Bass tuning question

[jnorion]

For the past couple of years I have been running all my bass through two RF 6x9s. I have them low-passed to either 120hz or 80hz and below (I've switched back and forth a couple of times) and I'm putting around 80W to each. They are capable of producing sound down to 30hz, so I have just run them as subwoofers the whole time. They sound great, are very clear, have quick response, etc. The only thing I don't like about them is that they can't handle much power (they're rated for 150W max at full range, obviously less as subs) and so they distort very quickly when I turn the volume up.

Yesterday I got some subs from a friend to test out in my car. They are nothing special -- Jensen 10s, I have no idea what model. They are in some kind of bandpass box, ported behind with plexiglass covering the airspace in front. I put them in my car, powered them with a 300 watt amp (bridged to just one channel powering both), and tested them out. The idea is that I would like to supplement or replace the 6x9s with something that will not distort as quickly. My first impression is that they sound like crap. The bass is muddy and response is slow. I have a few ideas about why they don't sound good, but I need some input.

1) The subs are just plain crap.
2) The box is not the correct design, I should have a sealed box for quicker response.
3) The subs are too big -- I should be running 8s for quicker response.
4) The trunk is not dynamatted and therefore I am losing thump to rattling body panels..
5) It's just never going to sound as crisp and clear with a sub in the trunk as it will with speakers actually firing into the passenger compartment.

Based on these ideas, it seems to me the best solution would be for me to get a pair of 8s that can handle a lot of power and are designed for bass, and mount them on the back deck where the 6x9s are now, and then dynamat the trunk.

So, are my conclusions correct? And if so, any recommendations on 8s to buy?

Holy **** I wrote a lot.

[zerocover]

The subs are crap. The box is probubly also crap. Bandpass = total crap for resonse, try a sealed box, I personaly enjoy ported sounds though.

My fosgate pounds up a storm. I have it set to basicly take care of all the cars bass needs.
I found that with the seats down I get almost the same sound as with the seats up. Bass just permeates through stuff, I wouldnt worry too much about it being in the trunk.

Ps why are you low passing your 6x9's, there big enough where they should handle anything.

[blue LEDz]

crappy subs + crappy box = really crappy sound

[jnorion]

Ps why are you low passing your 6x9's, there big enough where they should handle anything.

Low pass as in they only play the low frequencies... I'm using them as subs.

[whistler]

I would think that 10's work best for our sedans, don't you think 8's are a little too small? hence very sharp bass?

[jnorion]

Not sure exactly what you mean by "sharp" bass, but they should have very quick response, yes. That's a lot of what I like about them... keep in mind I'm used to 6x9s, which most likely are even quicker than that.

[blue LEDz]

quick bass = higher frequencies.

i don't know of many 10's that cannot accurately reproduce 120 hz. once you get up to the "super woofers" like the brahma, xxx, w7, idmax, etc, you should not low pass them over 80 hz, preferably lower, which is why you need very solid mid-bass up front to supplement them. people who complain about those woofers are trying to play too high of freq's with them.

[jnorion]

I've been looking at the RE 8's though... they are rated to 22hz, so they should be reproduce the low frequencies as well as a normal (not "super woofer") 10, right? Maybe not up to the same volume, but for normal usage anyway? This seems like a good compromise to me, because I get all the bass I want now but I can add in a sub later and already have the mid bass available.

[blue LEDz]

i'd just add a single 10. it'll require less power and the pair of 8's won't be noticably louder than a single 10.

[jnorion]

I wasn't expecting them to be louder. However, I think I might still go with that option, because I could mount them in the back deck and save on trunk space. Is there any specific drawback to using the 8's instead of a 10?

[blue LEDz]

unless you enclose them in the rear deck, the 8's would be free air. IMHO free air is a huge waste of time and money. but you might not be looking for the higher volumes i'm acustomed to

[jnorion]

I was actually imagining building a box that fit under the deck. A sealed box for two 8's shouldn't need to be much bigger than the minimum size that the speakers will even fit into, so it would be the width of most of the deck and extend maybe six or seven inches below. That would leave a lot more available trunk space than having a box sitting on the floor of the trunk, and it wouldn't slide around on fast corners. I'm sure you're right, I'm not looking for as much volume as you would be, but I would think that with a box they could come pretty close if not equal the power and volume of a standard sub (not the super woofers). Compare the two RE 8's to one RE 10... they have the same power handling capability and the same excursion, and between the two they should move as much or more air.

[Scott D]

I would think that 10's work best for our sedans, don't you think 8's are a little too small? hence very sharp bass?

Size doesn't really have much on freq. response... Sure, bigger drivers move more air, but a subwoofer is designed for lower frequencies. An 8" shouldn't play higher or hit harder than a 12".

But man, you should hear my car! Are you comin to the meet?

[blue LEDz]

Compare the two RE 8's to one RE 10... they have the same power handling capability and the same excursion, and between the two they should move as much or more air.

the two 8's would be louder, and would actually reproduce the lower notes better than a single 10 when in a common air space enclosure (due to more air displacement), but you won't be able to hear a difference in either, since it is such a minor difference. the biggest difference is that you'd need twice the power to make the 8's equal to the 10.

[blue LEDz]

An 8" shouldn't play higher or hit harder than a 12".

actually an 8 should be able to reproduce higher frequencies better than a 12 since there is much less cone mass. but that's getting up in the mid-bass and even mid-range area of freqs and doesn't really matter with subs. as for the "punch" of a sub, that's in reference to the transients and is hard to compare based on size. it has more to do with motor strength and is better to compare between different model subs, rather than different sized subs of the same model line.