New build for shop system

[AngrySailor]

I didn’t glue mine in until I did a frequency sweep, I’d try the long ones first but if you land within a few hz you’re gold. Remember to stay the diameter of the port away from any bracing or box walls (in line with the port) as that can affect the port.

 

[roccus]

Well this is a mock up (the one on the right) of what I will build the port on the mock up here is 5" but speaker is actual 18"

 

[AngrySailor]

Looks good, just plan for extra port length when you place your gussets in case you need to tune down, you don’t really want to get the end of the port much closer than 6” to a surface flat to the end of the port. Build em!

 

[roccus]

Looks good, just plan for extra port length when you place your gussets in case you need to tune down, you don’t really want to get the end of the port much closer than 6” to a surface flat to the end of the port. Build em!

I just ordered a couple of these and some other stuff for the build a couple days ago.... https://www.parts-express.com/speaker-cabinet-port-tube-6-id-x-6-l--260-401

 

[AngrySailor]

Link not works big but they’re 6x6” eh? Flanged for easy mounting I bet too. Decent.

 

[roccus]

Yes 6X6" with a flange, only $4 ea. They got here today. I have to put grills on these as they sit on the floor so been wrestling with a few ideas, I don't want to buy those ready made off the shelf grills. A couple ideas would mean better to mount the woofers flush instead or recessed like I was originally thinking......

 

[mlucitt]

How about a pair of these for the Shop System?
https://www.parts-express.com/dayto...ro-subwoofer-with-5-voice-coil-4-ohm--295-052

 

[J!m]

Duuuuuuude!

Four of those built into folded horns!

Output would look like a land based gas turbine air intake but DAMN! It should crack reinforced concrete!

 

[Bob Boyer]

I have no words for that speaker. It is too much in every good way possible.

 

[J!m]

My largest bass drum is 22"... I would expect very accurate low frequency reproduction.

I helped a friend build a folded horn for a 10" driver, and it was half the size of a refridgerator. Total face-ripper too. He paied it with a tweeter for his bass rig and it sounded awesome. He was using a little orange amp back then... Not Orange (brand) but orange colored. Not very well known but small and powerfull.

I sent him a link and he said it could actually crack the sky (which was a 70's prog band I was not familiar with). He figures the final opening would be a bit larger than a garage...

But building these into a three-way floorstander with first order crossovers... I'd be interested to see what that looked like, and more importantly, what it sounded like!

 

[roccus]

How about a pair of these for the Shop System?
https://www.parts-express.com/dayto...ro-subwoofer-with-5-voice-coil-4-ohm--295-052

Those things are beasts!!

 

[J!m]

I was bouncing ideas off my buddy and he said to get to 20 Hz we need an exit area of about 20x20 feet (and 100 feet long- hence the folding)

So, I figured we’d make it 10x 40 and call it a stage. First row would be pushed back and may have damaged internal organs, but it’s only rock n roll!

Fortunately, you don’t really need two of them.

 

[roccus]

For this tuning on these cabs as far as the port goes I am at a 6" round port, about 6" long..... lets say instead of 1 port I wanted to do 2 ports. Would that mean the size of the 6" set up would be cut in half t give me same frequency? Another words I would use 2 - 3" round ports about 3" long, or would the length stay the same??

 

[J!m]

I doubt it.

You need to find the area of the 6” circle (pi r ^2 I think) and then get the same area from multiple ports. They will end up larger than 3” if there are two of them. Or go with four 3” ports.

3” = 28.274”^2
6” = 113.097”^2

Anyone correct me if I’m wrong cuz I don’t make speakers.

 

[roccus]

I doubt it.

You need to find the area of the 6” circle (pi r ^2 I think) and then get the same area from multiple ports. They will end up larger than 3” if there are two of them. Or go with four 3” ports.

3” = 28.274”^2
6” = 113.097”^2

Anyone correct me if I’m wrong cuz I don’t make speakers.

I got ya, should have thought of that my self lol.... I'm just playing around with different ideas, I have a blank canvas here and I want to look at all possibilities and make a decision, I don't want to build them then think I wish I had done this or that instead, one thing I will not change is the size of the cab, but It is why I am not in a big hurry to build them, have started ordering stuff to build them by the time I buy the mdf I should have most everything here to build them complete....

 

[J!m]

Maybe another poet shape, with the appropriate area. Or maybe if the area changes, so does the length for tuning?

Angry Sailor probably knows.

 

[AngrySailor]

It’s more complicated than one 6” port or two 3” ports. You’re dealing with air as a fluid with mass and trying to make that resonate. For a single port, a larger port must be longer and this is due to the velocity of the moving mass being slower. I’m not an expert speaker designer or a mathematician so use a formula, online calculator or one of the many books and speaker design. The main thing you’re looking for is resonant frequency with a reasonable port velocity. Too fast you hear port chuffing, too slow (large port) the port will resonate after the input from the driver ceases. This is why many “audiophiles” demand sealed cabinets but the negative effects can be minimal if some thought is put into design.

 

[AngrySailor]

For a cool 7 grand you can have one of these...

https://gpcaraudio.com/deaf-bonce-db-832neo-32-subwoofer/

 

[J!m]

Passive radiator(s)?

 

[roccus]

Did you put speaker terminals on the backs of these? If so did you use 10ga wire to run from the terminal to the woofer?