Please help! How is this SOOO loud and low?

[Bias the Gate]

OK, I built this box, and it hit so hard and so low, I am floored. I need and understanding how this box is accomplishing this. Also I see simalarities between this and the

Box for 1 15(prior to 45 degree angles in the corners)

An externally hosted image should be here but it was not working when we last tested it.

Super Scooper for 1 18

An externally hosted image should be here but it was not working when we last tested it.

Please help

 

[Cal Weldon]

What is it you need help with? You built a box that's made for bass delivery. So is the scoop. It might not be delivering as low as you think but most people aren't aware of just how low 40 or 50 Hz really is to the ears.

 

[badman]

What is it you need help with? You built a box that's made for bass delivery. So is the scoop. It might not be delivering as low as you think but most people aren't aware of just how low 40 or 50 Hz really is to the ears.

He needs help massaging his ego, it would seem. And that box isn't anything like a scoop, it's some kinda quarterwave resonator, like a TL.

 

[Bias the Gate]

No my ego is fat enough, lol.

I need understanding WHY this is so loud. I have tried MANY speakers and MANY amps. almost all have done very well.

I have noticed this thing is very loud at 35-45hz. In 1/4 space it is really nice. But in 1/8 space. and with about 3Kw, I can barely stand to be near it.

Why is this so. How can I modify this design for say a 12, or 2 12s?

Can I modify this for 2 15s?

Has anyone tried the design I did?

Thank all who responded!

 

[Cal Weldon]

And that box isn't anything like a scoop

I was referring to the Mogale he posted.

3KW and you wonder why it is difficult to be near? Are you being funny with us? Do tell us what driver you have.

 

[Bias the Gate]

AudioQue HD315, little brother to the DD3515 from Digital Designs. I have a video of the performance if you guys want to see it....

 

[Cal Weldon]

I just watched a couple on YouTube. That kinda **** is too painful for me.

 

[Bias the Gate]

Heres my buddies car with one installed.

YouTube - 1 AudioQue HDC315 custom built in a Caddy, Flexing

I just want to re-apply this design to 2 12s and eventually 2 15s. I have Hornresp and Akabak, but as I have only been using these for about a week, I am still far behind by advanced horn designers expectations.

 

[letsbangout]

You won't be doing anything meaningful in hornresp with Digital Design products unless they give up Theile/Small parameters, or you measure them yourself. Why don't they give up proper specifications like the rest of the crap-driver companies (Pyle, Pyramid, Eminence, etc)? In my not so humble opinion, this company looks like a joke.

I've got a design in hornresp with six 15" crap-drivers in a front-loaded horn which will install in the back of my truck and do 142db at 55hz with 1500 watts input. Is there any combination of Digital Designs components in any of their recommended configurations that'll do 142db at any frequency given equal input power?

 

[davygrvy]

Dimensions are needed so someone (maybe myself) can create an akabak script for you. HR won't model a scoop/transmission line.

 

[Bias the Gate]

PM'd Davygrvy

 

[Bias the Gate]

Also here are the t/s parameters to the woofer

Specifications
Model HDC310-A HDC312-A HDC315-A HDC318-A
Woofer Size 15″
Fs 38 Hz
Sd 89m M2
Krm 12.686 mOhm
Erm 0.875
Kxm 144.352 mH
Exm 0.628
Vas 70.421 Ltr
Cms 62.609 uM/N
Mmd 253.635 g
Mms 268.902 g
BL 22.39 TM
Qms 7.405
Qes 0.444
Qts 0.419
Sensitivity 1W/1m 91.532 dB
Magnet Diameter 8.7″
Magnet Weight 340 oz
Coil Diameter 3.0″
Coil Length 2.135″
Useable Throw 3.0″
Continuous Power 1000 W
Music Peak Power 2000 W 2000 W
Mounting Depth 8.875″
Circle Cutout 14.0625″

 

[djk]

Funny, the help section of Hornresp shows how to model rear loaded horns (scoops).

 

[Glowbug]

Why don't they give up proper specifications like the rest of the crap-driver companies (Pyle, Pyramid, Eminence, etc)?

Because for the vast majority of people who buy DD, all they care about is how much it "bumps". If it does that in a generic ported box, they couldn't be happier.

Is there any combination of Digital Designs components in any of their recommended configurations that'll do 142db at any frequency given equal input power?

Sure. In the world of car stereo SPL competitions, 142dB at a single frequency is not that loud.

 

[Bias the Gate]

I have one 15 and its doing a solid 149db on music. Respectable, I've been told, that does not really matter.

This box is what I have questions about. Now you guys know what woofer I am using. I have also used DD9915(no parameters), Alpine Type R15s, Treo SSX15, Beyond Audio Inhuman15s, Kicker CVXs, RE XXX15(Pre-03), and one Stroker15(old style, reconed).

All were seriously loud and low in this box. This box trumps every box these woofers were ever in before, why? What is going on in this enclosure?

 

[just a guy]

What is going on in this enclosure?

Honestly, nothing special. I'd suggest that if this box seriously outperformed the others you have tried, there was either serious problems with the other boxes (like air leaks or something) or the boxes simply were not optomized for the drivers. On the other hand, can you measure frequency response? Maybe this box is actually performing terribly, but in a way you like...

 

[Andrew Eckhardt]

I have one 15 and its doing a solid 149db on music. Respectable, I've been told, that does not really matter.

This box is what I have questions about. Now you guys know what woofer I am using. I have also used DD9915(no parameters), Alpine Type R15s, Treo SSX15, Beyond Audio Inhuman15s, Kicker CVXs, RE XXX15(Pre-03), and one Stroker15(old style, reconed).

All were seriously loud and low in this box. This box trumps every box these woofers were ever in before, why? What is going on in this enclosure?

Most of the replies here seem to be dishing a fair amount of skepticism rather than hard interest in the performance. That's understandable because it doesn't look like much and you don't have any convincing response plots to compare against well understood designs. Unfortunately a rigorous analysis of that cabinet probably will take a little work since most software has been written to generate a response from a formulated construction with a driver of given perameters. One way to know exactly what's happening in that enclosure is to model it in a fluid dynamics software, which would take a little work to set up. If you wanted to give that a try maybe you could start here: CAElinux In any case you'll have to cough up a detailed drawing with dimensions before anyone else can help much.

It looks interesting but nothing about it would jump out to your average speaker builder and say "this should have great efficiency and extension because xyz", I don't think.

 

[Don Hills]

That box can be modeled in both Hornresp and Akabak. You need to provide a dimensioned drawing - that is a side-on (plan view) of the box with all of the lengths written in. Measure all of the straight piece lengths. Measure the distance from each piece end (for example, each partition end, and the peak of the kink behind the driver) to the nearest surfaces. In short, you need to provide enough detail so that someone can build an identical box.

 

[BP1Fanatic]

Looks like a rear loaded stepped horn.

 

[Bias the Gate]

I have a model in Sketchup. I will get to anyone who wants it. I took me sox hours, I just downleaded it, seriously. I had to conjur up old college

Also, I am here to find out WHY this box does what it does. (Hint - I posted a video) This is the hardest hitting 15 I have heard in a while.

Here is a thread of boxes I have built in a the past few months.
Just manipulating MDF - SSA Car Audio Forum

I kinda have a sort of a clue about what gets loud and how.

I will toss the box dimensions on here under the terms that seeing as how this box is "nothing special" I would like to see your underpaid professional acoustics engineers improve upon the design and in fact make it something special. I have a few sheets of MDF and all the necessary tools. Lemme make a pic of the unit with the dimensions.