Need to know correct port tube size!!!!!! and other Q's

[SuBXeRo]

My knowledge of ports and vents is rather limited, as most of my experience has been with sealed because i enjoy the crisp experience it gives, subwoofer wise. I have built customer subwoofer boxes for my car and have been rather successful with that. I have decided to try and take on a home speaker projext to solve the crappy acoustics in the family room in my house. We lack a subwoofer, and the protons we have in their cant hit lows for crap. I will be using a 5 X 100 watt sony surround sound amp to push these speakers, so i think that the rms should be fine for this. What size port should i buy for this setup so it doesnt sound like **** . Also, this setup pertains to a left and right channel. If this project is successful i will be designing a center channel as well. If it is very successful, these will be a rear left and rear right as i will build a 3-way left and right for the front speakers.

I plan on using the specs suggested on the Parts Express website as far as enclosure size goes. I also wanted to double check, i havent built enclosures in a while, but the drivers specs list the volume requirement with the volume of the driver included, or the enlclosure volume is the driver volume + recommended volume. I also plan to use 3/4" mdf as i feel that 1" is overkill considering my 2 500 watt rms subs are in a 3/4 inch enclosure and i feel 0 flexing or vibration from the enclosure.

Another question is, do i want to create chambers for each driver? My assumption is no because the tweerter is already enclosed and i am building ported, not sealed where it may be more of an issue, especially if the tweeter wasnt dome like the dayton.

I decided to build a vented enclsoure for these components:

This tweeter and 2-way crossover with either of the following woofers

Tweeter:
Dayton DC28FS-8 1-1/8" Shielded Silk Dome Tweeter

Crossover:
Dayton XO2W-2K 2-Way Crossover 2,000 Hz

Woofer 1:
Dayton RS150S-8 6" Reference Shielded Woofer 8 Ohm

Woofer 2:
Dayton RS225S-8 8" Reference Shielded Woofer 8 Ohm


Thanx in advance

[johnastockman]

My knowledge of ports and vents is rather limited, as most of my experience has been with sealed because i enjoy the crisp experience it gives, subwoofer wise. I have built customer subwoofer boxes for my car and have been rather successful with that. I have decided to try and take on a home speaker projext to solve the crappy acoustics in the family room in my house. We lack a subwoofer, and the protons we have in their cant hit lows for crap. I will be using a 5 X 100 watt sony surround sound amp to push these speakers, so i think that the rms should be fine for this. What size port should i buy for this setup so it doesnt sound like **** . Also, this setup pertains to a left and right channel. If this project is successful i will be designing a center channel as well. If it is very successful, these will be a rear left and rear right as i will build a 3-way left and right for the front speakers.

I plan on using the specs suggested on the Parts Express website as far as enclosure size goes. I also wanted to double check, i havent built enclosures in a while, but the drivers specs list the volume requirement with the volume of the driver included, or the enlclosure volume is the driver volume + recommended volume. I also plan to use 3/4" mdf as i feel that 1" is overkill considering my 2 500 watt rms subs are in a 3/4 inch enclosure and i feel 0 flexing or vibration from the enclosure.

Another question is, do i want to create chambers for each driver? My assumption is no because the tweerter is already enclosed and i am building ported, not sealed where it may be more of an issue, especially if the tweeter wasnt dome like the dayton.

I decided to build a vented enclsoure for these components:

This tweeter and 2-way crossover with either of the following woofers

Tweeter:
Dayton DC28FS-8 1-1/8" Shielded Silk Dome Tweeter

Crossover:
Dayton XO2W-2K 2-Way Crossover 2,000 Hz

Woofer 1:
Dayton RS150S-8 6" Reference Shielded Woofer 8 Ohm

Woofer 2:
Dayton RS225S-8 8" Reference Shielded Woofer 8 Ohm


Thanx in advance

The pre-made XO will be woefully inadequate with those drivers, or any drivers. Those are very nice units, especially the RS drivers. Look through the Project Showcase, or I can give some links to some very well designed speakers using those drivers in similar config's. This way, the XO is already worked up and tested (usually the best option if you haven't designed a XO yet). The pre-made XO's can't take into account all the variables regarding each drivers individual characteristics. Here's a terrific, simple box design program for free, WinISD and it's actually better than the PE suggestions IME:

http://www.linearteam.dk/default.aspx?pageid=winisd

Just enter the driver specs and it will give volume and/or port dimension info...it does sealed or vented enclosures. Make sure you adequately brace your cabinet internally. You can look at some of the members photos (or request some pics) and can see how they braced their cabinets. If you can afford a better tweeter, the RS28 is a much better match for those drivers, or the Seas 27TDFC is another excellent choice. I'm sure you'll get other responses, as there are guys here with more experience than I have that could help with your specific choices. Good luck and don't worry about "simple" or "dumb" questions...I sure had my share in the beginning!
There are many fine 2-ways that use the 8", 7" or 6" RS woofers. Here's a couple sites with great designs:

http://www.rjbaudio.com/projects.html

http://www.lonesaguaro.com/speakers/

There are more, but this can start you out.

John A.

[wlb]

If your going to make a speaker set up with two 8" daton refferance woofers in it you may want to look at the project showcased in the new flier this that just came out. The ZDT3.5. I don't see it on the PE website yet. It uses 2 of the refferance 7" drivers a dome mid and an inexpensive tweeter. The speakers in it are on sale and the Xover is already done . It looks real good.

[SuBXeRo]

i was attempting to avoid building a crossover as much as possible haha. I am good with soldering and what not, but i suppose as along as i found the schematics for it i could do it.

[wlb]

i was attempting to avoid building a crossover as much as possible haha. I am good with soldering and what not, but i suppose as along as i found the schematics for it i could do it.

If you want a good sounding speaker system you will need a well designed Xover to integrate the components properly. That is a well known Tennant of speaker building. If you can solder and read an electrical schematic then you can do one that is already designed by someone who knows what they're doing. Don't be afraid just jump in there and give it a try. If you goof it up someone will help you here. Their is nothing more satisfying than enjoying the fruits of your own labor .

[SuBXeRo]

hahahaha i know that feeling all to well, it is quite gratifying if i do say so myself.

Ill try and find some good schematics for this system

Also, whats the deal with 6db/octave and 12db/octave, whats the difference when building a XO, im trying to read up on building XO's right now and familiarizing myself with with everything.

[johnastockman]

hahahaha i know that feeling all to well, it is quite gratifying if i do say so myself.

Ill try and find some good schematics for this system

Also, whats the deal with 6db/octave and 12db/octave, whats the difference when building a XO, im trying to read up on building XO's right now and familiarizing myself with with everything.

The slopes (6, 12, 18dB, etc.) are dependent on each individual driver and how it matches up with the other drivers in the speaker, whether a 2, 3, or 4 way. That's why a XO that's designed specifically for the units used is always much better than something that's designed to work with unknown drivers. WLB is right, if you can decipher a schematic and solder, you can build a XO. There are lots of pics available to show how some of the guys lay out the parts. Here's a XO I recently made, from an excellent plan by one of the masters, Curt C. (his TriTrix design). High pass (tweeter) section on the left, low-pass (woofer) section on the right. For these I mounted the components on 1/8" hardboard (masonite) with hot glue.



If you want to learn more about XO's, I recommend "Speaker Building 201" by Ray Alden. Terrific for beginners and a lot more info about speaker design. It also has some nice projects that are included. If your budget won't allow, you can probably find it at the library.

John A.

[SuBXeRo]

they look so simple to build, i may take u up on ur suggestion and go to barnes and noble, my parents would probably have a stroke, i havent set foot in a bookstore for leisure in uhh, never.

*strokes* 100 bux used

[Andy_G]

I also plan to use 3/4" mdf as i feel that 1" is overkill considering my 2 500 watt rms subs are in a 3/4 inch enclosure and i feel 0 flexing or vibration from the enclosure.

Ah.. a common mistake. while the 3/4" may seem ok for the subs, the subs aren't dealing with midrange frequencies.

The midrange is generally where box issues come to the fore. I would use the 1" if you wish to minimise box resonances, which will adversely affect the sound quality.