2 OT 212, 4 titan 48 photo

[brodave2]

the double 18's trounce the T48's especially in the lower frequencies. In my side by side tests the double 18's went 4db louder at 60hz.

With equal power after accounting for the impedance differential?

depends on how you describe equal power. In my side by side tests, I pulled the speaker cable out of one and into the other with no other changes. I was testing two double 18's vs two titans. The titans would be a 5 ohm total load, vs the double 18's being a 2 ohm load. The voltage would be the same, but the double 18's would be getting 2.5x the wattage. Also, there is the increased capacity of the double 18's, they will handle more power. The titans rule as far as efficiency goes, but all things considered, they just aren't a fit for my application. I love the lighter weight and smaller footprint and having to run one amp instead of two, but they just didn't do what I needed them to. If I add more titans or have to use some kind of special placement, that defeats the purpose. Besides, rockers like to climb on top of my subs and the titans wouldn't be suited to that. While I am a fan of smaller, lighter, more efficient, I think some of my clients, rockers in their 40's, like the big bad look of the double 18's. All these things are considerations when selecting equipment. I am a huge fan of the omnitop 12's.

[Bill Fitzmaurice]

depends on how you describe equal power. In my side by side tests, I pulled the speaker cable out of one and into the other with no other changes.

That would account for a 4dB difference in and of itself. That means the only advantage to the 218s is in power handling. You could load the T48s with higher capacity drivers, like the Beyma 15SW1300 Nd, and that would level the playing field, but that's not exactly an inexpensive option, though compared to two decent eighteens not off the wall either.

[brodave2]

depends on how you describe equal power. In my side by side tests, I pulled the speaker cable out of one and into the other with no other changes.

That would account for a 4dB difference in and of itself. That means the only advantage to the 218s is in power handling. You could load the T48s with higher capacity drivers, like the Beyma 15SW1300 Nd, and that would level the playing field, but that's not exactly an inexpensive option, though compared to two decent eighteens not off the wall either.

It really doesn't matter where the difference is, one product works for me and the other doesn't. I already own the double 18's, they've served me well for many years. My hopes of finding a better alternative seem futile. I could up the power to my double 18's and get by with one on each side, but then my AC current needs would quadruple, running my amps in bridged mode. What I have now with the double 18's is efficiency in the form of multiple large drivers. I don't have to run them hard to get what I need. I don't have to worry about hurting my drivers, because they are loafing along and getting the job done. If I was starting from scratch, at this point I'd be looking at higher power handling drivers for my titans, but I'm not starting from scratch. I've done lower volume gigs with the titans and was very well pleased. I'll continue to use them for that, unless I sell them, which I'm not going to pursue.

[gdougherty]

I'll suggest it one more time if you ever get the time and inkling. Give building a 30" cab a shot. From the charts a pair of 30" should beat out your 24" even v-plated. If the v-plated pair kept up with the double 18" cabs, the 30" should as well. The weight increase and size isn't that huge a difference and still far better than most double 18". For the price of a few sheets of ply and some spare shop time, I'd give it a shot if it meant I could live with lighter more efficient cabs.

I know you said you're not interested in building, just strongly suggesting what I'd consider if I were in your shoes. Half the cost of a driver and a week of evenings to find out. Sell the unloaded cab if it doesn't work out better.

[DaveK]

I know someone else who had the same experience. You know the Low/Loud/Small tradeoff for speakers? There seems to be another dimension of Efficient. Horn-loaded subs get more SPL out of each watt, but they do it by shaping the air mass in front of the driver. That shaped air mass takes up cubic inches. You can get a smaller sub by removing the shaping horn and radiating directly, but you need more watts to achieve the same SPL.

The direct radiators also have more harmonic distortion, but that's a different thread.

[gdougherty]

Ran my pair of 30" T48's tonight in an old theater converted into a church. 30' ceilings, upper balcony, about 50' x 90' for the floor area. Ran hip-hop with 3xOT12's per side stacked on the stage with the top speaker tilted up to cover the balcony. Wall loaded the pair of T48's to the side of the sanctuary. Hip-hop content, subs cut 48db/octave at 40Hz.

As my rapping pastor friend Age says, it was bumpin. Back of the room you could feel the beats very well. Front of the room I had a hard time mixing monitors for clarity over the bass onstage.

Makes me want to take them into GC and A/B them with something like the SRX728's. I can't imagine a 2x18 could do much better unless those 18's could really move some air.

[Bill Fitzmaurice]

I can't imagine a 2x18 could do much better unless those 18's could really move some air.

With enough power and excursion they'll compete. D.B. Keele put it succinctly 30 years ago, when high powered amps first hit the scene: If you've got more money than time and pack space use direct radiators and gobs of power. If you've got the time to build them and the packspace to carry them use horns, and spend the money saved on drivers and amps for other things. In today's economy food and shelter would be high up on that list of 'other things'.