Questions about speaker pods v. putting 6 inch speakers into my E30

[ninjaotter]

So I've been working on improving the audio in my 1990 325is. Its up on blocks right now while I replace the transmission and refinish the BMW Style 10's, so I've got some time. Keep in mind I know absolutely jack all about car audio.

The main body is a PVC pipe coupler cut in half, the ring was included in the speaker kit, it just needed to be slightly ground down. I beveled the outside edge to clean up the overall look. It will be painted and/ or wrapped in vinyl before its finished. I'm currently working on the mounting system.

I have a couple of quick question for the speaker and car audio experts on the forum:

1 - Do mids need to be in ported or sealed enclosures? Does it matter?
2 - Should I line the interior of the pods with sound deadening material? Insulation? Nothing?

How I mount the pods will change depending on whether I have to seal them or not. I plan on mounting them on the door cards (with a backing plate to hold it securely of course) near the hand crank hole.

The other hardware:
The mids and tweeters: http://www.madisound.com/catalog/product_info.php?products_id=8472


The sub box has been painted and finished up. In the pictures its just tacked together, its since been completely buttoned up and had the ports added. The trunk of the 325is has had the trunk tar removed and replaced with sound deadening material with the sub box bolted down in several places.

The BMW in question:

[StereoInstaller1]

So you are planning on putting those 6.5's in the doors?

[ninjaotter]

So you are planning on putting those 6.5's in the doors?

More on the door then in it, but yeah. Going to mount them close to the hole for the manual window crank, as that's the largest open area, still leaves my map pockets intact, and already has a nice hole cut in it for my wires haha.

Suggestion for somewhere better?

[Jean]

1 - Do mids need to be in ported or sealed enclosures? Does it matter?
2 - Should I line the interior of the pods with sound deadening material? Insulation? Nothing?


1 - depends. it looks like yours are midbasses, and not midrange. some midbass drivers are better in ported, but most work good in sealed. it depends on each driver, you'll have to look at their t/s parameters.
2 - it's not going to hurt anything to make the enclosure as solid and resonance free as possible.

my 2 cents.

[StereoInstaller1]

oh yeah, I will throw my answers in there too:
1 Never use mids in a car ported. Porting works by phase inversion, as in the port reverses phase below the tuning frequency, so it would be out of phase with the woofer if there were any overlap...and I didn't hear any mention of 48db/oct crossovers. Plus, the woofer you have is gonna have a very high Qts (likely over .7)so a ported box is gonna be really tubby and boomy. Just go sealed, it will be easier.

2. You cannot go sealed, you do not have enough airspace. Even if you only expect that woofer to go down to 100Hz at 24db/oct and have absolutely no output below 90Hz (why the hell do a 6.5" mid then, what is the point?) you would STILL need at least 10 liters or your mid will sound all "boinky" from the resonant frequency being so high.

So, you can't go ported, you can't go sealed, what do you do?

Either cut a hole in your door (if late model, then its easy) or read a whole bunch about some "options" like transmission line, tapered quarter wave tubes or get even weirder, like me, and do a quasi-aperiodic design which works very well for midrange and midbass in a car.

Luke

[Serious Sam]

IMO,
I agree with Luke, with a couple added questions.
Dont seal. Again, not enough area behind then speaker to properly allow the driver to work - no low extension, and peaks in 150-200Hz region. Give it at least .5 CuFt, and your in the ballpark for sealed. Therefore, run IB by allowing into the door cavity. Xover 200Hz down to wherever the door wont rattle and affect your sound. Anything below 90HZ is going to buzz the door without some serious deadening. If well deadened and buzz free run the mid down to 50'ish HZ. Which answers your question about deadening. The more stable (resonant free) the speaker baffle and enclosure the better the performance of a loudspeaker. Good idea to deaden the baffle. Polyfill - thats a preference of your ears that will have to be tested. Also, make sure to xover your midbass at 200hz, and no higher. If you do, you start having issues with lower vocals and PLD's. Let your mids handle ALL vocals (200HZ to 6kHZ) and you'll be happy.

How do you plan to crossover?
I cant say that I would recommend your "other hardware". You plan to run a 6" mid and 6.5" midbass? IMO, that needs changing. It can work, but your overlapping too much. Go to a smaller mid (4" or 5.25") which will be easier to setup (listening) and install (stock location) as well. Or go to a larger midbass (7" or 8") whcih will absoulutely require deadening, but I think thats a given ANY time you put a speaker in the door.

Where are you planning to install your "other hardware"?

BTW, the best car I have heard had ported 9's in the door for midbass, BUT he had a 48 dB slope:)

TO ALL....MERRY CHRISTMAS!!

[ninjaotter]

1 - depends. it looks like yours are midbasses, and not midrange.

Looks like you're right. So they're 6.5in mid bass drivers.

*snip*

So, you can't go ported, you can't go sealed, what do you do?

Either cut a hole in your door (if late model, then its easy) or read a whole bunch about some "options" like transmission line, tapered quarter wave tubes or get even weirder, like me, and do a quasi-aperiodic design which works very well for midrange and midbass in a car.

Luke

So I'm sort of damned if I do, damned if I dont. Any pictures of a quasi aperiodic setup in a car? Otherwise I'm leaning towards cutting a hole in the door card and insulating the hell out of the doors.

How do you plan to crossover?

The Swan HiVi kit came with passive crossovers. http://www.swanspeaker.com/product/htm/view.asp?id=320

You plan to run a 6" mid and 6.5" midbass? IMO, that needs changing. It can work, but your overlapping too much. Go to a smaller mid (4" or 5.25") which will be easier to setup (listening) and install (stock location) as well. Or go to a larger midbass (7" or 8") whcih will absoulutely require deadening, but I think thats a given ANY time you put a speaker in the door.

Looks like I made a mistake, the speakers I'm mounting (and referring to in this thread are 6.5in mid woofers, so there aren't any 6in mid range speakers.

So do I need to pick up some true mid range speakers to complement the component setup I have now? Recommendations on brand/ model?

Where are you planning to install your "other hardware"?

What other hardware? The sub, amps, and crossovers are all in the trunk. The tweeters are being molded into the factory premium speaker locations. The mid bass drivers pictured here are being mounted on the doors.

Thanks guys, you've given me a lot to think about. I've got about 30 tabs open in firefox just from goggling stuff you guys have mentioned. Thankfully work is slow and I have lots of time to read.

Merry Christmas!

[Serious Sam]

Ah...I misunderstood, then. Sounded like you were talking about mounting a 6.5 with the enclosures shown in the pics, and then your refer to the other hardware and gave a link to madisound, where I saw a 6" tweet component set. I thought you were trying to run three way.

No need for a dedicated mid, if you are not seeking all out sound quality. 2 ways are easier to install, setup, and will sound plenty good.

I dont know what your fabrication skills are (although I like what you have done with the sub, but I have a question about that later), or what you want to do, but I would much rather install the 6's in the stock location (with some mods), and the tweets in the a pillars, instead of doors and sails. The left speaker set is just going to overcome the right, pull the stage to the left. You equlaize the pathlengths much better moving the speakers as far forward as you can. This improves the listening experience. If thats not on the agenda, then I should be ignored -and do what YOU want to do. I just always want to encourage people to go after better sound if its within reach.

You could also try to mount the mid as high in the door as you can so as to keep that spkr in close proximaty to the tweet. Running passive usually requires keeping the spkrs closer together. Sounds like you may not want to cut the door metal though. Speaking of door metal, try to mount you baffle to the door METAL not the door CARD. Again, it goes back to SOLID. You want to keep vibrations to a minimum!

To the sub, is the face of the sub sealed against the back of the bulkhead?
If not, then please take a moment and look at some of Luke's boxes for some insight as to how to properly seal the sub and sub box to the back of the bulkhead. This WILL improve your sub performance.

Altogether, I like what you are doing.

[ninjaotter]

Ah...I misunderstood, then. Sounded like you were talking about mounting a 6.5 with the enclosures shown in the pics, and then your refer to the other hardware and gave a link to madisound, where I saw a 6" tweet component set. I thought you were trying to run three way.

I was confused to, so it works out

No need for a dedicated mid, if you are not seeking all out sound quality. 2 ways are easier to install, setup, and will sound plenty good.

Eventually I'd like to run a 3 speaker setup, but that's another project and another car somewhere down the road.

I dont know what your fabrication skills are (although I like what you have done with the sub, but I have a question about that later), or what you want to do, but I would much rather install the 6's in the stock location (with some mods), and the tweets in the a pillars, instead of doors and sails.

I was under the impression that the stock locations blow ass? Fabrication skills aren't something I'm lacking, but metalwork isn't my cup of tea, so I'd love to continue with the door pod idea if the sound wont completely suck.

The left speaker set is just going to overcome the right, pull the stage to the left. You equlaize the pathlengths much better moving the speakers as far forward as you can. This improves the listening experience.

So would moving them as far forward on the door as humanly possible suffice? Or is the stock location the only acceptable choice.

If thats not on the agenda, then I should be ignored -and do what YOU want to do. I just always want to encourage people to go after better sound if its within reach.

You're giving me a whole pile of things to consider, all of which will serve to make my car sound better, so keep it coming.

You could also try to mount the mid as high in the door as you can so as to keep that spkr in close proximaty to the tweet. Running passive usually requires keeping the spkrs closer together. Sounds like you may not want to cut the door metal though. Speaking of door metal, try to mount you baffle to the door METAL not the door CARD. Again, it goes back to SOLID. You want to keep vibrations to a minimum!

So how does one screw the baffle to the door metal and still have it vent into the door? And it seems like cutting into the door metal is a bad idea, is there anyway to do it without compromising the structural integrity of the door?

I was planning on adding a backing of 1/4in acrylic to the door card, and bolting through the acrylic, through the door card, and into the baffle.

So if I need to run them as close together as possible, and as far forward as possible, I need to put the speaker pod in the top corner, as close to the front of the car as possible?

To the sub, is the face of the sub sealed against the back of the bulkhead? If not, then please take a moment and look at some of Luke's boxes for some insight as to how to properly seal the sub and sub box to the back of the bulkhead. This WILL improve your sub performance.

I've copied Luke's design for that front piece, its just not pictured.

Altogether, I like what you are doing.

Thanks! And thanks for all the help!

[Serious Sam]

I'd love to take some time and answer a couple of your questions.
But I'm exhausted.
Been building/assembling toys for the children most of the day, and a used bike took several hours of overhaul to make right.
Gotta hit the hey cause tomorrow is THE best day of the year!
Dont know if I'll get a chance to look at this till later in the weekend/first part of the week.
But have fun.
Sam

[StereoInstaller1]

I will say this emphatically: Door speakers sound better than the stock location in an E30.

I have heard the exact same set of speakers in the stock location, then moved to the doors. Yes, the stage was pulled a bit to the near side...but you could hear the damn speaker!

The greater dynamics from NOT being 60 degrees off axis on the near side totally makes up for the left bias.

Luke

[ninjaotter]

I'd love to take some time and answer a couple of your questions.
But I'm exhausted.
Been building/assembling toys for the children most of the day, and a used bike took several hours of overhaul to make right.
Gotta hit the hey cause tomorrow is THE best day of the year!
Dont know if I'll get a chance to look at this till later in the weekend/first part of the week.
But have fun.
Sam

Fun will be had! Thanks for all your help!

I will say this emphatically: Door speakers sound better than the stock location in an E30.

I have heard the exact same set of speakers in the stock location, then moved to the doors. Yes, the stage was pulled a bit to the near side...but you could hear the damn speaker!

The greater dynamics from NOT being 60 degrees off axis on the near side totally makes up for the left bias.

Luke

Suggestions for where on the door they should be mounted?

Thanks!

[StereoInstaller1]

Fun will be had! Thanks for all your help!



Suggestions for where on the door they should be mounted?

Thanks!

Early or late model?

[ninjaotter]

Early or late model?

1990, so late.

[StereoInstaller1]

There is a great spot at the very front of the door, just above the pocket. there will be a very little bit of metal cutting involved, but hardly nothing, and then you get 4 screws into metal.

If you do a chunk of "Defuser" type product, that pretty much eliminates most spurious resonance inside the door, and reduces outside noise pollution.

Early doors are fucked, though.

Luke