[aceinc]

I am currently in the design phase of a "full range" OB design.

As typical it is easy to get the 200+ hz taken care of, but now I am looking to do the bass section. For aesthetic reasons I would like to use 2 - 10" drivers.

What can I hope for as far as low frequency extension with two 10" drivers?

Does anyone have recommendations for specific drivers? I am hoping for ~90 DB at 8 ohm efficiency for the cabinet, to minimize xover complexity.

If not what should I be looking for in a driver? I know the rule of thumb is a high QTC. .70 or greater is ideal I think.

I have built a pair of GR Research 12" OB "W" style enclosures and they work well. This time I would like to try a non "kit."

My design question is;

When building a low frequency driver cabinet, the preferred designs place the drivers equidistant from the front and rear openings (H or W design). What are the reasons for not mounting the driver on a front baffle of an enclosure of the same size with an open back?

I assume it has something to do with a resonant cavity effect, but I would think the resonance of the box would be out of the band pass required of the enclosure.

[FullRangeMan]

I have tested 4x10 and they dont worked for me. I would suggest one 15 inches.

[aceinc]

I have tested 4x10 and they dont worked for me. I would suggest one 15 inches.

Which drivers?

What was the problems?

I know GR Research has a 3 x 8" which people seem to like.  I would think 2 x 10" should get some level of bass if not infrasonic frequencies.

[opnly bafld]

My design question is;

When building a low frequency driver cabinet, the preferred designs place the drivers equidistant from the front and rear openings (H or W design). What are the reasons for not mounting the driver on a front baffle of an enclosure of the same size with an open back?

I assume it has something to do with a resonant cavity effect, but I would think the resonance of the box would be out of the band pass required of the enclosure.

See post #6 by johnk... here: http://techtalk.parts-express.com/forum/tech-talk-forum/47428-open-baffle-u-fram...

Also http://www.quarter-wave.com/OBs/U_and_H_Frames.pdf
and https://www.linkwitzlab.com/H-U%20woofer2.htm

[aceinc]

See post #6 by johnk... here: http://techtalk.parts-express.com/forum/tech-talk-forum/47428-open-baffle-u-fram...

Also http://www.quarter-wave.com/OBs/U_and_H_Frames.pdf
and https://www.linkwitzlab.com/H-U%20woofer2.htm

My high level take away from those articles is, U frame designs can provide better or worse results than H frame designs, but to properly design a U frame requires a more complete understanding of the drivers and the algorithms needed to yield a good design. H frames require less work, design wise, to yield acceptable results.

Is that a fair assessment?

[opnly bafld]

I think so.

[FullRangeMan]

If nice look is important see this below, made by an AC member with the Alpha 15A.

[aceinc]

If nice look is important see this below, made by an AC member with the Alpha 15A.

If I can get some level of bass out of two 10" drivers in an H or W frame, I want to do that. If not, the remainder of my design will not work. The concept I have in mind is driven by aesthetics, and if I can't achieve the look I want, the concept falls apart.

So if anyone has some experience either empirical or theoretical regarding what I could expect frequency range wise with a pair of 10" drivers I would be interested in this.

I was thinking of something like this;

https://www.parts-express.com/DS18-SLC10S-Selelct-10-Paper-Cone-Subwoofer-4-Ohm-294-8076

Which appears to be a car sub, without a lot of specs, but has a high Qts. I have no idea how to determine what I could expect out of a pair of these drivers in an H or W frame. Is there a calculator I can use?

[opnly bafld]

A pair per side?
How will you drive a 2 ohm load?

[FullRangeMan]

The rule of thumb for OB bass attenuation is that 15"" start fall at 60Hz, for 12"" I read it start fall under 110Hz, all this without eq or DSP.

Try search a calculator at Google.

[FullRangeMan]

Do you could post a drawer of your project to show the intended looks ?

[aceinc]

A pair per side?
How will you drive a 2 ohm load?

I could handle 2 ohms per side with a separate amplifier, but since my target 88-90 DB per cabinet at 1 watt I was hoping to hook them in series, yielding an 8 ohm load.

[aceinc]

Do you could post a drawer of your project to show the intended looks ?

I don't have drawings yet, but my target woofer cabinet dimensions are ~13" wide x ~23" (or less) high x whatever the required depth for an H or W frame will be.

[Jstower]

Here’s a link, you may find some suitable 10” woofers. Good luck with your project.

https://www.audiocircle.com/index.php?topic=149613.0

Also I purchased some of the MCM 10” drivers, but unfortunately I have not done anything with them yet.

https://www.newark.com/mcm-audio-select/55-2972/10-woofer-with-poly-conerubber/dp/80R7011?MER=sy-me-pd-mi-acce#
Article:
http://www.mfk-projects.com/my_projects/Projects%202015/MCM%20woofers.html

[mcgsxr]

My own decade of OB exploration included some time with using car audio 12's on OB to augment bass.

I used a 3x4 foot baffle, with piano hinges to make it sort of a U shaped baffle - I didn't pull the wings back that far, but far enough to help them stand on their own, so close enough.

With a single 12 on each panel, biamping and with EQ I was able to get satisfying bass.  Not likely what I could have with more or larger drivers, but good enough I kept them in place for more than 8 years.

With a pair of 10's, your swept area will be larger than 1 12 but not quite 1 15.  That should prove useful and could prove to be enough for you in your room.

I don't love the foam surround on the speakers the OP listed, but the other specs (FS, XMAX, QTS are usually the big 3 - along with sensitivity if you don't anticipate biamping) all look good for playing around with.

Have fun with the project!