First DIY project for a guy looking to upgrade - multiple sealed 18s? - Page 16

yea i read it in another thread and did this

lol. I did that to your post. I think I said "whaa?" out loud.

So it's gonna be xmax for xmas?

lol

Right.The advantage of more powerful drivers comes in when you need more than the lesser driver can give from the same amount of space. An LMS or UXL will give comparable performance to two lesser drivers in half the space if you have the power.

^^ +1 we're all on the same page. (well maybe not all of us)

Dude no way I had to look myself and unbelievable. May snag a few more to stockpile myself.

Continuing about the 18HO; some people just don't like "game changers". But that's the nature of the hobby we're in when things advance. More for less, doing more with less $ etc. As much as I'm completely satisfied with our dual dts-10's $/size/output/pwr consumption, sure the dayton 18's are intriguing to think about. And the bass head contemplates what if. . .

Well yeah. This is obvious to me (maybe not everyone else watching) so I don't fully get Bosso's numbers. I get that on a driver to driver/box to box comparison that both the UXL and LMS-U are much more capable. We're talking multiples here. Pretty much everyone around here knows that the best performance is had with multiples. Your numbers show that the UXL and LMS-U have roughly 6dB of extra output potential over the Dayton 18HO. So add a second with the same amount of power and we're back to zero difference. Bosso is saying now with the Dayton 18HO that one would need 3-4 drivers to equal a single of the more capable drivers. This is where I am now lost.

If it's something really obvious that I'm just missing or forgetting then please, let me know. I'm not the smartest person here but I am confident that my math is correct and that that two Dayton 18HO's should be nearly equal to one UXL/LMS-U. One just has to use twice as much air space.

Booo. That is a killer price on those. Too bad they are out of stock online. They don't carry them in my podunkville either.

Hey Bass Addict,

Which part of 'podunkville' are you in -- not alot of us on this forum.

I'm talking about what I originally said, which is: 2 X UXL-18 will mop the floor with 4 X 18HO.

The amplification should not be any part of the debate. It clouds a simple issue unnecessarily. It's simple to get lost in cherry picking Josh's numbers and finding the rest of the data in WinISD, et, al, but his adding voltage numbers should open the door wide enough to make it crystal clear, if the amplification is to be considered.

He fed that Dayton driver a 10,000W burst to get the CEA # at 40 Hz. Do any of you out there know of a DIY sub that can attenuate that much power down to 600W when a ULF effect hits at 10 Hz, which is all that was used to drive the Dayton to the 10 Hz CEA # y'all are using for comparison? I don't. In any normal scenario (like EQing the Dayton system in a room and playing WOTW), the Dayton would explode.

You can use sims and ignore reality, like LTD is wont to do, all you want, but I prefer putting actual subs in an actual system and seeing what they can do.

As far as the sims go, look at the graph I posted. The 3 Dayton sims posted by various and sundry folk are not even close to what Josh saw from the test. To then look at the same sims and predict the subs excursion after EQ to get a decent response in-room when playing soundtracks with 10,000W of power is a bit absurd. No, check that, it's insanity.

Josh's numbers tell me what the difference would be. I've built enough subs and seen for myself what the difference is when using 4 Dayton-type drivers vs 2 Tumult-type drivers, so I stand by my statement and no one has offered any data that would sway me from it at all.

LTD says, for example, a pair of Daytons has higher sensitivity down low than a single UXL. How so? Aren't the Daytons 3.41 ohm drivers? How would he wire them? Surely not parallel, which would be 1.7 ohms. No, you'd wire them in series. Double the resistance and what happens to your sensitivity? To clock the CEA # at 10 Hz Josh applied a 600W burst. To limit the system to a 600W burst at 10 Hz, your 40 Hz max burst number drops by -12dB. Wire 2 of them in series and apply the same burst and you get zero gain dBSPL, therefore zero sensitivity gain. You would need to double the burst power to yield a +3dB result, not +6dB as LTD suggested.

To drive the Dayton to where it couldn't go any further, Josh applied a 2500W burst @ 10 Hz. Assuming the driver can operate safely connected to a 2500W amp with actual source (which I don't), that pulls your 40 Hz # down by -6dB.

MKT suggested 8 X Dayton vs 4 X UXL with a clone FP14000. The Daytons would result in either A) 2 channels X 4 ohms (4400W/CH) or 1 channel X 8 ohms (8800W Bridged), same difference either way. A plausible system, IMO and experience and using Josh's data. 88dB @ 2M @ 10 Hz short term drives the system close to its max, plus 18dB = 106dB.

The UXL X4 system would be 14000W Bridged into 4 ohms. Another plausible system, IMO and experience. 96dB @ 2M @ 10 Hz short term drives the system close to its max plus 12dB = 108dB.

When you look at the compression difference of driving these 2 to where they can go no further, the gap widens in favor of the UXL.

That looks like at least 3 Daytons to 1 UXL to me.

IOW, the max CEA #s tell me the UXL = 3 Daytons. That's the only conclusion one can draw from those numbers. Look at the posted graph with the actual numbers plotted on it. Bring amplification/sensitivity, etc into it and let's look at the system in a room with WOTW. That's what I do. Others, like LTD look at WinISD and draw their conclusions while apparently ignoring the rest of Josh's data, or how it translates to a real world system in actual use.

I would port the Dayton driver. That's what it's made for. It has too large a disparity from 100 to 10 Hz to believe it will drive a viable full BW system, like the UXL is designed to do. That's just me. For a full BW sealed system, UXL all day long. What will happen is most will think the Dayton is the cheaper alternative and the UXL will go the way of the dodo for lack of sales.

It's interesting... Often a lot I don't pay direct attention to sensitivity numbers of sub systems with multiples. I usually just look at a system and then drill it down to a singlular bass unit (driver, box and amp) and then add 3/6/12/etc dB for multiples. I'll have to look again at the numbers but what you say does make sense to me.

Still, I think the Dayton is a nice alternative driver and a real nice one for the budget. I would certainly NOT like to see the UXL-18 disappear. Sure wish I saw more builds with them, actually. It's a great driver too for the money but up in a higher ....umm ... "grade" than the Daytons.

Good catch. No dice for the Clone.

as popa already stated, that is correct. Safe to keep them at 4 ohm stereo, or 8 ohm bridged...kind of a bummer, but I am not really that into blowing $1,000 amps, even if they are a huge deal over the real ones.

"You can use sims and ignore reality, like LTD is wont to do, all you want, but I prefer putting actual subs in an actual system and seeing what they can do."

that is exactly what ricci did. the dual ho's provide more clean spl than the uxl.



"LTD says, for example, a pair of Daytons has higher sensitivity down low than a single UXL. How so? Aren't the Daytons 3.41 ohm drivers? How would he wire them? Surely not parallel, which would be 1.7 ohms."

you could wire them in parallel if you had nominal 2 ohm stable amp channels.

but of course that is another topic than the bet.

"Josh's numbers tell me what the difference would be. I've built enough subs and seen for myself what the difference is when using 4 Dayton-type drivers vs 2 Tumult-type drivers, so I stand by my statement and no one has offered any data that would sway me from it at all."

that's not so. i've explained it several different ways. you've chosen to just ignore it all.

"IOW, the max CEA #s tell me the UXL = 3 Daytons. That's the only conclusion one can draw from those numbers."

nope. 1 uxl got beat by 2 daytons.

"I would port the Dayton driver. That's what it's made for. It has too large a disparity from 100 to 10 Hz to believe it will drive a viable full BW system, like the UXL is designed to do. That's just me."

if you eq down the top end, you still benefit from the sensitivity. two dayton ho's have more throw on the bottom end than the uxl. that is why they produced more clean spl down there.

i just grabbed the data off data-bass. level matched at 100hz, the dayton has *less* rolloff at 10hz than the uxl, but that really doesn't matter.


Edited by LTD02 - 11/27/12 at 1:16pm

Hey Dave,

what do the SSD's that you currently run offer over the HO's? I kinda feel like a system of 8 HO's in comparo to your SSD setup in the blackbirds would be virtually the same thing! And I know from your graphs the ability those systems have achieved! I don't mean to be rude here but it kinda seems to me like the pot/kettle argument since you settled on a multi/less capable/cheaper/sub system yourself?

So... in this UXL is 3 times better than the Dayton HO's scenario. All you care about is quantity, not quality?

Why not? According to their specs they are 4 ohm stable in bridged mode.

The $4K-6K+ OEM LG FP14000, yes.

The $900 Chinese Clone, no.

Ah, gotcha.

"So... in this UXL is 3 times better than the Dayton HO's scenario."

ain't gonna happen. the uxl would need 69mm of excursion one way to keep up with three ho's.

I think this falls under the "there's no replacement for displacement" scenario.

Bosso,

You mention the voltages used to produce the burst numbers. Someone mentioned that it would be interesting to see that data so I just recently started doing it. It was a good suggestion. You are using this data for the RS18 but not the UXL. I hadn't started logging it yet so I don't have the calculated numbers for the UXL or any older stuff unfortunately. However every sub driver is being given the whole amp at 63Hz and above. Most long throws will take the whole amp at 50Hz. Some really long throw ones will take everything in a short burst at 40Hz. I just redid the XXX's and they will take everything the amp has in a 4.5 cube box at 10 and 12.5Hz without running into xmech. (They really do need a much larger enclosure than this and are handicapped.) Anyway the point being that the UXL was being given similar power 40Hz and above and probably equal if not considerably more power than the RS to produce it's output #'s in the low bass in the same box.

Obviously the amount of power supplied to get the burst numbers in the top of the range will launch the cone out of the driver like what happened with the UXL in the lower bass freq's and set the coil on fire in short order if applied more than momentarily. One cannot look at the burst numbers at 40Hz and above and assume they will get that type of output with 1/4 to 1/10th of the amplifier. You are spot on with that assessment. I know a lot of guys are probably doing this mistakenly. The reason that this big of an amp is used is to make the driver the limiting factor as much as possible. Unfortunately along with that comes the assumption that their EP2500 is going to be just as capable. As far as determining a realistic amp match from the DB results the best course is probably to look at an amplifier that provides power that falls in the range of the voltages used in the two highest compression sweeps. Since there won't be danger of mechanical damage in the low bass.

One other thing to consider is that a lot of the compression in drivers is not just thermal but a large part is loss of BL and suspension non linearity. At the top power levels most drivers are no longer responding to the power increases in a linear fashion even though they are short bursts. For example the RS18 takes a crap ton of extra power to get the last 2 dB in the low bass.

I know you get all of this I'm just clarifying for others who might bot have thought of this.

Yeah, i get that. But thats abit beside my point, you skipped the question related to what you quoted
(No worries, the question was more directed at Bosso anyways)

for all practical purposes, i don't see anything in the measurements that would suggest the uxl is materially different to the dual daytons when it comes to distortion except for the relatively high le/re, but it doesn't seem to have affected the impulse response.

So, do I need to send another UXL-18 driver to Ricci to complete testing? Last time we didn't do so well.


EDIT: I wish I had seen this thread earlier and participated.

Gorilla asked about reliability which I thought I'd comment....

I've received 4 UXL-18 drivers. 2 in-person from Mark, 2 from shipping.

1st driver went to Ricci, you know the story. Replacement driver (hand-delivered) working perfectly.
2nd driver got siliconed to an eD cab (I'm dumb). This one is making a rub at very high excursions which only happens when I'm demoing subsonic stuff. I'm planning on sending back to Mark and he said he will take care of it (once I actually figure out HOW to get it out--help).
3rd driver (hand-delivered) originally wired as a dual voice coil working perfectly.
4th driver (mailed) seems to have an air leak that I need to lock down but do not believe (after 4x installing in box with putty seal and the normal stuff) it is the driver to cab seal.
Since nothing is noticeable until I'm pushing them hard I haven't really gotten after perfecting it all yet.

Mark has taken care of any issues that have arisen thus far and I appreciate that in this day and age. I think the shipping and the weight of the drivers that has been discussed before may have caused issues. Many people with even larger FTW21s seem to have had no issues.

I swear its just me. All of my sub build components have had issues. See my thread for fun laughter and my pillow punching.
Edited by HuskerOmaha - 11/27/12 at 4:04pm

One point of correction, Bosso never referenced bridging the FP14k at 4ohms. He said 2) 4 ohm stereo channels or 1) 8ohm bridged. 8 of these on a clone would be effortless output for both the drivers and amp. IMO 4 of these wired for a 4ohm load bridged is the sweet spot (highest amp output, max efficiency) for something like the marathon or crown and cerwin Vega amps referenced earlier. Or...8 on the clone either stereo or bridged.