Finally! Omni 12 Tall Boy build

[Grant Bunter]

The Deltalite 2512 should be limited to 40V.
Don't ask me where that came from or how to find it. Probably a "if I can because my DSP lets me, what should I limit my tops to" kinda thread.

As Seth so rightly pointed out, you will hear distortion before you hit 40V, and if you hear distortion, you should turn down.
If you work on 40V, then an 8 ohm cab means that = 200W.

That's in keeping with what Seth quoted above, and gives you a great start point. Throw in some headroom as well...

[Bruce Weldy]

This is the Dayton amp with DSP and 4x100 watts.
It will run fine off my 40v batteries and should have enough juice with two of the channels bridged.

It really seems perfect, has all the peripheral options I need, it should make a really polished product.

https://www.parts-express.com/Dayton-Au ... SP-325-434

Specifications
Power output (w/ 36 VDC power supply): 4 x 100W @ 6 ohms
SNR: 97 dB 2 x 50W @ 8 ohm, THD+N=1%, 26 dB, A-weighting
THD+N: 0.07% 10W @ 6 ohm 1 kHz 26 dB
Frequency response: 20 to 20,000 Hz (±3 dB)
Impedance: 4-8 ohms
Recommended power supply: 36 VDC, 5-10A
Working Voltage: 10 to 39 VDC
Board mounting holes center to center spacing: 4.1" x 3.2" (111.76 x 81.28 mm)
Hole diameter: 0.15" (3.8 mm)
Dimensions: 4.8" L x 3.6" W x 1.5" H

I see a few issues with that little amp. Specs don't say if the rating is RMS. Rating is at 6 ohms, so 8 ohm drivers are probably more in line with the SNR line that says 2 x 50W @ 8 ohms.

I just have a hard time believing that thing can truly put out 4 x 100 watts.....at any ohms. For a home stereo build - sounds like a good one to try. But, if you are planning to use the TallBoy outside - it will grossly underperform what you are expecting or even close to what it can do with proper amplification. Now, if you just want some background easy listening music - take a couple of home stereo speakers with you and not carry around a full-sized, heavy cab. It's like carrying around a .44 mag filled with .22 shorts.

I'm not trying to be the nattering nabob of negativity (only the old guys remember that), but it just seems like a total mis-match to me - like putting regular gas in a nitro funny car.....just ain't gonna' run as good as it should.

If it was me, I'd at least go for the Dayton PPA800

https://www.parts-express.com/Dayton-Au ... th-300-798

You could build the passive crossover for the mid and low and power it off the low amp and use the high amp for the tweeter. That would give you enough punch to make it all worthwhile. Plus, it's got bluetooth.....(and it works really nice in my SLA Pro/T24 combo)

Now, whether that amp can run on your power limitations is out of my league.

[Bill Fitzmaurice]

The PPA800 HF amp won't go below 1kHz, the crossover to the O12 midrange is 400Hz. You'd still have to run the woofer and midrange together with the passive, powering the tweeter with the HF amp.

[CarterKraft]

This is the Dayton amp with DSP and 4x100 watts.
It will run fine off my 40v batteries and should have enough juice with two of the channels bridged.

It really seems perfect, has all the peripheral options I need, it should make a really polished product.

https://www.parts-express.com/Dayton-Au ... SP-325-434

Specifications
Power output (w/ 36 VDC power supply): 4 x 100W @ 6 ohms
SNR: 97 dB 2 x 50W @ 8 ohm, THD+N=1%, 26 dB, A-weighting
THD+N: 0.07% 10W @ 6 ohm 1 kHz 26 dB
Frequency response: 20 to 20,000 Hz (±3 dB)
Impedance: 4-8 ohms
Recommended power supply: 36 VDC, 5-10A
Working Voltage: 10 to 39 VDC
Board mounting holes center to center spacing: 4.1" x 3.2" (111.76 x 81.28 mm)
Hole diameter: 0.15" (3.8 mm)
Dimensions: 4.8" L x 3.6" W x 1.5" H

I see a few issues with that little amp. Specs don't say if the rating is RMS. Rating is at 6 ohms, so 8 ohm drivers are probably more in line with the SNR line that says 2 x 50W @ 8 ohms.

I just have a hard time believing that thing can truly put out 4 x 100 watts.....at any ohms. For a home stereo build - sounds like a good one to try. But, if you are planning to use the TallBoy outside - it will grossly underperform what you are expecting or even close to what it can do with proper amplification. Now, if you just want some background easy listening music - take a couple of home stereo speakers with you and not carry around a full-sized, heavy cab. It's like carrying around a .44 mag filled with .22 shorts.

I'm not trying to be the nattering nabob of negativity (only the old guys remember that), but it just seems like a total mis-match to me - like putting regular gas in a nitro funny car.....just ain't gonna' run as good as it should.

If it was me, I'd at least go for the Dayton PPA800

https://www.parts-express.com/Dayton-Au ... th-300-798

You could build the passive crossover for the mid and low and power it off the low amp and use the high amp for the tweeter. That would give you enough punch to make it all worthwhile. Plus, it's got bluetooth.....(and it works really nice in my SLA Pro/T24 combo)

Now, whether that amp can run on your power limitations is out of my league.

Point taken.
I doubted some of these amps ratings and I know for sure the lower ohm ratings help them.
The Taramps I linked earlier is garunteed to make it's power, they are thoroughly tested and are really impressive in that regard.

The amp I linked above would have 2 channels bridged for the woofer so maybe around 100w? Then the other channels maybe 20-30 each.

Given those watt ratings are accurate does that equal 185 watts?

No love lost if it doesn't make the power, I have other uses for it.

[CarterKraft]

So it seems like 200w is a good target from both of your suggestions.

I will re-evaluate the amps and see if there is another solution.

If I have DSP for all the channels do I need any crossover parts? I want to get them coming so I don't have any delays due to the current shipping dilemas.

[Bruce Weldy]

So it seems like 200w is a good target from both of your suggestions.

I will re-evaluate the amps and see if there is another solution.

If I have DSP for all the channels do I need any crossover parts? I want to get them coming so I don't have any delays due to the current shipping dilemas.

If you have good DSP, then you shouldn't need any other filters.......

[CarterKraft]

Understood

[Bill Fitzmaurice]

The midrange and tweeter still require capacitors in series to protect them from turn on/turn off transients.

[CarterKraft]

I ordered the DSP 4x100 board and peripherals to hook it up and use it. We will see if it's accurate in it's description.

All I need now is plywood...
I hope to get the good stuff this time.

[CarterKraft]

Here's the datasheet for the supplier of the amp chip.
Not a hifidelity amp I'm sure but it might work out.

Looks like 80w per channel at 8 ohms 10% thd

https://www.st.com/en/audio-ics/tda7498.html

[Grant Bunter]

Hmmm,
So it's the LF driver that wants 200W to get to 40V.
If you were to build with filters, they would reduce power to the mid driver and HF section appropriately.
So 80W/channel 8 ohms just isn't enough juice to get towards it's capabilities...

[CarterKraft]

As it stands if the ohm to power ratings are to be believed there would be 160w to the LF driver, 80w to the mid and 80 to the HF.
No filtering losses.

I am not too worried, if it doesn't work out I will have some selection criteria to improve on.

[CarterKraft]

As a comparison this speaker was at the river this year and was our groups main sound system for 40 ish people.
It was very loud, not that clear at that level but drunkerds didn't mind.

it claims to have a total system power of 50 watts.
When it was paired with another campers unit there was A LOT of volume in that open camp ground.

https://ecoxgear.com/collections/party- ... ecoxplorer

[CarterKraft]

Ok, all the REAL Baltic Burch has been cut and sanded for assembly.

While the woofer doubler ring was gluing up I started laying out the mid and tweeter on the face.

I was going to use the APT 150 horn instead of the 80 as this will be a PA/recorded music speaker only..
Looking at the 7.5" wide flange of the tweeter and the 11" opening of the mid its getting crowded on the 19" wide front panel.

Any suggestions as to the optimal layout, plans say
"The tweeter and mid horn mount side by side on the cabinet front. Mark the holes as high on the cabinet as possible. Place the mid horn on the cabinet front, tracing its location. If you don’t use a tweeter center the mid horn as high as possible on the cab front. "

Are there any rules as to how close the mid horn and tweeter can get?

[Bill Fitzmaurice]

As close as possible.