Ricci

There was some question of why I chose this driver to replace the XXX's and how its extremely strong motor and over-damped response with a rising top end translate into a system design versus a more traditional driver. I'll attempt to explain part of my thought process here. Let's start with the sensitivity of the (4ohm) XXX drivers at 2 volts and compare it to the response of the (2ohm) T3 19 drivers at 1.4volts in the same cabinet. We can see that the 19 has much higher top end sensitivity but the XXX has much greater mid-band sensitivity. The 19 is operating with a low qtc in the sealed test box to the point that it is very over damped. The XXX on the other hand is in a box much smaller than optimum in the same cabinet. This shows up in the low end response of both systems with the 19 exhibiting a much shallower roll off and the XXX having one that is steeper than 12dB octave from 10-20Hz. This ends up giving the 19 an advantage in sensitivity in the deep bass.

Couple of things that were asked for earlier in the thread. Close mic of the 19 versus a 2m GP measurement. In general close mic exhibits slight top end roll off and slight increase in LF. Hinge point seems to be near 50-70Hz somewhere. Also if more data is needed on this effect in particular I have probably 20 sets of close mic FR directly comparable with outdoor GP. I've already posted a few of the Othorn with different drivers. All of my data on it comes from a few sealed cabs and one tapped horn. Close mics are taken inside my garage. Different baffle sizes may have a large effect.

Might be interesting to try a test at the impedance maximum and see what type of voltage reading you get there.

Typically if the impedance gets higher the amplifier will be limited by the amount of voltage it can swing. If voltage is the limitation, rather than current demand, which will drop as the impedance increases, then the voltage limit should plateau with little fluctuation as long as the signals used are similar.

Luke It seems odd that the voltage recorded at 40Hz was lower than at 20Hz in both tests even with a higher impedance.

You will...

Bro...They can't all be Roy Rogers films.

Ok just checking.

Out of curiosity. When you were having the strange issues with the test rig were you measuring an amplifier that was bridged or a bridged configuration?

Well there it is. Another one I'll be skipping. It's weird to me that there is so much clipping getting through onto the final product. I understand loudness wars and going to 11 and all of that but the thing is this stuff is audibly distorted a lot of the time. It doesn't sound good to anyone I know. It sounds like something is overloaded or clipping. I can understand it with music / movie mixing for an occasional effect and a change in tone on certain parts but some of this is in the dialog, the center and main channels and just sounds like a distorted mess or a blown speaker. I don't see how this could be missed during mixing or construed as intentional for effect? I'm thinking of movies like Immortals here. Has anyone listened to that on a HTIB or soundbar type system? I have and it seems to sound even worse on those types of capability limited systems. There is an art to getting a highly compressed "crushed" mix with little dynamic range that is right up to the edge of digital clipping but remains just under. The music engineers have been doing it for decades but you don't typically hear this type of problem even in very heavily compressed mixes.

Wow...Sorry about your string of bad luck. You are correct there should not be voltage across your outputs with no signal. DC coupled in marketing literature means that the unit has the ability to pass a DC current from the outputs but there should never be voltage present on all of those outputs even with no signal present. Something is funky somewhere.

Guess I'm no one. I was interested in the Hobbit movies. I dug the LOTR trilogy movies and thought the sound work was good. Read all the books as a kid. I'd say a gigantic fire breathing dragon should have had a bit of low end as well. It's not like that wasn't a very big movie as well. It had plenty of backing. There was like no bass at all...Or damn near. Not even a loud 40Hz rumble rehashed 50x in a row. Avengers at least had some bass. Generic action movie bass to be sure but at least it wasn't MIA completely.

I'm just saying that I don't predicate whether a movie has a worthwhile soundtrack solely on the bass extension. For example I thought the soundtrack to Whiplash was excellent but there isn't anything crazy going on below 20Hz. Pretty close match which doesn't bode well. It probably is a generic 30Hz rumble film. Hopefully it isn't clipped at least. I wouldn't call Avengers the biggest bass disappointment ever either. A letdown for sure but my vote for worst would be for 2012 or the Hobbit or even HTTYD2.

Spectre might still be all right. You can't expect every movie to have WCS peak levels with rising bass down to 1Hz. I'm more worried about things like whether the soundtrack is clipped, how dynamic it is and how varied the bass sounds are. Also whether the movie is good. It certainly might be a loud, clipped all to hell, 30Hz recycled rumble for every explosion type of movie. I'm hoping not though. We've got plenty of those already.

Damn...Sorry to hear that. I'd be pissed off at receiving another defective unit. Doesn't give me a warm fuzzy about Motu.

The overhung version has quite a lot more motor force than the split coil so it works in a smaller box. It doesn't model like the split coil version. 6 to 8 cubes should be just fine.

The 5400 just got bought and the Dayton UM18 is gone. Still available. BMS 18N862's B&C 21IPAL's RE Audio XXX 18d2 v2's Rockford T3S2-19 Chane SBE-118 Chane VBE-118

We did spend time listening to the Radian's when I was at Beast's GTG but they were run for surround duties only. From what I heard they are quite good. I never heard them struggle and they didn't otherwise draw attention to themselves which is a good thing in my book.

Transporter: Refueled taps out at 25...Tons of 30-40Hz rumbles no doubt.

January 2016 Updated for sale list... I'm in the Louisville KY metro area. No international shipping. All equipment is used and may have a few cosmetic blemishes, etc... but is otherwise in correct functional shape. 2 RE AudioXXX 18d2's Two left. Both are the overhung version 2 which has much higher motor force and the RE logo. $550ea shipped or $450 each local pickup. I will drive a bit to meet. Chane Audio SBE-118 and a Chane VBE-118. Both are passive cabs with a single Eminence built 18" driver. SBE-118 is sealed (Roughly 22" cube) the other VBE-118 is slot vented and tuned to the 17Hz range (Roughly 23x23x36"). Local pickup only. $175 each. I will drive to meet. BMS 18n862 18's. 1 pair. Low distortion with excellent all around performance. Little bit of oxidation on the motors. $450 each shipped. $400 each local pickup. B&C 21 IPAL's. 1 pair. Barely used at all. $900 each shipped. $825 each local pickup. Will drive to meet. SOLD!!! TC Sounds LMS 5400 18. SOLD!!!! Working condition. This one has a surround glue joint which has been repaired. The surround detached from the cone after heating up in the summer sun. Has been re-glued with Loctite 416 rubberized glue. It is NOT pretty but it functions 10/10. The measurement data for the LMS driver posted here were taken from this driver AFTER it was repaired so rest assured it functions just fine. Will post a few pics when I get a chance. Would be a good choice if the driver is to be downfired, behind a grille, or in a horn. Have the original packaging. $650 shipped. $550 local pickup. Will drive to meet. SOLD!!!! Rockford Fosgate T3S2-19. Basically new. Bought and tested. Factory packaging. $1350 shipped. $1250 local pickup. Will drive to meet. SOLD! Dayton Audio UM18-22 SOLD! New in box. Never even opened the packaging yet. $240 shipped. SOLD!

Post #17 has a before and after...It used to be easy to post up a measured electrical signal after EQ when I used the DCX's not so easy after the amps. I'll see if I can whip something up. Basically a slight 2dB wide band boost centered at 20Hz and a sharp cut near 43Hz for the peak and a little bit of wider band cutting of a couple dB near 60-90Hz. I have been lazy over the holidays and haven't been motivated to tweak it any more yet.

Always surprises me how little bracing some of the car audio guys have in their boxes. Makes me want a CNC really bad though. I'm really happy with these drivers. I've been watching some movies on the big rig over the holidays. Nothing has come close to making the drivers sweat so far. Ran Olympus has Fallen, Oblivion and John Wick over the holidays. I had OHF set to REF and pushed the subs to +4 over and it was nothing for them. Probably run EOT and WOTW at stupid levels soon but I need the house to myself. I also removed the DCX's from the system and switched to the DSP in the K20's for the bass. That got me a bit less signal chain roll off. Had to completely redo my gain staging though but without the DCX's in the loop it is now much less complicated. The T3's require less overall signal manipulation compared to the high inductance, high qtc sealed alignment with the XXX's and have way better top end sensitivity and extension. Thermal handling and overall efficiency are much better as well. I can't really say it sounds a whole lot different but it does seem like these changes resulted in a much better upper bass range through the crossover region. It definitely seems like there is a better sense of attack and punch on kick drums and sharp upper bass transients when the system is cranked up. Could just be placebo but I'd like to think all of those small changes added up. If I had to guess I'd say that the XXX's were compressing a bit on the top end due to quite a bit of power being applied to the coils in that range after equalization. The T3's are probably using 1/3 to 1/4 the power.

Just watched star wars. I've got high hopes for the mix. Hopefully it's done right. There are a ton of scenes which could be stellar both for surround work and bass. Surround info sounded pretty good in the theater I went to but the bass in there is a joke. I thought it was a solid movie as well.

Thanks Max!

How much room you got behind your screen to the back wall Beast? Just curious in case I come up that way again.