Bought a bunch of plans still haven't built anything...

[Bill Fitzmaurice]

If you are interested in the inner workings of the DB XL2 you can see a clear version here.
https://www.stevemeadedesigns.com/board ... d-project/

It's a bass reflex box, loaded with these woofers: https://www.parts-express.com/dayton-au ... m--290-216

They do go to 35Hz, but with low sensitivity. Six of them in that size cab can put out 110dB at 50Hz at full power, which is displacement limited to 100 watts. A 14 inch wide T39 loaded with a Kappa Pro LF Ten driven to its maximum displacement limited power limit of 250 watts will reach 120dB at 50Hz.

[CarterKraft]

Good find, I was thinking they were Tang Band, maybe same difference?

The T39 would be a great performer but it would lose the suitcase portability.
When I started out thinking about this I convinced myself a "slightly" larger cab would be ok but that pretty quickly gets up to "waaay too big" if you aren't careful.

If I try to stick to the original 36x24x12 oversize DB XL2 layout, Do I stay with some sort of Truck Tuba in the back plane or just do the same 6 Daytons as the DB Xl2 does and use the mini SLA PROs for the top end?

[Bill Fitzmaurice]

I would not use six Daytons, or six of any five inch woofers, for sub duty. Fives are for mains, not subs. If you want a high sensitivity sub for outdoor use it's going to be large, you can't get around the physics. If you must go smaller than a T39 the way to do it is with a larger driver in a ported box, like the Simplexx 15 Sub pro-sound version, which is capable of 120dB at 50Hz using the 3015LF.

[CarterKraft]

I just looked at those Simplex cabs yesterday as a possibility, I'll review those again.

[Seth]

The T39 would be a great performer but it would lose the suitcase portability.

Hypothetically, if both options had the same output capability and I had to choose which one to tote from the parking lot to the field... I'd much rather roll my 60lb T39 out vs. carry my 50lb TruckTuba, even if it did have a strap handle and look like a suitcase.

A TruckTuba of those dimensions (36x24x12) may seem like suitcase portability in your mind, or even in a picture with a strap handle on it. However, once it's loaded up with drivers, batteries, and electronics... my guess is you'll be putting wheels on it after the first use.

But, again... I totally get that a T39 doesn't fit the vision you're working toward. Just putting it out there for consideration.


Another thing to take into consideration is, for every 3dB of increased sensitivity you'll get close to twice the play time on the same battery at the same output level, or require about half the battery capacity to have the same play time at the same volume. Either of which is a benefit of just choosing a path with speakers of higher sensitivity. Another benefit is the system having a greater maximum output with identical amplification.

[Bruce Weldy]

This whole project really depends on the user's expectations. Once that expensive boom box gets out in the open, the low end will disappear faster than the French army in a war.

If you need even sound across all frequencies and you want it to carry for any distance at all - you'll need a bigger sub. If it just needs to be enough to be heard and sound quality is less of an issue, then that's a different animal.

[CarterKraft]

I understand both of your suggestions, and I am trying to be honest with myself on the expectations.

If I build something so large it won't be easily moved, setup or played (by my wife and daughter for example) then it will be a bust.

The PE Blast Box is probably all I actually need and it fits the bill I described easily.
I was thinking if there was a way to greatly improve on that or the DB XL2 I could do that instead.

Having not ever built or heard one of these BFM designs I can't gauge the output.

[Seth]

Taking that into account... it may be better off just getting something pre-made. Something like Amazon Basics Party Speaker perhaps. Half the price of the PE Blast Box. Or if you're really wanting a DIY project, build a Jack 10 and put amp/bluetooth/battery in that... or just do the PE Blast Box.

IMO, anything larger will not be a go-to device unless the output and frequency response is mandatory.

Honestly, some of the larger Bluetooth speakers (+/- 16" wide) on the market today sound really good and put out a fair bit of volume... Plus, most are already internally/electronically EQ'd, Dynamic EQ'd, and limited for clean, smooth, balanced output at nearly any volume setting.

[Strange Kevin]

Hey guys interesting thread here!

I'm a little surprised the Omni Tall Boy hasn't been mentioned yet.

The form factor would be different and I'm sure it would be heavier than you typically "Boombox" but with some good wheels and a luggage handle on the back it shouldn't be too hard to roll around.

Finding a nice plate amp/battery combo has been a bit cost prohibitive on my initial investigation. It would almost be worth it to rip the import bits out of a Harbinger RT25 or somthing similar as a proof of concept.

For size reference, the Omni Tall boy 12 is 33"×20"×15" (H×W×D)
Check out the sales page for a SPL chart, it doesn't seem to be listed with the rest of the graphs here in the fourm.... (Not to be confused with the Omni Top designs!)

[CarterKraft]

I was researching the other designs today and the regular Omni 12 (not top) seems perfect for the job.
It will be mono though does that seem to matter?

For amplification, what sort of power would be ideal? 500w mono amp is available or bi amp with DSP?

[Bill Fitzmaurice]

500w will be more than enough. It doesn't need bi-amping and response is flat enough to get away without DSP. Use two tens for maximum low end sensitivity.

[Seth]

I was researching the other designs today and the regular Omni 12 (not top) seems perfect for the job.
It will be mono though does that seem to matter?

For amplification, what sort of power would be ideal? 500w mono amp is available or bi amp with DSP?

Not sure which amp you're looking at, but this one (on clearance) grabbed my attention. Requires 25-50volts DC, so a readily available 48volt e-bike battery pack with charger could be used to power it and they can be had at a somewhat reasonable cost.

And looking at the Omni12 plans and sketchup, it looks like there's plenty of space to mount a battery and amplifier inside.

The only downside I'm envisioning is you're still going to be looking at a ±70 pound solution... which may not be the type of thing your wife or daughter wants to schlep. But, maybe they do! Who knows? Just a thought.

If the S2010 is an option , it could shave some weight while also keeping the cost in check (Just checked the T/S parameters and the S2010 suits well). Also, Bill has those Alphalite 6 CBMR's for a decent price... that could shave a little weight off too.

[CarterKraft]

Thanks for the reply Seth,

After making this earlier post I thought I would check the PE Blast box ETA and found it was in stock! I ordered it and it should be here in a few days.
It's not going to be a BFM powerhouse but it should be decent for this job, if not I have a use for the components in another project so I can revisit the portable boom box idea.

Looking through the threads it seems there used to be a Omni 10 that might help with the weight/size.
Any idea what that was or was it something all together different?

[Seth]

Thanks for the reply Seth,

After making this earlier post I thought I would check the PE Blast box ETA and found it was in stock! I ordered it and it should be here in a few days.
It's not going to be a BFM powerhouse but it should be decent for this job, if not I have a use for the components in another project so I can revisit the portable boom box idea.

Looking through the threads it seems there used to be a Omni 10 that might help with the weight/size.
Any idea what that was or was it something all together different?

I just did a quick search on the Omni10 and from what I can tell it was replaced by the Jack10, which is the route I'd take if I were in your shoes. Seems way more compact. And, at 30 pounds plus electronics, much more reasonable for the ladies.

I look forward to hearing about the build process and how satisfied you are with the results of the PE Blast Box. Please keep us informed

[CarterKraft]

So Blast Box came in and I got it put together that Friday night ready for the last Volleyball game bus ride on Monday night.

As for a report.... The bass is EXCELLENT, very strong and punchy. In a room the gain is tremendous, remarkable output.
The volume/clarity is an issue. The little amp runs out of steam on the mids/highs VERY fast, almost to the point that I think there might be something wrong.
I am going to pull the passive radiator out and power it off another amp I have to see where the problem is. I don't expect pro sound level volumes but this amp/speaker combo seriously lacks upper volume range headroom.
I ran it off a 24v power supply I have as well to see if that was the hold up but that didn't seem to change anything even though it is suggested by reviewers at Parts Express.

So I have turned my sights to the Jack 10 lite for this purpose, but I am concerned about the low end extension of the Jack or lack thereof.
I like the form factor of it though and I think the top end will be adequate but I can't shake the other ideas we have thrown around.
For todays hip-hop / pop music how much low end will be missing from the Jack 10?