melded array watts

For unmatched sensitivity.
Post Reply
Message
Author
Paddlsonic
Posts: 27
Joined: Mon Sep 07, 2020 8:54 pm
Location: Australia

melded array watts

#1 Post by Paddlsonic »

Just about to order all the piezos for a melded array for the DR200's i'm building. Goldwood 1016's.

In terms of getting a proper sized amp to drive the cabs, What wattage does the melded array come in at using the Goldwood 1016's. Are they rms-ing at 50watts a piece?
So looking at 16 x 50watts? That would seem to come in at a whopping 800watts + the Woofer for each cab.........
Where are my calculations going awry?

I'll be using a delta pro 8a for the woofer , so just trying to sort the appropriate amp size for the pair.

Any help, much appreciated

Cheers

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: melded array watts

#2 Post by Grant Bunter »

I do know in the past a limit of 40V for a deltalite 2510 loaded DR250 has been discussed, and also note that there will be significant distortion that will urge us to turn down before we get to that voltage.

Speaking of distortion, if you regularly find you're reaching distortion with your tops/mains after you build, build more!

40V @ 8ohms is 200W ( single cab), or 400W @ 4ohms (2 cabs/channel in parallel). So I have some headroom, the amp I run on my 2 pairs of DR250's is 600W @ 4ohms.

The Delta pro 8 won't take quite that much I would think.
Don't stress at all about the piezo's, unless your planning to bi-amp ( there is really no need for that).
The filters in the plans, for the piezo's, reduce power to them enough that they won't be blown.
IIRC, it's a third or 4th order LR filter which has a reduction in power to the piezo's of at least 12dB, which is less than 1/4 of the power the woofer/mid driver will receive...
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...

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28620
Joined: Tue May 02, 2006 5:59 pm

Re: melded array watts

#3 Post by Bill Fitzmaurice »

Paddlsonic wrote: Mon Sep 21, 2020 2:39 am So looking at 16 x 50watts? That would seem to come in at a whopping 800watts + the Woofer for each cab.........
Where are my calculations going awry?
Piezos aren't power limited, they're voltage limited. With the wiring scheme of the array it will take at least 50v. The woofer will blow long before the array could.

User avatar
Seth
Posts: 2733
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: melded array watts

#4 Post by Seth »

Paddlsonic wrote: Mon Sep 21, 2020 2:39 am ...just trying to sort the appropriate amp size...
I had the same question and it boiled down to 150 watts per channel for DR200's... IIRC.
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

Paddlsonic
Posts: 27
Joined: Mon Sep 07, 2020 8:54 pm
Location: Australia

Re: melded array watts

#5 Post by Paddlsonic »

Thanks guys,

All the responses are great and teaching me alot.
When i get all of this straight in my head, i'm sure the amp question will fall into place.
Addictive this stuff. Can't get enough....

Cheers

User avatar
Seth
Posts: 2733
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: melded array watts

#6 Post by Seth »

Paddlsonic wrote: Tue Sep 22, 2020 2:30 am Thanks guys,

All the responses are great and teaching me alot.
When i get all of this straight in my head, i'm sure the amp question will fall into place.
Addictive this stuff. Can't get enough....

Cheers
Guess I'll add a little chit chat...

The more time you spend on this forum, the more and more you'll realize Volts is the primary currency around here, instead of Watts. It is a challenge to let go of what I thought for the first 30 years of my life was the primary focus of loud and clear audio reproduction, Watts. While I can't identify any reason to completely ignore the significance in the value of the Watt, I've come to learn and realize the significance and value of using Volts in audio. And I'm sure there's more significance to using Volts than I realize at this point in time, most likely in the design of passive crossovers which I have no clue about.

Anyway, I'm sure that confused things a little. The point is, try not to get too caught up in the Watts of everything. In the end, it doesn't mean what you think it means. At least, that's what I've learned.

The power rating on the Delta Pro 8a is 225w rms and 450w program, meaning it can withstand a constant 250 watts (think heat, not sound) without the voice coil melting and non continuous impulses of power up to 450 watts without melting (as long as the RMS/power average doesn't exceed the RMS rating). That's it. It's only about not melting the voice coil. Has nothing to do with the sound.

Sound wise, the distance the cone of any particular driver travels back and forth is directly related to the voltage it sees. And each driver has a limit to how far the cone can travel (excursion) while keeping relative control over the cone, keeping the coil within the magnetic field of the magnet (or something to that effect)... which is xMax. How much the cone moves with a specific Voltage is highly dependent on the enclosure it's in. It will be different for every different enclosure. In one enclosure the speaker cone will reach it's maximum reliable excursion at one voltage. In another enclosure it may require way more or less voltage to reach the same excursion.

It's not always the case, but a Mid/High enclosure will likely get distorted and sound very bad before reaching it's thermal limit. But, so far, I haven't found anyone who knows what voltage is appropriate to get the most out of a DR200 without audible distortion. The best I have found is to have more than 30 volts available, with 35 being reasonably close.

To calculate Watts from Volts, so you know what amp to get... Volts x Volts divided by driver Ohms = Watts... 35 x 35 / 8 = 153 Watts

Still doesn't answer your question, but gives you a little to chew on.
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

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28620
Joined: Tue May 02, 2006 5:59 pm

Re: melded array watts

#7 Post by Bill Fitzmaurice »

The main reason watts are so prominent in the literature is marketing. The average person equates more watts with better results, giving them a reason to spend more money.

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: melded array watts

#8 Post by Bruce Weldy »

Bill Fitzmaurice wrote: Tue Sep 22, 2020 3:37 pm The main reason watts are so prominent in the literature is marketing. The average person equates more watts with better results, giving them a reason to spend more money.
And every year, they put out the same box with exact same components, with the same limiting, and add 500 watts of peak power so that's it NEW and Improved!......Yahoo!!!!

I see all of these so-called 1000 watt boxes pushing a single 12 and a horn. I doubt that any of 'em see more than 300-400 watts to the woofer. And if you kick in the "DEEP" button, it will be limited down to less than that.

Had a Fender rep tell me about the little 10 inch Fender monitor he had.....400 watts! I told him there was no way that box could deliver 400 watts of 60 hz to that little woofer.....I went home and looked it up....I was right - he was talking about peak power. Those guys don't even know the difference. It's all just a number.

While I'm telling stories here......A friend of mine bought 6 JBL EON boxes for mains and monitors from Sweetwater. I asked if he bought a Sub. Said he didn't need one because the rep told him that if he put the switch in the back on EXT SUB, that box would become a sub (uh...no...that just means that you are using an external sub and it kicks in the high pass).

Instead of arguing with him, I just sent him the verbiage from the manual. He ended up buying a sub and Sweetwater had to throw in a bunch of extras for his trouble. Don't get me wrong, I like Sweetwater - but do your homework and know what you are doing. You can't trust that the guy on the other end of the phone knows what he's talking about.

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."

User avatar
Seth
Posts: 2733
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: melded array watts

#9 Post by Seth »

Bill Fitzmaurice wrote: Tue Sep 22, 2020 3:37 pm The main reason watts are so prominent in the literature is marketing. The average person equates more watts with better results, giving them a reason to spend more money.
That was totally me. Thanks to you and what you've created here, I'm able to see a little more truth in the world of audio. Thanks Bill :thumbsup:

I've spoken to more than a couple guys that have QSC K12.2 and/or KS118 powered speakers/subs. And their eyes get really big, wide open, when they tell me they're 2000/3600 watts each. They don't always like hearing me say it's complete BS, so I keep that to myself if I don't know them well enough. I do say "I'd like to compare my (soon to be) +/- 1500 Watt system to your 11,200 Watt system sometime"... They may snicker now, but... :chainsaw: :evil: they'll learn a thing or two later. Or not.

I've got nothing against the QSC gear. It's not bad. But, their marketing is getting a little wild lately. I guess you do whacha gotta do to stay in the game, sell your products, and keep the doors to your business open.
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

User avatar
Seth
Posts: 2733
Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
Contact:

Re: melded array watts

#10 Post by Seth »

Bruce Weldy wrote: Tue Sep 22, 2020 4:55 pm
Bill Fitzmaurice wrote: Tue Sep 22, 2020 3:37 pm The main reason watts are so prominent in the literature is marketing. The average person equates more watts with better results, giving them a reason to spend more money.
Had a Fender rep tell me about the little 10 inch Fender monitor he had.....400 watts! I told him there was no way that box could deliver 400 watts of 60 hz to that little woofer.....I went home and looked it up....I was right - he was talking about peak power. Those guys don't even know the difference. It's all just a number.
I'm curious, do you recall what it measured? I'm gonna guess 30-35v.
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

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: melded array watts

#11 Post by Bruce Weldy »

SethRocksYou wrote: Tue Sep 22, 2020 4:59 pm
I've got nothing against the QSC gear. It's not bad. But, their marketing is getting a little wild lately. .
I actually like their gear a lot. I mixed on their KLA boxes last Saturday. Sounded good (of course, I'm the one who EQed the room and balanced it - so I'm not about to say it sucked... :mrgreen: )

But, you are correct about the marketing......it's all of 'em.

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."

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: melded array watts

#12 Post by Grant Bunter »

This is now kinda off topic in regards to the OP's original post, but since it's been brought up, I want to add this about Watts.

Watts is a unit of power, in fact, it's a product of voltage and amperes. P=I x V.
Where P is power in watts, I is current, and V is voltage.
As such, we can't measure watts on the fly, so to speak.
We can measure voltage, and amperes, even both at the same time if we use 2 different DMM's on the amp outputs at the same time.
But to determine watts we need to then calculate the 2 values.

So watts becomes meaningless. Or does it?
No.
Remembering watts reminds us to remember amperes too. And as impedance lowers, amperes rises.

And the last part is much more important when it comes to amp channel loads. If we can maintain higher impedance amp channel loads, we can reduce current loads to the cabs, and demands on the power supply of the amps...
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...

Post Reply