Astral

OK, so here's a sound clip: http://ilp303.com/temp/octoberstar_clip.mp3 (587kb)

Can your sub play the lowest notes of that bassline? I attached a sonogram of the bass region of that clip. As you can see, the lowest note is 36Hz (D2). All of the bassline notes are of equal volume (verified by sonogram and by playing the clip at 2x and 3x the speed).

My sub loses the lowest notes (e.g. the one that starts at 8 seconds in the clip), and even some of the lower ones closer to that are not as loud.

What I want is a sound system that plays that whole bassline with even volume, so each bassline note comes out strong and as loud as the last one.

Is anyone running a setup that can hit those notes? (at the same volume, without peaky high bass?) If so, what are you running?


Another thing is I'm running a 10" sealed sub (Elemental Designs e10o.14) at the limit of its power (500W RMS) in a 4080 enclosure. It's an inefficient sub, but that should give me a lower freq response. I have at my disposal an Alpine MRD-M1005 with 700W RMS @ 4ohm and 1000W RMS at 2ohm.

Now, with my current sub, I feel like I'm pushing it to the limits when I turn it up (and it's not that loud), and I definitely get power compression.. so I feel that if I try to lower the higher freqs with EQ and bump the lowest freqs a little (to basically flatten out the frequency response curve), I will overdrive the sub at these lowest freqs. Maybe I should just try it, but I figured that if at 50hz I can get it to start slightly distorting with 500W (the sub's rating), then no way can I bring that 36Hz out of the dead.

So then the other question is: what 10" sub can I run in a sealed 0.9cuft enclosure with up to 700 or 1000W RMS that will be able to hit those 36hz notes (after EQ, of course)?

I don't need really loud or anything, I just want moderately loud EVEN bass response.

RX4life

im not very educated on this.. but i believe you need a ported box as a first stepp.. personally i think a sealed box is a dub idea...defeats the whole purpose of bass.. i have yet to see a "home subwoofer" that is sealed.. anyways... a 10 inch might be too small for low bass...i thnk 12 inch sub is the way to go...

anyways.. im sure someone can correct me or elaborate..

Asmoran

I don't think you're going to get a nice strong 36hz signal from a sealed 10. Perhaps if you were to custom build a box expressly for that purpose, but then you'd be losing quality at other tones.

Visit www.caraudioforum.com and ask around there. There are several extremely knowledgable people there who could help you out.

Astral

Yup, I asked on caraudioforum.com right after I posted this... thanks.. was curious to see whether anyone had a ported setup or some other setup that they could hear the entire bassline on properly.

forbidden

Any sub can play a 36hz note with ease. What differs is the subs ability to play that note with amplitude. This is usually a function of the driver, the box or a combination of both. 99% of purchasers of subs these days buy the "hot deal" or the "most talked about" sub based on forum input. Please realize that 99% of these people are telling you things that they have heard elsewhere or are currenty using and have not had the luxury of using other things.

This is where old dog come into play. Some of us do have the experience necessary to make an informed and educated decision to give to a person seeking information. When a person is faced with the 99% saying buy this and the 1% saying don't, who usually wins the first round? That person will never know the difference that a properly designed and engineered system is truly capable of. Then one day they hear a proper system and they go back to square one again. Buy things once, do it right the first time.

It is truly all about the box. Put the sub into a box too small and you limit the ability of the sub to play deep bass with amplitude. Put it into a box too big and you have amplitude but no control.

A sealed box will indeed play this note if the box is the proper size and the sub has, for lack of better words, the ***** to do it. I like to use Eclipse in this application as I know that it does indeed have what it takes to do so. The box size after 8 years of messing around is 1.25 cu.ft sealed.

In some cases a ported box will indeed play more output (depending on the tuning point of the port). In some cases if the tuning point is too high, don't expect to get lots of output at the lower frequencies, as is commonly the case.

Basically this comes down to the information that you are given and the choices you make. If you are starting the process backwards, don't expect to get the results you want. If you want the results, you have to progress on that track and not the I have a box and I bought this sub, what can I do to....

forbidden

RX4life, a box has a purpose. This purpose is to isolate the front pressure wave from the back. If this pressure wave is not isolated, the two waves can interact and they actually cancel each other out. A box fully contains the inward stroke of the sub and keeps that pressure wave from coming out and cancelling out the front pressure wave. A simple experiment here is to go to your home stereo speaker or any car subwoofer and remove the sub from the box and listen to it.

A sealed box with the right sub can and will play deep bass with authority. As pointed out above, screw up the box or the sub in the box and you will not get the desired results.

A ported box is a sealed box with a twist. The port is actually a tuning device. The port is a specific length and width for the sub and the box volume. Here is how it differs. When a sub not mounted in a box is producing a note, it makes two pressure waves, one going in each direction. This is also called 180 degrees out of phase. When you put the sub into a ported box, something has changed, the back pressure wave has hit a solid object, the box walls, and has reversed direction 180 degrees again. This back pressure wave is now inphase with the front pressure wave, meaning they are now both going in the same direction. The port allows this wave to exit the box and interact with the front pressure wave of the sub. End result is more output across the entire frequency spectrum. If the box is "tweaked" by manipulating the box volume, or the port length and width (tuning frequency), this can add enormous amounts of output at a specific frequency.

This does not mean that ported is better by any means. Never ever ever arbitrarily port a sub box, that is a recipe for heading out and buying a new sub. A port helps to control what the sub is doing, get it right and the results are great, get it wrong and the thing is going to sound like a wet fart.

A bigger sub is not necessarily a better sub or can play a low note louder. There is much more to it than that. Again it is all about the proper matching together of all components of a system that makes the difference.

Astral

forbidden, which Eclipse subs do you like to use?

Of course, what I meant by "playing down to" was reproducing 36Hz within 3db of the rest of the bass.

Anyways, while it's true that I'm working backwards by restricting my choice to a sealed 10" sub in a 0.9cuft box (w/ optional polyfill), I want to do two things:

1) Explore my options. The current sub sounds great for lots of music. However, some types of music hit lower and I'd like to know how much better I can get given the constraint. Maybe I won't be able to get F3 of 36hz, but maybe 38Hz.

2) Ask what other setups people are running and whether they can hear that bassline nice and even, just so that eventually I can finally break down, get over the nice 10" 4080 box and spend lots of $$$$ on something custom, larger, possibly ported, etc.

Astral

Actually, I just pulled my the RTA I ran the other day, forgot all about this:



Only pay attention up to 100Hz. The top two lines are smooth bass sweeps at two different volumes. The bottom two lines are pink noise captures.

So there's a huge hump from 43Hz to 74Hz, which is part of my problem. Overall, it seems to peaks about 9db (!) louder than the higher freqs (74hz+) and about 12db (!!) louder than the lower freqs (43hz-).

B'oh... I wonder whether it's the car or the sub that's primarily causing the hump.

I am going to go and do an unscientific out-of-the-car ground-plane measurement of the sub to try to get an idea of whether this is a funky cabin resonance/cabin gain thing, or whether the sub is actually out of spec or something like that.