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Re: Titan48 driver question

Posted: Thu Sep 24, 2020 6:47 am
by Bill Fitzmaurice
jemo1234567890 wrote: Thu Sep 24, 2020 5:27 am If I understand how to calculate the voltage limits in relationship to the Xmax than there are so many interesting drivers (especially 15 inches drivers) which have a very high power rating on paper but also a high Vd.
It's easy, if you are an expert in using HornResp speaker modeling software.
If you're looking for the most output per cab possible, you're probably not looking to build as many cabs as you will ultimately need. If you're hitting the limiter with the cabs you have, you need to build more.
Exactly.

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 10:17 am
by jemo1234567890
Hey all,

sorry that I ask a again a question about the Titan48.

I finished the build of my 3012lf loaded T39 for "home usage" :P

Now I would like to choose the next step for my summer rig.

I've tested some tracks I'm listening and saw that a HP of 35 Hz will be better than 40 Hz.
In the plans is written that I need a stack of more than four T48 to lower the HP.
Now I would like to build four T48 (3012lf loaded) with the narrow 18 inches internal width beccause it's much more easy to transport than a double loaded cab. Is it possible to lower the HP for this configuration? Is this meaning that I could lower the HP for two double loaded caps too?
Or do I need eight single loaded (equals four double loaded cabs) for lowering the HP to 35 Hz?
This a topic I don't understand exactly with the plans.

Thank you very much for your help.


Best regards
Josh

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 11:04 am
by Bruce Weldy
It's real simple.....excursion is excursion....if you send lower frequencies to the driver, the cone moves further. Whether you use one cab or eight....if you try to hit them with full power with a lower high pass, you increase the excursion of the driver. If you lower the high pass, you'll need more cabs so that you can decrease the voltage some.

Using a v-'plate will extend the mouth and get you lower.

Remember - your high pass filter isn't a brick wall. Lower frequencies still get through, just at a lower volume. I'd build more cabs, leave the high pass at 40, use a v-plate and you'll not miss any content. Plus, you'll have a better chance of protecting your drivers. If you go down to 35hz, then you should really use as steep a slope as possible on your high pass filter.

It's all a trade off.....if you go lower, you have to back off some on the power....and build more cabs.

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 12:48 pm
by jemo1234567890
Thanks a lot Bruce.
That's real simple.

I think too that it would be safer to leave the recommended HP at 40 Hz untouched and use a 24 dB slope instead of knocking the hell out of the cabs with the lower HP and use the 48 dB slope.
I could imagine that this would sound “warmer“ too.

Thanks

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 12:50 pm
by Seth
Hey Josh, good job getting the first one done :thumbsup: What configuration did you settle on? Is it a single loaded, 19" wide (external)?
jemo1234567890 wrote: Mon Jan 18, 2021 10:17 am ...Is this meaning that I could lower the HP for two double loaded cabs too? ...
My interpretation of it is, two double loaded cabs is equal to 4 single loaded cabs of half the internal width, and therefore would meet the guidelines to reduce the High-pass cutoff.

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 3:33 pm
by Seth
jemo1234567890 wrote: Mon Jan 18, 2021 12:48 pm Thanks a lot Bruce.
That's real simple.

I think too that it would be safer to leave the recommended HP at 40 Hz untouched and use a 24 dB slope instead of knocking the hell out of the cabs with the lower HP and use the 48 dB slope.
I could imagine that this would sound “warmer“ too.

Thanks
I tested my T39 with recorded music and found that the 24dB slope at the higher x-over point (45Hz, in the T39) was much more pleasing than a 48dB slope at 40Hz. The steeper slope, even at the elevated cutoff point, cuts out a lot of content in the recorded material I was listening to. It seems much of today's recordings have usable content in the 30-40Hz spectrum.
For live music, the 48dB slope wouldn't be too noticeable. And really, even with recorded content, 99% of the general public wouldn't notice the difference unless they were looking for it... even with EDM.

I'm pretty sure the "one size fit's all" recommended limiter and high pass configurations are based on minimum width cabinets and are figures rounded toward the conservative side. However, I doubt there's much left on the table either. My initial instinct was to achieve the most I could from the cab. But, my mind has settled into a belief of/that, if I'm running that close to the limits on a regular basis, I need more cabs so I'm not constantly at the limit. Or, a different cab, if the limit I'm constantly pushing is the cabs bottom end extension.

Still, I'm fairly sure you'll be okay with 50volts on a 24dB slope at 35Hz with 4 19" cabs. Bill would be able to verify.

One of these days I'm going to take the time and learn to use Hornresp. Which I'm pretty sure is the tool Bill uses to model the cab/driver combo's and also derives the power:High-pass cutoff excursion limits. Would love to see the effects of all the different variables.

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 4:30 pm
by jemo1234567890
A big thumbs up for you Seth, thanks so much.

So I think we are one the same route for limitation and filter settings.

I only would like to get help in interprating of the recommendations in the plans.
Seth wrote: Mon Jan 18, 2021 3:33 pm What configuration did you settle on? Is it a single loaded, 19" wide (external)?
Yeah I finished the second T39 with 19" external this weekend.

Next I'm going to build two DR200 or two OT8 (because they are more easy to build :wink: ). And after that I would like to build the single loaded T48 with 14" internal to get easy transportable (double) twelves with the V-Plate for the summer :hyper:

Best regards

Re: Titan48 driver question

Posted: Mon Jan 18, 2021 7:08 pm
by Seth
jemo1234567890 wrote: Mon Jan 18, 2021 4:30 pm A big thumbs up for you Seth, thanks so much.

So I think we are one the same route for limitation and filter settings.

I only would like to get help in interprating of the recommendations in the plans.
Seth wrote: Mon Jan 18, 2021 3:33 pm What configuration did you settle on? Is it a single loaded, 19" wide (external)?
Yeah I finished the second T39 with 19" external this weekend.

Next I'm going to build two DR200 or two OT8 (because they are more easy to build :wink: ). And after that I would like to build the single loaded T48 with 14" internal to get easy transportable (double) twelves with the V-Plate for the summer :hyper:

Best regards
Would love to see a pic of the pair together :thumbsup:

Re: Titan48 driver question

Posted: Tue Jan 19, 2021 1:13 am
by Tom Smit
jemo1234567890 wrote: Mon Jan 18, 2021 4:30 pm And after that I would like to build the single loaded T48 with 14" internal to get easy transportable (double) twelves with the V-Plate for the summer :hyper:

Best regards
Josh, are you limited in transportation space so much that you can only do the 14"? (I haven't looked at your other posts). Here is a graph to show how much more one can get with more width.

Re: Titan48 driver question

Posted: Tue Jan 19, 2021 3:25 am
by jemo1234567890
Hello Tom,

this wasn't clear for me that this would make such a huge difference...
Thank you very much.

I know that it would be much better if I would go wider to get the most out of each driver. My initial plan was to build a double twelve but decided to build splitted for easy transportation.
Because if I go to a width of 24" I could equip with a fifteen but the 3012LF I have four on my shelf :-P
I will play a little with the SPL Tool and maybe choose a different width.

Re: Titan48 driver question

Posted: Tue Jan 19, 2021 4:16 am
by jemo1234567890
I find interesting that the difference between the T39 and T48 isn't huge if you calculate with SPLmax with the voltage limits written in the plans:


[EDIT: added two T48, 15" wide with 3012lf under SPLmax and T48 24" wide with 3015lf under SPLmax]

Re: Titan48 driver question

Posted: Tue Jan 19, 2021 4:43 am
by Seth
jemo1234567890 wrote: Tue Jan 19, 2021 3:25 am Hello Tom,

this wasn't clear for me that this would make such a huge difference...
Thank you very much.

I know that it would be much better if I would go wider to get the most out of each driver. My initial plan was to build a double twelve but decided to build splitted for easy transportation.
Because if I go to a width of 24" I could equip with a fifteen but the 3012LF I have four on my shelf :-P
I will play a little with the SPL Tool and maybe choose a different width.
If you can go 24, do it. And use the 12's. You'll not be disappointed.

At 40Hz, a single 24" is nearly the same output as two 15" wide cabs.

Put another way, if the driver could hypothetically take it, it would take nearly 1200watts in a 15" wide cab to match what a 24" cab will do on 300 watts at 40Hz.

But, if you absolutely need/want a slim cab for ease transport for smaller gigs, do that. They are still stellar performers and they can still be added to the stack of wider cabs for larger gigs.

Good call Tom :thumbsup:

Edit: Goofed my numbers and made a couple corrections.

Re: Titan48 driver question

Posted: Tue Jan 19, 2021 4:50 am
by Seth
jemo1234567890 wrote: Tue Jan 19, 2021 4:16 am I find interesting that the difference between the T39 and T48 isn't huge if you calculate with SPLmax with the voltage limits written in the plans:


[EDIT: added two T48, 15" wide with 3012lf under SPLmax and T48 24" wide with 3015lf under SPLmax]
They are similar. Except the T48 keeps the driver loaded for a little more allowable extension.

I think these are measured results (instead of estimated)


Re: Titan48 driver question

Posted: Tue Jan 19, 2021 4:57 am
by jemo1234567890
Seth wrote: Tue Jan 19, 2021 4:50 am Where did you see that file/code option?
Just added the faktor in dBs
Seth wrote: Tue Jan 19, 2021 4:43 am If you can go 24, do it. And use the 12's. You'll not be disappointed.

At 40Hz, a single 24" is nearly twice the output of two 15" wide cabs on the same voltage (twice the power/watts).

Put another way, if the driver could hypothetically take it, it would take nearly 1200watts in a 15" wide cab to match what a 24" cab will do on 300 watts at 40Hz.

But, if you absolutely need/want a slim cab for ease transport for smaller gigs, do that. They are still stellar performers and they can still be added to the stack of wider cabs for larger gigs.
Thank you all for your help. I will calculate and measure which route I will choose :-P