Fitting new drivers on old titans! Some questions.

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jmanso
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Fitting new drivers on old titans! Some questions.

#1 Post by jmanso »

Hi there!

First of all many thanks to Sean Hennessey that has helped me through all of this and has taught me more about speaker design and performance than I can name. But I can't keep nagging him every time I have a question, so I decided it best to start this thread here.

It's been a while since I posted but long story short I've been building 4 titan 48 for the last couple of years, building has been going on and off but is finally complete!!

Our initial plan was to build with Eminence LAB12s' but we ran into some issues with it as they weren't performing exactly as expected and we eventually blew one driver due to overheating as best as I can tell.

We do bass music nights, heavy on the 30hz - 65hz range and after running the lab12 for some 50, 60 hours it broke.

We have changed drivers to now use 18sound 12NLW9300.

Our "new" titans have been built using these drivers in mind so they fit perfectly, also they were built without the reducer panels as they are not needed.

Now for the real problem, retrofitting the new drivers to the old titans.

The 18sound are about 2mm thicker than the LAB12s, so I had to use a rasp (i think that's what it's called in english) around the baffle to make them fit.

Luckily all the screw holes lined up perfectly so the new drivers actually fit quite nice.

But now I'm left with 2 titans with reducer panels, and 2 without.

Will this be a problem ?

Can I just drill a bunch of holes on the reducers or do I have to actually cut a panel off?

and if it's ok to leave the reducer panels intact, how should i plug them ?

my plan is to have 2 T48s on parallel on each channel of the amp, should I keep the reducer ones together or mix it up ?

And on that note, another question.

Our original amp that does around 650w 8ohm was more than enough to power the lab12s but is now seriously underpowered for the 18sound.

We're really running on a budget here and Portugal doesnt really have that great of an offering in second hand amps.

I was thinking of maybe getting 2 Behringer inuke3000 and run them in bridged mode, running 2 subs on each.

Now I've read both horrifying and great things about these inuke amps, I know they don't really reach the stated power ratings.

These are rated at 3000w 4ohm (bridged) and I only need around 1600w so I'm guessing it's probably all right. Also, they can be bought from less than 200€ each so it's really cheap.

Keep in mind we'll do at the most 1 party per month, so the usage is not exactly club like.

Any thoughts on these, or alternatives anyone ?


Anyway, thanks for any help you can provide !

Cheers.

Bruce Weldy
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Re: Fitting new drivers on old titans! Some questions.

#2 Post by Bruce Weldy »

jmanso wrote:Hi there!


We do bass music nights, heavy on the 30hz - 65hz range and after running the lab12 for some 50, 60 hours it broke.


Our original amp that does around 650w 8ohm was more than enough to power the lab12s but is now seriously underpowered for the 18sound.
If you check the plans, you'll see that the T48 should be high-passed at 35hz - if you were running to 30hz consistently, that may have been why you were blowing them.

As per the plans - the 12NLW9300 should be limited to 70 volts and that's only 612 watts at 8 ohms....so maybe you should give your current amp a try before buying something else. If you aren't limiting properly, you'll blow these new drivers, too.

I don't have any knowledge about the reducers - someone else will have to chime in.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Tom Smit
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Re: Fitting new drivers on old titans! Some questions.

#3 Post by Tom Smit »

If you check the response graphs, you'll see that the 18Sound has a frequency response beginning at 45 hz, whereas the LAB12 starts at 25hz. If you are desiring to play 30 hz, this may be a problem. Also, the lower hi-pass limit is 35 hz when there are 4 or more cabs, rather than the 40 hz for less than 4 cabs.
http://www.usspeaker.com/lab12-1.htm
http://www.usspeaker.com/eighteensound-12NLW9300-1.htm

The reducers can be left in if you want. Read your plans on page 10.
TomS

jmanso
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Re: Fitting new drivers on old titans! Some questions.

#4 Post by jmanso »

I have the limiter and crossover set up according to plans, I just said the type of music is very heavy there so you would know.

Our current amp starts to reach the peak LED at around 57 ~ 59 v if I remember correctly.

It was bought second hand from a Portuguese made brand and I don't have a ton of specs on it.


Thanks on the tip on the reducers.

jmanso
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Re: Fitting new drivers on old titans! Some questions.

#5 Post by jmanso »

another question if you don't mind.

using http://www.ohmslawcalculator.com/ohms-law-calculator

and inputing values 70v and 8ohm it returns 612.5 watts.

according to the plans
With paralleled drivers or cabs voltage is the

same across each load, so the voltage limit that applies to one applies to all.
so if I understand correctly I now have to input values 70v and 4ohm which returns 1220w

that's the minimum I should look for is 1220w 4ohm amp ? What would you recommend so I wont stress the amp as minimum ? 1500w? 2000w ?

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DJPhatman
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Re: Fitting new drivers on old titans! Some questions.

#6 Post by DJPhatman »

It would help immensely if you would go to your "User Control Panel" and fill out what country you are in. We have builders all over the world that can give you advice. Also go through the "Tips, Techniques and Supplier Links" topic and look through the threads that apply to your country.

With that said, you want an amp that that can drive your cabs to 5-10% more than your limit, in your case, I would look for an amp that outputs around 1400-1500 watts @ 4 Ohm. BUT, I would also suggest you limit your cabs back from the 70V limit Bill has in the plans, a "Safety zone". I would suggest you set your limiters to 55-60V, as long term, repeatedly hitting the limit is going to build up heat and burn-out the VC anyway. If you are not getting enough bass at a 55V limit, you need more cabs, not more amp. Doubling power only gets you +3dB. Doubling cabs gets you +6dB, +3dB for the doubling of drivers, and +3dB for doubling mouth area, assuming all cabs are the same width. YMMV.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

jmanso
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Re: Fitting new drivers on old titans! Some questions.

#7 Post by jmanso »

Sorted the location, thanks on the tip.

Well i guess i need to take some measurements on the amp to see some real voltage outputs before returning here.

The 18sound is rated 800w at 8ohm so thats 80v, bill states a 70v limit, 55 to 60 is only about 2/3 of rated power, isnt this a bit too low? Isnt a 65v limit enough to help prevent overheating?

I know i'll only have some reference once i power the 4 subs and listen to it, but wont those 15v provide a noticeable difference?

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DJPhatman
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Re: Fitting new drivers on old titans! Some questions.

#8 Post by DJPhatman »

jmanso wrote:Sorted the location, thanks on the tip.

Well i guess i need to take some measurements on the amp to see some real voltage outputs before returning here.

The 18sound is rated 800w at 8ohm so thats 80v, bill states a 70v limit, 55 to 60 is only about 2/3 of rated power, isnt this a bit too low? Isnt a 65v limit enough to help prevent overheating?

I know i'll only have some reference once i power the 4 subs and listen to it, but wont those 15v provide a noticeable difference?
Measurable difference, yes, noticeable difference, I highly doubt it. Doubling power only adds +3dB. But, you will also start to run into power compression as you close in on the upper limit. That could eat up your +3dB, and maybe more.

Lets say you are rowing a boat. How far would you last rowing as hard as you can? How far can you last rowing at an easier pace, say half your power? Running any electric/electronic device to its limit can cause heat build-up, which is deadly to electronics. And speaker voice coils. If 55-60V is not loud enough, you need more cabs. If you have 4, 4 more would net you +6dB, or perceived as twice as loud.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

jmanso
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Re: Fitting new drivers on old titans! Some questions.

#9 Post by jmanso »

Makes perfect sense. Thanks

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DJPhatman
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Re: Fitting new drivers on old titans! Some questions.

#10 Post by DJPhatman »

jmanso wrote:Makes perfect sense. Thanks
I know it's not the answer you were hoping for, and it goes against everything you have learned about doing PA. But this is a no bull shit forum. We give you "Big-Boy" sound without the "Big-Boy" price tag!

BTW, have you thought about tops? What tops you use, and whether they can keep up, is very important to what is perceived as bass. If you are crossing over to the tops at say 80Hz, but the tops are -6dB from the subs at 80Hz, your sound is going to be off.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

jmanso
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Re: Fitting new drivers on old titans! Some questions.

#11 Post by jmanso »

Yes i have bought a pair of ot12 from a fellow forum user, we've been running 2 tops 2 subs for over a year now. I run it all through a dbx pa+ or whatever the model is called.

Its a pain to eq on but it does the job

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Re: Fitting new drivers on old titans! Some questions.

#12 Post by Grant Bunter »

jmanso wrote: that's the minimum I should look for is 1220w 4ohm amp ? What would you recommend so I wont stress the amp as minimum ? 1500w? 2000w ?
1500W/4 ohms should be ok.

Sometimes people are tempted to purchase hugely overpowered amplifiers, and one of the problems with that is that it is almost impossible to limit amplifier output to the specified value, without having the DSP ( in your case the PA+) constantly engaging the limiter.

DJP is correct.
Although you might have some drivers capable of X voltage, you don't want to run them that hard all the time, or sooner or later they will break.
Even though you have added 2 more cabs, if you find yourself trying to push all 4 cabs to their maximum output in voltage, then you need more cabs...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
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jmanso
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Re: Fitting new drivers on old titans! Some questions.

#13 Post by jmanso »

so I had a look at both thomann and musicstore,

and we have a budget of around 450€ to get our rack sorted, we have a decent amp for the tops, already have a 10 or 12u rack case and as I said, already have the dbx unit.

I understand the part where having an overpowered amp will lead to constantly engaging the limiter but there just aren't any amps that deliver 1500w 4ohm at this price range.

I narrowed it down to 2 options,

option one is this:
https://www.thomann.de/pt/the_tamp_tsa_4000.htm

It's Thomann brand, the T.amp, and its rated at 1500w / 4ohm and it costs around 450€.

Other option was the behringer I showed earlier that is rated at 3000w/4ohm in bridged mode,
https://www.thomann.de/pt/behringer_inu ... 0_259406_0

but after some research I found a thread in the diyaudio.com forum that states this:


Behringer lists these specs in the iNuke 3000 DSP brochure.

NU3000:
RMS
Stereo
-------
8 Ohm per channel, stereo 315 W
4 Ohm per channel, stereo 620 W
2 Ohm per channel, stereo 1040 W

Bridged mono
---------------
8 Ohm 1250 W
4 Ohm 2075 W

so either I get 1 t.amp or 2 behringers, which will end up costing just about the same, but I guess the behringer will allow me to possible add 2 more titans if needed without needing a new amp.

Thoughts ?

Grant Bunter
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Re: Fitting new drivers on old titans! Some questions.

#14 Post by Grant Bunter »

When should you bridge an amp?
If you can avoid it, never,unless it's the only way to get the voltage swing you require.

The Berry 3000, if it has real world output of 2075W/4ohms, = 91V
That's 21V of limiting to do.

I honestly don't know if the PA+ can achieve that, without hitting the limiter constantly, as described earlier. Someone who has limited an amp a lot with a PA+ may be able to help with that.

If you're looking for an amp that can do 1500W/4ohms, well, that's pretty much what a Crown XLS 1500 does bridged. Same for the "newer" version, the XLS 1502...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Bruce Weldy
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Re: Fitting new drivers on old titans! Some questions.

#15 Post by Bruce Weldy »

Grant Bunter wrote: I honestly don't know if the PA+ can achieve that, without hitting the limiter constantly, as described earlier. Someone who has limited an amp a lot with a PA+ may be able to help with that.

If you're looking for an amp that can do 1500W/4ohms, well, that's pretty much what a Crown XLS 1500 does bridged. Same for the "newer" version, the XLS 1502...
This looks like a job for
Superman.jpg
Superman.jpg (13.92 KiB) Viewed 1756 times

or....me. As I have limited amps with the driveracks and I have specifically used (and still use) Crown XLS 1500s in bridge mode - here's the skinny. I feel like I have to limit a little more than I'd like. Not a problem, but it's a bit more power than 2 Titans at 55 volts needs. But, it's as close as I've been able to come and still have enough headroom without it being too much.

The Behringer (if the specs can be believed) is too much for the application. The driverack will be into the limiter too much and too often.

Find a better solution. Either less power in bridge mode or more power per channel at 4 ohms (or 8 and get two amps)

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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