18” down-firing EGG shaped sub build…

[GMichael]

After all that work I sure hope it lives up to your expectations. Are you going to equalize it? Sealed subs tend to have an early roll off which means boosting the lower frequencies (usually 30Hz and under) to achieve a flat low end is almost a given necessity. With that surface area and the power behind on tap you should have plenty of headroom to allow for EQ.
Now, you need to play 'Bass, I love you' - Bassotronics (heavy sub 20Hz content). Actually a very enjoyable song to listen to, and with flex your woof like no other. I can send it to you via email. SVSubwoofers have selection of films in their FAQ that contain serious bass also.
If this doesn't get you in trouble with your neighbours, nothing else will:-)

Thanks.

I'm thinking of a BFD. A friend told me that he has an "extra one" whatever that means.

My nearest neighbour is through the woods. I don't think he can hear anything I do.

[GMichael]

Thank Feanor. It sure was a ton of work. I can finally start working on the yard.....

[kexodusc]

Well done, GM! Any noticeable differences in sound from the Titanic other than output and extension?

[GMichael]

Well done, GM! Any noticeable differences in sound from the Titanic other than output and extension?

Thanks Kex,

Yes, I have noticed a difference right away. It has much lower extension than the Titanic had. It's not calibrated yet so it's hard to know what the overall sound will be when I'm done. Here is what I measured last night. It wasn't so easy to get these numbers. Ever try to explain to a 10 month old that she needs to be quiet while Daddy plays with his Db meter?

[kexodusc]

Ever try to explain to a 10 month old that she needs to be quiet while Daddy plays with his Db meter?

Is that what you call it? Really, you shouldn't be subjecting her to your adult extra-curricular activities.

[GMichael]

Is that what you call it? Really, you shouldn't be subjecting her to your adult extra-curricular activities.

So much for my dad of the year award.

How do you like that spike at 31.5 htz?

[kexodusc]

My guess is it's related to one of the dimensions of your room.
Honestly, your measurmenets are way better than any of my rooms have been before treatment and EQ...so not bad

Did you take measurments at 1/6th ocatave frequencies?
Usually I see BFD charts with measurements at: 16, 18, 20, 22, 25, 28, 31.5, 36, 40, 45, 50, 56, 63, 71, 80, 85, 90,100 etc...

In my case, you'd be surprised how many suckouts or peaks you can find in between these even...but at some point you just gotta move on.

[GMichael]

My guess is it's related to one of the dimensions of your room.
Honestly, your measurmenets are way better than any of my rooms have been before treatment and EQ...so not bad

Did you take measurments at 1/6th ocatave frequencies?
Usually I see BFD charts with measurements at: 16, 18, 20, 22, 25, 28, 31.5, 36, 40, 45, 50, 56, 63, 71, 80, 85, 90,100 etc...

In my case, you'd be surprised how many suckouts or peaks you can find in between these even...but at some point you just gotta move on.

Yeah, I figure it's the room too. It's a very noticable peak.
My Rives disc only produces the frequencies on my graph. What are you using to get all those 1/6th ocatave frequencies?

[GMichael]

Here was the last result before the BFD. I ran this test several times and got the same numbers +/- 1/2 db.

[kexodusc]

Oh, over at the HTShack, the BFD guide has a link to test frequencies you can download...don't have the link handy but Googling BFD guide should suffice.

[GMichael]

Oh, over at the HTShack, the BFD guide has a link to test frequencies you can download...don't have the link handy but Googling BFD guide should suffice.

Download? Uht oh. You mean to a CD or something? I have no laptop to speak of. Could the PS/3 download it you think? Or would an Ipod work?

[kexodusc]

Download? Uht oh. You mean to a CD or something? I have no laptop to speak of. Could the PS/3 download it you think? Or would an Ipod work?

Hmmm, I think they are just mp3's so the PS3 should work fine.

[GMichael]

Thanks!

I'll give it a try this weekend.
Just ordered a BFD from a friend on another sight. $60 shipped. He said he bought two but ended up changing his system and only needing one.

[audio amateur]

There's a tone generator with WinISD. Would that work?

[GMichael]

There's a tone generator with WinISD. Would that work?

Thanks. I'll keep exploring options.
I just read through the whole BFD guide last night. Why do I feel so overwhelmed? Seriously, calibrate my sound card? It may turn out to be easy, but it sure is wordy.

[L.J.]

Well? Have u got the BFD set up yet? Did u ever get those tones downloaded?

[GMichael]

Well? Have u got the BFD set up yet? Did u ever get those tones downloaded?

Hey LJ!

The BFD did come in. I set a few filters manually based on the initial results I had. In theory, it should be a pretty flat response now. When I went to check it, the Db meter was flucking up. It was giving me numbers below 50 Db for frequencies that I could clearly hear rocking the house, and then 90+ db readings for frequencies that were more subdued. I ran the tests several times and got different answers every time. It does sound good though. At this point I can only hope that it is at least close to flat. Eventually I’ll buy a new meter, but not at this time. Baby’s gotta eat.

When I run the test tones, I can hear/feel tones down to 10 hz. It seems to reach very low. As it goes through the tones, volumes increase until it hits 16 hz, and then it seems to slowly drop off a little at each tone. When I get a new meter (or if someone comes over with theirs) I’ll post new numbers.

[L.J.]

Wow, pretty easy start. Looks like a few filters were plenty.

Well if your Titanic starts collecting dust (cough cough) I would be willing to accept donations

[GMichael]

Wow, pretty easy start. Looks like a few filters were plenty.

Well if your Titanic starts collecting dust (cough cough) I would be willing to accept donations

Thanks.

I ended up with 5 filters. None of them are more than +3db or -5db. It sounds right, but it's only guesswork until I can get a new meter.

I noticed that the BFD can have two filtered outputs at a time. The Titanic might end up behind the sectional with settings all it's own. A little extra bass never hurt anyone.

(that i know of)

[L.J.]

Thanks.

I ended up with 5 filters. None of them are more than +3db or -5db. It sounds right, but it's only guesswork until I can get a new meter.

I noticed that the BFD can have two filtered outputs at a time. The Titanic might end up behind the sectional with settings all it's own. A little extra bass never hurt anyone.

(that i know of)

Wish I had room for 2 subs

[GMichael]

Wish I had room for 2 subs

It was all part of my master plan. 5 years ago, when we were looking through floor plans for our house, I picked out the one that gave us a huge living room. The closets and bathrooms are a little small, but the living room and master bedroom are nice.

I love it when a plan comes together.

[GMichael]

Interesting chart from the BFD. How does it work? Does it sweep a single tone or a more complex waveform like pink noise?

Tuning from a pure feedback point condition has it's limitations in a dynamic environment. That being mentioned, for theatre it could be a good way to go. What about the rest of the system? Any electronically assisted tuning there?

Not criticizing - just wanting to open up some discussion on the equipment and how it works.

Thanks. It was a h.ll of a project. I still have a smashed fingernail to prove it.

The BFD software I found can do a sweep, but I don’t have a laptop to run it in the HT room. I burned a CD of test tones ranging from 10 Hz to 143 and used a Db meter.

The rest of the system is as follows:

Yamaha RX-V2500 AVR (Auto set-up ran, but EQ re-set to flat)
Onix Strata Mini for the mains. (Planner hybrids with built in subwoofers: The subs are set at less than half power with crossovers set to 100)
Infinity Primus center, surrounds and rears.

[bobsticks]

This thread is awesomely surreal. I tried to give you Greenies but was denied.

I love the absolute commitment and attention to detail...on the egg!. Every additional post in this thread makes me happy. Thanks for sharing GM!