[HowdyDuty]

Good afternoon!

I'm in the midst of building two sonotube sealed subs. Initially they'll be used for one light DJ application, and then make themselves at home for theater use. I can definitly provide pictures if there's interest. Right now everything is still in pieces but I do have some questions.

I was thinking of using the Dayton 15" HF sub. When I plug the values into unibox I come up with 3.8 cu ft for a sealed enclosure, plus .5 cu ft for driver displacement, arriving at a 4.3 cu ft enclosure. The plan is to use doubled up 3/4" MDF for the end caps. So right now I have an 18" diameter tube with an overall length of 32.5".

How much stuffing should I use? 1 Lb per cu ft?
Will pollyfill be sufficient or is acoustastuff necessary?

I built a sealed sonotube enclosure for the subwoofer in my truck with outstanding results and was hoping to reproduce its awesomeness in my home.

Thanks for the feedback.

-HD

 

[Mike P.]

The more pics you post the better. There is always interest in a subwoofer build! :yes: Is the sub your referring to the RSS390HF-4? Stuffing is only necessary if the box is smaller then optimum.

 

[HowdyDuty]

Yes, the RSS390HF-4 is the one! I thought stuffing was always required to get rid of the bad waves inside the box. I know there's a much more technical term for it, but I can't think of it right now. Please let me know your thoughts on the dimensions.

Thanks!

-HD

 

[tcarcio]

Looking forward to your build.:T

 

[Mike P.]

What will you be powering the subs with?

 

[HowdyDuty]

Behringer EP2500.

 

[Mike P.]

An 18" diameter tube with an overall length of 32.5" will give you a net volume of about 4.2 cu.ft. The sub can handle 500 watts, with that amount of power you'll need a high pass filter at 25 hz to protect the sub from over excursion. Here's SPL graph of the expected performance.

 

[HowdyDuty]

Ok... so, thoughts on the SPL graph?? Is that a desirable response? It looks considerably different than the graph unibox displayed. From what little I know about DIY subs, that response curve doesn't look very "flat". Although I'll be able to supply 500 watts to these subs, I don't intend to. What's the max wattage I can supply without exceeding the xmax? As long as I stay under that wattage I can run the entire frequency range up to 60 or 80 hz, correct?

Any specific comments regarding the spl curve in respect to the enclosure? Stuff it or leave it empty?

Thanks so much for the responses so far!

-Howdy

 

[Mike P.]

To stay within Xmax without a HPF you lower the input power and give up SPL. Green is 500 watts with a HPF at 25 hz. Yellow is 165 watts with no HPF. Both models are 4.2 cu.ft.

 

[1Michael]

Line the walls with fiberglass or egg crate type foam.

 

[HowdyDuty]

Good evening!

Two months later and the project is finished. Here are some build pics:

In this picture, I'm ready to glue the end caps together. I use a liberal amount of liquid nails. The far one has this step already completed.

This picture shows the tubes lined, capped, and ready for a finish of some kind.

I decided to finish the tubes with a vinyl covering. No sanding, no primer, no painting, no mess. Turned out ok in my book. Here's a completed sub.

The last picture is the entire setup.

It's obviously not in optimal placement but given the room constraints I have right now, it's what I have available. The white speakers are actually an Allison Acoustics 2-way in-wall speaker. I have a wedding to DJ before these take their place in a home theater wall, so a box for each one was the only way to go. The small boxes are about .5 cu ft.

I'm using a Yamaha RX-V663 receiver and a Beringer 2500 amp. I ended up having to use a bump box. For that I used the samson s-convert. Even with the bump box I still had to raise the db output on the receiver to at least 5.5 before I'd get anything out of it. I have it set at 8 db right now. The bump box is also boosted a little as well.

So, how does it sound? Incredible. I haven't heard bass like this before. I'm very pleased with the results. I don't have the equipment to measure anything, but how it sounds is good enough for me.

Thanks for all the help and assistance. I couldn't have done it without the advice from the great people that frequent the forum.

-HD

 

[Mike P.]

Glad to hear you're enjoying the subs.

 

[Veltinorian]

Very good dayton sub and sonotube :clap: me myself have the 10-inch ligttle brother and is awesome

i made some calculations with BassBox Pro with the tube length of 32.5. This yelds frequencz F3=33.1 Hz.
Is that the actual tube length you have built it?

 

[HowdyDuty]

The tube length is 32.5 but I used 1.5" thick end caps. The back cap is solid and consumes an entire 1.5" where the front has the 15" circle cut for the sub. I figured that with the sub displacement it would be close enough in comparison to a solid cap. So to answer your question, yes the physical tube is 32.5 inches however I used 32.5 - 3 = 29.5" length for all of my calculations.

Radius: 9"
PI: 3.142"
Height: 29.25"
Volcume 7444.184 Cubic inches
Cu in to Cu ft 0.000579

= 4.3 Cu ft

How does that model?

-HD

 

[Veltinorian]

as this design yields an amplification (this causes considerable unlinearities too, especially when room specs come into action-this with roll-offs at several points) of 1-2 db at 50Hz this will be the 0point on Y axis and -3db are at 30Hz (the software says 26.72Hz but this value is actually a -4 to 4.5db point) here is the graph:

When i run the program with the recommended High Fidelity option checked (without your constraints of the height-"free mode") it yields height 65.04 inches - in this case reaches down to 18.74Hz wow, here dayton really shines in its full potential. i will post a screenshot tomorrow