T48 drivers 2022

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Bill Fitzmaurice
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Re: T48 drivers 2022

#16 Post by Bill Fitzmaurice »

I don't recommend the Kappa Pro for any application because of the very low Q. I don't recommend PAudio because they tend to widely deviate from their published specs.

Camillo
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Re: T48 drivers 2022

#17 Post by Camillo »

Sweet :thumbsup:


Anyway, I guess we'll pick up where we left off...
Previous discussion wrote:...that driver will be displacement limited to 95 volts. Using the equation V × V ÷ Ω = Watts, you'll need an amplifier capable of at least 1100 honest watts per channel.
I've been reading a bit since i got the dbx 260, you wrote limited to 95 volts? How did you come up with that? I tried some pages to calculate but they show different and some over 100v.. Can/do i set the limit for each channel/speaker or only on the sub? I really try to educate myself but i think it is hard to get a good grip on things 😆😆 it's a lot! 😆
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

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Seth
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Re: T48 drivers 2022

#18 Post by Seth »

Hey Camillo :thumbsup:,

A word of caution that we all should be mentioning when recommending the dbx Driverack is, do not set limiters the way they instruct in their manual. Doing so will not protect your drivers. Absolutely read the manual and become familiar with the functionality of the unit... Just don't take the information to be an audio textbook. When it comes time to set your limiters, do a search on this site or feel free to ask too.

The voltage limit of a specific driver in a specific cab is derived by using modeling software. Hornresp is the software most use to predict the performance potential of horn loaded speaker cabinets and drivers used in them. The program calculates various performance parameters of the driver and enclosure. One of which is diaphragm displacement, sometimes called excursion. It's the distance the cone travels in one direction from it's at rest position. With identical input voltage, the excursion varies widely throughout the frequency range. The voltage that causes the cone to move the furthest at some frequency without exceeding the driver's Xmax rating is what we consider to be the maximum safe voltage. Unless the driver's RMS power/voltage is less, that's where we limit the voltage.

I've reverse engineered Bills cabs from the SketchUp files and entered the dimensions I've taken from that into the program. I assume the dimensions I use aren't exactly what Bill has used. I do believe they're close enough to get a reasonable idea of how specific drivers will behave in the cabs though. And Bill, please step in and correct anything in need.

Here's your driver's diaphragm displacement in a 36" wide T48 with 95 volts, using a 24dB Butterworth highpass filter set to 40Hz.
Screenshot (195).png
Screenshot (195).png (11.19 KiB) Viewed 2275 times
Displacement crests 12mm just below 60Hz, the driver's Xmax is 12.1mm.

So, you can put more into it. And you can probably do it safely. But, the gains to be had after that point are slim. At less excursion than Xmax, the cone movement is fairly linear and doubling power typically net's an additional 3dB in output. But, beyond Xmax, cone movement is less and less linear and doubling power will net less than 3dB. There's less coil in the magnetic field to translate the voltage into cone movement and the cone's suspension becomes increasingly resistant the further out the cone is. So, you get less and less output the more you increase the voltage beyond it's designed useful limits. That's typically what leads to driver failure, especially with horn loaded subs, because they sound so great and don't exhibit the audible que's direct radiating subs do when pushed too hard. Louder, louder, louder, pop.

So, we limit voltage at Xmax and that's how I came up with 95v.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Re: T48 drivers 2022

#19 Post by Seth »

Camillo wrote: Sun Jul 03, 2022 5:18 am Can/do i set the limit for each channel/speaker or only on the sub?
As long as you (or whoever is controlling it) is/are not pushing the system deeply into audible distortion, it's only required for the sub/s. But, since I have the ability and "why not", I also set limiters on my tops. I set mine at the RMS rating of the speaker to protect from inadvertent pops, clicks, and whatnot. Others, and I believe Bill too, have mentioned setting them for half RMS value... I believe the rational is tops typically exhibit audible distortion by then. But, that's just a guess.

Limiters are set while the speakers are disconnected, using a Digital Multimeter set to read AC Volts, while playing a sinewave through the system. I typically use 60Hz for the subs and 600Hz for the tops. Never have, but would likely use 6000Hz if I was setting limiters for a tweeter.

We'll walk you through it when the time comes. :thumbsup:
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Camillo
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Re: T48 drivers 2022

#20 Post by Camillo »

Seth wrote: Sun Jul 03, 2022 1:14 pm
Camillo wrote: Sun Jul 03, 2022 5:18 am Can/do i set the limit for each channel/speaker or only on the sub?
As long as you (or whoever is controlling it) is/are not pushing the system deeply into audible distortion, it's only required for the sub/s. But, since I have the ability and "why not", I also set limiters on my tops. I set mine at the RMS rating of the speaker to protect from inadvertent pops, clicks, and whatnot. Others, and I believe Bill too, have mentioned setting them for half RMS value... I believe the rational is tops typically exhibit audible distortion by then. But, that's just a guess.

Limiters are set while the speakers are disconnected, using a Digital Multimeter set to read AC Volts, while playing a sinewave through the system. I typically use 60Hz for the subs and 600Hz for the tops. Never have, but would likely use 6000Hz if I was setting limiters for a tweeter.

We'll walk you through it when the time comes. :thumbsup:
Thank you! I tried from a thread here, 60hz and did set the mixer to unity measuring approx 45 volt from the amp i'm using (500w rms only, non bridged) pushing the fader to max gave me 60v. I will change amplifier later but my question is, would it be "safe" to use a weak amp if it only delivers 60v at full or is this a bad idea? And since i dont reach the 95v i dont know how i can limit it up there or should i then limit lower? . These are questions of curiosity, will test it with a stronger amplifier and see what it delivers:) and sadly it will be bridged then 😜
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

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Seth
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Re: T48 drivers 2022

#21 Post by Seth »

Camillo wrote: Wed Jul 20, 2022 1:50 pm ...would it be "safe" to use a weak amp if it only delivers 60v at full or is this a bad idea? And since i dont reach the 95v i dont know how i can limit it up there or should i then limit lower? . These are questions of curiosity, will test it with a stronger amplifier and see what it delivers:) and sadly it will be bridged then 😜
Good to hear from you Camillo :thumbsup:

It's not a horrible idea. But, also not a good idea. It's something I might do myself. But, also something I'd tell others not to do. Willing to chance my own stuff, not yours.

The "best practices" recommendation is, don't run without a brick wall limiter.

Chances are it would be fine. Slight chance it wont.

Up to you if it's worth it or not.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Camillo
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Location: Sweden

Re: T48 drivers 2022

#22 Post by Camillo »

Seth wrote: Thu Jul 21, 2022 11:29 pm
Camillo wrote: Wed Jul 20, 2022 1:50 pm ...would it be "safe" to use a weak amp if it only delivers 60v at full or is this a bad idea? And since i dont reach the 95v i dont know how i can limit it up there or should i then limit lower? . These are questions of curiosity, will test it with a stronger amplifier and see what it delivers:) and sadly it will be bridged then 😜
Good to hear from you Camillo :thumbsup:

It's not a horrible idea. But, also not a good idea. It's something I might do myself. But, also something I'd tell others not to do. Willing to chance my own stuff, not yours.

The "best practices" recommendation is, don't run without a brick wall limiter.

Chances are it would be fine. Slight chance it wont.

Up to you if it's worth it or not.
I see, that's a good answer. I would probably be fine then, for a while at least😜 i just dont figure out how to set the brick wall limiter when i dont reach the maximum intended volts. Might be a language barrier, i might search for it in swedish then. Would it be correct to use, lets say, an amplifier with hotter output and set the treshold at 95v with that and then plug in the weaker amp with the same setting? I guess not? Or should i limit it at lower volts using that 500w amp?

Thanks a lot by the way! :)
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

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Seth
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Re: T48 drivers 2022

#23 Post by Seth »

You're welcome. Happy to help out :thumbsup:
Camillo wrote: Fri Jul 22, 2022 4:54 am ...how to set the brick wall limiter when i dont reach the maximum intended volts....
Play a 60Hz sinewave with the speaker disconnected and amp at full gain, turn up the source volume until the amplifier's clip light turns on. Then reduce the limiter's threshold setting until the clip light turns off. This will limit voltage to just before the amp starts to clip.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Camillo
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Location: Sweden

Re: T48 drivers 2022

#24 Post by Camillo »

http://www.loudspeakerdatabase.com/18Sound/15w700

Putting it in this thread aswell. How would it perform compared to the Eminence budget alternatives recommended? :)
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

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Seth
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Re: T48 drivers 2022

#25 Post by Seth »

I'm not currently inspired to delve deeply into it. But, it's within spec and should work just fine.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Camillo
Posts: 64
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Location: Sweden

Re: T48 drivers 2022

#26 Post by Camillo »

Thanks Seth! I eBayed it.

Without digging to deep, what to think about mixing coupled titans with different elements? I did build a lavoce one with almost the double VD. Do i want to run them at equal power or run both to their different limits? V-Coupled, that is.

Seth wrote: Wed Apr 05, 2023 9:47 am I'm not currently inspired to delve deeply into it. But, it's within spec and should work just fine.
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

Camillo
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Location: Sweden

Re: T48 drivers 2022

#27 Post by Camillo »

Oh i know, just thought on the top of your (or anyones) head. Not the specific elements, just in general of mixing elements what could be bad and what can work 🙂 perhaps there is no universal answer🤷‍♂️ and also, thanks for previous help!
Camillo wrote: Fri Apr 07, 2023 10:10 am Thanks Seth! I eBayed it.

Without digging to deep, what to think about mixing coupled titans with different elements? I did build a lavoce one with almost the double VD. Do i want to run them at equal power or run both to their different limits? V-Coupled, that is.

Seth wrote: Wed Apr 05, 2023 9:47 am I'm not currently inspired to delve deeply into it. But, it's within spec and should work just fine.
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

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Bill Fitzmaurice
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Re: T48 drivers 2022

#28 Post by Bill Fitzmaurice »

Camillo wrote: Fri Apr 07, 2023 10:10 am Without digging to deep, what to think about mixing coupled titans with different elements?
Bad idea. You'd be creating a chain with a weak link.
I did build a lavoce one with almost the double VD
Double the Vd equals 6dB additional maximum output. You don't want cabs with more than 2dB difference in maximum SPL.

Camillo
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Re: T48 drivers 2022

#29 Post by Camillo »

Ah i see, it makes sense! The high vd was something i could get fast when i needed it. If I understand you correctly i should build more cabs rather than few with high output (according to budget) . With that knowledge, if i now build more cabs and use elements with lower vd and run the system according to them instead, is it okay to keep the one with high vd and just dont run it full, ignoring it and call it just a hard part of the chain or should i sell it and buy a similar element to the ones with lower vd?


Bill Fitzmaurice wrote: Fri Apr 07, 2023 11:10 am
Camillo wrote: Fri Apr 07, 2023 10:10 am Without digging to deep, what to think about mixing coupled titans with different elements?
Bad idea. You'd be creating a chain with a weak link.
I did build a lavoce one with almost the double VD
Double the Vd equals 6dB additional maximum output. You don't want cabs with more than 2dB difference in maximum SPL.
2x Titan48 26" - Lavoce waf.154.00 & Emin. 3015lf
2x OmniTop15 - Em.Deltalite 2515II- FaitalPro HF107
1x Titan48 "scrappy"- 12" MTX thunder8k car woofer
1x Omni15 TallBoy - 18sound 15g700 Mon. tf0615mr

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Bill Fitzmaurice
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Re: T48 drivers 2022

#30 Post by Bill Fitzmaurice »

The last thing I'd recommend is lower Vd, unless it's your only option due to cost. I'd rather spend more for high Vd and use half the number of cabinets. With the skyrocketed cost of plywood a high Vd driver rather than two low Vd drivers may prove the less expensive option anyway.

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