# Let's talk back door mounted midbass...



## Hillbilly SQ (Jan 26, 2007)

Anyone who knows me knows I don't like having speakers showing in my install, and pillar/dash pods for sure aren't my cup of tea. I simply don't like messing with the beauty of a stock interior. It's personal preference and I realize I'm missing out. The most I'll do is corner load small tweeters on the dash. Being the only drivers that are beaming I'm willing to make an exception for those since they're so small. 

Now that my personal rant is out of the way, I've heard of people running midbass in the back doors/rear of the vehicle with good results. I've heard it a couple of times with my own ears and wouldn't have known they were back there if the owner wouldn't have told me. Can midbass mounted in the back doors give at least close to the results having them in the front doors does? We can plop drivers that are low in the doors or in kicks firmly on the dash and forward of the windshield with time alignment without any evidence that there's even anything playing below eye level. Does getting midbass playing from 70-250ish from the back doors up to the dash follow the same rules that they do if they're low in the doors in a traditional setup? I'm considering trading my white pig in on a midsize suv (Honda Pilot or GMC Acadia) in the next year and already planning a somewhat stealth install for whatever I get. If there's no usable dash location it would really make life easier for me if I could put like a 4" midrange in the doors, tweets on the dash, and midbass in back doors.


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## jpf150 (May 22, 2013)

Do it! I think it would be fine even though I haven't heard a setup like that yet. I didn't get a chance to listen to Andy's car at the last meet. I was planning on trying it in the truck so I'd love to see more installs with people doing it. Everything I read about it though confirmed that it worked as long as you crossed at 250 or lower, obviously with lower being better.


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## rawdawg (Apr 27, 2007)

Geometrically speaking, I think rear quarter panels have a better chance of falling into Lycan's Circle of Confusion.


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## mikey7182 (Jan 16, 2008)

I had them mounted behind me in my truck. I know Mitch has 2204H in the rear quarters of his Acura. As long as you aren't trying to play them much above 250-300 and have a strong midrange to help focus forward, I would go for it.


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## oabeieo (Feb 22, 2015)

If you not using any processing like logic 7 or any enhancements I would be ok doing it so long as the path length is very close to the front location and symmetrical in mounting i.e stock door locations on a Acadia , but imho I would just do midbass/mid from front and rear like a 6 in all 4 doors and plays fronts and rears down to 100 or whatnot and play with the crossover and timing on the rear , I think if the car is friendly with you acoustically you might be able to steer the center image using just the rears and let the fronts have no delay against them making a much wider sound . Or delay fronts and not rears , depending on how the car acoustically fights you. That's what I would do, unless your running HLCDS, I don't see it working very well with just a 4 coming from up front, but I do like rears , just don't think it's going to do what you want. If you are running logic7 or something effects wise I think the rears pathleinghts are not as important.


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## XSIV SPL (Jun 24, 2014)

While you're talking about a low-pass of 250ish, a rearward location could present some directional issues, but at somewhat lower frequencies (say 160 Hz for example) where directionality isn't as much an issue, I would not hesitate to place them behind the listening position and pull their perceived presence forward with time correction.


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## Hillbilly SQ (Jan 26, 2007)

If I could run something like a Scanspeak 15f down to 150ish and have a STRONG tweeter that can meet the 5.5" driver in the doors below beaming (around 3500) I should be ok then?


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## gstokes (Apr 20, 2014)

Anytime you mount a speaker such as a midbass so it's not even close to being on-axial i think you're asking for more problems than you need especially if you're goal is SQ..


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## jpf150 (May 22, 2013)

gstokes said:


> Anytime you mount a speaker such as a midbass so it's not even close to being on-axial i think you're asking for more problems than you need especially if you're goal is SQ..


How so?


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## naiku (May 28, 2008)

I would be curious to know if this would be effective or not, my front doors are fairly limited to mounting depth, where as in the rear I have about another inch of mounting depth. 

In my vehicle where I have the seat positioned, the rear speakers are not actually that far behind me. They are placed in the front lower corner of the doors and since I have the seat fairly far back, they are only just behind me.


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## troutspinner (Nov 8, 2013)

I played with this idea pretty thoroughly. No matter what my frequency cuts were, the stage was dragged to the center of the vehicle. The best results I achieved was bringing the levels way down in the rear so that it accompanied what I had going up front but at that point it actually sounded better full range as it added ambience.

In a setup that has rear speakers, I think it is best to have 2 DSP configs. One that limits the levels for ambience and another that plays the rears at full range and full volume. The shear volume in the cab with rears running at full range and volume is pretty intense and fun at times but it does wreck the stage.


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## Hillbilly SQ (Jan 26, 2007)

gstokes said:


> Anytime you mount a speaker such as a midbass so it's not even close to being on-axial i think you're asking for more problems than you need especially if you're goal is SQ..


Are you saying that you are going to mount everything straight-up on axis in your own ride even though as long as the driver isn't beaming it really won't matter much in the end?

That said, I'll probably change my mind on what vehicle I get a hundred times between now and when it happens. I might just go with the original idea and do an extended cab canyon/Colorado and devote the whole back end to subs and amps. I think this truck has a stock dash location and if it's like the Sierra/Silverado the dash drivers are positioned somewhat frontward and firing at each other instead of firing straight up at the glass. The people that know me know I'll wish I had the open bed back after hooking up to the trailer a few times to haul something that I don't want sharing cab space with me. Maybe I'll just get a fiberglass shell for my next truck so I can lock things up back there which is more than half the reason for me wanting an suv over a pickup in the first place.


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## damonryoung (Mar 23, 2012)

Like mikey said, as long as you're playing below 250-300Hz, you're not gonna be able to localize them as long as you have a couple things figured out:

1. Getting the phase aligned with your mids...
2. Ensuring that you've eliminated vibration associated with the midbass. Otherwise, you're "playing" frequencies that are easily localized.

While my midbass are not behind me, they are at my hip and they play on the dash just fine...


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## BigAl205 (May 20, 2009)

The Speakerworks Grand National had 12" midbass in the rear sides


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## danssoslow (Nov 28, 2006)

rawdawg said:


> Geometrically speaking, I think rear quarter panels have a better chance of falling into Lycan's Circle of Confusion.


Cone of Confusion.


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## thehatedguy (May 4, 2007)

Nearly every Speaker Works car competing back in the day had rear mounted midbasses. Only the GN played them to about 300 or so, the others were up around 6-800 range and did well, but not like the GN did.

The 250-300 range is about where I could get with really basic level, slopes, and polarity before everything started pulling to the rear. 150 is as high as I could go with a single sub in the skipass before everything collapsed to the center.


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## Hillbilly SQ (Jan 26, 2007)

Sounds like I just might be able to pull this off. Depending on what I end up getting it may involve a BM and a pair of TM65's back there.


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## thehatedguy (May 4, 2007)

If you have the room, why limit yourself to a 6.5? To me, that's not big enough to warrant to work to put them back there when you could do that in front.


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## Hillbilly SQ (Jan 26, 2007)

thehatedguy said:


> If you have the room, why limit yourself to a 6.5? To me, that's not big enough to warrant to work to put them back there when you could do that in front.


Because I would be putting a larger 4-5" midrange in the front doors.


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## t3sn4f2 (Jan 3, 2007)

thehatedguy said:


> If you have the room, why limit yourself to a 6.5? To me, that's not big enough to warrant to work to put them back there when you could do that in front.


You do gain the advantage however of not having the driver vibrating on your leg. I cant stand that and I rest my foot on the dead pedal so my leg doesnt ever really touch a door panel.


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## nanohead (Oct 21, 2013)

Moderate threadjack... 

If you're looking at mid size SUVs, gander at the Durango if you're open to it. If you get the better audio option, it has a fantastic set of mounting locations for speakers, including center dash, a pillars, 4 doors, and rear D pillars. Ours is leased, and its going back soon, and I've resisted mutilating it. We may buy our next one outright, and then I'm gonna go to town. FWIW, its been the best SUV we've ever had, bar none. Had about 12 of them over the past decade and a half (including an Acadia) and the new Durango is as nice as the Mercedes (not really kidding)


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## Hillbilly SQ (Jan 26, 2007)

t3sn4f2 said:


> You do gain the advantage however of not having the driver vibrating on your leg. I cant stand that and I rest my foot on the dead pedal so my leg doesnt ever really touch a door panel.


I've had lots of issues with my floorboard vibrating. I know where to find a sheet of lead to fix that problem but getting the old man to turn loose of it would be a problem. I am one of the guys that hurt their back lifting the 300lb rolls of it into the bed of his truck, but I owed the guy a HUGE favor. At least I know where to find lead bars for pouring jigheads for fishing. Just gotta be sneaky about how I obtain them by going through his grandson who has been my best friend for the past 15 years...


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## Hillbilly SQ (Jan 26, 2007)

nanohead said:


> Moderate threadjack...
> 
> If you're looking at mid size SUVs, gander at the Durango if you're open to it. If you get the better audio option, it has a fantastic set of mounting locations for speakers, including center dash, a pillars, 4 doors, and rear D pillars. Ours is leased, and its going back soon, and I've resisted mutilating it. We may buy our next one outright, and then I'm gonna go to town. FWIW, its been the best SUV we've ever had, bar none. Had about 12 of them over the past decade and a half (including an Acadia) and the new Durango is as nice as the Mercedes (not really kidding)


I've looked at them. The test drive will be what makes my mind up. A guy that my dad goes to church with is a sales manager at one of the biggest dealerships in the state and they carry nearly all brands in their dealer empire. I'll be able to get my new truck at dealer cost or close to it. He's at the Ford dealership now and it's going to be hard for me to get away from a real pickup truck. I heard the new Ranger (whatever it's going to be called) is coming out next year so will look hard at it as well. If they put the 2.7 ecobust v6 in it the little truck will be a rocket AND likely get nearly 30mpg on the hwy. The f-150 claims 26 on the hwy with the 2.7 in it. The more I think about it the more I think it wouldn't be a good idea to pull a trailer with a fwd or awd midsize suv so that puts the Durango and Grand Cherokee in the top of the running in that respect for an suv. I like the Exploder but towing capacity is pretty piss poor.


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## thehatedguy (May 4, 2007)

So why are you stopping at a 6.5?


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## Alrojoca (Oct 5, 2012)

Interested in the subject to get updates and more opinions


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## gstokes (Apr 20, 2014)

BigAl205 said:


> The Speakerworks Grand National had 12" midbass in the rear sides


A 12" midbass, are you sure that's not the woofer ?


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## Hillbilly SQ (Jan 26, 2007)

thehatedguy said:


> So why are you stopping at a 6.5?


Because I'm not much on fabrication and that's usually the biggest you can fit without going deep into modification. Unless you're referring to possibly going something like 8" or 10" midbass firing up in the rear floorboard? Hmm, I have a pair of Usher 8945a's and an extra pair of processor channels not being used at the moment...and a pair of amp channels that can be freed up to try it in my truck now. Hmm.


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## Hillbilly SQ (Jan 26, 2007)

gstokes said:


> A 12" midbass, are you sure that's not the woofer ?


Pretty sure it's the midbass. I think they had a pair of 15" subs in the trunk area.


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## seafish (Aug 1, 2012)

Hillbilly SQ said:


> Unless you're referring to possibly going something like 8" or 10" midbass firing up in the rear floorboard? Hmm, I have a pair of Usher 8945a's and an extra pair of processor channels not being used at the moment...and a pair of amp channels that can be freed up to try it in my truck now. Hmm.


NOW your talking!!! lol


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## Hillbilly SQ (Jan 26, 2007)

Since we're on that subject I could go pro audio and have the impact wagon from hell:lol:Finding a tweeter that could keep up and sound good doing it would be a different story...


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## seafish (Aug 1, 2012)

Yup…I am NOT a basshead, do NOT need the whole street shaking, but I am STILL thinking about using 2 IDQ10v2 in my truck under the back seats as two channel stereo woofers running from 50 to 125 hz, and high passing to the ID XS69 located in the front doors and low passing them to a single SI BMmkIV down firing in the center console seat. I AM in fact concerned whether my 3" midrange and Illusion tweeters mounted up on the dash will in fact be able to "keep up", but I will start another thread about that. One of the things going in my favor, I think, is that I don't have to play all that bass lout, just want to level match all the speakers so that it all blends really well.


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## sqnut (Dec 24, 2009)

Hillbilly SQ said:


> Because I would be putting a larger 4-5" midrange in the front doors.


If you are planning on putting the midrange driver down low in the door, it will pull your stage down. Typically drivers playing ~800 hz and higher should be located physically higher. We can tell higher/lower beyond ~800 hz. There's a reason why mounting the mids and tweets on the dash works so well.


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## Hillbilly SQ (Jan 26, 2007)

sqnut said:


> If you are planning on putting the midrange driver down low in the door, it will pull your stage down. Typically drivers playing ~800 hz and higher should be located physically higher. We can tell higher/lower beyond ~800 hz. There's a reason why mounting the mids and tweets on the dash works so well.


If that's the case what about kick mounted midranges and horn installs that stage at eye level?


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## sqnut (Dec 24, 2009)

Hillbilly SQ said:


> If that's the case what about kick mounted midranges and horn installs that stage at eye level?


With the setup you heard, is just the centre at eye level or the entire sound stage including extreme left and right. Think back and try to remember.


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## Hillbilly SQ (Jan 26, 2007)

Ahh the dreaded rainbow effect. Been too long ago. Kick mounted midranges are so 10 years ago:lol:


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## danssoslow (Nov 28, 2006)

gstokes said:


> A 12" midbass, are you sure that's not the woofer ?


Not only is Hillbilly SQ correct; but there are two pictures of the sub's in the photo you pasted. The top right, and upper center picture. Notice the trunk lid with the "turbo 6" embroidered in the liner.


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## BigAl205 (May 20, 2009)

gstokes said:


> A 12" midbass, are you sure that's not the woofer ?


Yeah, 12" carbon fiber midbass in the rear sides...and 15" servo-controlled subs behind the seat in an aperiodic enclosure.


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## mitchyz250f (May 14, 2005)

I am running JBL 2204 in my back quarters (RSX - no rear doors) in a sealed enclosures. The front speakers are Pro Audio PHL 1120 (95db @300Hz) w/Morel MT22 tweeter. The mid-bases are _almost_ at the same distance and angle as the fronts (cone of confusion) from my ears. I am using a JBL MS8 and I have experimented w crossovers between the mid-bass and fronts at both 300 and 400Hz. My concerns are dynamics more so than staging. 

Crossed at 400Hz the stage is pretty solidly up front. Most drum hits or bass guitar notes sound like they are coming from the front to me. The exceptions are music with sustained mid-bass notes like from a cello or piano, something with substantial decay. Doesn't sound bad to me more like an ambiance effect than anything else. With the car moving I think it would be impossible to tell any sound is coming from the rear. 

Crossed and 300Hz the bass is always solidly planted upfront.

But the dynamics of 12” mid-basses cannot be overrated or replicated by 10s or 8s. If you haven’t heard them in a car driven by a good amp you don’t understand. To make it simple if I could get 15s in my car I would do it.


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## thehatedguy (May 4, 2007)

Well technically they were JBL 2204H midbasses in the rear quarters and Emilar 15s in AP enclosures. No servo.


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## Orion525iT (Mar 6, 2011)

sqnut said:


> If you are planning on putting the midrange driver down low in the door, it will pull your stage down. Typically drivers playing ~800 hz and higher should be located physically higher. We can tell higher/lower beyond ~800 hz. There's a reason why mounting the mids and tweets on the dash works so well.


I think this is a vehicle dependent thing. I have had good luck with kick mounted mids, but I drive little cars with the seat as far back as it will go. In a truck, or if your driving position is closer, they may not work very well. In my opinion, one of the reasons that you don't see many kick panel installs any more is not because they don't work, but it is because the ubiquitous use of DSP has compensated for asymmetries. 



mitchyz250f said:


> I am running JBL 2204 in my back quarters (RSX - no rear doors) in a sealed enclosures. The front speakers are Pro Audio PHL 1120 (95db @300Hz) w/Morel MT22 tweeter. The mid-bases are _almost_ at the same distance and angle as the fronts (cone of confusion) from my ears. I am using a JBL MS8 and I have experimented w crossovers between the mid-bass and fronts at both 300 and 400Hz. My concerns are dynamics more so than staging.
> 
> Crossed at 400Hz the stage is pretty solidly up front. Most drum hits or bass guitar notes sound like they are coming from the front to me. The exceptions are music with sustained mid-bass notes like from a cello or piano, something with substantial decay. Doesn't sound bad to me more like an ambiance effect than anything else. With the car moving I think it would be impossible to tell any sound is coming from the rear.
> 
> ...


I have subs stuffed in my quarters that play IB by sealing off the backwave and making it go over the wheel arch and exit through the vents in the trunk. I only let them play up to 150hz right now. But in a loose state of tune (tape measure TA, no eq), the bass is up front. I have noticed that if I slide the seat forward a bit, the bass stages even better. I am not sure if that is an issue of TA or if I am more inside the "cone" between the subs and the midbass. I am not sure how high up I can run the subs yet, but I don't need more than 150hz out of them. I would start getting into inductance issues with the subs after 300hz or so in any case.


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## BigAl205 (May 20, 2009)

thehatedguy said:


> Well technically they were JBL 2204H midbasses in the rear quarters and Emilar 15s in AP enclosures. No servo.


Just for clarification, I said "Speakerworks Grand National, but I was referring to the changes that Richard Clark made, as is evident in the magazine article snippet that I posted.


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## thehatedguy (May 4, 2007)

He didn't make any changes to the midbass or subwoofer drivers- they are clearly JBL and Emilar drivers.

If you look at the original build pictures of the car, the horns have what look like 2" exit Radian or Emilar compression drivers on them...and they according to SW went to the top of the firewall. Then you see RC holding the horns in that article with Altec 288Gs drivers on them, which are 1.4" drivers. Now with horns, you decrease the length of the horn as you increase the driver size...so those horns needed to be longer for the smaller exit drivers. And the drivers are sooo much larger than the original pictures...which were supposed to have been as big as they could go.

So, what does that mean? Either the Altecs were or were not in the car. And the horns which already had serious design flaws were even more flawed by putting the Altecs on them. And do you believe everything RC said about the car?

To the last point...I judged a 2 day show with Harry Kimura and talked with him a bit on the phone until he went AWOL years back, and the topic of the GN came up because at the time RC was saying on Carsound that he had added 4" mids in steel enclosures under the horns that were gated so that they played at low volumes and only had higher volumes the 12s kicked in. Harry said that he and Eric Holdaway saw him and the car at a show (Perry I think), and that Eric went through the car with a finetooth comb and those speakers in question were not to be found in the car.

So I take what RC says about what was in the car with a grain of salt. But that's just me.


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## BigAl205 (May 20, 2009)

Ah, I was going by the article, but you've got inside knowledge...sorry. After comparing pics from the Speakerworks article and the RC article, I really can't see any actual changes.


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## thehatedguy (May 4, 2007)

It's all good.

The servo thing...I never asked about that. That could have happened and was true,


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## Hillbilly SQ (Jan 26, 2007)

With the amount of secrecy going on in car audio back then can you believe ANYTHING that you can't confirm with your own eyes? It's still going on today but MOST of the people I've talked to in person are pretty open about what they're running. Those that aren't open about what they're doing either have something to hide because they're cheating or they have self esteem problems that need to be addressed. That's a whole other can of worms though. I know of a car that has "prototype" drivers in the dash that aren't prototype drivers at all. Those of us in the know were asked to keep the secret so he wouldn't get busted for cheating in his class. I've since cut ties with that team but out of respect for the car owner I won't say who it was. Don't give a **** about the now defunct team leader. He pissed me off and lied to me way too many times.


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## Hillbilly SQ (Jan 26, 2007)

Now that my rant and observations are out of the way, the talk about running subs up into the midbass region in stereo seems to be a great idea. PaulD is/was running 8w3's in his doors up to a pair of 12m's in the kicks. All the way up to the 250 range iirc. I've always wanted to give pro audio mids a try and if I could run a pair of subs directly behind the front seats in stereo it just might work. I think I remember seeing the new F-150 has the speakers higher up in the front doors. Might be able to do a 5" pro audio mid in them with a good tweeter on top of the dash firing on axis. A pair of Dayton ho10's would be perfect as sub/midbass drivers since they have such low inductance. I'm thinking out loud to keep the "out of the box" discussion going and to work on a solid plan for what I end up buying in the next year or so.


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## analogrocker (Aug 1, 2009)

3 years ago I experimented with rear midbass. I installed some Eminence pro 12s in my rear quarter panels. They're still in there to this day, but I can't say I'm impressed with this setup. I've spent a lot of time tuning it but I can still tell that the midbass is coming from the back. I don't have any panel vibrations, either. So that's not the issue. I've found that to make it sound more like what I'm after I need to have front "helper" midbasses. That, however, kind of defeats the purpose for me. Soon I'm going to be doing a complete system overhaul and I plan to experiment with underseat midbasses. The only things I intend to use in the rear are small widebanders to act as rear fill.


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## thehatedguy (May 4, 2007)

There was always "prototype" mids going on in competition as long as I have/was involved. Kicker was notorious about that back in the day with their KCG mids...most were 5" Scan Revelators and a few Focals. Team Pioneer was about as bad. I know I had several custom built speakers when I was sponsored by Image Dynamics- and I ran a lot of mids that I always said were ID that clearly were not...PHL, Scan Revelators, Seas Excels (we told people those were Rainbow References because they looked like them and the References were new at the time and about 4 grand a set). 

But I don't recall anything in the rules prohibiting such things...or it ever was considered cheating.

It was like motorsports racing- win on Sunday and sell on Monday. We did well in competition on the weekend and the sponsors sold more product...we all knew what was going on, and everyone was ok with it.

But during RC's time the secrecy was real because there was real money involved with winning, and you didn't want to give up your secrets and someone copy your hard work and take you out of the spot light (and take "your" money).


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## Hillbilly SQ (Jan 26, 2007)

The car I was referring to has a 4" midrange in the dash that would bump him up to the next class if word got out. And that "special sauce" used to coat the drivers isn't such a secret anymore.


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## Ultimateherts (Nov 13, 2006)

Hillbilly SQ said:


> Now that my rant and observations are out of the way, the talk about running subs up into the midbass region in stereo seems to be a great idea. PaulD is/was running 8w3's in his doors up to a pair of 12m's in the kicks. All the way up to the 250 range iirc. I've always wanted to give pro audio mids a try and if I could run a pair of subs directly behind the front seats in stereo it just might work. I think I remember seeing the new F-150 has the speakers higher up in the front doors. Might be able to do a 5" pro audio mid in them with a good tweeter on top of the dash firing on axis. A pair of Dayton ho10's would be perfect as sub/midbass drivers since they have such low inductance. I'm thinking out loud to keep the "out of the box" discussion going and to work on a solid plan for what I end up buying in the next year or so.


It's funny that you mentioned the Dayton HO woofers because when Zaph tested them that was his conclusion as well. The funny thing is anyone that asks about them as midbass on here usually gets bashed pretty hard! You should also look into Hivi F10 or the Dayton RS 270. I know at one point I had considered these, but they were just a hair too large.


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## Hillbilly SQ (Jan 26, 2007)

I'm going to give the proposed system a try in my existing truck before sending it down the road since I've worked with the same cab for 6 years now (had an 09 Ram before the 11 I have now) and am familiar with its acoustical quirks. My existing JBL 12's run in stereo for sub-midbass will have to do for now. They're firing up to the roof with one behind each front seat so placement is about as good as it's gonna get in that regard. Haven't decided if I want to go with the Fountek aluminum cone 5.25" and LPG aluminum or Scan 15f and LPG fabric. Reason for the LPG's is the hinge mount for aiming. I figure any decent 5.25" woofer should be good down to 150 without tossing its cookies. We'll see what happens. If anything I won't be out much in mids and tweets to make this happen properly.


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## Orion525iT (Mar 6, 2011)

Hillbilly SQ said:


> I'm going to give the proposed system a try in my existing truck before sending it down the road since I've worked with the same cab for 6 years now (had an 09 Ram before the 11 I have now) and am familiar with its acoustical quirks. My existing JBL 12's run in stereo for sub-midbass will have to do for now. They're firing up to the roof with one behind each front seat so placement is about as good as it's gonna get in that regard. Haven't decided if I want to go with the Fountek aluminum cone 5.25" and LPG aluminum or Scan 15f and LPG fabric. Reason for the LPG's is the hinge mount for aiming. I figure any decent 5.25" woofer should be good down to 150 without tossing its cookies. We'll see what happens. If anything I won't be out much in mids and tweets to make this happen properly.


I got an idea for you. I almost did something similar in my car before I made my homebrew LATs.

Rebuild the boxes, but don't use the subs as direct radiators. Instead, slot load them with the slot firing at the farthest edges of the interior. The advantage here is the output from the 12" cone is concentrated as wide as possible. Make the slot no deeper than the cone, and any lowpass effect and rolloff should be far outside of any desirable crossover frequency. If you physical connect the boxes (or make a single divided box) then you also get the added benefit of force cancellation. 

I think you should be able to get width comparable to most door midbass placement. You could go even wider if you dig into things a bit.


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## Patrick Bateman (Sep 11, 2006)

thehatedguy said:


> He didn't make any changes to the midbass or subwoofer drivers- they are clearly JBL and Emilar drivers.
> 
> If you look at the original build pictures of the car, the horns have what look like 2" exit Radian or Emilar compression drivers on them...and they according to SW went to the top of the firewall. Then you see RC holding the horns in that article with Altec 288Gs drivers on them, which are 1.4" drivers. Now with horns, you decrease the length of the horn as you increase the driver size...so those horns needed to be longer for the smaller exit drivers. And the drivers are sooo much larger than the original pictures...which were supposed to have been as big as they could go.
> 
> ...


I've wondered the same thing. I hung on every word that Clark posted at audiogroupforum, but he seemed to enjoy throwing up smokescreens in regards to that car.

I've studied that car a lot, and I'm learning new things every day. Here's my latest discovery:

In the past couple weeks, phase response finally 'clicked' for me. Up until this month, I didn't really have a grasp on it.









Now that I understand phase, I realize that the lowpass filter on the JBL midranges in the Grand National would introduce a delay. Assuming a 4th order lowpass of 700hz, *you'll introduce a delay of about one millisecond.*

I don't know if Eric is a genius or he just got lucky, because that midbass placement achieves four interesting things:

1) The one millisecond of delay introduced by the lowpass filter will allow the midbasses to be mounted about 13" closer than normal. That might not sound like a big deal, but keep in mind this was the 1990s, nobody had DSP delay.

2) I think the height of the midbasses is interesting. I've noticed that it's pretty easy to tell what the height of a midbass is. So the rear quarter panel location should "raise" the soundstage. I'll bet it's noticeably higher than having a midbass in the lower door, or the floor.

3) A few years back I did an exhaustive analysis of those JBL midbasses, and the output levels are just unheard of. It's really hard to appreciate how much output is possible from a 12" prosound woofer with a 4" voice coil. My Gedlee Summas used a 15" prosound woofer with a 4" voice coil and it's amazing how much dynamics are "missing" from conventional loudspeakers. Using a fifteen for a midbass is crazy and amazing.

4) Keep in mind that the maximum width is achieved when the midbasses are immediately to the left and to the right. IE, when you have midbasses located in the conventional location in a stereo triangle, your maximum width is defined by the width of that triangle. (sixty degrees.) *When you move the midbasses to your left and to your right, the maximum width is now 180 degrees.*









Oddly enough, Eric Holdaway basically stumbled upon an Opsodis arrangement in the 1980s. The only real difference is that the tweeters aren't in the center. You could turn the GN into a true Opsodis setup by using the horn loaded compression drivers as midranges, and adding a couple of tweeters running from 5khz and up.


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## Patrick Bateman (Sep 11, 2006)

Orion525iT said:


> I got an idea for you. I almost did something similar in my car before I made my homebrew LATs.
> 
> Rebuild the boxes, but don't use the subs as direct radiators. Instead, slot load them with the slot firing at the farthest edges of the interior. The advantage here is the output from the 12" cone is concentrated as wide as possible. Make the slot no deeper than the cone, and any lowpass effect and rolloff should be far outside of any desirable crossover frequency. If you physical connect the boxes (or make a single divided box) then you also get the added benefit of force cancellation.
> 
> I think you should be able to get width comparable to most door midbass placement. You could go even wider if you dig into things a bit.


Yeah you can change the size and shape of the wavefront quite easily.

For instance, if you have a 12" woofer firing up in to the roof, and the cabin is four feet wide, *then the center to center spacing is 3'.*









But you can widen that center-to-center gap by firing the driver through a baffle. For instance, Nexo uses this trick to turn the output of an 8" woofer into the shape of two smaller drivers.

















In my last pair of Synergy horns I used the same trick to change the size of a 15" TC Sounds woofer into something that's about the size of 8" ribbon. So I reduced the apparent size of the radiator by over 75%.

This definitely introduces a low pass, just like slot loading does, but that was a bonus because I needed to low pass it anyways.

If I was running twelve inch midbasses in a truck I'd probably mount them vertically, similar to the Grand National


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## seafish (Aug 1, 2012)

PB, this is good to know, but I thought that stage width was more determined by midrange, not necessarily mid bass.

Can you clarify what bandpass are you calling mid bass??


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## Orion525iT (Mar 6, 2011)

seafish said:


> PB, this is good to know, but I thought that stage width was more determined by midrange, not necessarily mid bass.
> 
> Can you clarify what bandpass are you calling mid bass??


My guess would be 80 to about 800-1000hz where ITD is prominent.

But what you can get away with and still have the illusion of a wider stage is a different question.


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## seafish (Aug 1, 2012)

I would think that 80 might be a little low to be considered mid bass, but what do I know?? 

The reason I am asking is that I am seriously thinking about installing a second IDQ10v2 in my truck under the back seats and then run them in STEREO instead of mono. I have ID XS69 mid bass mounted thigh high in my doors that will run from 120 to 250 and am thinking of band passing the IDQ10 from 50 to 120, while letting a single BMmkIV mounted in the center seat console/downfiring take over below 50hz. Just trying to understand roughly what XO I would need to use to blend everything well.

Midrange and tweets will be high, wide and deep on the dash,

I realize that IS a lot of speakers, but I already do have the amps and dsp to run them all active and the capability to insatll them all. … I am designing my system install not just by what is usually done, but ALSO by what might be done to improve the clarity and image of the sound stage as well as the overall impact of the system. My esoteric understanding is that running ALL speakers only well within their range actually improves clarity and stage by reducing cone distortion as well as adding to total cone displacement as long as they are bandpassed and insatlled/located as high, wide and deep, as well as as far away from the listener, as possible in a vehicle.

PB's recent observation about mid bass actually helps me, but just wanted to clarify the definition of mid bass.


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## thehatedguy (May 4, 2007)

I don't think that setup is going to achieve what you want it to, and is going to be more complicated than needs to be.


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## seafish (Aug 1, 2012)

thehatedguy said:


> I don't think that setup is going to achieve what you want it to, and is going to be more complicated than needs to be.


Thanks for the vote of confidence…JK

I realize that it is definitely going to be complicated but why do you think I won;t be able to achieve high SQ with it??? 

I think that I have VERY nice speaker locations picked out and I will insatll them with properly rigid and heavy baffles and spend time adjusting aim. 
Between the DRZ9255 and the H800/C800 I will have plenty of eq , ta and other tuning abilities..…the 3 way front stage should be very nice, just want to augment with clean, and subtle bass…of course, I WILL try it first with only the pair of IDQ10 running mono, then running stereo, and only then try adding the BMmkIV. I can also try running ONLY the BMmkIV and compare that as well, in fact I should probably try that FIRST. 

That being said, I DO realize it this IS experimental install in nature, if only because not many people are running dual STEREOPHONIC subwoofers in vehicles, probably for a good reason, but if the only reason is because it is harder to do CORRECTLY, then I am going to ignore that and keep trying and eat crow later only if I HAVE to,,,LOL


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## thehatedguy (May 4, 2007)

Most music doesn't have stereo bass is one reason most people don't do it.

And you can't get enough width between the subs to really appear as stereo is another reason.

It's going to cause pretty massive phasing problems too.


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## Patrick Bateman (Sep 11, 2006)

seafish said:


> PB, this is good to know, but I thought that stage width was more determined by midrange, not necessarily mid bass.
> 
> Can you clarify what bandpass are you calling mid bass??


If you were trying to copy what Holdaway did in the Grand National, you'd probably be looking at something like this:

subs : 22hz -87.5hz (two octaves)

midbass : 87.5hz - 700hz ( three octaves)

tweeters : 700hz - 20khz (five octaves)

300hz is the width of the car, so once you get down to those frequencies you can't really localize them. I agree with the folks at Autosound 2000, that what most people perceive as 'up front bass' can be accomplished by minimizing high frequency cues from the sub box. Also knows as "rattles".


As usual, the critical octaves that really give away location are the two octaves from 500hz to 2khz. They're critical for a couple of reasons. First, in those octaves we can perceive both phase *and* amplitude. And second, due to the Fletcher Munson curves, we're most sensitive to those frequencies.

I think that one of the reasons that horns were so dominant wasn't necessarily because they're efficient or dynamic, but mostly because you can run them an octave lower than a dome tweeter. IE, there isn't a dome tweeter in the world that can live with a 700hz xover, but there's a handful of compression drivers that can, and dozens that can be crossed over at 1khz. It allows you to 'funnel' the majority of the sound through a point source.

Of course Synergy horns can do that too...


TLDR: IMHO, you really want to get everything perfect in the two octaves from 500hz to 2khz. There's no easy way to 'fake' where those speakers are. You have some leeway with the other frequencies. IMHO, a big part of the winning formula of the Holdaway cars was getting everything from 700hz and up to radiate from one location.


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## Hillbilly SQ (Jan 26, 2007)

Right now everything from 1000 and up is radiating from the same locations. If you're familiar with the dash locations of the 09 and up Ram (VERY different from the 02-08 Ram dash MOST people think of so get that truck COMPLETELY out of your head!) the locations in mine are as wide as possible up there and loading against the pillars. My amt tweeters are sitting on top of the dash grill and corner loaded on axis. With only one pair of drivers crossed to beam and being on axis magic happened. I'll try to stick with tweeters mounted directly on axis and corner loaded against the windshield and pillars. Erin swayed me in this direction and when he tells me to try something I'm all ears!

NOW, something that crossed my mind the other day was giving midbass in a 4th order a try. What sparked this idea was the "slot loaded" subs to control directivity. This way I could have a 1" or 2" tube firing on the outer reaches of each side. The one time I ran an 8" sub in a 4th order I fell in love with the impact it added to the music and wish it could have gotten me up a little higher with that impact but the design was tweaked to get the woofer to play as low as possible as flat as possible with cabin gain taken into consideration. If I could do this with a pair of pro audio 8's or maybe some sls 6.5's...


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## Patrick Bateman (Sep 11, 2006)

Hillbilly SQ said:


> Right now everything from 1000 and up is radiating from the same locations. If you're familiar with the dash locations of the 09 and up Ram (VERY different from the 02-08 Ram dash MOST people think of so get that truck COMPLETELY out of your head!) the locations in mine are as wide as possible up there and loading against the pillars. My amt tweeters are sitting on top of the dash grill and corner loaded on axis. With only one pair of drivers crossed to beam and being on axis magic happened. I'll try to stick with tweeters mounted directly on axis and corner loaded against the windshield and pillars. Erin swayed me in this direction and when he tells me to try something I'm all ears!
> 
> NOW, something that crossed my mind the other day was giving midbass in a 4th order a try. What sparked this idea was the "slot loaded" subs to control directivity. This way I could have a 1" or 2" tube firing on the outer reaches of each side. The one time I ran an 8" sub in a 4th order I fell in love with the impact it added to the music and wish it could have gotten me up a little higher with that impact but the design was tweaked to get the woofer to play as low as possible as flat as possible with cabin gain taken into consideration. If I could do this with a pair of pro audio 8's or maybe some sls 6.5's...


Stay tuned to my build thread, just about every driver is going to be in a 4th order box. I'm 3D printing the midbass enclosures as we speak. (Each one takes 24 hours to print, ugh)

http://www.diymobileaudio.com/forum...r-audio-discussion/180497-28-weeks-later.html


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## Orion525iT (Mar 6, 2011)

Hillbilly SQ said:


> What sparked this idea was the "slot loaded" subs to control directivity.


To be clear, the idea of the slot load is to get your drivers to aurally "appear" wider than they actually are...and the slot actually reduces directivity by widening the polar response along the short axis. Chances are, you would never play them high enough to see a change in the polars, but it could be part of the design if one wanted.

Doing this with a _true_ port sounds like a fun experiment.


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## Orion525iT (Mar 6, 2011)

Patrick Bateman said:


> *300hz is the width of the car, so once you get down to those frequencies you can't really localize them.* I agree with the folks at Autosound 2000, that what most people perceive as 'up front bass' can be accomplished by minimizing high frequency cues from the sub box. Also knows as "rattles".


I understand that localizing them front to rear may not be possible under the ideal conditions below a certain frequency. But placement is still important in regards to perceived width because you can't cheat ITD. So being able to localize is not the entire story, I don't think.


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## tjswarbrick (Nov 27, 2013)

Orion525iT said:


> To be clear, the idea of the slot load is to get your drivers to aurally "appear" wider than they actually are...and the slot actually reduces directivity by widening the polar response along the short axis. Chances are, you would never play them high enough to see a change in the polars, but it could be part of the design if one wanted.
> 
> Doing this with a _true_ port sounds like a fun experiment.


Hopfully not dragging this too far off topic, but does this imply that side-firing vents on an underseat midbass could be utilized to increase perceived soundstage width?


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## Orion525iT (Mar 6, 2011)

tjswarbrick said:


> Hopfully not dragging this too far off topic, but does this imply that side-firing vents on an underseat midbass could be utilized to increase perceived soundstage width?


I think so. It is one of the things that I considered quite a bit, but decided I didn't really have the room to pull it off. Might be far more feasible in a larger vehicle, but I drive a pod sized car. Of course it might introduce a host of other issues to deal with too depending upon exactly where and how the vent mouth is located.


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## tjswarbrick (Nov 27, 2013)

> I think so. It is one of the things that I considered quite a bit, but decided I didn't really have the room to pull it off. Might be far more feasible in a larger vehicle, but I drive a pod sized car. Of course it might introduce a host of other issues to deal with too depending upon exactly where and how the vent mouth is located.


Good to know. One more thing to discuss with the installer when I get my next build going.

Now, back to back door midbasses.


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## seafish (Aug 1, 2012)

Hey guys, I found this thread from 2003 in which Holdaway, Richard CLark, and Harry Kimura and others all talk about the rear mid bass in the GN from 1993. Its pretty dam interesting and somewhat revealing about that car, so I thought that you might want to read some or all of it--

how did the buick grand national get away with the midbass in the rear side panels? - CARSOUND.COM Forum

Post #27 on page 3 seems is particularly detailed about frequencies and imaging…NOT that it is anything that PB or others haven't talked about in other threads and even here, but succinct nonetheless.

http://www.audiogroupforum.com/csforum/showpost.php?p=7206&postcount=27


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## thehatedguy (May 4, 2007)

Harry mentions his car and what the new owner found or might have found when the car was taken apart...well that owner didn't take the car apart. But the guy who bought it from Ryan did take it apart and rebuilt it (actually Mark Elridge eventually rebuilt it)...well when it was taken apart, Harry's car did have Dynaudio midbasses in the front doors. It was told to me they were left overs from when it have kickpanels and they weren't hooked up. Dunno if they were hooked or not, but the car did have midbasses in the front when it was taken apart.


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## Hillbilly SQ (Jan 26, 2007)

tjswarbrick said:


> Hopfully not dragging this too far off topic, but does this imply that side-firing vents on an underseat midbass could be utilized to increase perceived soundstage width?


Under my Ram front seats I have about 4.5" of height and a freakishly large area. It's enough room for a pair of Mosconi 120.4's and a pair of d-blocks. That's just under ONE seat. However, I don't want to move the amps so was thinking about maybe trying some 8" midbasses ported where my 12's are currently sitting and go back to a sub mounted under the back seat. Might oughta just get a BM for under the back seat and get it over with. It's the right tool for the job in that respect so...and with ported midbasses I could play around with pvc port aiming. I'm seriously thinking about keeping this truck after all and buying a new boat, then in a few years getting a fuel efficient crossover type vehicle that could still pull my smaller flatbottom boat if needed. I'll probably get the 19' Tracker with a 115hp Mercury 4-stroke and keep my 1436 jon boat with a 20hp for skinny water and stump piles. Need the bigger boat for bigger water and so dad can ride along comfortably. And I miss the extra room and stability for flipping a jig into structure. It's been harder than I thought to find something fuel efficient, midsize, and decent towing. It's like Hoffmans Iron Law, gotta give up one out of three qualities. My Ram is a beast that rides like a dream but drinks gas in town. 14mpg on average.


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## thehatedguy (May 4, 2007)

You only get output from the ports at/near tuning, so I don't know what you would accomplish from aiming them.


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## Hillbilly SQ (Jan 26, 2007)

Didn't think about that. Either way ported midbass in the rear would be fun to try from around 60-150. It would give me more options for pro audio drivers up front like a 5" and really efficient tweeter.


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## Patrick Bateman (Sep 11, 2006)

Orion525iT said:


> To be clear, the idea of the slot load is to get your drivers to aurally "appear" wider than they actually are...and the slot actually reduces directivity by widening the polar response along the short axis. Chances are, you would never play them high enough to see a change in the polars, but it could be part of the design if one wanted.
> 
> Doing this with a _true_ port sounds like a fun experiment.


Slot loading also changes the apparent source of the sound.

The easiest way to visualize this is to picture a loudspeaker connected to a ten foot long piece of pipe. One end is sealed. One end is open. *The apparent source of the sound won't be the loudspeaker at one end of the pipe, it will be where the sound radiates from the other end.*

There will be a delay to due to pathlength, but that can be compensated with DSP.

Bottom line - you can use a duct to move the apparent source of the sound from one location to another.


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## Patrick Bateman (Sep 11, 2006)

Hillbilly SQ said:


> Under my Ram front seats I have about 4.5" of height and a freakishly large area. It's enough room for a pair of Mosconi 120.4's and a pair of d-blocks. That's just under ONE seat. However, I don't want to move the amps so was thinking about maybe trying some 8" midbasses ported where my 12'
> s are currently sitting and go back to a sub mounted under the back seat. Might oughta just get a BM for under the back seat and get it over with. It's the right tool for the job in that respect so...and with ported midbasses I could play around with pvc port aiming. I'm seriously thinking about keeping this truck after all and buying a new boat, then in a few years getting a fuel efficient crossover type vehicle that could still pull my smaller flatbottom boat if needed. I'll probably get the 19' Tracker with a 115hp Mercury 4-stroke and keep my 1436 jon boat with a 20hp for skinny water and stump piles. Need the bigger boat for bigger water and so dad can ride along comfortably. And I miss the extra room and stability for flipping a jig into structure. It's been harder than I thought to find something fuel efficient, midsize, and decent towing. It's like Hoffmans Iron Law, gotta give up one out of three qualities. My Ram is a beast that rides like a dream but drinks gas in town. 14mpg on average.











There's some real oddball vehicles that can tow a boat. My father in-law always gives me **** for putting a hitch on my Hyundai Genesis but I refuse to ruin the interior by putting anything from Home Depot in there.









If push comes to shove, this is how I haul stuff. Living a block away from Home Depot is the best.


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## Hillbilly SQ (Jan 26, 2007)

Patrick Bateman said:


> There's some real oddball vehicles that can tow a boat. My father in-law always gives me **** for putting a hitch on my Hyundai Genesis but I refuse to ruin the interior by putting anything from Home Depot in there.
> 
> 
> 
> ...


I prefer to have AT LEAST double the towing capacity of what's needed especially when driving through town and in the mountains here in Arkansas. Brakes are also a big factor since most of the stuff I tow don't even have surge brakes. My Ram will stop 2 tons of trailer on dry pavement so fast it will make your head spin. And the nearly 400hp under the hood turning 3.92 gears will snatch the load around like it's not even back there. One time I was pulling a friends boat about half an hour behind him and he was pulling a 24' camper. His wife was with me because she had to tie up some loose ends at the house and I offered to wait up. We cross an area that must have been the perfect storm of bumps and wind because about 3000lbs of boat, motor, and trailer started going crazy trying to rip my 09 Ram with 500 miles on it to pieces. His wife started freaking out as I let off and regained control. My buddy had the same thing happen to him pulling the camper but the swaybars helped cushion the blow there. Another time his grandpa was pulling a 26' camper and about 2 tons of bass boat at the same time with a half ton Sierra. Wind and rough roads took control of him and nearly totaled his brand new truck, totaled the camper, camper landed on the nose of the Champion 196 with 200hp Merc on it, bent the trailer out of shape but only scratched the boat. The boat is WAY overbuilt and that's one reason Champion is amongst the best right up there with Ranger. 

As for what something is "capable" of towing, you have to wonder how long it will do it before having problems. And if things get sketchy you want the tow rig to control the trailer, not the other way aroundIn Texas they tow heavy stuff like horse trailers with smaller trucks all the time but when they hit the mountains they have to rely on their 3/4 and 1 ton buddies to pull their horses for them. My cousin has had to do it and they live on the edge of the Ozark National Forest. They breed and train Foxtrotters.


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## Patrick Bateman (Sep 11, 2006)

Hillbilly SQ said:


> I prefer to have AT LEAST double the towing capacity of what's needed especially when driving through town and in the mountains here in Arkansas. Brakes are also a big factor since most of the stuff I tow don't even have surge brakes. My Ram will stop 2 tons of trailer on dry pavement so fast it will make your head spin. And the nearly 400hp under the hood turning 3.92 gears will snatch the load around like it's not even back there. One time I was pulling a friends boat about half an hour behind him and he was pulling a 24' camper. His wife was with me because she had to tie up some loose ends at the house and I offered to wait up. We cross an area that must have been the perfect storm of bumps and wind because about 3000lbs of boat, motor, and trailer started going crazy trying to rip my 09 Ram with 500 miles on it to pieces. His wife started freaking out as I let off and regained control. My buddy had the same thing happen to him pulling the camper but the swaybars helped cushion the blow there. Another time his grandpa was pulling a 26' camper and about 2 tons of bass boat at the same time with a half ton Sierra. Wind and rough roads took control of him and nearly totaled his brand new truck, totaled the camper, camper landed on the nose of the Champion 196 with 200hp Merc on it, bent the trailer out of shape but only scratched the boat. The boat is WAY overbuilt and that's one reason Champion is amongst the best right up there with Ranger.
> 
> As for what something is "capable" of towing, you have to wonder how long it will do it before having problems. And if things get sketchy you want the tow rig to control the trailer, not the other way aroundIn Texas they tow heavy stuff like horse trailers with smaller trucks all the time but when they hit the mountains they have to rely on their 3/4 and 1 ton buddies to pull their horses for them. My cousin has had to do it and they live on the edge of the Ozark National Forest. They breed and train Foxtrotters.


I built my trailer from a kit (DIY right?)

The kit wasn't well designed and the trailer broke in half on the I5 freeway in Seattle, in the pouring rain.

So always take my advice with a grain of salt. It's one thing to have a failed loudspeaker, but failed trailers are a real dangerou thing :O

On the upside, when the trailer broke in half I managed to pull over before the thing completely came apart, and had enough tools on hand to limp home. The problem with the kit was that the vibration would loosen the bolts. (I fixed that.)


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## Patrick Bateman (Sep 11, 2006)

thehatedguy said:


> Harry mentions his car and what the new owner found or might have found when the car was taken apart...well that owner didn't take the car apart. But the guy who bought it from Ryan did take it apart and rebuilt it (actually Mark Elridge eventually rebuilt it)...well when it was taken apart, Harry's car did have Dynaudio midbasses in the front doors. It was told to me they were left overs from when it have kickpanels and they weren't hooked up. Dunno if they were hooked or not, but the car did have midbasses in the front when it was taken apart.


I totally forgot that SpeakerWorks originally had a really elaborate setup in Harry's Legend. If you google it, there's a magazine article on the original setup.

Harry explains those door mounted midbasses here:

how did the buick grand national get away with the midbass in the rear side panels? - Page 3 - CARSOUND.COM Forum

_"We looked at putting Midbasses upfront and we even played around with 8's in the doors ( old remnant of the original kick-panel system ). The 8's upfront did more harm than good so we elected not to use them. We also looked into doing something in the floor, but it just wasn't worth the trouble. If it was feasible, we would have put some midbasses upfront, but given that the car was a daily driver, definitely set some limitations."_


On a side note, it's kind of embarassing how long we've been talking about rear mounted midbasses. I googled the subject, looking for some insight into it. I found my own posts, on audiogroupforum, from eleven years ago. In the thread are half of the people talking about it here:

1) Jason Winslow
2) Richard Clark
3) Harry Kimura
4) Me
5) Eric Holdaway
6) Andy Wehmeyer


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## Hillbilly SQ (Jan 26, 2007)

Patrick Bateman said:


> I built my trailer from a kit (DIY right?)
> 
> The kit wasn't well designed and the trailer broke in half on the I5 freeway in Seattle, in the pouring rain.
> 
> ...


Preparing a new to me flatbottom boat, motor and trailer before having knee surgery (was in A LOT of pain) I lowered one side of the trailer with brand new tires on it to torque the lugnuts down. The one on the drivers side never got tightened. There's an old "Chevrolet style" rim with a brand new tire with about 5 miles on it laying in the woods on the side of the road and likely shreaded on the way out. The other brand new tire is my spare now. The trailer itself has a brand new 3500lb axle and heavy duty tongue on it and the trailer itself is built fairly solid. It's held up great for something built in 1985. And the setup as a whole is a lot easier on my wallet than the big bass boats I had before it. I've been taught to take great caution when trailering and make sure what I'm pulling has been properly maintained if it's not mine (happens more than you might think in my circle of friends and aquaintances). Lucky for me I hang with other country boys who know how to take care of their stuff. It might not always be by the book but going by the book isn't always the best way anyway


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## evo9 (Jul 6, 2005)

Hillbilly SQ said:


> Because I'm not much on fabrication and that's usually the biggest you can fit without going deep into modification. Unless you're referring to possibly going something like 8" or 10" midbass firing up in the rear floorboard? Hmm, I have a pair of Usher 8945a's and an extra pair of processor channels not being used at the moment...and a pair of amp channels that can be freed up to try it in my truck now. Hmm.



If you go with the Acadia, the doors will have a lot of real estate to work with. A Dyn MW172 would fit with very little effort. I'm also considering the midbass in the rear door too. Not in the Acadia since that's my wife's chariot, but in my 2013 TSX. This car is the Tech Package that has speakers in the rear door. I can tell you with the stock ELS factory system, I cannot localize the rear door while they are playing. This is one reason why I'm going to try this setup too.


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## Hillbilly SQ (Jan 26, 2007)

I think I'm going to keep my Ram and buy a new boat that will fit my needs and still be able to pay it off quick. Tracker 175 with the center rod box and 75hp or Tracker 190 with 115hp are the front runners because layout is king and every other tin rig failed miserably even though Xpress is about the best but I'm not buying their Exclusive series when I can get a new glass rig with the same hp and more stability for about the same price if I went with something that broke $30k. Anyway, run-on sentences and babbling about my main hobby aside (car audio is secondary) when the boat is paid for I'll decide whether to keep the Ram and get a smaller fuel efficient cuv or trade the Ram in for a new truck or larger suv like the Acadia or even a good used Tahoe. Probably be smarter to just put liability on the truck and hang on to it since by then one good lick would total it anyway. And with a second vehicle as a daily driver my current 10k miles a year on the truck would go down to just a few thousand at the most. And in theory a beat up old truck would be less of a target to thieves when parked at a secluded boat launch. Just gotta keep the interior visible so they'll have a clear view of NOTHING TO STEAL!


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## oabeieo (Feb 22, 2015)

Patrick Bateman said:


> I totally forgot that SpeakerWorks originally had a really elaborate setup in Harry's Legend. If you google it, there's a magazine article on the original setup.
> 
> Harry explains those door mounted midbasses here:
> 
> ...


What a waste of 4 hours I read the entire post! 11 pages of nothing about midbass in rear , I must have enjoyed the read tho . So who is npdang I've seen that user name throughout the years? 

I actually read that post years ago . 
I would love to build a car that out does the GN just to give folks something else to talk about 30 years later .


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## Patrick Bateman (Sep 11, 2006)

oabeieo said:


> What a waste of 4 hours I read the entire post! 11 pages of nothing about midbass in rear , I must have enjoyed the read tho . So who is npdang I've seen that user name throughout the years?


Nguyen P Dang. Founder of diymobileaudio. Sold the site to Ant a few years back. Google says he's a lawyer now. 





oabeieo said:


> I actually read that post years ago .
> I would love to build a car that out does the GN just to give folks something else to talk about 30 years later .


If you read the Car Audio and Electronics writeup on the Grand National, there's a lot of talk about motorization and unobtanium tweeters and signal processing.

But the basic blueprint for the Grand National was used over and over by SpeakerWorks:

1) Horn loaded compression drivers, which allow you to push the xover point down to 900hz or so. Basically allows you to use one driver for the midrange, where problems are so audible.

2) Completely over-the top midbasses. We're talking about drivers that are capable of ten or even twenty decibels more output than a 6" woofer, drivers that are just loafing along at 110dB

3) Bass in a car is easy, there's nothing special about the Speaker Works subs. They're not bad, they get the job done, the only truly remarkable thing about them is that they keep excursion low which likely reduces rattles, which helps eliminate cues that would make you think they're behind you

This formula was done over and over again by SpeakerWorks. The only big difference with the GN is that everything was a little larger than life. The midbasses in particular were bigger than what Harry or Mark were running.

As for all the other stuff, like the Altec compression drivers, I'm not convinced they were ever in the car. A huge part of the car's success was Richard's stories, he convinced everyone that it was one-of-a-kind. And the truth is, we'll never know if he was exaggerating or not.


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## thehatedguy (May 4, 2007)

Mark who? Elridge wasn't ever part of the SW crew...he always had 8s in the front of his old 4 Runner either Veritas or JBL (always as in asa far back as I could find published info on the vehicle).

11 years huh? And I still haven't put them in the rear yet...lol. I did make a rear deck for my old Accord that had a pair of 2204s on it, but it never got played. Might have pictures of that somewhere- built a box between the speakers and fillled it with 15 pounds of mortar mix to kill any panel resonances.


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## Patrick Bateman (Sep 11, 2006)

thehatedguy said:


> Mark who? Elridge wasn't ever part of the SW crew...he always had 8s in the front of his old 4 Runner either Veritas or JBL (always as in asa far back as I could find published info on the vehicle).
> 
> 11 years huh? And I still haven't put them in the rear yet...lol. I did make a rear deck for my old Accord that had a pair of 2204s on it, but it never got played. Might have pictures of that somewhere- built a box between the speakers and fillled it with 15 pounds of mortar mix to kill any panel resonances.












I was thinking of Todd Matsubara. For some reason I was thinking his name was "Mark"


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## thehatedguy (May 4, 2007)

Gotcha.

Mark and Richard were TIGHT back in the day, didn't know if that was where the confusion came from.


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## pocket5s (Jan 6, 2012)

Don't know about Richards use of the Altec, but marks 4Runner did use them. It's in the build log book (he still has the book) and he still has them. Passed one around at the class I attended. It's a damn heavy beast. 

He did mention that he also used a tweeter in the pillar to help with the upper end as the Altecs would only go so high.

Sent from my iPhone using Tapatalk


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## oabeieo (Feb 22, 2015)

I thought it was funny that that Graig Dood didn't know what over easy limiter was or a fast attack gate. All he had to do was Google it


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## oabeieo (Feb 22, 2015)

Patrick Bateman said:


> I was thinking of Todd Matsubara. For some reason I was thinking his name was "Mark"


Didn't that have horns and old Alesis meq230s in the visors with zapco psi
Iirc?


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## mitchyz250f (May 14, 2005)

mitchyz250f said:


> I am running JBL 2204 in my back quarters (RSX - no rear doors) in a sealed enclosures. The front speakers are Pro Audio PHL 1120 (95db @300Hz) w/Morel MT22 tweeter. The mid-bases are _almost_ at the same distance and angle as the fronts (cone of confusion) from my ears. I am using a JBL MS8 and I have experimented w crossovers between the mid-bass and fronts at both 300 and 400Hz. My concerns are dynamics more so than staging.
> 
> Crossed at 400Hz the stage is pretty solidly up front. Most drum hits or bass guitar notes sound like they are coming from the front to me. The exceptions are music with sustained mid-bass notes like from a cello or piano, something with substantial decay. Doesn't sound bad to me more like an ambiance effect than anything else. With the car moving I think it would be impossible to tell any sound is coming from the rear.
> 
> ...



Just wanted to make a correction to something I have said many times. With the crossover of from my quarter panel mounted midbass at 400Hz the stage will wander from front to back. Sometimes it sounds like ambience and other times it sounds like the guitar player, singer whatever is walking from the back to the front of the car. Most people think it is cool but we know it is wrong. If you want a solid front stage you have to cross below 300Hz.


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## Patrick Bateman (Sep 11, 2006)

pocket5s said:


> Don't know about Richards use of the Altec, but marks 4Runner did use them. It's in the build log book (he still has the book) and he still has them. Passed one around at the class I attended. It's a damn heavy beast.
> 
> He did mention that he also used a tweeter in the pillar to help with the upper end as the Altecs would only go so high.
> 
> Sent from my iPhone using Tapatalk


I've definitely considered doing something along these lines again. 

In my 01 Accord I had a setup like that. I ran that until eight years ago, then started doing Unity horns. 

Back then I didn't know half as much as I know now, and I now know how to fix a lot of the fundamental problems with underdash horns. 

In particular, how to raise the stage and get extension to 20khz.


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## pocket5s (Jan 6, 2012)

As a gee-wiz, FYI for those interested, in the pic of Richard holding the horn and altec, he did run Altecs I recently learned. The waveguide in the pic is the one that was in the car when he got it, but _not_ the one he ran for a while. So the altec was one of his spares, put onto the waveguide for the benefit of taking a picture for the magazine.


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## Patrick Bateman (Sep 11, 2006)

pocket5s said:


> As a gee-wiz, FYI for those interested, in the pic of Richard holding the horn and altec, he did run Altecs I recently learned. The waveguide in the pic is the one that was in the car when he got it, but _not_ the one he ran for a while. So the altec was one of his spares, put onto the waveguide for the benefit of taking a picture for the magazine.


Ten years ago I wandered into the audiogroupforum and opened that can of worms. (I wasn't trolling, seriously!)

In the process I learned a few things:
1) There's only one dude who knows what was in the GN, and he isn't saying
2) There's a fairly decent chance that RC said a lot of things to gain a competitive advantage.

RC is a great showman; I think part of the reason that he was so successful is that he built a mystique around that car. It reminds me of Howard Stern in a way; he's incredibly good at self-promotion. (Did you know that Howard Stern makes more money than Tom Cruise and Brad Pitt? Takes real talent to get someone to write you a $500,000,000 check.)

None of us know what was in that car. I think there's a fairly decent chance that RC simply bought the GN because he wanted another GN, then tuned the existing stereo with a TEF analyzer. TEF was way ahead of it's time in the late 80s, and it would give someone a real advantage.


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