Custom SDA's 120dbl and climbing

ben62670

I have been working on some custom SDA's that are 6 feet tall. They presently have 8mw's, 2 10" passives, and 4 tweets. Right now I'm messing with cabinet volume, and crossovers. They are being run purely stereo for the moment with an electronic crossover set at 2500 high pass low pass. A GFA-555 is running the woofers, and 2 channels of a GFA-7500 are running the tweeters. I am attaining 120dbl clean C weighted slow response with a radio shack digital spl meter. My apartment has paneling walls that are vibrating to the point of being blurry. The bass is so nice and tight. The vocals of Billy Joel have never sounded so clean. I am debating wether to tri amp these home brews so they each have 8 stereo drivers, 4 dimensional, and 4 tweeters. With the 3rd amp running dimensional duty so the stereo drivers will not be tainted in any way by the dimensional array.

When will the madness stop!
Ben

hoosier21

pictures and more details please

Polkersince85

Be sure to wear your white lab coat. Easier to tell when your ears start bleeding.

ben62670

Polkersince85 wrote:

Be sure to wear your white lab coat. Easier to tell when your ears start bleeding.

I used to run A/D/S 320Is in my 68 Bronco with an A/D/S PQ10 amp bridged, and I thought that was loud, and clear. I am thoroughly amazed at how loud and clear these are!

PS Thare are no caps or inductors within these speakers walls. I am now listening to some Kenny Rollins The Bridge, and the sax, and symbols never sounded so Good!

PolkWannabie

ben62670 wrote:

When will the madness stop!

I guess when you're deaf ...

The SRT's can make 120+ dB as well but it's pointless to take them there ...

F1nut

I think it's cool that you're experimenting, I'm sure you're having fun. 120dB is quite loud, but in short durations should be ok on the ears. Just not something you want make a habit of. I'm surprised your apt. neighbors aren't calling the police. :eek:

I've had my 2.3TL's peak at 117db at 2 meters, more than loud enough for me and I only did it once to test the limits, which were not reached.

Of note, the SRT's can hit 125dB and came with warnings about hearing loss.

ben62670

What?


Thats peak from about 12 feet. I'd say average sustained is 115dbl from seating position. Which is really really too loud to listen to for any length of time. I really wish you guys were closer so you could hear these, and I could hear your's Now i just have to figure out how to get the SDA affect into the puzzle!

PS No neighbors

BaggedLancer

ben62670 wrote:

I used to run A/D/S 320Is in my 68 Bronco with an A/D/S PQ10 amp bridged, and I thought that was loud, and clear. I am thoroughly amazed at how loud and clear these are!

Sorry but I just noticed this. I had that same amp for a LONG time. Unbeleivable quality in the smallest package. Hell it even took 10 gauge wire to power it on. Great amp, I still have mine laying around. I'll have to find it.

Anyway, awesome speakers, they look incredible. Any plans on finishing them? Veneer? Laquer?

ben62670

I think I am going to wrap them in cherry veneer. I have a cabinet shop at my full disposal.

BaggedLancer

I've been dying to redo the veneer on my monitors....just can't get myself to do it cause I know I'll leave it worse than it was.

Can't wait to see the finished pics of those in the cherry.

ben62670

Are your monitors square edged or are they rounded? If they are square it is actually pretty easily done. The stuff goes on just like contact paper!

PolkWannabie

ben62670 wrote:

Now i just have to figure out how to get the SDA affect into the puzzle!

If you want to try an experiment ...

The SRT's are built with separate inputs for the Stereo and SDA arrays. The stereo ( inside ) array containing tweeters can be fed directly by the amp output. The SDA ( outside ) array is fed by the amp output first being fed through the SRT controller. The controller is in essense the SDA wiring removed from the speakers and put inside another box.

So ... One would think that you could achieve the SDA effect by ordering an SRT controller from Polk ( Yes the last I checked they still have them ) and using it in this manner. You would of course need to have different binding posts on your speakers for the Stereo and SDA arrays and internally they would need to be separate arrays.

ben62670

Very interesting. I will have to look into that.
Thanks
Ben

ben62670

OK I have finally had the time to wire the SDA effect into my speakers. I used the SDA1.2TL approach with an inductor between the ground of the dimensional speakers. I am running 8 Ohm speakers instead of 4 Ohms. The Resistance of the inductor is almost 3 Ohms alone. The SDA effect is definitely there. Not as prevalent as my SDA2's. I will be ordering new low resistance inductors to replace the inductors that I have now. They also need to be a different value due to the change in the impedance of the dimensional array. The end result is somewhere between where I am now, and my SDA2's. Pink Floyd sounds awesome now, but I know that the depth isn't quite there.
I'm back at it
Ben

hangon

I have the new rti12's and they hit the 120 db level at 10 feet and at 2 feet they hit over the 130 db limit on my meter. These babys really scream, I still am waiting for a pair of SRS or SDA's to come my way.

F1nut

hangon wrote:

I have the new rti12's and they hit the 120 db level at 10 feet and at 2 feet they hit over the 130 db limit on my meter. These babys really scream, I still am waiting for a pair of SRS or SDA's to come my way.

Really??? What are using for power?

schwarcw

hangon wrote:

I have the new rti12's and they hit the 120 db level at 10 feet and at 2 feet they hit over the 130 db limit on my meter. These babys really scream.

WOW! I'm glad you don't live next door:D

jdhdiggs

hangon wrote:

I have the new rti12's and they hit the 120 db level at 10 feet and at 2 feet they hit over the 130 db limit on my meter. These babys really scream, I still am waiting for a pair of SRS or SDA's to come my way.

Uh, that would be requiring 1000W/Channel. So you own the power company or something?

Refefer

ben62670 wrote:

OK I have finally had the time to wire the SDA effect into my speakers. I used the SDA1.2TL approach with an inductor between the ground of the dimensional speakers. I am running 8 Ohm speakers instead of 4 Ohms. The Resistance of the inductor is almost 3 Ohms alone. The SDA effect is definitely there. Not as prevalent as my SDA2's. I will be ordering new low resistance inductors to replace the inductors that I have now. They also need to be a different value due to the change in the impedance of the dimensional array. The end result is somewhere between where I am now, and my SDA2's. Pink Floyd sounds awesome now, but I know that the depth isn't quite there.
I'm back at it
Ben

Wow, I've never actually seen someone try to build a pair of SDA's from the ground up, with all the bells and whistles.

Any chance we could get some pics of the cabinet's insides?

RuSsMaN

This thread is so silly.

We can start making a list of memorable hangon quotes.

Smell inside it when it is warmed up. If a transmitter is getting to hot or ready to burn out it gets hot and smells burnt. This only works sometimes.

2-ohm for limited time Polks cant take that much power.

...and the 130db gem above.

Just looking at the numbers for 1m distance, you'll need 512 watts to hit 116db with the 90db RTi12's. Right at the top of their power limits. You'll need 16,392 watts to hit 131db (if they could handle that, which they obviously cannot).

Cheers,
Russ

jdhdiggs

Eh, I was giving him the benifit of having a 5.1 system playing balls out at 1000W/channel to get the 130. Or course I thought they were 92's not 90's. Yup, sparkling gems...

PolkWannabie

What I wanted to know was what he had covering his ears when measuring 130 db at one meter ... It's either that or he ain't hearing nuttin no mo ...

ben62670

Refefer wrote:

Wow, I've never actually seen someone try to build a pair of SDA's from the ground up, with all the bells and whistles.

Any chance we could get some pics of the cabinet's insides?

These are cabinets that are just "prototypes" that have been modified for different configurations. The bracing in these is decent, but not how I am going to do the finished product. I will post pics of the insides of the finished product. The 2 10's are about 15% undersized from the big boy SDA's. The 1.2's and the 2.3's both have 15 inch PRs. The 1.2's have 8 MW's in them, and the 2.3's have 6 MWs in them. I am going to reface these one more time to try 3 10's. The PR's are over extending at full throttle @ 50hz and below. The next prototype may have 8 drivers for the stereo, and 4 for the SDA effect. If I do decide to go with 12 MW's in each cabinet I may use 4 10's in them. I haven't decided whether or not to have a separate chamber for the dimensional drivers to increase overall efficiency, and accuracy. I will be running a GFA-585 for the stereo, GFA 7500 for the dimensional, and GFA-7500 for the tweeters all electronically crossed over. On the stereo and dimensional drivers I want to place a fader on the outputs to the amps so I can adjust the SDA effect. I am going to experiment with the phase, and stereo separation of the dimensional drivers. It is so nice to be able to independently control the levels, and crossover slopes of all the drivers.

Plugging away
Ben

BaggedLancer

RuSsMaN wrote:

This thread is so silly.

We can start making a list of memorable hangon quotes.





...and the 130db gem above.

Just looking at the numbers for 1m distance, you'll need 512 watts to hit 116db with the 90db RTi12's. Right at the top of their power limits. You'll need 16,392 watts to hit 131db (if they could handle that, which they obviously cannot).

Cheers,
Russ

Come on russ, how could you not have an amp that does 16,392 watts/channel? Everyone else on this forum does.....

Soon as my flux capacitor is finished I'll have an amp that does 16,393 watts per channel and I'll be able to to hit 132db!

read-alot

"What I wanted to know was what he had covering his ears when measuring 130 db at one meter ... It's either that or he ain't hearing nuttin no mo "...

Yeah and stare at the sun while breathing ground up asbestos dust, may as well kill your eyes and lungs with your fried ear drums.

Stupid is as stupid does.

shack

RuSsMaN wrote:

This thread is so silly.

We can start making a list of memorable hangon quotes.

hangon wrote:

Smell inside it when it is warmed up. If a transmitter is getting to hot or ready to burn out it gets hot and smells burnt. This only works sometimes.

hangon wrote:

2-ohm for limited time Polks cant take that much power

...and the 130db gem above.

Just looking at the numbers for 1m distance, you'll need 512 watts to hit 116db with the 90db RTi12's. Right at the top of their power limits. You'll need 16,392 watts to hit 131db (if they could handle that, which they obviously cannot).

Cheers,
Russ

What's the problem? Is this not the INTERNET? I can't believe you are doubting that hangon hit 131db. :rolleyes: Since it has been posted on the internet...it must be true.

disneyjoe7

This is the Joke thread right?

ben62670

disneyjoe7 wrote:

This is the Joke thread right?

You picking on me:)

hangon

Well get a CineNova amp and try it yourself, dont beleive me?
The Earthquake Company makes them!!
Use earplugs duh.

F1nut

It's a real stretch (next to impossible) to hit 120dB and flat out impossible to hit 130dB with your amp and your speakers. So, no WE don't believe you!

tonyb

Maybe we should have a thread on how to use a sound pressure meter.
As Russ stated,numbers don't add up.12'S hitting 130 db ?Give me some of what your smokeing.