jmecbr900

His design of a 3 way front stage will allow him a greater sound quality front stage. The 3 way will have a bass driver, a mid/bass driver, and a tweet.

Black Diamond makes a very very good point. A syst***s design can be very simple or very complicated. Follow his example and it will focus the design in the right direction. It is easy to overspend and overkill. Make sure you figure out what you're after and focus on that.

One thing to remember is that the waveguides are awesome, but in our cars are not all that great to install. Normally they are installed flat up against the underside of the dash, right above the footwells. In your GS, notice how that area is neither perfectly flat nor very high. If you mount the guides there, you will feel shoe-horned in the car when you get in to drive. I'm claustrophobic, so that wouldn't work for me. Know what I mean?

mumbles

It has grown to quite the thread, and you're right about there being a lot of good input... in fact you just made some of the most important. Individual taste plays a huge part of the stereo purchase/install. I don't know whether I'd ever make it big in sound-offs, mainly because equipment that seems to win frequently just doesn't sound quite "right" to me. You mentioned tube amps and McIntosh, I have no personal experience with either, but I have had with Dynaudio and wave guides... that's why I hate to recommend equipment to other folks.
BTW, I've seen your screen name many times, but don't know if I've ever met you at any of the ATL meets... if I have, I apologize.

mumbles

Correct, the two channel would be for the rear fill. And as Jaime says later on, the front stage would be tweets, mids, and mid-bass. Some folks feel like six drivers for a front stage is too much, but I follow the philosophy of a specific speaker should handle the proper frequencies, so if you have a 2 way front stage, you are asking the larger driver to handle everything between the highs and the subs... too much in my opinion. By adding a mid-bass, you can dedicate one speaker to handle just the mid-range, and then the mid-bass driver would bridge the gap between the mid-range and the sub-bass helping to keep the image up front. This has just been my experience, and there are lots of people who have had success doing it the other way.
Here's a list of my equipment; keep in mind, this is fairly old equipment, but it was built well back then, and the head unit/processor section was way ahead of it's time...

Front stage
MB Quart; .75" tweets, 5.25" mids, 6.5" mid bass

Rear effects
MB Quart; 4" mids

Subs
JL Audio; three 10W6's with AutoSound 2000 aperiodic membranes

Head Unit / Processors
Original Sony Mobile ES system;
XES-P1 (Parametric EQ, Digital Time Alignment, Digital Effects, Remote In-dash Display)
XES-X1 (Digital Crossover)
XES-T1 (Tuner Module)
XES-C1 (10 Disc Changer)

Amps
PPI A404 (4x50W for tweets and mids)
PPI A404 (4x50W for mid bass and effects)
PPI A600 (300W bridged for subs)

Hameed

But isn't one of the purposes of an equalizer to separate the frequencies and send them to the appropriate speakers - thereby not sending the whole frequency spectrum to a theoretical 2-way front stage? Or are you trying to accomplishing two things here - keeping the stage up front as much as possible including bass?
Why do you need to keep the bass up front? After all the length of a low frequency wave is much longer than a car's length, so why should it matter if the bass is coming from the front or the back of the car? The hearing effect would be the same would it not?
Looks like some awesome equipment there. Please explain what a "aperiodic membrane is".

I have heard great things about the Sony HU you have. Don't know much about the EQ's you listed though - my inexperience obviously with this audio stuff.

04GS300

An EQ is simply a gain control for specific frequencies. It can be set flat, or can boost or cut certain frequencies. The X-way means how many frequency ranges it can adjust. For example, a 10-way EQ has 10 sliders, each set to adjust (boost or cut) a specific frequency range. It has nothing to do with routing frequencies to certain speakers.

A crossover is used to separate frequencies and send them to the correct speakers. 2-way component sets have 2-way crossovers. One has a high-pass filter that cuts the musical signal below a certain frequency, and then sends that signal to the tweeter. The other is a low pass filter, that cuts the musical signal above a certain frequency and then sends that signal to the midbass driver.

It is generally accepted that you need 3 drivers for best SQ, but it's hard to find room for them all in a car. It is a lot to ask of a midbass driver to play all the midrange and bass, and a 3-way component system allows you to send high, mid, and low signals to 3 different speakers, rather than just high to a tweeter and everything else to one lonely midbass.

Front soundstage is making the sound seem like it's coming from in front of you, just as the real event would. You wouldn't sit in the middle of the band, or with your back to the band. Ideally, your subs and everything would be in front of you like a home audio setup, but you can't do that in a car, so it's important that you have as much bass as possible in front of you. Very low frequencies are non-directional, which means that the human ear can't effectively discern from which direction the sound is coming. That is why you can get away with subs in your trunk. I'm not sure at which exact frequency bass becomes non-directional, but I would guess it's no more than 80 Hz. On the same token, this is why you want a low pass filter on your subs in the trunk because you don't want any high frequencies coming from your trunk because your ear will detect that they're coming from behind you, thus ruining your soundstage. In my old setup, I sent a full range signal to my front components so I would have as much bass as possible coming from the front for my soundstage. I then set my subs to an 80 Hz low pass, so the subs would not get any signal above 80 Hz. This worked pretty well.

mumbles

Hameed,
I can't really explain your first two questions any better than 04GS300 did, I'll just add that an ideal crossover frequency between your front mid-bass drivers and your rear subs would allow just enough overlap that the transition from directional to non-directional bass frequencies becomes transparent, thus all the sound seems to be coming from in front of you.

An aperiodic membrane is used to restrict the movement of the subwoofer cone... so it basically acts like an enclosure. The membranes are made from a material that opposes the movement of the cone, but is not completely air tight, in other words, it breathes. There are several different types, the ones I have came from Autosound 2000, a company founded by David Navone and Richard Clark. They use a fiberglass matting suspended between MDF rings (picture one of those things your mother might have used for embroidery), which is mounted to the face of the subwoofer. Additionally, there is a small box that installs in-line with the input to your sub amp, and it provides a boost to certain frequency ranges to compensate for the loss introduced by the membrane. Typically, the membranes are speaker model specific, although there are (were) generic brands available.

johnp66

Hameed, I've run some of the components you have discussed for the last 18 months or so. I have the Pioneer P9/DEQ with Dynaudio 240/160s in the doors, a McIntosh 440 driving every speaker with its own channel, and a bridged Arc 4150 driving an IDQ10, I never run my volume above 91 or 92 dbl because I plan to be hearing fine music on down the road.

The Pioneer DEQ can drive you crazy. I was forever tuning in the crossovers, timing and front-to-back balance. And, honestly, I could start over every time I changed the sample track because the critical freqs and imaging can vary with every recording. Heck, a passenger signicatly alters the mage, and you have multiple settings for that purpose. I believe once you have quality components, and most importantly quality source material, you have to tune your system. With everything else being relatively equal -- and I believe they generally are above a certain level -- it's the cabin tuning that wll have the most impact on SQ. Tunability was the most important consideration for me, once I satisfied myself that I had quality components. That's what we're buying with the big investment.

Will it win a contest? Mine wins the only contest that matters to me every morning when I slide under the wheel. But I doubt anyone else would set it up the way I do. -- john