakers and a rough crossover on all drivers, all by ear. If you have an RTA you can address each channel one at a time, or if you don't, then only listen to (or only pay attention to) one pair of channels at a time at first. This is where you can get your rough EQ and rough time alignment done. Then repeat from the top, except don't touch the gain settings. Then repeat again. And again. Also, take breaks every 15 minutes or so otherwise you'll end up with something sounding amazing at the time, but you'll come back later and it'll be crap.

I don't have the time right now, but maybe some of the other members can help you out and link the thread about _time alignment using noise tracks by ear_.


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## Hanatsu (Nov 9, 2010)

Frequency response issue most likely. Make sure slope and levels at crossover point are correct. Would be lots easier if you got some kind measurement gear to setup your system. An out of phase sub will create a null at the xover. The one-note-wonder issue is common, large FR peaking and modal ringing combined are major contributors to this.

Tapaaatalk!!


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## Hanatsu (Nov 9, 2010)

Jazzi said:


> Also, take breaks every 15 minutes or so otherwise you'll end up with something sounding amazing at the time, but you'll come back later and it'll be crap.


Haha. Such a common "nerd" mistake. Know this so well...

Tapaaatalk!!


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## tjswarbrick (Nov 27, 2013)

Crossfired - that's a great offer, and I used to want a BA Pro 10's SOOO BAD (like 20 years ago), but at this point I'm not sure it'll gain me much. I'd happily buy you that lunch if you have some portable measurement equipment we could hook up and determine a few things.

Oldguy - thank you. Tweets are in the factory locations in the Sail panels. Mids are in factory locations in the doors. Sub is in a fiberglass enclosure behind the driver's side wheel well. After the 3 months I spent building it, nothing's moving. So now it's all about tuning for the locations they're in.

Jazzi - How's school? I'll take a look at your build log. Sounds like a great read. I haven't played with an O'Scope for 20 years, and don't have access to one anymore. So that's out.

Hanatsu - thanks as always for the tips. My slopes are not adjustable, and my points are haphazard guesses at the moment. I actually brought the crossover point a bit higher, and turned up the 125Hz on the bass channel EQ. My first 2 albums surprised me how much more full the kick sounds now, and it didn't pull to the rear. So maybe the T/A is okay after all.

Looks like it's time for a calibrated measurement mic and wires outside again.
Unless anyone local has a weekend to kill...

Thanks again, all, for great ideas. This place is always so helpful.


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## 2010hummerguy (Oct 7, 2009)

Kaigoss69 has this on lockdown.

I would add that ultra low distortion drivers, especially the sub makes doing this even easier since it won't attract much attention to itself. My SI subs make this an effortless task.

And capable front mids are a big deal to match output or else that gap in response in the mid/sub transition will localize the sub to your ear.

Last but not least, all rattles must be fixed. Those can localize the sub to your ear if not dealt with.


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## sqnut (Dec 24, 2009)

I agree, it's a response issue. But lets get phase out of the way first. To integrate your sub and mids you need to get the timing right between the drivers and you need the correct response. Imho crossing at 50-60hz gives a cleaner sound than 80-90hz. Try crossing at 60hz with 24db slopes all round for a start. 

I'm not sure if your processor allows you to play one driver at a time. If so, play the driver side mid and the sub and listen to some music with low end. Your sub and mid are in phase when you can locate the entire sound, including the lowest notes, as coming from your mid. Play with delay on your mid till you get to this point. 

There will be a range of delay in which you will get this effect. Within this range, look for the delay setting that gives the best clarity. As you add delay to mid, the drivers are going from out of phase to in phase to out again. The sound will go from sightly thin and diffused, to focused with a rich low end, to a heavier low end but a muddier veiled sound. Back up on the delay till you get the clarity. Now do the same for the other mid and sub. Once both mids are in phase with the sub, they are also in phase with each other. 

A slightly more scientific way is to use test tones or the pink noise tracks and measure the FR around your xover point. With the sub and mid in phase you will get a response peak at the xover frequency. Add delay till you get this peak and then play around a bit for clarity. The best way of course is to use a mic and do the impulse response. 

All this is assuming your processor allows you to set delay on each driver vs delaying one set of drivers vs another. Two very different things. Once your phase is in the ballpark, you can park it. No matter how you measure or set it it's always going to be ballpark, cause the distance from your ears to each speaker will never be constant even over a short period of time. You can use timing to fine tune the response but that is for much later. For now just fill it, shut it and forget it.

Good sound in a car is 80% response and 20% timing or TA. Due to a constrained and highly reflective environment, in a car we are talking about two types of responses, a measured response and a perceived response.

It's 3am here. If you want I can continue the rant on response tmrw.


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## subterFUSE (Sep 21, 2009)

sqnut said:


> I agree, it's a response issue. But lets get phase out of the way first. To integrate your sub and mids you need to get the timing right between the drivers and you need the correct response. Imho crossing at 50-60hz gives a cleaner sound than 80-90hz. Try crossing at 60hz with 24db slopes all round for a start.
> 
> I'm not sure if your processor allows you to play one driver at a time. If so, play the driver side mid and the sub and listen to some music with low end. Your sub and mid are in phase when you can locate the entire sound, including the lowest notes, as coming from your mid. Play with delay on your mid till you get to this point.
> 
> ...


Some great info here. 

As for your crossover suggestion in the 60Hz area, if I were trying this should I be concerned about my midbass having an Fs = 70Hz? Any risk crossing them below that?


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## tjswarbrick (Nov 27, 2013)

For the sub's sake, I like a 60Hz crossover, but with these mids I think 80 is much more realistic. Right now it's a bit higher- though I don't, honestly, know where - I need to improve the resolution on my measurement system.

All I can delay is fronts with respect to sub, and left with respect to right. L/R is quite good, and front to rear is decent but I'll try refining it for optimal clarity. That is a great tip - I usually see "for max output" - but that varies with frequency when there is a node vs a mode (null vs boost) so it's hard to use without a very good mic. Clarity I can at least hear.

Thanks again for the very useful info.


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## smgreen20 (Oct 13, 2006)

I too, run the 6 1/2" SilverFlutes. My question to you is, are you running them IB/OA or sealed?

You want low extension out off those Flutes, seal them. I has mine sealed at .15 cf and 170 watts each. Had them bandpassed from 4k-50 Hz both ends at 12 dB/oct. Never had any problems and it's been the best set up I've ever had mid wise. Second would be the Dynaudio 7" mids.


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## sqnut (Dec 24, 2009)

subterFUSE said:


> Some great info here.
> 
> As for your crossover suggestion in the 60Hz area, if I were trying this should I be concerned about my midbass having an Fs = 70Hz? Any risk crossing them below that?


Depends on the slope you have on them and the volume you listen at. My mids have an Fs of 60 and I have been running them at 50hz on 24db HP for the last six years. They are getting ~140 watts each. My peak listening level is low to mid 90db with the average around 85db. 

Running your mid at or even a touch under the Fs, on steep slopes just means that you will have a slow roll off starting a bit above your Fs. A little work on eq'ing the sub and mids response in this range will help in smoothing out the overall response. By crossing close to the Fs you are adding a little more distortion in your low end and this is often perceived as 'warmth'. Another benefit I find is that the overall sound is much cleaner when I cross low. 

Crossing low means 80% of the low end is being carried by your mids. I'm not a big fan of playing mid bass frequencies from the sub.


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## Hanatsu (Nov 9, 2010)

Playing through Fs is quite common with mids and subs. Not exactly a big risk but it can result in higher distortion.


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## SPLEclipse (Aug 17, 2012)

The key to good blending is to turn the subs down. I'm not even joking. Second most important thing is to control rattles. When you do those two you're 75% there. THEN you can work on integration and FR.


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## sqnut (Dec 24, 2009)

I mentioned that both measured and perceived response are important in a car. In a room the two are more or less the same thing. The cars environment is smaller and much more reflective. Early reflections make the incident sound louder. Frequencies above ~500hz are more prone to reflections. This is why if you set both 300hz and 2khz PN to say 80db and play them back to back the 2khz will sound much louder. The measured response is the same but you are perceiving 2khz as louder. A flat response will work in a room but *never* in a car. It's not even a good starting point. 

The 31 band eq on your processor is where you should focus. Since you don't have TA and eq per driver, don't worry about imaging etc and just use the eq to get the overall response right. The audio spectrum across 20hz-20khz can roughly be broken down into 5 ranges

20-60hz - Sub Bass
70-300hz - mid bass
400-1.5khz - midrange
2-6khz - upper midrange
6khz+ - highs

In a car the right response is one where these ranges sound balanced relative to each other. No one range dominates. You're looking for a response that is perceived as balanced in this environment. When you measure what is perceived as balanced you come up with a sloping response from 20-20khz. 

As a ballpark you are looking for a 20-25db roll off from ~30hz to 20khz. Of this 25db, 10-12 db occurs from 30-125hz. The roll off bottoms out 160-200 which are ~14db below 30. From ~300-1khz I aim for a slight 3db rise in response. This is for better clarity of midrange and vocals. From 1khz-4khz I'm looking at a 10db roll off and then a 3db roll off over the last two octaves. Try this as a baseline and run it for a few days. All you need for this are the pink noise tracks and some sort of measuring device. Try this for a few days and remember this is only a base curve.


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## tjswarbrick (Nov 27, 2013)

SPL - You're 100% spot on on both. Only rattle I had after damping was crossover in the driver's door. Took care of that when I mounted the Flutes. And, now that its response is good, turning down the sub goes a long way toward reducing the issues I've been having. 

smgreen - mine are just IB in the factory door locations. I Roadkilled the panels and mounting flange, but didn't seal 'em off. I don't think I need extreme extension out of 'em - just trying to get a smooth handoff to the single 10.


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## Hanatsu (Nov 9, 2010)

SPLeclipse is right indeed. Sub integration is IN MANY CASES just a level issue. Mids and subs must be EQed to the same level at Xover.

Tapaaatalk!!


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## tjswarbrick (Nov 27, 2013)

Spent a bit of time last night zeroing out then matching the gains. Accidentally killed the T/A in the process, so re-did that as well.

Kinda wierd gain-matching. DQ-61 has "input level" as well as "output level" control.
Processor, X-Over and Amp gains set to 0, I could turn it up ALL THE WAY at the head unit, and got no discernible distortion from the rear speakers (running off factory amp), and no discernible sound from fronts or sub.

Turning up Input Level on Processor had no effect. So I set it to the middle and called it good.
From there, I went through the "turn it up until distortion sets in" procedure starting with the Processor, working through the X-Over, then focusing on front amp and finishing with sub amp. 

It helped A LOT.

Re-set left-to-right T/A. Right back where it was, which is as good as it gets with this setup (which is darn good, actually.)

Then I re-set the front-to-sub T/A. Used a lot less delay than before, but when I went farther it sounded like the bass was moving back to the rear. 
I note that the bass amp gain is down quite a bit from where it used to be. On initial tracks last night and this morning, kick-drum is much tighter and cleaner than before, and overall max "clean" volume is significantly higher (didn't measure it, but I can sure hear it.) Sub-bass is solid and weighty, but not nearly as overbearing as it seemed before. And it doesn't move from the front stage - which is awesome. Sounds, to me, like I don't have a "sub" but rather powerful full-range mains.

I haven't touched X/O settings or EQ. Unless I hear something amiss, I'm trying to hold off until I get a decent measurement mic.

Thanks, everyone, for the advice.


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## dengland (May 25, 2014)

sqnut said:


> I agree, it's a response issue. But lets get phase out of the way first. To integrate your sub and mids you need to get the timing right between the drivers and you need the correct response. Imho crossing at 50-60hz gives a cleaner sound than 80-90hz. Try crossing at 60hz with 24db slopes all round for a start.
> 
> I'm not sure if your processor allows you to play one driver at a time. If so, play the driver side mid and the sub and listen to some music with low end. Your sub and mid are in phase when you can locate the entire sound, including the lowest notes, as coming from your mid. Play with delay on your mid till you get to this point.
> 
> ...


So, I am running a Helix Pro that allows me to adjust each speaker individually. I had previously had set the distance for each speaker to a point on the driver's headrest. I have a mic so I played pink noised and I measured for the peak at the crossover frequency. I effectively increased the delay for the door midbass (made the distance greater). For the passenger door midbass decreasing the delay (setting the distance to a smaller value). 

When I played all speakers together, the center stage was quite diffused. It sounded out of phase. Not sure why that would happen. 

Mids are playing 60-1900Hz.

Any thoughts?

Thanks


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## Holmz (Jul 12, 2017)

Wat was it before? What did you set it to? When you set it back did it return to how it was?

Then did you take some baby steps (in both directions)?


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## dengland (May 25, 2014)

Thanks for the response.

I did the initial delays so long ago .....

I found the following for the group X delay (This should be read as the before):

Driver door: 108.08 cm, 42.95", 1.68 ms
Passenger door: 166.10 cm, 65.40", 0.00 ms
Sub: 0 cm, 0", 4.89 ms

All Phases set to 0 degrees. All polarities set to normal. I don't know why the sub is set to a zero distance.

My attempt to blend the mids with the sub I mention in my previous post resulted in:

Driver door (Delay Group 1): 476.71 cm, 187.68", 0.00 ms
Passenger door (Delay Group 2): 17.71 cm, 6.97", 13.49 ms
Sub: 0.00 cm, 0.0", 14.01 ms

Sub delay was not touched.

In both cases the crossover was 60Hz acoustic. (55Hz electric driver's door, 50Hz passenger door, 60Hz sub). A great deal of parametric EQ on top of that to follow the desired curve.

I did not play much with the above settings at the time. I quickly went back to the original delay settings and all was good. I still have the attempt stored in one of the memory positions in the Helix, so I could go back to it and tweak via ear with musical content.


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## gijoe (Mar 25, 2008)

Start with physical measurements. If you don't sit 3 and a half feet from the driver side mid, the delay should not be set for 3 and a half feet. Use a measuring tape to get actual distances and start there. You'll need to tweak it a bit from there, but if you find yourself more than a few inches from the actual distance then you've gone too far. Set all of the distances, then mute everything except 1 pair of speakers, fine tune them until they give a center image, then move to the next pair. You shouldn't need more than a couple inches of wiggle room in the TA.


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## EmptyKim (Jun 17, 2010)

I think your sub should be 0 delay. It’s the furthest from you. Everything else should be delayed depending on distance from you. One of the members has a link in their signature with quick distance / delay calculator. Forgot who.


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## dengland (May 25, 2014)

EmptyKim said:


> I think your sub should be 0 delay. It’s the furthest from you. Everything else should be delayed depending on distance from you. One of the members has a link in their signature with quick distance / delay calculator. Forgot who.


Thanks. You are probably thinking of Jazzi:

http://www.diymobileaudio.com/forum...1-jazzis-tuning-companion-room-eq-wizard.html

I will run through it again. This time with the sub actually entered. Not sure what happened the 1st time with the sub entry.


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## gijoe (Mar 25, 2008)

He's talking about Erin's calculator. 
http://tracerite.com/calc.html


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