Garbage Gamer

i am using a component setup for the fronts.
what people have generally told me is to avoid rear fill as it will destroy the imaging up front,
but personally, i like the surround type of feel i get from having speakers in the rear.

so what i am here for is any general advice or info on rear speakers.
i have heard that with coaxials, the high frequencies from the speakers will interfere with the soundstage of the front, so the general advice i have heard was to use dedicated midbass drivers if i want speakers in the back.

if i use midbass, do i have to match to get optimum performance? in other words, do i need the same midbass driver (model and type) as my component set in the front? or can i get any other midbass driver? can i just use a coaxial and use a x-over to filter out the high frequencies? wouldn't this almost be the same as a midbass driver?
any brands/setups recommended for such a rear-fill application?

Percy

You'll have two camps firmly entrenched in this. One is the "absolutely NO rearfill" and the other is "rearfill needed, but must be done carefully". I take the second approach for a couple of reasons. If you go to a concert, you'll still get sound from the back of you due to reflections. Even at a string concert which is non amplified, though the effects are less noticable. To prove this, take a sound meter (you'll look strange, but who cares...it might start up a conversation with an intelligent person) and point it at the rear of the room during a performance. You'll still pick up reflected sound.

In a car audio enviroment you have the headrests blocking some of the sound, plus the speakers are firing at our knees. There's less "sound flow", if you will, to get to the rear, much less to our ears. In all of the cases that I've listened to that had front fill only, the setup sounded "dry". These were on demo cars. One was the BMW from McIntosh, another was the Sony XES Z50 (full blown and then some) demo system.

As for rear fill speakers, the coaxials will more than likely pull the soundstage back. Just pad down the treble by quite a bit, same with the mids so that they're barely noticable. I've heard of rear fill speakers that were stock speakers (not recommended...they have too much of a midrange "hump" if you will) and also speakers that were matched with the front set (recommended, but not absolutely necessary - makes things easier though). The key here is to make sure the levels aren't loud enough to pull the staging back, but rather add "depth" to the music.

Percy

Garbage Gamer

thanks for the reply Percy.

I agree with you on the rear fill theory, people have told me to stay away from it, but having rear fill in all my previous setups, i find myself to be in love with the extra surround sound type of feel i get from using the rear fill.

though most of my setups in the past were far from a sq imaging type setup (I didn't use the fader and actually ran a bigger amplifier/more power to my rear speakers than my components up front), so i am far from an expert on imaging.

to tell the truth, my brother uses components up front and factory speakers for the rear. fronts are mb quarts powered by a phoenix gold xs2300 and rears powered by the head-unit. i heard this is highly non-recomendded but to my non-trained ears, you wouldn't hear a complaint from me (except for the tweeters from the mb-quarts being too sharp).

this is my first setup in trying to get my feet wet in the sq world, so maybe i wouldn't know how a properly tuned sq setup should sound.
i would like to try matching, but it seems to be the most costly method.
I am using the dynaudio 240 set up front, matched to the arc xxk 2100 amp

so to match, i believe another pair of dyn MW160 mm drivers would cost around $400, plus i would have to find another amp to run this.

i am leaning towards trying to get away with a $100 pair of coaxials and a cheap 50x2 amp for the rear and use a x-over (perhaps even the internal one i get from the cheap amp) and set the low pass filter to say 2kHz?

i am basically wondering if now would be a good time to cut corners and save $

thanks

Percy

Go for another set of Dyns and a good amp. Would be a shame to go cheap on stuff now!

Percy

Garbage Gamer

somehow your one vote seems to hold more weight than what others have been telling me.
(i suppose you being a moderator in this forum must go parallel with your experience in car audio)

i assume when you say get another pair of dyns, you dont mean to buy another complete component set do you?

you mean just buy a pair of the Dyn MW160 millimeter drivers (w/out the tweeters and x-overs) right?

and with this response, you're probably in favor of skip no corner on the install?
i.e. dynamat, component tweeter within 8 inch proximity of midbass driver?

does the component crossover have to be installed close to the tweeter and midrange too? or does that not matter?

and would the rear fill need dynamat too now?

(i was previously going to skip the dynamat thinking the lx470 cabin is well insulated)

thanks again Percy!

Percy

You only need the MW160 speakers themselves for the rear fill. Dynamat isn't really necessary since the car is fairly well insulated, but if you want to dynamat at a later time, you can do so. Tweets/crossover are only necessary if you plan on having a few passengers in the car (and in the back area), but that's an option. Also, it depends on how many times you have passengers in the back!

Lots of options right now, but if you're driving by yourself mostly, I'd try to keep it simple.

Percy

Garbage Gamer

i'll try to dig/save up a lil more money to get an extra pair of dyn drivers.
if i do get it, i'll let you know how everything goes/sounds.

thanks for your input Percy, much appreciated

engin_ear

iTrader: (1)

I pretty much agree with Percy, with the exception that I HIGHLY recommend Dynamatting the rear since you're going to have it open to work on it. The rear doors of a GS have a nasty resonance that will make the rear fill unnecessarily peaky and unconstrained (I have this problem in my car now and I need to re-do it and add more dampening, even though I used the CAE stuff on the inside of the doors.) The Deflex pads that Percy has recommended to others would work well in addition to the Dynamat to deaden things inside the door.
Case in point: Note the sound that your rear door handle makes if you raise it up and then let it spring back down - your rear door sounds like it's an empty tuna fish can. Once you sound deaden it, you get rid of the nasty resonant vibration, and the door now sounds much more solid - like that of a BMW or Mercedes, and not a Camry. That natural resonance has a very detrimental effect on the sound quality. I happen to drive my rear speakers very hard compared to the way most people would, to generate more of the dance club feel, which is not staged and is multi-directional in terms of sound power. The rear door resonance, given the power that I'm feeding the rears, drives me nuts.

I also recommend using as much of a full range driver as you can put back there, IF you can EQ the rear separately and tune it to your tastes. Reason being that acoustical reflections within any room space are not frequency-specific, and highs can be bounced around as well as mids and lows, contributing to the overall acoustical character of the particular space. Thus, there is no one correct setting of the EQ for the rear fill, but a setting that represents the characteristics YOU prefer in a listening room or hall, and what YOU think sounds accurate, pleasing, warm, etc. Same goes for rear fill level (volume).

Yeah, you won't go wrong if you put another set of Dyn's in the rear.

Garbage Gamer

never knew about the resonance factor in the rear.

install is currently stuck half-way. the shop basically told me they deal with dyn's alot and the arc amp really will not push the dyn's hard enough. they said they know 100 rms is on the factory recommended power to feed the dyn's, but they said Dyn only said that for warranty issues.

currently, the arc amp only sounds good with the dyns at low to moderate levels, but seems to want more power at higher volumes.

seems like now i need a bigger amp than the arc 2100 to power these.

basically, the installer told me that based on experience, i would need at least 150 to 250 watts rms to power these properly.
he told me i can get an amp that puts out 150x2 or 75x4 and he can bridge it, and i would either lose fader or balance.

are Dyns really this power hungry, or am i just falling into a sales pitch to buy another amp?
if they are, would there be a degradation in sound with the lower ohm load?


if i really need such a huge amp to power a dyn set, seems like dyns for the back would be hard.
the installer wants $300 to install each dyn set, then i would need a huge amp.

thanks

GaryDell

$600 to install 4 speakers?!? Just thinking of that makes my rectum sore.

Unless you really have money to **** away, I would NOT spend money on a set of drivers like Dynaudio for rear fill. Regardless of whether one prefers using rearfill speakers or not, there's no doubt that those rearfills SHOULD be highly attentuated. If your rear speakers are playing at the same volume as your front speakers, your soundstage is going to be drawn to the rear of the vehicle (not ideal IMO). A setup similar to your brothers' would be sufficient. As for the xover, it doesn't necessarily have to be close to either of the drivers. If you want to show them off in your trunk next to your amp, go for it.

You wouldn't have to lose fading/balance by bridging a pair of amps/4 channel amp. Arc makes quality products, so if you want to go with a 2100 on each side, that's be a very solid setup.

Percy

The Dyns are fairly power hungry so anything more than 50wpc is highly recommended. If you're going for a rearfill config (with no passengers in the back) then you can get away with no xover.

Percy

engin_ear

iTrader: (1)

SALES PITCH. You have 110 watts RMS power in the Arc 2100. Plenty. Arc is a good brand, so you can trust the specs more than, say, Sony. I'm not sure what you're hearing when you say the Dyns only sound good at low/moderate levels, you may have a problem with the install or resonances when you turn them up. The amp vs. speakers are fine - you're not powering a sub. Unless that particular Arc amp is not true to specs... (you're supposed to be able to get 110 W @ 0.05% distortion).