Finally! Omni 12 Tall Boy build

High power and fidelity from an easy to build cabinet.
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CarterKraft
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Re: Finally! Omni 12 Tall Boy build

#226 Post by CarterKraft »

Seth wrote: Mon Feb 20, 2023 1:33 pm Oh man... Tuning isn't real time? That could seriously be a PITA. We'll get it there though. I'm on board as long as you are.

I love that your wife had such a great reaction. You've put a lot of time and energy into this project and it does, in fact, look fabulous. You deserve the kudos. :thumbsup:

Its tricky... It is real time, until its not.
I am not sure if my junky shop laptop is the problem or if it just an issue with the DSP board/software that has some limits on bandwidth or maybe I am just over powering the onboard chip with commands.

It shouldn't prevent me from getting the job done it just takes a little longer vs just cranking knobs as I will need to write the software after each change.

I'm not discouraged, its worth the struggle I think.
Weldon Carter

CarterKraft
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Joined: Thu Oct 22, 2020 1:46 pm
Location: DFW

Re: Finally! Omni 12 Tall Boy build

#227 Post by CarterKraft »

Update time!
I have played this thing for MANY hours both cordless and corded.
Everyone (including myself) has been over the moon with it.

I took it to work for a lunch cookout and had mixed reviews...
The parts warehouse guys over 300' away down the center isle of the two main shops thought it was awesome, they were blown away from the clarity of the vocals. The parts counter and phone guys were annoyed they couldn't properly hear the people at the counter or on the phones :hyper:

The co-workers in the shop were just simply amazed. I have been showing them pictures for many months since I started the build and they just could not believe the output or the clarity at the output.
2 of the guys have requested to purchase this exact cabinet or copies at the $2k price I have mentioned prior.
Weldon Carter

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Tom Smit
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Re: Finally! Omni 12 Tall Boy build

#228 Post by Tom Smit »

:clap: :clap:
TomS

CarterKraft
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Re: Finally! Omni 12 Tall Boy build

#229 Post by CarterKraft »

My Laptop screen broke mid post the other day and I quickly posted that message before the screen bleed took over...

I am going to attempt one more time to increase the bottom end at the elevated sound levels.
The way I have the bass boost now (I am using the boost module due to problems I had with the real time portion of the DSP chip) it's heavy in the bottom third of the volume range, medium to light in the mid and then light in the top.
I need to see if I can taper that less in the upper range.

I also found out what I was doing wrong with the DSP, in some of my previous posts (re-reading those is funny too me now) I could get the sound well dailed either by ear or by measurement using Seths guide then listen to it for the afternoon feeling good to find in a few days later I was not as happy as I remembered.

What was happening was I wasn't ever writing the changes to the EPROM. I would work in the programming environment and get something I was happy with a and then not finish the process by flashing the memory with the changes, that left all my hard work in the volatile memory to be purged as soon as I unplugged the power. :wall:

After figuring that out I threw the tune back in it, sort of quick and dirty and have been running it like that for a few months.
It's awesome as I said but I would like to attempt to maximize the low end.
This woofer is not the LF and I'm not sure if changing to that driver alone would be worth the $$$ to do so.
I want to try just tuning the bass boost or scrap the boost and do it in the EQ with a signal limiter to cap the maximum output.
Weldon Carter

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Bill Fitzmaurice
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Re: Finally! Omni 12 Tall Boy build

#230 Post by Bill Fitzmaurice »

Going to an LF driver only helps if you have enough power to make use of the additional xmax. The 3012HO will take 180w without exceeding xmax.

CarterKraft
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Re: Finally! Omni 12 Tall Boy build

#231 Post by CarterKraft »

Gotcha, that won't help much in the current power configuration.

At a extreme cost/weight penalty how about the 2x 3010LF option.
The Vd increase is substantial and the lower ohm load would increase the useful output of the chip amp.
Worth it? No idea.

A think my next setup is to stack a CD horn Jack 12 Lite and tuba sub of unknown flavor. And understand that I am a perpetual fixer, gearhead by birth, nothing is ever perfect just good enough for NOW.

I'm not disappointed, for general listening this Omni12TB is damn good, has output for days and just looks awesome.
Not one person believes me that I built it until they see the pictures.

My son sent me these pix of some he found on the net, the idea is growing.
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Weldon Carter

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Bill Fitzmaurice
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Re: Finally! Omni 12 Tall Boy build

#232 Post by Bill Fitzmaurice »

Same deal with the 2x10, you don't have enough power for it to make a substantial difference.

CarterKraft
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Re: Finally! Omni 12 Tall Boy build

#233 Post by CarterKraft »

Gotcha.
Thanks again Bill.
Weldon Carter

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Seth
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Re: Finally! Omni 12 Tall Boy build

#234 Post by Seth »

Weldon, will you post a link to the information on the bass boost plug-in you're using? Too lazy to dig the information out of the thread right now.

Did you ever tune it using RTA without the bass plug-in or with it disabled?

I'd definitely verify whether or not the bottom end at high volume you're looking for can't be achieved with the set up you have now before considering other hardware options.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

CarterKraft
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Location: DFW

Re: Finally! Omni 12 Tall Boy build

#235 Post by CarterKraft »

I'll have to check my notes to see which one I ended up with, I was having such trouble during that time getting and keeping the tune the troubleshooting got a little haphazard.

I believe I am using this module, "dynamic bass boost"

https://wiki.analog.com/resources/tools ... cbassboost
Weldon Carter

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Seth
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Re: Finally! Omni 12 Tall Boy build

#236 Post by Seth »

Yeah, so you want to tune the system to your target curve first, without any dynamic bass boost (disable it). You can do the initial tuning with pink noise at whatever volume is 10-15dB above ambient, doesn't have to be super loud. Once that's dialed in, then play some music, turn it up, and make sure you like how it sounds at/near full volume. Adjust EQ as needed.

THEN, leaving the EQ alone, apply the dynamic bass boost module and dial it's settings in at low volume, which will increase the bass at lower volumes when our ears are less sensitive to low frequencies. Once you get the bass where you like it at the lowest volume, slowly turn the volume up and listen for even consistent perceived bass levels throughout all volume settings and make adjustment to the DBB settings as needed. When it's dialed in well, it "should" sound relatively the same at all volumes.

My guess is you tuned the system with DBB on. Which would explain why bass is insufficient at higher volume levels... DBB reduces boost to the base EQ values as volume is turned up.

If the bass farts out at max volume with the target response, it's time to investigate the psychoacoustic bass plug-in. I forget what it's called, but we'll figure it out if/when it's needed.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

CarterKraft
Posts: 255
Joined: Thu Oct 22, 2020 1:46 pm
Location: DFW

Re: Finally! Omni 12 Tall Boy build

#237 Post by CarterKraft »

10-4

The problem I had before when doing RTA I couldn't get the "boost" in the low end using the EQ bands, it was like nothing, nothing then next bump would be farting/distorting.
Using the DBB made it work correctly and sound really good but I estimate I have the gain pullback to high and it's pulling back on BB as the signal level increases.

Thanks for the help Seth.

I've shelved the project for now because it's so good in the normal listening range but any day I could grab it and go setup testing.

Got my high school car back on the road that's keeping me occupied.
Weldon Carter

CarterKraft
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Location: DFW

Re: Finally! Omni 12 Tall Boy build

#238 Post by CarterKraft »

This is not going to be a ideal test track for most of you guys but my daughter and her friends are pretty jazzed for the powder puff football game tomorrow. :hyper:

The speaker is that small greenish/blue light behind the goal post, I am standing at the 50 yard line and the speaker is 30 yards behind the goal line.
(the camera "zooms" the mic with the lens, I have since found that setting and turned it off)

I think I was being too critical of the low end, it doesn't scale with the top end for sure but within 20 yards of the speaker there is a still ample low end, it just doesn't carry like the mids.


https://photos.app.goo.gl/K5UrY3Bbg1QJkfqb7
Weldon Carter

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Bill Fitzmaurice
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Re: Finally! Omni 12 Tall Boy build

#239 Post by Bill Fitzmaurice »

Listen indoors, it will be totally different.

CarterKraft
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Location: DFW

Re: Finally! Omni 12 Tall Boy build

#240 Post by CarterKraft »

Bill Fitzmaurice wrote: Thu May 25, 2023 12:46 pm Listen indoors, it will be totally different.
Like a gymnasium size indoors?

That test last night had everyone including myself smiling.
My wife hadn't heard "war" volume until last night, she actually suggested the sound check because she thought it might not be loud enough...
Weldon Carter

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