titan 48 vs. double 18

[brodave2]

I have 6 double 18 subs that I built several years ago and I have made a lot of money using them. Never any complaints about the bass. I just finished a pair of titan 48-24" with 3015lf. I pulled one of the double 18's (carvin 18" drivers which appear to be eminence omega pro)and marked a spot on my concrete driveway and laid it down. I ran an 80hz sine wave at 5.6v, measured the output at 2 meters. 98db with a radio shack meter. I pulled out my titans one at a time and did the exact same test in the exact same place. One titan did 103db and the other did 104db. I wouldn't have believed it if I hadn't seen it with my own eyes. That was actually 2w total, 1 watt to each driver in the double 18, so they were already seeing double the power. I'd have to double the power two more times to get the double 18 up to the level of the titan. Someone help me with my math, but it looks like I'd have to double the power 3 times to level these guys out. Notice, I was testing the titans one at a time. Had I coupled the titans it would have been off the chart.

[Bill Fitzmaurice]

Stacking both T48s parallel wired will increase output by 6dB, so you can figure 109.5dB from their two fifteens, as opposed to 98dB from two eighteens in the reflex box, with the same voltage input.

[mty]

Stacking both T48s parallel wired will increase output by 6dB, so you can figure 109.5dB from their two fifteens, as opposed to 98dB from two eighteens in the reflex box, with the same voltage input.

Hy .Bill could the T36 give more output that the T48 pair .

[klocwerk]

Stacking both T48s parallel wired will increase output by 6dB, so you can figure 109.5dB from their two fifteens, as opposed to 98dB from two eighteens in the reflex box, with the same voltage input.

Hy .Bill could the T36 give more output that the T48 pair .

http://billfitzmaurice.com/phpBB2/viewtopic.php?t=358

[brodave2]

I rechecked my earlier comparisons and found that my tests were flawed. I wired my double 18's with separate leads coming from each driver to the 4 contacts on the speakons, and had special speaker cables that I used only with them. In my test I used a regular speaker cable, and as such, only one 18 in the double 18 cab was connected. I redid the comparison and found that the double 18 and the Titan were a dead heat at 80hz, they had the same output with the same input voltage wise. Of course, the double 18 is 4 ohms vs 10 ohms for the titan, so the double 18 took 2.5 times the power to get there. Below 80hz it was another story. The double 18 goes much lower. So there it is, the Titan is still awesome, just not nearly as awesome as I had thought. Also, the double 18 weighs at least 1.5 times what the titan weighs.

[gdougherty]

I rechecked my earlier comparisons and found that my tests were flawed. I wired my double 18's with separate leads coming from each driver to the 4 contacts on the speakons, and had special speaker cables that I used only with them. In my test I used a regular speaker cable, and as such, only one 18 in the double 18 cab was connected. I redid the comparison and found that the double 18 and the Titan were a dead heat at 80hz, they had the same output with the same input voltage wise. Of course, the double 18 is 4 ohms vs 10 ohms for the titan, so the double 18 took 2.5 times the power to get there. Below 80hz it was another story. The double 18 goes much lower. So there it is, the Titan is still awesome, just not nearly as awesome as I had thought. Also, the double 18 weighs at least 1.5 times what the titan weighs.

Curious about testing, are you using an RTA to compare the two, if so can you put up some comparison charts? Mostly interested in specific definition of the "lower" performance of the double 18 vs the Titan not getting there. Also curious about power input, how much were you putting into them and how much output can you get from them at say 53V into each cabinet? Are you high passing either of them? As I recall, the T48 only extends to about 38Hz, so HP at 40Hz is recommended for protection and live rock won't be missing much down there anyway, so is the lower extension of the double 18 really that big a deal? I'd also think an RTA might show the amount of added distortion on the top end of the double 18 if you had them low passed at 80-100Hz.

[brodave2]

I did check them with pink noise, but I did not save the graph. As I recall, the titans had a peak at 80-100hz, then dropped off pretty quick. The double 18 peaked at probably 60hz, and was tapering off slowly below that. The tests I did were at low to medium volume. I took the speaker cable out of the double 18 and then put it into the titan with no changes so that the tests would be identical, regardless of what the voltage was. I tested both with music in the same manner, and with main speaker going so that it would sound musical. It's hard to do a hearing test with subwoofers without top speakers added in. The double 18's went audibly lower, sounded fatter than the titans. Possibly eq would help the low freq extension, but then adding volume with eq uses power the same as adding volume otherwise, 3db requires doubling the power. I also did listening tests with the subs paired, two double 18's vs two titans, because I know folded horns have better low frequency performance when in multiples. I think if you have 4 double 18's vs. 4 titans, it would even out, because the quad of titans would give you the low frequency extension. I haven't ruled out the titans for my smaller rig due to the GREATLY less load they would put on the sometimes severely limited electricl power available in many venues. The double 18 require 2.5 times the power, that would be at least as much difference in the AC current draw. The titans are an incredible design. Keep in mind that I am comparing them to a sub at least half again heavier and costing much more, although easier to build, and drawing 2.5 times the power.

[LelandCrooks]

. I took the speaker cable out of the double 18 and then put it into the titan with no changes so that the tests would be identical, regardless of what the voltage was.

I hate these kind of nitpicks, but I have to. You mentioned it earlier, impedance. The t48 was getting about 1/2 the power of the dual 18. 4 ohms vs 10 ohms.

The double 18 require 2.5 times the power, that would be at least as much difference in the AC current draw. The titans are an incredible design. Keep in mind that I am comparing them to a sub at least half again heavier and costing much more, although easier to build, and drawing 2.5 times the power.

Dead on. Try it again compensating for the impedance mismatch. I think you'll find it a much closer match. Two t48's are bigger than a double 18 in pack space, but for an equivalent test, that would be closer, in impedance and driver complement.

[brodave2]

I hate these kind of nitpicks, but I have to. You mentioned it earlier, impedance. The t48 was getting about 1/2 the power of the dual 18. 4 ohms vs 10 ohms.

I mentioned that several times. By switching the cable from one speaker to the next without changing anything else, I maintained the same voltage, but of course, the double 18 drew 2.5 times the wattage. This is a big deal, because quite often one 15 amp circuit is all that is available and the less current draw, the better. I've done many gigs where the voltage dipped 5 volts every time the bass drum hits. That is not conducive to good sound. I did a gig with the two titans on a PLX 2402 in stereo mode and 4 omnitop 12's on a PLX 1602 in stereo mode, with three monitor mixes running, each on one side of a PLX 2402, all this on one circuit, and there was no dipping of the voltage when the bass hit. The bass drum was hitting 105db 50 feet back. Two titans would blow away one double 18 obviously. My new trailer I am building for this rig is just under 6' wide inside. A pair of 27" wide subs would be perfect. Double 12 titans might be just the trick, or maybe I should look into Tuba 36's 27" wide.

[LelandCrooks]

I used to run two guitar and 1 bass amp, self powered monitors, 3 xls402 amps into 4 DR250's and 4 T24's, mixer and outboard gear off of 1 circuit.

Never popped a breaker anywhere. That's a real bonus of these.

I wasn't getting on you Dave, I just wanted to be sure it was clear. Your experience is far over mine.

[Bill Fitzmaurice]

The double 18 goes much lower. So there it is, the Titan is still awesome, just not nearly as awesome as I had thought. Also, the double 18 weighs at least 1.5 times what the titan weighs.

You're also overlooking the fact that whether you use one 2x18 or ten the response will remain the same. Adding more Titans extends the LF response and sensitivity, so the more of them in the pile the better they work. That can make a crucial difference is a venue where running at high levels to low frequencies is a desired but you don't have the option of using 5kW to do it.

[brodave2]

That can make a crucial difference is a venue where running at high levels to low frequencies is a desired but you don't have the option of using 5kW to do it.

Yes, that is abundantly clear. In MOST situations, there is limited AC power available, and while I have an 80 amp 240v distro, I don't like to use it unless it's a really big venue. That 4-4 SO cable is SO heavy at the end of the night. I met a guy several years ago who did the sound reinforcement for some really big name ministries, in really big venues (10,000 +). His fave was Klipsh LaScala, which are horn loaded. He enlightened me on the value of efficient speakers vs. AC requirements. This was 18 years ago. When I was directed to this sight I was looking for plans to build efficient cabs, because my experience has been limited AC availability and also looking for lighter weight. I am totally enjoying my omnitop 12's, and planning on building several more.

[Mark Coward]

The double 18's went audibly lower, sounded fatter than the titans.

Were you still testing outdoors? How far away from the subs were you? I've found that the 18's will sound big and fat up close, but past 30' or so it gets wimpy. The tubas and titans seem to fill a room evenly indoors, and carry farther outdoors. I know that "long throw" is supposed to not really be possible but I've walked around a very large outdoor area while running a pair of T30's, and it was quite amazing how much low end there was even 300' + away.

I've also noticed that quite often, bands running typical 18" subs will have a muddy low end when the whole band gets cranking - it's hard to distinguish the kick drum or bass notes, it all becomes just one big thud.

[brodave2]

my most recent tests were indoors. I have not made any final judgments. I haven't had much work lately, so it's hard for me to come to any solid conclusions. I have heard what you say with other folded horns. They do seem to reach farther. It's hard to set up and compare without disturbing the peace. When I'm doing a critical gig, I like to use my tried and true. Other less critical gigs, I like to try stuff out. I do know that on my first gig using the titans, I was underpowering them. Even so, they didn't do that bad. Even with the omnitops, I'm still experimenting with how to eq them. I always RTA them, but do I cut the frequencies that are too loud, or boost the ones that are too low, or a little of each? Right now I have my DR260 set with a little hi shelving boost, and a little parametric (wide Q) cut on the lower mids, then I flatten it out with the graphic.

[jeffbabcock]

IMHO it's not a fair test in terms of the way this was conducted.
It's one thing to measure at low levels but another thing entirely to see how a cab behaves when powered closer to its limits.

I would suggest testing again, running very close to the 450W @ 10 ohms requirement of the T48, then do the same with your double 18's. You will notice that it shouldn't necessarily measure exactly the same, and in particular as you push the double 18 more and more the distortion will get worse, shooting a bunch of midrange harmonics into your mix. Some people like this sound, others do not. I view it as uncontrollable, un EQable junk being added to my mix, and there are only a very few scenarios where I would intentionally want to choose this situation, most times I rather have a clean horn.

Also dave you said you ran 2 t48's on a stereo plx2402 for a show? That's considerably underpowering them IMHO. No wonder you were disappointed.

I agree that 1 on 1 a T48 will get close but won't quite keep up with a double 18 unless you corner load it. Certainly not in LF extension. BUT, get into the 4 vs 4 scenario and the tables will drastically turn in favor of the T48.