Dayton 18" HO Ported Build Thread

[1Randy]

Yes, the T/S parameters define a driver precisely, very precisely in fact, in terms of box tuning design. There are many autocad type programs for modelling a speaker, that greatly speed up the design and do it accurately. There are also programs to assist with crossover design.

One would need more information than that to begin a design process. Price, one or two, associated equipment etc. A sub needs to be thought of in terms of total system design, but I admit it often is not, and that can, and often does, compromise results.

I likely have some designs on file that might fit your description. I am off to Mayo for testing

Have a great day

 

[lovinthehd]

@1Randy have you tried modelling your own sub with appropriate software? Something like BassBoxPro or WinISD?

 

[1Randy]

@1Randy have you tried modelling your own sub with appropriate software? Something like BassBoxPro or WinISD?

No I have not , not really good with computers to be honest ..But I do love building.
I've seen youtubers model subwoofers with these softwares,... changing port size/length,.. enclosure size,.. and you can see the different F.R.
TLS Guy Mentioned to me changing box size rand tuning to get more extension,can come at the cost of Quality. I would not know how to get "Optimum" enclosure design

....

 

[TLS Guy]

No I have not , not really good with computers to be honest ..But I do love building.
I've seen youtubers model subwoofers with these softwares,... changing port size/length,.. enclosure size,.. and you can see the different F.R.
TLS Guy Mentioned to me changing box size rand tuning to get more extension,can come at the cost of Quality. I would not know how to get "Optimum" enclosure design

....

What is your budget and upper size limit? I have quite a few worked designs on file, so I might be able to solve this for you quite quickly.

 

[1Randy]

What is your budget and upper size limit? I have quite a few worked designs on file, so I might be able to solve this for you quite quickly.

No bigger than this pic....Driver alone up to $750

750

 

[TLS Guy]

No bigger than this pic....Driver alone up to $750 View attachment 77694750

That is not the way you design a speaker. I can get it roughly the same size. A cube is a bad idea as all the internal reflections combine to make a peak, so I will avoid that. I will try and get about the same volume. You never design backwards with a cabinet, and find a driver to use. ALWAYS the other way round.

 

[Verdinut]

That is not the way you design a speaker. I can get it roughly the same size. A cube is a bad idea as all the internal reflections combine to make a peak, so I will avoid that. I will try and get about the same volume. You never design backwards with a cabinet, and find a driver to use. ALWAYS the other way round.

At some subwoofer frequencies, a cubic enclosure cannot become problematic. Wave lengths in enclosure sizes are involved with frequencies which are a lot higher than those reproduced by a subwoofer. As an example, a 30 Hz note has a wave length of 114.33 meters.

 

[highfigh]

For a home theater subwoofer is the first step determining your box size limit ?

The parameters need to be used in a good box design program- the size will be determined by this. Parts Express has modeled a lot of drivers and if you click on Manuals and Resources for any drivers you're considering, you'll see info that includes examples of designs with various response specs.

 

[1Randy]

@1Randy have you tried modelling your own sub with appropriate software? Something like BassBoxPro or WinISD?

No I have not , not really good with computers to be honest ..But I do love building.
I've seen youtubers model subwoofers with these softwares,... changing port size/length,.. enclosure size,.. and you can see the different F.R. but like the height and length of the room at just the right ratio, it tends to spread out the modes.So

....

That is not the way you design a speaker. I can get it roughly the same size. A cube is a bad idea as all the internal reflections combine to make a peak, so I will avoid that. I will try and get about the same volume. You never design backwards with a cabinet, and find a driver to use. ALWAYS the other way round.

Yes i understand,...I would like to use the RSS390HF Driver BUT...i dont want a fridge size enclosure, so I do need set a size limit.

The GSG enclosure in pic was just an example of (Total Vol), not specific dimentions.

 

[1Randy]

At some subwoofer frequencies, a cubic enclosure cannot become problematic. Wave lengths in enclosure sizes are involved with frequencies which are a lot higher than those reproduced by a subwoofer. As an example, a 30 Hz note has a wave length of 114.33 meters.

...Your math is wrong i think

 

[1Randy]

The parameters need to be used in a good box design program- the size will be determined by this. Parts Express has modeled a lot of drivers and if you click on Manuals and Resources for any drivers you're considering, you'll see info that includes examples of designs with various response specs.

Thank you, I will check that out

 

[Verdinut]

No I have not , not really good with computers to be honest ..But I do love building.
I've seen youtubers model subwoofers with these softwares,... changing port size/length,.. enclosure size,.. and you can see the different F.R. but like the height and length of the room at just the right ratio, it tends to spread out the modes.So

....
Yes i understand,...I would like to use the RSS390HF Driver BUT...i dont want a fridge size enclosure, so I do need set a size limit.

The GSG enclosure in pic was just an example of (Total Vol), not specific dimentions.

I am currently using 3 TRSS390HF-4 in my HT system. This driver needs a cabinet with an internal volume of about 9.5 cubic feet for a ported enclosure for best results, as per Chris's answer to one of the questions on Parts-Express site. It looks like you can also use a smaller volume down to 3 cf as indicated by P-E with the sub info summary. You would then have to contact them for specific porting for such small volume. Such a small volume would definitely limit its low frequency response.

 

[1Randy]

I am currently using 3 TRSS390HF-4 in my HT system. This driver needs a cabinet with an internal volume of about 9.5 cubic feet for a ported enclosure for best results, as per Chris's answer to one of the questions on Parts-Express site. It looks like you can also use a smaller volume down to 3 cf as indicated by P-E with the sub info summary. You would then have to contact them for specific porting for such small volume. Such a small volume would definitely limit its low frequency response.

This driver has a Fs of 19.5...why does Parts Express recommend an enclosure of 3cu/ft and a f3 of 27 hz ??

And what is (Vas)

 

[1Randy]

The parameters need to be used in a good box design program- the size will be determined by this. Parts Express has modeled a lot of drivers and if you click on Manuals and Resources for any drivers you're considering, you'll see info that includes examples of designs with various response specs.

...Is this the same as the recommended box volume in the "overview" section ?

 

[Verdinut]

This driver has a Fs of 19.5...why does Parts Express recommend an enclosure of 3cu/ft and a f3 of 27 hz ??

And what is (Vas)

As I wrote earlier, with a smaller ported box you can't reach the lower frequencies which are obtained in the bigger one. You would however be able to get the lower frequencies using a sealed cabinet, with the help of adequate EQ.

Edit:
Vas:
(Equivalent Compliance Volume) represents the volume of air that has the same stiffness (acoustic compliance) as a speaker driver's suspension system (spider and surround). It indicates how "soft" or "stiff" the suspension is, directly affecting the required enclosure size and low-frequency performance.

To help you understand better, I recommend that you get one of the books on speaker building, either the one by Alden or Weems:

https://www.amazon.com/s?k=speaker+building+book&crid=3MRAMX6G8P5HG&sprefix=Speker+building%2Caps%2C179&ref=nb_sb_ss_p13n-expert-pd-ops-ranker_4_15

 

[TLS Guy]

This driver has a Fs of 19.5...why does Parts Express recommend an enclosure of 3cu/ft and a f3 of 27 hz ??

And what is (Vas)

Vas is the volume of air that has the same compliance as the driver.

The design I posted fits your description.

That should be an easy cost effective build and you can easily build two of them and come out in budget. Time to get building if that is what you want to do. They will be very good subs.

 

[Verdinut]

Vas is the volume of air that has the same compliance as the driver.

The design I posted fits your description.

That should be an easy cost effective build and you can easily build two of them and come out in budget. Time to get building if that is what you want to do. They will be very good subs.

1Randy is interested in the Dayton RSS390HF-4 subwoofer, not the RSS315.

 

[TLS Guy]

1Randy is interested in the Dayton RSS390HF-4 subwoofer, not the RSS315.

I know that, but the driver I selected will so what he wants and the HO won't.

 

[1Randy]

1Randy is interested in the Dayton RSS390HF-4 subwoofer, not the RSS315.

...Takes too big of an enclosure for me

 

[TLS Guy]

...Takes too big of an enclosure for me

It is about the same size as the picture you posted.

The one below will do the job in a smaller cabinet.