might have lost my mind. thinking of building a7 cabinets

[cradeldorf]

Okay I'll flicker them tomorrow and post them on this thread.

[cradeldorf]

Here it is, The bottom part of the main horn was actually gonna be a bunch of laminated 3/4 plywood pieces that would also form the upper mouth of the bottom rear wave horn. The sides of the upper horn would also be constructed this way as to eliminate hollow area's that might resonate. Also there was gonna be a laminated half arc piece behind and above the speaker to eliminate some of the square corners inside the cabinet. The entire path the rear wave was to follow would be very fluent.

BTW this is not the standard A7 cabinet size, I think it's smaller. Also the bottom horn is not calculated at all. It' was just a thought and a drawing.

SpeakerCabinetSmall | Flickr - Photo Sharing!

[Phil-G]

thats a great drawing
i was thinking of a horn similar to what your drawing shows. but i need to draw what i'm thinking.

[GM]

If it can be done with without looking different/odd, I'd go for it!

I'm sure it would sound fine, but too me, the look wouldn't be right. Did GM say why he suggested it? Does it have an advantage?

Don?t recall what I posted, but a few things come to mind WRT round Vs other shape vents:

1] Round is the most efficient, so is the shortest for a given tuning.
2] Round is easiest to make, fine tune.
3] Because of [2], no need for gasketed plates that can leak, altering tuning.

As far as cosmetics go, that?s what grill cloth or similar is for plus I?ve found that most vented alignments benefit from minimal internal damping combined with ?critically damping? the vent, so the grill cloth can do double duty as part/all of the damping.

GM

[Phil-G]

thanks GM. how would the smaller port work in a larger venue? like a 90 x120' or would it only work in a smaller room like a living room size 15x30'

[GM]

You're welcome! It would depend on the room's acoustics, speaker location and how far away the listening position is no matter what the room size, but as a general rule a high tuning would be used for prosound/really big rooms apps and add a separate sub system if usable output below ~60 Hz is desired.

GM

[Audio_by_Goodwill]

Don?t recall what I posted, but a few things come to mind WRT round Vs other shape vents:

1] Round is the most efficient, so is the shortest for a given tuning.
2] Round is easiest to make, fine tune.
3] Because of [2], no need for gasketed plates that can leak, altering tuning.

As far as cosmetics go, that?s what grill cloth or similar is for plus I?ve found that most vented alignments benefit from minimal internal damping combined with ?critically damping? the vent, so the grill cloth can do double duty as part/all of the damping.

GM

GM, if we're talking about an A7, they typically have a port only as thick as the wood used, and often don't have grills.

You mentioned efficiency, but in what regards?

[Phil-G]

pretty good chance we're talking a7 or 828 somethings here.
although what i end up with will more than likely have an asterix at the end of the title. being a diy project it's not uncommon to vear off the typical. and anything that improves on a 40 year old design is going to be used.

[GM]

GM, if we're talking about an A7, they typically have a port only as thick as the wood used, and often don't have grills.

You mentioned efficiency, but in what regards?

[1], [2] for any vented alignment and all three for reflex [baffle thickness vent].

Acoustic efficiency, i.e. round has the least frictional area WRT cross sectional area [CSA] , ergo for a given tuning it will have the shortest vent.

I don't see where having grills or not is relevant per se, i.e. it's a design choice which in the case of the VOTTs is probably ?bean counter? related and from a purely technical POV, critically damping the vent is normally required for best practical sound quality [SQ] and always with a reflex vent in a HIFI/HT app.

In your case it can be shaped to imply an A7?s full width slot or even the later 828H ?window screen? variant, which to is the best looking short of the whole cab being ?grilled? with a horizontal accent below the horn.

GM

[Phil-G]

had the cabinets laid out,, and i know i said i didn't care about looks but, after looking at the plywood i decided to finish them with a nice blond woodgrain finish. so instead of bondo, battleship gray, and chainlink grills NINs style. i spent the last couple days truing up the edges for a cleaner look. so tomorrow i fit everything and bond them together. hopefully monday i start on the horn flanges. i want almost more than anything to hear these beasts roar in less than three weeks.