18" build (Arande) - Page 2

Yep

-11 (F) here atm.. Don't think I'll be making it out until it is above 10 (afternoon)

Except for Monday, I've been snowed out all week (and schooled out )

Forecast is good for the weekend, good news

I am doing my best to get a camera, who knew it would be this hard

This weekend, it may be possible to get near a cell phone.. maybe even a real-life ($800) camera...

And to those who commented on me saying a movie slips in every once in a while, I guess I did not correctly say it. I may listen to music most of the time, but I must have watched over 30 movies since I started this thread

Over half of them being the newest movies too..

Today we got to gluing...

There is actually a camera here now, so later today I should have something up..?

The worst mess-up so far is beginning to cut an inner piece at the wrong diameter. Luckily it was figured out in time..


If things go to plan, tomorrow I should be able to finish gluing/sanding and get to painting/mounting issues not long thereafter. Due to my limited time during weeks, 'not long thereafter' may prove not to be until next weekend.. We will see..

It is supposed to get to 30 tomorrow (almost to freezing!) after over a week of 0 or below most of the time.

If there are any queries I have now, they are:

bolt size for Fi drivers (or any drivers?)
What to expect
Approximate time to mount a driver/bottom plate (w/drilling) and glue the final thing together..
time to sand surfaces that are not perfectly even, and sandpaper needed..

I believe I underestimated the time required for sanding... At least 10k strokes so far

I am getting coarser paper, I think that will help...

As close as I am to finishing the sanding, I think it is too late to justify the cost of a $30-40 power sander.

My forearms/shoulders are also used to heavy/high-rep type stuff because I exercise them in that manner (plate curls, high-strength grippers, plate pinches.. another hobby)

Anyway here's a cell phone picture.. It may help somewhat. The hole is the mistake I made, but it's only one sheet and likely won't have any effect.



You see that's on the kitchen table. I have not done much sanding on that particular part you see, but I have on the inner layers, before it was glued. That is basically THE sheet that hasn't been sanded, along with the bottom plate.

I can't get complete pictures yet, but... all cell phone pics




Not completely installed driver






That last one is nearly completed version in its current spot.. Sorry for the mess and bad pics..

So far I am honestly not impressed at all. Playing tones at full power between 20-30hz are barely detectable, and not detectable 15-20hz. I start to feel a little pressure on my ears 12-15hz and the fireplace hates it.

I watched Pirates of the Caribbean (for the first time, I liked it) and The Matrix. The subwoofer is better than nothing, as I can somewhat feel it. I can't really hear any deep bass as I was kinda expecting, though.


I need to get a graph and an SPL meter so I can figure out what the problem is (besides lack of power - I would think 100 watts would be pretty strong at 20-30hz). It is not very detectable outside.

Taking the top plate off leaving a 6ft open Sonotube is a lot louder, more even, boomy, not too different otherwise. I really think something is a bit off here in room placement..?


Any recommendations would be nice as help for troubleshooting...

Right

Well I don't plan on taking the top plate off again. It was before complete assembly. Are you sure it would REALLY damage the driver with 100 watts? Not much excursion there.. I don't understand how that would damage the driver...

Anyway, in my quest to fix the problem, I have moved the subwoofer over 2 feet away from the center of the wall. It has helped the perception of the sub 30hz range, but not much. It has improved the realism in testing of The Matrix and Pirates of the Caribbean. I may try moving it to the corner, but that is tile and from my experience, it may not actually work out very well.

After getting the real amp and measuring to find out what is going on, I believe I will be able to EQ (house curve as well as other EQ)...

The model tells me I need like 35V to reach xmech. And yes, my amp's manual says 85w (20hz-20khz) .1% THD 8ohm. With the switch changed into the 4-ohm position and with a 4-ohm driver, I am guessing it is less.

How I long for an SPL meter

Latest news...


Pushing it into the corner does not help as the vibrations that travel through the floor create a lot of noise. If I play a loud 20hz tone all I hear is vibrations of the floor and not the actual 20hz.

So, I believe it is time to... crawl for bass

I have tried the crawl for bass method and it made an improvement

Pros, improved deep bass, a lot of rattle gone
Cons, less output, EQ still needed, more power needed, still rattles that make it easy to localize

So, that said, I can tell I will need to build a second sub to get rid of the rattle localization issue and for more output.

Also, I can see I might need to figure out how to stop so much rattling.

Hi. I am aware that I not getting full power from the receiver, and hope to fix that soon. I have not tested my tune yet (will do that shortly), but I know it dips to around 3.5ohms, certainly not what the receiver is rated for. I have the receiver switched to 4-ohm mode just to try to avoid hurting it as much as possible.

About the second sub, I won't jump to conclusions until I try the amp. A second sub would cost about 1.5x an amp anyway.


Ahh, yes, this is what I am thinking of, too. I have the program, but not a mic that is suitable, yet. Although, I think it is the other way around - I believe I am wanting a strong house curve with a slightly hot presentation overall.


YES!
---


I have a bass boost circuit that has 3dB boost at 73hz and rises to a 14dB boost at 11.2hz and drops off. I am about to do some testing with that to see what happens.

I have a pair of headphones and they are stronger in the deeper bass than this, so far. It is definitely more involving and it sounds more balanced to my ear.

As soon I can REW test, I bet it will answer a lot of my questions. So will the SPL meter.

I am thinking of renting an amp just so I can know what to do next.

Testing my amp shows there is some roll-off in the <20hz region.


I might try raising the tune if I think that's the only option left, depending on what a bigger amp tells me.

Anyway, off to do some testing...

I have been testing... the rising low frequency boost helps a lot, but the problem is that anything 15-27hz is undetectable (except for sub noise?) at full power anyway, save for my chair vibrating 22-27hz.

Another problem is the localization of the subwoofer. At 12hz I feel equal pressure on both ears, but 27hz
I feel more pressure on my right ear. 40-45hz+ I am in a null and I hear harmonics (from the subwoofer?) rather than the tone. How much noise should the subwoofer be making anyway?

I am hoping to figure this out? From the impressions I read, something must be wrong.

Tried some other new positions. I found one good position, but I also am finding that my listening position (near middle) just doesn't sit well with the deep stuff. The idea of changing my room around a bit to accomodate the localization issue of the back right corner subwoofer and also get the deep bass does not seem like it would be a small undertaking.

But... I wouldn't mind doing it. It's the other members of the household I might have a problem with. We will see.

For now, I have the subwoofer set for LFE only and not music - the localization is just so annoying. I would rather settle for crappy 45hz extension than be distracted by localized deep bass >.<<br />
I have further testing to do if I am to get the deep bass - namely finding the correct new listening spot.

A full 80-watt tone is much stronger than it was now and all frequencies below 30hz to 11hz are strongly detectable (to 9hz with port extended) in the right spots in the room. So... that will be next.. after some movies and sleep and homework and more work...

Well, all I do is stick a piece of Sonotube into the top of the sub, not sure you need a picture to understand that Plus, it's no good as I lose output where I need it most and I can't detect it all at full power in the extended range, save for the slow movement of everything in the room.




Update:
Certainly not satisfied yet - my idea was that I should be able to have more than enough output with 100w with 10dB for peak/transient/short bursts (with the 1000w amp) and the 80w sine waves are nowhere near enough.

I understand I am pressurizing 8000 cubic feet, but like I said, my listening position is a null.

The problem is that any spot I've listened at so far that is at least OKAY for bass output will be crap (read:near wall) for sound staging in the main speakers or being able to see the TV without it being in the middle of the room (27" is crap).

I am hoping this can be solved without too much work.

I should say that I've never actually heard a setup that impressed me, only headphone listening has gotten close. At full power my headphones do pretty well at producing the <40hz range, but they are just not enough and the sound staging is not there like it is in non-direct radiation (pinnae). Binaural recordings are not convincing.

What has impressed me though is how great live performance has sounded. The symphonic bass drum live sounds great, but when I try to produce it in my house, full power is required to get the output, but all the rattling and seat shaking ruins it. How come it takes so much to achieve it in my house when it naturally sounds like that in a concert hall (acoustics)?





Maybe there is a setup somewhere near my area I can hear.. hope so...


Maybe I am really picky, or my ears are messed up.. or...

I finally got a hold of an SPL meter... I will post some different response graphs when I can.

My computer kept freezing so I could not get a measurement saved.

I can say that my listening position has a 12dB hump around 40hz (I think that is causing a lot of the 'no deep bass' problem as I am probably using that to calibrate). There also a slight dip centered at 23hz (4-5dB). Then between 11-14hz I get a strong 8dB hump (maybe the opening in my room acts as a port?).

SPL meter testing at MAX power gives me 95dB (corrected) at listening position and 106dB max if I go around trying to find the loud spots (all near walls).

I can say I sure do like the 106dB better! Also can't localize it, it seems, at the loud spots.

It may be that full 1kW power (near 120dB at loud spots) might be enough.. but 2 subwoofers would even it out and still gain at least 3dB, if not 6 (maybe more due to the improved loading?), also with less distortion.

I don't know exactly what the deal is with the middle of the room having bass THAT weak... (95dB throughout most of the range at full power).

The 106dB spot is almost as loud as my headphones (probably 112dB I am guessing).

It seems I am getting no information.. so first I ask..

96dB from 80 watts seems a bit small does it not? I would think the 106dB at the corners should be more since they would be gaining on the subwoofer's output.

So would it be the subwoofer itself or my room that has the problem?

Hello

I've tried it with the mains on and off, the mains only help.

I still believe 80 watts should do more than it is. I really think something is wrong or at least off... but I don't know how to go about figuring it out. I am sure that I should be getting the same 96dB with no more than 10 watts, maybe 15, but NOT 80.


Tonight I watched 2 movies without realizing the subwoofer was off because it makes that little difference. Sounds better that way right now - I was going to come on here and comment on how well it seemed to integrate, but no, it was not even on.