I've got 3 pairs of kick panels, and last night the drivers along with most of the preliminary crossover parts came in.

The plan is to build the preliminary crossover, then build some MDF rings for the drivers and begin experimenting with driver placement. Once I come up with an arrangement that I like best, I'll build the prototype kick panel enclosure, take measurements, then start designing the final crossover. Hopefully this set of drivers will work out so that I don't have to do a redesign halfway through.

If I get a chance tonight I'll take a couple pics of the drivers.

 

How often does that work out. Good luck.....

 

I spent a lot of time picking out these drivers ahead of time, so hopefully it'll work. My preliminary crossover works well in simulation. My major concerns are 2 fold:

1: high frequency breakup in the woofer might not be well enough attenuated unless you're way off axis. If this is the case, the farther mid (passenger side for the driver and vise versa) will sound "harsh" and not the same as the closer driver. The breakup is attenuated around 20dB directly on axis though, so my hopes are that with good driver placement, it'll be inaudable in the car.

2: not enough midbass from the driver. My whole philosophy about using a low qts driver might slap me in the face if I don't get enough cabin gain and boundary reinforcement in the car.

Problem #1 is easy to work around with a crossover redesign. Problem 2 would depend on just how bad it is. A higher Q woofer is just going to boost the output at 150-200hz instead of under 100hz where I need it, so it will wind up being a toss up between the lesser of two evils. The woofer I'm using models with an f3 at around 110hz in the tiny sealed enclosure that I'm planning, but my hope is that with cabin gain I'll get an f3 of 80hz, which will provide good integration with a sub.

 

What is cabin gain and how does it reduce the f3? If this works, you may have to certify yourself as a genius
What drivers are you using?

 

What drivers are you using?

Cabin gain is the effects that the car has to the sound output. In smaller area such as cars the actual output of a speaker is made to sound greater due to the structure of the vehicle. The same speaker in a open are will not sound as loud. Now how you you find out if the cabin gain helps you is ususlly more testing (which jim is doing) Im sure Jim can go way more indepth than I can but thats the basics of it.

 

Thanks for taking the time to respond, but I kinda figured that much I was hoping for the techincal answer. I'm well aware of the effects speaker location has on sound quality, frequency response, etc (it's why I'm a huge supporter of kick panel mounts in the first place). Speakers only sound as good as their environment allows (enclosure type and size, position, surroundings, etc). For instance, I know I'm missing some frequencies with my sub firing directly into the hatch window, which is why I'm thinking about making a new box so that it fires more into the hatch well area. I'm pleased with the low end, but am really missing out on some drum kick that is on the border of the midbass range, and I'm sure it's due to cabin gain (or in this case, the opposite). I'm aware of this because I have turned my box upside down so that the driver fires directly into the well, and the frequency response is drastically different. Unfortunately, the box was created so that it doesn't fit in this orientation.

 

Hold the bus, SEALED...
I’m intrigued. Care to elaborate

 

Pics?

 

Sorry, no pics yet. I spent the weekend in Boston at the Beer Summit.

Cabin gain is basically just what 9177 stated. As you go lower in frequency, the wavelength gets longer. Once your wavelength approaches the longest interior dimension, you get a 12dB/octave transfer function. This is why you can't get bass at home like you can get in your car... unless of course your living room is the size of a camry interior.

In a camaro, the length from the dash to the back of the hatch is somewhere in the 10 or 11 foot range. This is about the wavelength of a signal at around 90-100hz, which means that cabin gain is just starting to come into play where these speakers start to naturally roll off. I won't know for sure until I can measure them.

BTW, I'm not saying what drivers I'm using. I can't give away ALL of my secrets.

 

mmmmmm beeeeeeer

as interested as i am to buy Jim's stuff, i won't be spending any more money on car audio for a while (say it ain't so!!). maybe in about 3 years, so keep up the good work!!!

 

I'm curius about how many RMS watts I could expect to pump into these beasts? I'd love for them to be 2ohm's a piece...

that way I could throw 150rms at 'em

And it's pretty cool that you're working this hard on the design of the box as well as the crossover... I bet these will sound wicked...

 

I'm not sure what their power handling will be, but I'm sure somebody will put a couple monoblocks on them and blow the voice coils clear across the car. My goal with these speakers isn't SPL, it's sound quality. They're only 5.5" woofers, so I wouldn't expect them to get super loud.

I may try a design with 6.5s if I can too. I've modeled it, and the low frequency output is exactly the same as with the 5.5s. The only benefit will be the extra power handling, but the drawback is that they'll need a lower crossover point because the larger drivers start to beam at lower frequencies, and the lower crossover point is going to put more stress on the tweeter, or require me to use a much more expensive tweeter.

 

weird, why wouldn't the 6.5 have a stronger bass output? it's a larger cone surface... are the magnets the same size or something?

 

We're talking about sticking a couple speakers into a grossly undersized enclosure. The optimum enclosure for the 6.5 is larger than the 5.5 (no surprise here), so the enclsoure that I'm stuck with is more undersized for the 6.5 than it is for the 5.5. When I model them, the result is virtually identical bass response from both.

 

gotcha.

do you think it would ever help to put a component woofer in an infinite-baffle setup versus a sealed?

 

Absolutely. That's what they are designed for.

I can only think of one commercially available component set that comes with a low Q woofer designed specifically for a sealed enclosure (RE XXX Component set). Everything else comes with a high Q woofer that's specifically designed for infinite-baffle door mounting situations. With these woofers, very good midbass results can be had by mounting them in the doors.

In an ideal thirdgen situation, I would use a 3 way setup with a tweeter and small (4.5") midrange in the kick panels, and a 7" or even 8" midbass in a heavily damped door. Unfortunately, this setup doesn't work well in a thirdgen because the power window motor is mounted right where the ideal woofer mounting position is. You either need to build the door out a mile, or deal with the comprimises assocated with stuffing a woofer into the kick panel.

 

I am wondering, if you have a car without power windows, is there anything there to stop you from mounting a speaker? IIRC I've seen it done before, but I want to make sure. I have limited leg room as is, and am contemplating what to do for front speakers.

 

I put a 6.5" midwoofer into the doors of my old firebird with manual windows. It's a very tight fit between the plastic kick panel trim and the window crank, but it is possible to get something in there.

The doors are so frieking big, that the outer panel sings like a canary if you don't damp the hell out of it. I would expect 4 or 5 layers of dynamat as a MINIMUM to properly damp those doors.

In terms of imaging quality, I found a significant improvement by pushing the mids forward into the kicks. With a regular 2-way component set, I would definately put the mids in the kicks instead of the doors, but if you've got a 3 way component set, then I'd definately say that the midbass will work great in the doors.

 

what if you got a 3-way system as you've mentioned earlier, (Rockford is the only one I've ever seen,) could you mount the midrange and tweeter in the kicks, and the midbass in the sails?

I love the way the newer monsoon system sound, and they have some (3-4)" woofers in the sails, closer to the armrest, and they put out an amazing amount of bass for what they are...

I even pulled off all the speaker grilles just to see where the hell all the damn bass was coming from!

anyways, this way you don't have high-frequency sounds coming from behind your head, and "ruining your imaging," as many people on this forum seem to think... I personally like my "four-way 6x9s" in the rear so I can hear 'em.

/I chuckle when I hear 4-way/5-way

 

Almost every speaker company that sells higher end stuff has a 3 way set. CDT, Boston Acoustics, Phoenix Gold, MB Quart, Rainbow, and dozens of others have 3-way component sets.

Having the midbass in the sails will kill your sound with a 3 way. A typical woofer in a 3 way probably crosses somewhere between 200 and 800hz to the midrange. That's too high to put the midbass in the back and not get an awful smear of your image, especially male vocals. Plus, having any driver that far away from the others is going to create nasty phase issues at the crossover frequency. You're better off keeping them close together.

 

Is the clang you hear when you close the doors, which gets even louder if the windows are down, caused by the huge sheet of undamped metal or the window apparatus/motor inside?

 

When the window is down, I think that you're hearing the window and the track rattle. With it up, it might be that or it might be one of the other 300 things rattling. I doubt it's the outer door skin, although when that's damped, you don't hear the rattle so badly outside the car.

 

yeah my car is pretty noisy when you close the doors... plus the upper black trim is loose... time for some liquid nails.

hrm, how hard would it be to create some 3-way kickpanels?

 

I see that no one has asked about the price... any estimates on how much these components will sell for once you finish them?

I'm also not quite clear on the installation. Are you sending out these kick panels fully assembled and ready to be put in the car once they arrive, or is there going to be some assembly required?

Thanks again, Jim. You're doing the thirdgen audio community a great service by making these high quality audio peices for us. Put me down for a garunteed set once you get them working (and, of course, assuming I have the money at the time ).

 

Nate, a while back I made a post (or hijacked somebody elses, I can't remember) that went into a lot of depth about the particulars of my kickpanel design. You may want to do a search and read up on it if you find that sort of thing interresting.

My target price is $400 complete. I definately won't go over $450. This includes a bolt-on attachment to your kicks (or you send me the kicks and modify them, depending on my final design) with the speakers already installed, and will include a separate crossover network.

I'm very anxious to get this done, but I'm not releasing anything until I'm happy with the sound.

 

Sounds good. Keep us updated.

 

dang, from that earlier hi-jacked thread, it sounded like these were gonna be like $600 with woofers/kickpanels

hell, I'd take you up on a pair for $400... if they sound anywhere as nice as I think they will.

 

hey Jim... I'm a tad confused... so for a theoretical <$450... you do, or you do not get a complete kickpanel enclosure with woofers along with it (pair of kicks, and pair of woofers/tweets)

I was a tad confused by the "bolt-on attachment" that you referred to...

would this mean that we would keep our old factory kicks and this would fit over them? (that would be fairly strange, because the space between the kick and body would be wasted...) -- unless that space is negliblable, and a great deal of time/money is saved by going the "add-on" route.

Thanks,

Steven

 

the space behind the existing kick panels is negligible. the 450 includes everything: speakers, crossovers, kicks.

 

The space behind the kicks is neglegable.

My design is such that I will be able to mail you a piece that bolts to your existing kick panels. This makes life easier for all parties because it makes it unnecessary for the buyer to ship his kick panels to me for modification, although I will probably still offer this option at an extra cost for those who aren't willing/able to do it themselves.

Rather than wrapping the whole kick panel in fiberglass (which I think also ruins the stock appearance), I'm going to have a fiberglass section that is inserted into the flat part of the kick panel. This will give the panel an appearance that's more similar to the stock Bose setup as opposed to the goofy looking Q-Logic panels.

Here's a picture of a set of kicks that I'm building for a guy right now. In all liklihood, the ones I design for this project are going to be very similar:



In the pictures you can see that I made an MDF ring that sits in the "pocket" that was originally occupied by the stock kick panel carpet. The fleece will be wrapped around that MDF ring, as well as the woofer and tweeter ring in order to form the shape of the new kick panel. This entire piece will then be used to make a mold that I'll lay the new fiberglass into for the new kick panel inserts. Once the pieces are completed, they will bolt to the kickpanel and occupy the space that originally had carpet in it. This will maintain a stock-ish appearance to the kick panel.

Scrap,
The $400-450 will get you this new kick panel insert, with a woofer and tweeter already installed. The insert will be carpeted whatever color you want, and will have steel grill covers to protect the speakers. You will also get a crossover network just like you would get with any set of component speakers, except that mine will be hand made out of much higher quality parts.

 

I would be worried about the tweeter being that low, knowing that an eventual accumulation of dust, dirt, and assorted grime would turn the sound quality to crap in a heartbeat. I would probably kick it on accident two or three times a week.

 

Jim it looks great... I find it interesting that the speakers are essentially firing perpindicular to the side of the car... but like you said earlier, you are looking at woofers that have an incredible off-axis sound...

I'm curious though, through your research, have you decided that the tweeter being that low will help imaging? I'm not too concerned about damage, because they will be covered with grilles. But what about foot blockage?

Also... what carpet are you guys talking about? my 1990 doesn't have any, nor does it appear to have EVER had any carpet in that area!

One more thing Jim... I'm curious as to why it would be so much harder to make a full kickpanel, because aren't all thirdgen kickpanels identical? I don't see why they would need to be mailed to you...

 

Scrap,
when dealing with a 6.5" woofer, you run out of room FAST down there. There aren't many places to put a tweeter once you use up all of the woofer space. It can go above, or below, or farther toward the firewall.

Above results in the driver side being blocked by the under-dash panel, and and both sides being way off axis with respect to the closest listener. Farther toward the firewall results in the driver side being blocked by your knee in most comfortable positions, and the driver tweet being completely blocked for the passenger. Below only seems to have blockage by the steering wheel in certain conditions. Overall, you get the most direct shot of the tweeter the most often. But, I've found that the extreme high frequencies are so reflective, that there really isn't much of a change in overall sound by moving the tweeter a little bit, and even if you've got a blockage, you only seem to get a minor drop in SPL. Most of your imaging qualities come from the midrange positioning.

The carpet only came on the kick panels when you got some sort of upgraded or premium interior package. The base models didn't have it. The carpet was inserted in the "sunken in" flat area in each kick panel.

The difficulty in making a whole kick panel is that there's no decent, easy way to make one that way that still maintains the stock-type appearance. I'm a big proponent of keeping everything as stock looking as possible. If I wrap the fiberglass around the kick, then I need to figure out a way to get that OEM texture back. Then I have to be very careful when making a mold and when making kicks to ensure that there are no flaws in the texture. Then I have to paint them and make sure they match. Too much work and it'll drive cost through the roof for no good reason. I think this offers a simpler, better looking solution.

The mids are tilted more than it looks in the pictures. I need to tape a string to the kicks and measure the actual angle, but I think from the driver's seat, I'm not much worse than 45* off axis with the driver side and about 30* off axis with the passenger side. I may try to tilt the mids down toward the floor to see if I can get both mids the same amount off axis for both seats, but then I might wind up with tweeter mounting problems. We'll see... I'm a long way from done on this.

 

Well, those look wonderful, and the saving begins today for me! I'll be buying a pair as soon as they are done!

 

My tweets are above the woofer, and Jim is right, I am missing a little SPL in certain frequencies where the dash blocks the tweeter.
I was wondering if you could mount the tweeter over the woofer? I noticed some brands do this with their components. It would stick out more
How much woofer clearance are you getting with the bolt-on apparatus? It doesn't look like much at all.

 

I haven't experimented with the tweeter mounted coaxially because I want better time alignment with the woofer and tweeter. When you mount a woofer and tweeter on a flat baffle (like a normal home speaker) you actually have a situation where the tweeter is acoustically closer than the woofer, because the acoustic origin of the sound on a woofer is actually back near the voice coil, or at the very least, at the inner portion of the cone. This can be seen on impulse response plots. In any case, the layout I'm using should put both drivers at the same acoustic distance for better time alignment. This should make it easier for me to design a crossover that's got a good coherent sound and not one that makes it sound like a woofer and a tweeter.

Woofer clearance? I'm not sure what you mean, but if you're asking how close the magnet of the woofer is to the kick panel, it's actually sticking through the back of the kick panel slightly.

 

Yeah, I was referring to mounting depth. So you cut a hole in the plastic kick panel to get more room?

The other information is good to know.

 

yeah, I cut a hole. Whether I re-seal it with fiberglass or leave it open will depend on how much of a difference it makes when I listen both ways. I think venting the back of the kick will actually provide a benefit as opposed to the super tiny sealed enclosure.

 

I think that is part of the problem I'm having with my kicks. The only opening is the hole for the wires to fit through, which isn't much. As a result, the woofers think they're in a super tiny sealed enclosure. That is probably why I'm not getting good extension into the lower mid-bass region and getting some annoyingly loud higher frequency midbass (both characteristic of a sealed enclosure that is too small). Tell me how it works for you, cause I might have to do some cutting on mine!
I know there was an old thread on here where one guy vented his towards the bottom and it worked for him.

 

Sounds like you have everything already figured out Jim... but one thing... and this may sound stupid, but the actual rings of mdf and wooden bracing will be covered with fiberglass, right? or as you were talking about venting the woofers, are they just going to be wide open like that? (painted of course)

I honestly like the way sealed kicks look like, but yours are looking promising too, as I like stock-looking equipment as well...

but as a side note, I could care less what ANY of my equipment looked like, as long as it had excellent sound quality.

 

The hole will be in the back, so you won't see it. I'm not sure what the other ones looked like with the vent in the front...

 

The woofers are just mounted like that right now so that I can experiment with placement. Once I get them where I want them, I'll lay fiberglass around all of the wood to seal it all up, then I'm going to make a mold out of it so that I can reproduce them.

 

sounds great to me

 

If it looks anything like one of your older setups that you posted a pic of...



I will be more than happy. Keep up the good work, Jim.

 

I really hope the tweeter being down so low will help out, I really like the way that pic that nate posted looks!

 

Jim, was the tweeter blocked by the dash in the photo Nate posted?

 

it's blocked depending on where you're sitting... The more I think about it, I like the tweeter being on the bottom now... as long as you don't block it with your foot, you're good to go..

I'll just learn to accomodate the new kicks... because I'll take high fidelity over comfort ANY day.

 

He speaks the truth!

Really it's not all that uncomfortable, even if you're driving a stick (if you can get your foot to clear the speakers while you're shifting). I haven't noticed a big change in comfort, and my kicks stick out farther than Jim's.

 

that's good to hear... I mean, I'd adjust to pretty much anything... as long as I have about 2 or 3 configurations for my feet to sit... for the 2-hour commute I make every week...

 

It was blocked from the passenger seat. In the driver seat, you had a direct shot unless you rested your knee against the door.