Sub box, and rear speakers

[jcocker]

Ok, I have two questions.

1) I have heard many times that its better to run only front components and a sub in an E30. Is there any particular reason for this? Since car company's are starting to put more and more speakers in their cars, my friend finds it hard to believe that taking the rear speakers out makes better sound.
I'm thinking it would cause a more balanced sound.

2) I need suggestions on the specs of an enclosure, both ported and sealed, for an Audiobahn AW1006Q, and a good amp to use. This is for my friends Volvo S70.

Thanks,

-Joe

[cobraken]

It all depends on what better sound means to you. I have had and would never have another car without back speakers. Its hell on the backseaters with just subs and no mids and highs.

[netcsk]

The reason for no rear speakers in an e30 is that they are at your ear level and the deflection from the rear glass causes them to have much more SPL than your front speakers.

If you have an external amp and can adjust your gain levels to bring the rear speakers far lower than the front, you'll be fine. You always want a front stage to your sound system, and if you get it setup right, there is no reason to have rear speakers for the front seat driver and passenger. But if you care about the rear passengers at all, it matters.

As far as the sub specs. Most manufactures give a spec sheet with their subs that tell what should be used with a given setup. If they don't; then you can send me a speaker and I'll tell you exactly what you should build depending on what you want :) (through testing to obtain actual, uninflated numbers).

[AndrewBird]

I don't think it is so much that rear speakers make it sound worse as it is they are not neccisary for it to sound good. Rear speakers aren't needed, but they will add.

[jcocker]

ok thanks...

But as for the enclosure... Manufactures flat out lie about the correct box size, saying that it needs much smaller than it does to put out nice sound.

So on that note, im wondering what a nice box size would be... I'll more than likely make a ported box, so what size port should I use, And also what amp would you recommend

[jcocker]

And I guess it would be more convenient to use only front speakers as well? then you can just use a 4 channel for the components and run the sub of a mono...

thanks

-Joe

[StereoInstaller1]

Why not rear speakers?

OK, so lets get into the physics of sound for a minuite.

Sound propagates through the air much the same as waves through water.

Imagine a smooth lake. Now imagine dropping a pebble in. Concentric waves spreading from the point of impact, correct?

Now imagine 2 pebbles, at (or near) the same time, dropping into the lake. Put them 2 feet apart, just for the sake of argument. Wherever the waves crash over each other is less clear.

This is called "Phase Cancellation" and is a primary reason you should not have 2 different sources for the same wave.

If absolute clarity is your primary goal, that alone is the main reason you should not run rear speakers.

Now, back to our lake.

Imagine if you dropped a fairly large rock, say, 30 pounds...and that same pebble. The waves would not crash over each other, but the two different wave sizes would simply pass through one another.

So, given that this crap is the truth and NOT opinion, let us delve into opinion.

1. Bad sound for rear-seaters: I don't generally have rear seat passengers. Maybe you do. Maybe you care about what they hear. Generally, when I have rear seater passengers, we are talking, so no tunes.

However, this is YOUR car, not mine. Do as you feel.

2. Rear speakers too loud (drowning out the front): again, personal preference. I cannot stand music coming from behind me...so when I had rear speakers in my E30, they were run from a seperate amp, so I was able to turn them down.

3. Cost: duh.

4. Ease of install: again, duh.

In my experience larger cars are better of with all 4 corners having speakers.

Again, personal preference.

Luke

[jcocker]

Thankyou Luke... finally some actual proof... and done in easy physics... I'm studying engineering so I can understand it, but my friend can't...

Do you have any opinions on an enclosure and/or amp?
Once again for my friends volvo S70.

Thankyou very much

-Joe

[StereoInstaller1]

Dude, I have opinions about EVERTHING, including shit I know nothing about.

Tell me more about what you have in mind.

Luke

[jcocker]

Well, it's a pretty high powered sub I believe, and he's not too concerned about weight or size, so porting would probably be the best option. He also seems to like the idea of the sub facing backwords, cause it is a decent looking sub.

He listens to a lot of hip-hop and he also has a set of 6X9's and 6.5's, all audiobahn. With a detachable tweeter.

The only thing he doesn't have is an amp, and I have a pretty complete workshop in my shed so building it isn't an issue I just need some specs to follow...

I'm thinking of just a simple, decent looking enclosure, that can compliment the sub.

Thankyou,

-Joe

[StereoInstaller1]

Joe, if you follow Audiobahns' spec for the largest box the show for that AW1006Q, you will be amazed at the SPL and the quality of the bass.

A good cheap woofer that is. One of my favorites. I try and keep them in stock.

What are you doing for a sub amp?

Luke

[jcocker]

What are you doing for a sub amp?

That was one of my questions... My friend is looking for a decent, cheap amp... Suggestions for both a sub amp and a multi-channel for the components would be great.

[StereoInstaller1]

That was one of my questions... My friend is looking for a decent, cheap amp... Suggestions for both a sub amp and a multi-channel for the components would be great.

See if tyler (europlates or something like that) has anything for you. He had some Lightning Audio Mono amps.

For $200 bux, you could go to Walmart and buy 2 Sony 4 channels.

You would have to wire them in quite an odd fashion though. You would need to bridge 2 channels of each (only 2 channels are bridgeable!) to run one voice coil on the woofer, then the other 2 channels would run either front or rear...odd, but would give you about 25WRMS X4 AND 200 WRMS on the sub.

Balancing the two sub channels is critical...done right, the thing would just rock.

Luke

[jcocker]

Aight sweet, thankyou very much

-Joe