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Horn Sub Input Please - Build In Progress!

73398 Views 260 Replies 20 Participants Last post by  iconrl
I am in the process of layout/design of my new theater room. I am going to be using PI 4 Speakers for LCR, and PI 1 Speakers for Surrounds. I designed a set of OD Horn Speakers to compliment the LCR and surround speakers as flanking subs to tame room modes. So the frequency range is 50-200hz

Since this is my 1st attempt at Hornresp and Sketchup, I am looking for input on my design and folding before proceeding further. So there will be 7 total of these flanking subs the front 3 will be under the PI 4's and the 4rears will be under the surrounds in a column configuration. The will be driven with 20 watts RMS.

I will be using a miniDSP 10x10hd, and the plan is to cross the flanking subs, with there respective mains, as well as matrix the LFE channel to theses subs as well for frequencies above 50hz, and then use the Low LFE subs for everything under 50-60hz.

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Stayner is only five hours away.

I might be able to hear your system from my place!
Ha yeah there is the possibility that you will. Don't you think the driver modled pretty good? I have tried a bunch of different drivers, and some are way off, and some are very close to what I have. I would hate to have to re model and re fold again...
Take the driver I suggested.

Slap it into your horn. You will be able to do two things. Shrink the rear chamber, and if you have ripple take a look at how much ripple. An undulation of 3 db up or down is not really noticeable.

Also if you buy eight or more of the Dayton Pro woofers you will get a discount.

The Selenium driver has very little excursion capability and therefore will have much higher distortion in a horn.
Im sorry but I have modeled that driver already, and the selenium was better resposonse wise, the driver you are suggesting is 1.5mm more Xmax, and I will be driving my design no where near 3.5mm anyhow, not sure why this will warrent a complete redesign.

Earlier you said the graphs looked good. Confused...
Graphs are one part of the design.

When you need a rear volume of 140 liters on a back loaded horn you have a driver that is not suited to horn loading.

Your choice. This is advice not a dictatorship.

I chimed in because I have been designing horns for the past twenty years, and I work as a consultant in driver and loudspeaker design.

There is an existing design up on this forum that meets almost all that you seek. And it is proven.

So this is not advice from someone who has simmed only.
No insult meant, simply trying to understand. The sims looked okay with that driver down to around 70L rear chamber volume, but I knew I had the additional space, so I increased the size, which also reduced the ripple in hornresp.

I do know that sims are not the end all be all, but can you please enlighten me on how the dimensions of a sealed enclouser affects the driver, and why such a large volume is bad if you have room?

Short story is a long day and a short fuse.

I'll give you a good explanation in the morning.
A horn is a balancing act of motor strength versus the compression wave you want to force down the horn path. The stronger the motor the better the control over the way the cone moves. A proper horn is a very hostile environment for a woofer compared to a vented box or a sealed box. There is quite a bit of pressure generated on the cone. The rear chamber should be sized in such a manner that it provides a restorative force to the driver. A balance of pressure. The very large Chambers you propose will have very little of any spring or restorative force to keep the driver in check. The front of the driver will see a high pressure whereas the back will not. A great invitation to nonlinear behavior. That's a fancy word for distortion.

The Selenium driver has two strikes against it. Weak motor and a very short voice cool. Not a good combination for a horn.

Even though there is an approximately four to one reduction on the excursion versus sound pressure level musical impacts, and movie effects will ask your drivers to shift some serious air.
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Here is a quick sim of the Dayton 12" you recommended. With a 70L rear chamber, is this more acceptable?

Thanks for your input so far!


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I just want to thank you guys for your excellent Q & A session! :T I'm sure that others are following along and share my thoughts as well.
Oh yes. Learning a boatload. More than I ever have reading about horns. I have the room an haven't started my SI18 LLT. So maybe.......
I'm back.

Sometime today I will post a sub design for you.

But I will not fold it.

That is the fun part :doh:

What is your maximum area?

And Volume?

This is a riser correct?

How high to the ceiling do you want to be?

And if I remember correctly you want four subs?
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Thanks for your offer it is much appreciated.

The plan is to have 2 ULF subs behind the screen; max size internal volume - 66cm x 68cm x 180cm
And Have between 1-4 subs under the riser depending on the size; internal volume - 40.64cm x 249cm x 365cm
The max height of the riser is 16" or 40.64cm, so the most I could go is a 15" driver.
Would prefer 2 or 4 though so they can be opposed in the same rear chamber.
Max budget would be $600-$800 for the woofers.

They also don't have to be the same design or frequency range as they will be feed though seperate outputs of my miniDSP to adjust phase and crossover points.

I can fold it up no problem!

Also the lower the better :hsd:

Thanks Again!
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Here is something that should knock your socks off:

Text Line Parallel Font Design

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I like that looks perfect and would fit 4 under the riser and 2 up front!
Not to bad for 20 minutes!
Twenty minutes and twenty years and if you look closely 400 plus sims in the last three years.
Yeah that helps.

So you think the Dayton is my best bet?
Bang for the buck, yes.

They are a very well made driver. And that sim is done from measured specs. I have two of these drivers in my collection.

And in the interest of keeping things simple your other subs could be done the same way.

How are you planning on ordering the drivers?

I have a commercial account with PE. If the order is over $500 they ship for free.

Send me a P.M. if you are interested.
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