Bass port: front, back or side?

[CT_Ohio]

I'm taking a bunch of spare parts and leftover plywood and making a 2-way 'spare parts' bookshelf pair for light listening and/or PC use. The TS params point to a ported box, so that's what I'm going to do. The boxes will be a bit odd vs typical commercial bookshelvers; to fit where I want them, they're wider than they are deep. That shape has me wondering whether I can put the bass port on the side and not front or back.

Any opinions? Love it, hate it, throw rocks at it? As with everything audio I've done up to now, this is really just a test system and not one to show off. Just don't want to fill n drill if my first port isn't right.

Box params, from some website calculator: 0.49 cuft; port for 40hz would be 1" dia x 2" long. 1"x1" would be 48hz and match the box fs more closely.

 

[comish4]

Port in back for me or use a passive radiator! Just my 2 cents

 

[musichal]

Port in front if it is to be close to or on wall. Can always make it L-shaped if the indicated port length ends too near back baffle, or widen the port to shorten the length to the same volume as the longer.

 

[Tom Brennan]

Given the long wavelengths of the frequencies coming from the vent I doubt it makes much difference where the vent is, provided it isn’t totally blocked. If having them on the side suits your needs then have at it.

 

[the skipper]

Front porting gives the most placement options.

 

[nexus]

Front PR. and you can easily experiment with tunings a bit.

 

[CT_Ohio]

Thanks for the ideas. Was looking to avoid a front port as the possible placements aren't very attractive. But these aren't about looks, so...

Given the long wavelengths of the frequencies coming from the vent I doubt it makes much difference where the vent is, provided it isn’t totally blocked. If having them on the side suits your needs then have at it.

These won't be right up against the wall, but maybe 5-6" off it. Not a lot of room for sound there.

 

[Tom Brennan]

These won't be right up against the wall, but maybe 5-6" off it. Not a lot of room for sound there.

That’s enough room for low frequencies as they bend around corners, such as with folded horns.

 

[sKiZo]

You can always purty up a front port by just finishing the edges and adding a tube with a dressed front edge. Trick is figuring out size and length of the tube - there's a whole science to that sort of stuff.

I do like the idea of a passive driver on the back directly opposite the woofer ...

 

[robgmn]

Even high end speakers can exhibit port chuffing with some music. If it can happen to them, it can happen with a DIY.
Rear port placement can minimize the audibility if there IS any unwanted noise.

 

[xero-D-hero]

Dependant upon your skill at building cabinets,I'd give slot ported out the front some consideration.
Have seem more than a few "oddball" sized studio monitors done like that.

JM2¢ ~ FWIW

Bret P.

 

[jimfet]

If the port is on the back, you can't use it as a bookshelf speaker if you are putting it on a bookshelf.

 

[CT_Ohio]

Dependant upon your skill at building cabinets,I'd give slot ported out the front some consideration.
Have seem more than a few "oddball" sized studio monitors done like that.

JM2¢ ~ FWIW

Bret P.

Am considering that; can I assume that if I have a calculated round port, I just translate the same volume to a slot design?

 

[musichal]

Am considering that; can I assume that if I have a calculated round port, I just translate the same volume to a slot design?

Good idea. Never heard chuff from a slot, but only heard larger speakers with that type port. Same volume is what I'm thinking, too.

 

[CT_Ohio]

Well for now I'm doing a round port in the back, only because I found some cheap tubes which match the port size needed... discarded clear orange medicine bottles. Yes this is a real ghetto build but can't argue with free materials. Turns out a hole from a 35mm Forstner bit (plus a bit of sanding) will accommodate the connector end of the bottle quite well; and is just enough room to route out a flare on exterior side. Cut off closed end with the scroll saw, hot glue it in and go. Think I will wrap them in duct/Gorilla tape to prevent any resonance on em. Rear vs front or side: making rear baffle removable so if I need to change these tubes, won't have to screw w/side panel.

Thanks for the replies, info I can use in my next build too.