Ok so I've decided that I need some REAL midbass. The kind that no 6.5" can possibly produce without huge xmax and a massive amount of power on tap.

Problem is, I have no room for kicks, and I can't see any way I can fit 8" midbass's in my doors (i'll explain this soon). Basically, I want a cone area factor closer to what an 8" can provide.

My options WOULD be (in each door):

2 X 6.5" midbass (cone area factor of 84.5)
2 X 5.5" midbass (cone area factor of 60.5)
3 X 5.25" midbass (cone area factor of 82.68)
1 X 8" midbass (cone area factor of 64)


Options that lack the 80-100hz response I am after:
1 X 6.5" midbass (cone area factor of 42.45)
2 X 5.25" midbass (cone area factor of 55.125)

Before you ask, yes my doors are fully deadened, and yes my door skins are sealed with mdf in the access holes
Problem is that I have window winders (and I don't want to get power window'd doors because the assembly makes the outer door skin impossible to deaden) and that means that I can't really fit any array of midbass =( Since I may have to cross them as far up as 500hz, I can't place the cones any further apart than 686mm from center to centre (ideally even closer together than that. I don't know if any of you have seen a VT commodore trim before, but those winders have an OBNOXIOUSLY wide arc that means that all of the best speaker spots are taken.

I was actually thinking of modifying a pair of ratchets to act as window winders so that they would only have to use a semicircular arc, but surely there is another way... anybody got any ideas?

Common mistake people make when using more than one driver, is they assume that two 6.5 inch speakers will play lower than one 6.5inch speaker. This is not true (unless some form of EQ is used).

Two 6.5inchs will play louder at the lower frequency, but, will also play louder at the higher frequencies. Ill give an example.


1 x 6.5inch with 200watts.

95db @ 180hz
93db @ 100hz
90db @ 80hz

2 x 6.5inch with 400watts (200each)
98db @ 180hz
96db @ 100hz
93db @ 80hz


Notice when two 6.5inchs are used, they play louder, but, notice that 80hz is 5db lower than 180hz on both drivers.

The above numbers were made up, and assumed 100% efficiency of adding another driver. They represent a good example, but are not 100% accurate.

Have you heard a car with 8's in it??? Might not be all that better then what you have now with a slight boost in the correct region.


*EDIT* To further clarify, I was assuming you were talking about a 2-way system, rather then a 3-way, but I might have missread this.

get a decent 6.5inch driver and a heap of power, then if that doesn't work for you, try the dual 6.5 drivers in an array of sorts, my midbasses drive from 50hz to 300 and they sound great, maybe later on if i get an urge i can still double up the midbasses if i think they are lacking.

what gear do you have and what were you looking at getting?>?

Hmmm.... interesting responses.....

If you put a larger midbass in your car, and do it properly, you'll never regret it. The gains are simply too much, and will always put a big smile on your face. The dynamics, the ease of reproduction, the physcial response to the music, the absolute feeling of power....... 6.5's will never/can never compete.

If you really like the snap, and the kidney punch that some music can provide, then 6.5 arrays (2 pairs) are definitely a step up too. Sure you might need to shape the response, but the result can be simply unbelievable, and definitely worth the effort.

If you're struggling for room, have a look at the ID 6x9. It has the cone area of an 8, extremely high sensitivity (93dB@2.83V), multiple lower level breakup nodes (because of the unusual shape), and best of all, it can play quite high with ease.

if you use 60 x 1in tweeters you will get a fair cone area...


if you can fit 8's then get 8's.

if you want serious midbass, track down an old member on here called "the kid" he has my old 10in USD midbass's and im sure he is wanting to sell them

The ID 6x9's would be my choice, they are incredible!!

yeah wouldnt be bad teggy, but they produce over sounds and we have round ear holes, it will never work properly... just like them square subs. just cant hear square waves properly..



:|

Hahahah! Ya spaz!

lol

I'd fit 2x 6.5"s...

Wouldn't this give you more 'depth' if mounted horizontally???

oh dont be silly!! you need to mount them down lower! preferably under the car, mebbe in the ground somewhat.
mounting them horizontally will just give you flat oval sounds that wont fit in any ears, you will need to get a HU that will do RA (round alignment) and a fattener setting to give it the depth and the shape you need

you are a fool Fuddly, and you should be banned from making those sort of statements.

Round Alignment indeed....

sif you doubt me.. cause your running hx-r2-d2-c3po that doesnt have RA

bastard

You can fit 8" drivers in your door, another member here has 8's in his commodore door similar model etc... VTviper I think it is, he has an install thread somewhere.

Thanks for all the responses guys. Yes I know that 2 X 6.5's will play all of their frequency range louder but with L/R independent 31 band eq that is no problem. I just have issues now with 6.5's of any kind always over excursing (sp) below 100hz.

I would personally LOVE 2 X 6.5's or an 8 in each door, and i know it has been done in VT's before, just not sure whether it's been done when window winders are present. =/ I am also going fully active 3 way.

I'm thinking peerless SLS8 subs (many people are running them as midbass with great results) might be a good, cheapish, and hard hitting option for me. I hope 150W each is enough for them, I'm running low on funds as it is.

My mids are still something I haven't got worked out. I want them in my pillars, so they can't be very large. Best option seems to be (for SO many reasons)vertical MTM arrays of 2" or 2.5" mids moulded into some fibreglass pods (either attached to, or part of my a pillars.*

My tweeters will definately be vifa XT25's (they can be crossed as low as 2k without being too harsh sounding) provided i can get versions without ceramic surrounds (or they can be be removed). These will be ideally rear mounted with a small amount of conical "waveguide" for lower distortion due to less gain being required.

*having HUGE issues here. Trying to find small mids (or full ranges) that have the following properties:

*no larger than 2.5"
*have at least 10 watts rms power rating
*have at least 86db sensitivity
*have an f3 lower than 250hz.

One large cookie to anyone who can point me towards such a midrange driver. =)

I am talking about a 3 way. A slight boost in the correct region is making my speakers slap. I know there are higher excursion 6.5's out there, but due to awful mounting postition in commodore's i have decided to go 3 way to get those mids singing nice and high. 6.5" midbass in 3 way setup = fail.

Polk SR6500's
2 Polk SR104's

Tweeters are awesome, subs are awesome, mids are nice if they are on axis but in my commodore they drag my stage down something fierce and they just sound horrid above 600hz-ish. Midbass is lacking (I have heard this about APP cones before), and wouldn't be such a problem if the mids sounded good, like they did in my house when i had them on axis.

What I am looking at getting:

Peerless SLS 8" subs as midbass
????? 2 or 2.5" mids in an MTM array crossed as low as possible (probably 250-500 somewhere) ON AXIS
Vifa Xt25 tweeters with slight waveguide/horn cross as low as possible (2k-2.5k somewhere) ON AXIS

I think what you want, 2.5" http://www.madisound.com/catalog/PDF/830985.pdf

They also do a 2" as well as the 3" which you probably know of.

Forget about an MTM in the pillars, unless you can individually TA each individual speaker. The pathlengths simply arent far enough, and for an MTM to work correctly (as they are designed for polar response....) all the drivers NEED to be equal pathlengths from the listener.....

SLS 8"........absolute sex.....

they are not 100% installed....i have the rings in with some liquid nails in there to seal up the large holes....then just gotta glass some in there.

they are nice and low. running 80-250. i wanna go higher to match up with the SS15M when i get them but xover aint connected yet........

they are deep thought....only just fit in my pulsar. but a commadore will be bigger

Well your buddy abmolech seemed to think it was a good idea as long as i use the basic principle of keeping everything on axis, coplanar, and high enough off the dash. He told me that T/A for each driver might help with steering, but its effect would be minimal. As long as the basic theory of keeping the mids closer than one wavelength of the crossover frequency and having tweeters close to ear level (height), everything should work out.

It might not be 100% ideal, but the advantage of matching power response, smooth transition from woofer to mid to tweeter, high soundstage, better vertical polar response, higher spl for less excursion on the mids, and almost perfect on-axis listening (all be it not true stereo format, which kills almost ALL car audio) are MUCH bigger and better than the disadvantages of poor mid-tweeter transition, off axis listening and plain old inconvenience of having to find somewhere in those awful doortrims for decent midrange.

I don't know, but the only real disadvantage exists if I can't get the arrays up to "average" ear level. How many people really listen to their MTM array'd speakers with all drivers at exactly equal pathlengths anyway? In car or home?

That one sounds like it's what I need, though they suggest an enclosure size of 0.5L, there's no way I'll get that, maybe I'll have to try an AP membrane. No idea how to do it though

Mounting depth isn't the issue. Winders are the issue. I'll probably have to make up some dumbass looking pod that starts as a 6.5" ring and get bigger to encase the motor and cone. Ugh, it'll be like having subboxes hanging off my door. Oh for a legal way to remove window winding altogether. Sealed, water free doors for ever. With 150W each are they gonna thirst for more power?

May i also point anyone who is skeptical about MTM arrays in various places to
werewolf's thread on this exact topic

and see if you're not convinced.

Oh, it can definitely work, but it needs to be done VERY well to work. Heaps of people have tried and failed, because they couldnt implement properly. The biggest problem is the environment itself.

Take note of Jeff's points, the most important being both midranges at equal pathlengths and the tweeter on-axis. Also, perpendicular to the reflective surfaces you wish to avoid.

And Dean's posts refer to MTM array's along the dash, coupling the windscreen to lower the acoustic impedance mismatch. If you do it like that, you'll get closer then most. Durwood has something similar (he's over at DIYMA as well). But I said along the pillars. Running up the pillar's is a bad idea, and will only work depending on your vehicle's Apillar location.

My name is Jeff too. I was kind of "take note of my posts???" and then i knew who you were talking about.
Yeah you've certainly got a strong point there, I have no intention of running the array up the apillars as they are. The hardest part of the project will be finding a fibreglass specialist who can be as precise as i need them to be. The first thing will be to get the tweeter position at the best approximation to the average ear level as possible (I believe a 5" threshold will have to suffice, everyone is different heights and has the seats at different angles, but surely even in more ideal rooms this same issue occurs so there must be SOME margin for error).

The arrays themselves will be SOMEWHAT perpendicular to the windshield. I think more importantly (as far as I know) to get pathlengths correct they will HAVE to be perfectly vertical. This is also very difficult to do in a car because nothing can be used as a reference, and unless the car is parked on a 100% perfectly flat surface with all 4 tires at exactly the same pressure and tread, a spirit level is of no use either.

As for reflections, they shouldn't be a huge issue. The arrays will be pointing away from the windscreen, probably extending out so they are sitting on top of the front of the dash, right in between the door sails and the dials on the driver's side, probably about 12º or so off axis, to point straight at the driver (mirrored on the passenger side for 2 seat listening). Reflections should still be too early to cause problems. Yes ideally they should be further back to take full advantage of the windscreen, but then the they can no longer be vertical, and this is probably more important than gaining spl (unless somehow the position I have chosen has some nasty reflections that I haven't considered )

Since the apillar location itself is terrible, I should have made sure I mentioned that the apillar will only be the way the arrays are fastened in place, not the actual location of the arrays themselves.

Lol, sorry. Jeff = werewolf and Dean = abmolech.

I'll have a look for Durwoods install, and does look really good, and effective for such an array.

FWIR, there was a large discussion over at ECA or CA about this, in quite a lot of depth. It concluded by basically stating that left and right channel arrays, equally angled between the windscreen and the dash pointing up (so basically around 20-odd degrees on axis to the listener) and tucked as far wide into the corners as possible were most effective. No angle left to right though, from memory. Just a big horn throated looking waveguide.

There was a car that, from the forum, actually went about installing it and measuring the results. He used 2-whispers and a dayton from memory, per side. All running from a carputer though.

One thing to take note on. The midrange is most important, and will decide the overall outcome. The tweeter is secondary. Placement of the mids is crucial. Actually, I think one of the Vics on here is trying it with some Legatia L3's... cant remember who though...??

I've done some rough measurements and it seems that I may actually have to put the arrays on an angle the opposite to the angle of my a-pillars. This means they'll almost be "hanging" (well it might LOOK that way anyway) from the apillars and extend almost all the way out to the level of the door sails at the bottom. This way I should (more precise measurements will tell) be able to fit 3" mids. Whether this sort of setup is going to be a "defective vehicle" issue remains to be seen. I will still be able to see both of my side mirrors though.

I kind of want to keep the arrays out of the dash since the throat of the waveguide that the windscreen makes with the dash is very different on the driver's side, and this also means taking the ENTIRE dash out, which NO part of me is the slightest bit interested in.

I know the mids are the most important part to get right, but if the tweeters are at the right height/angle, the mids will naturally do what they are supposed to when implemented in the same plane. Creating something of a minor horn type (circular, not square, and not protruding anywhere near as far as a horn does, probably only 3/4") waveguide for the tweeter means that I should be able to cross it lower, taking some of the pressure to be "perfect" off the mids. Ideally, anyway. None of this has happened yet.

I don't know if it has been discussed before, but I have plans to recess the tweeter and the mouth of the "horn" would be coplanar with the mids. It has been said that the tweeter should be in line with the mids, but looking at the JMlabs utopia series of loudspeakers, it looks as if they see it much the same way I do.

I'll try to take a photo and paint in where I think the arrays should go. Any feedback from people in the know would be wonderful. This is not easy stuff, and actually FINDING people who know about all this stuff is also not easy.

Anyway I'm keen to get this happening pretty soon, tax return time is a wonderful time of year =)

I'm just thinking, if this fails, what does it mean? If it sounds horrid I just deactivate one of the mids and change my crossovers a bit. I still get a higher sound stage either way. And no loss is really endured if i get cheap mids. It'll LOOK cool anyway

If I succeed, the gains are INCREDIBLE:

* A fantasticly high sound stage
* Very low distortion figures in mids and tweeter due to on axis placement and running dual mids per channel, and waveguide implementation
* floor/ceiling reflections becoming a very minor issue due to poor vertical dispersion
* An MTM goes a long way to achieving a 24 degree polar response, not far enough, but MUCH better than most other choices we have in a car.

But here's why I don't think I can fail. Using small mids and low tweeter Xover points, I can still achieve the center to center spacing required for line arrays. This essentially means that the crucial placement of the mids becomes significantly less so, and as long as the ear is actually sitting above the top of the steering wheel, it should work as planned.

2 mids hardly makes a line array, 12 might

I was merely suggesting that, like a line array, proper attention to CTC spacing in an MTM array will provide me with a larger vertical sweet spot (the same way line array spacing does)

ahhh i see, if like you said you get the spacing correct, and baffle step responce correct

could someone give me a few thoughts about whether or not I should be considering a vertical MTM array in my doors? specifically in the top section nearest the dash (ie as high up as possible)?

my thoughts are that
positives
it would be an excellent way to control dispersion
it would get the tweeter away from the reflective areas of the dash
could be built more or less on axis without too much problem
the tweeter could be built so that it sits deeper into the door than the mids, and could be used with a horn like waveguide (like a PA speaker?)

negatives
the array wouldnt be at ear level
it would mean that the drivers are very close to the listener, and depth might suffer (this is probably the most difficult one to overcome)
it would mean buying another set of midranges (no big deal, they're cheap)
the calculations could be hard to do to get driver layout correct
I have no idea about arrays and have no consequent idea if this would work
I suck at DIY (ask blanket and Sierra), making the door card difficult to get right.

thoughts?

dunno if an array in the door would help, your so close to the speakers, you wouldnt really to equal dispertion, youd still be able to "pick the speaker"

the array at the top of this tower is pretty much exactly what I had in mind to do at the top of my doors next to the dash

The main reason I want to do an MTM array is because my car doesn't really allow anything close to on axis mids of a decent enough size. That and I love to experiment. The angles I will have to mount them on will be VERY obscure to get them to work.

If you're going to do this and your ear isn't at tweeter level, you'll have to figure out how far up you can angle your mounting baffle to get the mids at equal pathlengths to your ears. If the baffle can't be on that sharp an angle, then it's probably best to give MTM a miss. Get some 4 to 5" mids, put them as close to your tweets as possible, get some tweeters with waveguides and cross them as low as you can ("harsh" tweeters are not a result of crossing them too low, per se, they usually sound harsh because of overextension, waveguides can help to reduce the stress on them in that range.)

Also consider polar response. You don't want your mids beaming at the crossover point and your tweeters spraying sound out in a nice wide hemishpere (assuming 2pi steradians).

the only car in australia with a MTM setup that ive heard of was the PPI art series JLaudio mini.

as far as home speakers are concerned avoid MTM like the plague, however the MTM seems to be relatively cleaner/louder compared to the typical single mid single tweeter arrangements ive heard. I would choose a line array over an MTM setup for home audio any day of the week.

here's a thought though, once the mockup door panel is done (ie frame built with no F/G or finishing, then it would be quite easy to plug and unplug different speakers, turning the MTM into either a TM or MT arrangement, wouldn't it.

Then, by adding the extra speaker in, you could test pretty easily to see which sounded best.

I have also built some a-pillar tweeter mounts, so I could vary them in different configurations (ie mid in door, tweet in a-pillar versus MT versus MTM). Sounds like a lot of testing...which I dont tend to have a lot of patience for...but anyway!

also, BR85, why wouldnt you want the tweeter spreading sound out in a nice hemisphere? is it cause one side would hit the dash?

just found this on the web too...interesting reading





D'Appolito
A loudspeaker configuration developed by and named for Joe D'Appolito, in which a high frequency driver, or tweeter, is positioned between two midrange or low frequency drivers that each cover the same frequency range. Depending on the exact implementation the speakers can be positioned with a vertical and/or horizontal orientation. In either case the two midrange drivers serve a couple of purposes: they combine to create a larger effective woofer or midrange driver size, and they also serve to control the dispersion of the tweeter. The tweeter's output is somewhat corralled or contained by the sound coming from the midrange drivers in a similar way to how two parallel surfaces control dispersion. There are some variations on the design where two same sized woofer/midrange drivers may cover slightly different frequency ranges, however those aren't considered true D'Appolito designs. (Input from an inSync Reader The D'Appolito design specifies a third order crossover network. �The tweeter is coordinated with the woofer so that at the selected crossover frequency, the drivers all have similar horizontal dispersion. �(This is not easily accomplished because many drivers behave badly at the extremes of their range.) The advantage of doing it all correctly is one of the most seamless blending of drivers possible. The result is an absence of any sudden change in directivity with frequency. This may not mean much for monitors where there is a limited listening area, but in a typical room where a large percentage of the sound is reflected by the room, the effect is dramatic.

note

since the differences between the MTM and TM setups for home audio was depth and width of sound stage this really doesnt apply to car audio where you struggle to get depth or width with any setup. So MTM might be the way to go.

ive heard the ppi jlaudio mini and it sounded not too bad from memory, however i found the drivers a little too close to the listener. Anyone else remember this setup??

well, if I could hazard a guess...I would say that the distances in my massive land yacht are just sliiiightly larger than those in a mini....

chalk and cheese?

MTM is the bomb hahaha, you cant knock it cause im building a mtm setup for the mains in my HT setup

more height, as the phase work across the gap.
if you mount them one-above-the-other, that will increase width,

AFAIK the only way to increase depth is to move the mids away from you

The install is as (if not more important) than the driver.

I'd be happy to discuss this if you wish.

Phil

cheers phil, will send you an email about it.

cant you say it in the forum? id be interested to hear

Agreed. Since I'm in need of some help too (and I started this thread) would be good to have some discussion from as many "in-the know" people as possible.

Matt VIP - the reason I was stating that you don't want hemispherical dispersion at the crossover point only applies when the midrange has a narrow dispersion there. Mostly since on axis listening in a car means not being quite so on axis to the opposite MTM setup, which means the sound coming from the left channel would be terrible. (read: very poor FR immediately below the XO point) Basically you want a similar radiation pattern from the mids and the tweeters at the crossover point. I.e cross those tweeters low and there shouldn't be a problem. Mind you, doing that means very wide dispersion all around, which is not much good when it comes to minimising reflections, which you are right to draw attention to.

Ugh this stuff is so full of compromise. Waveguides are the best answer, but I don't know sweet fa about them, and there is very little theoretical stuff on the net that can be understood by a normal person...


And yes, generally vertical MTM's will be very close to the listener in the car. I'm willing to deal with it seeing as I love good on axis, loud, clean, pure tone over the poor approximation to the stereo effect. If I can hear both channels (even if the one closest too me is 9db louder) I don't care.

Side note, horizontal MTM's suck if they're not right in front of you. This is why so many HT setups have unclear dialog. Toppled MTM arrays look nice, very impractical.