Omni 15 and Omni Sub

[tarduare]

Nine months later I have finally found the time to post some pix of my exploits. These speakers have exceeded my expectations in all respects.I would like to thank Leland Crooks for supplying the raw materials for the builds, as well as BFM for an outstanding design. I have used these cabs for DJ work over the summer with a QSC 1850 and passive xovers I am throughly impressed with the sound quality as well as the value for dollar.

http://www.flickr.com/photos/30933200@N05/2900953142/
http://www.flickr.com/photos/30933200@N05/2900952946/
http://www.flickr.com/photos/30933200@N05/2900952774/

I am unsure about inserting actual photos into posts and all I can do is hope that these links to flickr pix work.
A helping hand would not be unappreciated.

[Chris_Allen]

That's an awful lot of bass!



Nice and clean cabs, like the way you have separate wheel boards to reduce pack space.

[Tom Smit]

The stacks look good (which proves that the links work)

Toms

[Scott Brochu]

Nine months later I have finally found the time to post some pix of my exploits. These speakers have exceeded my expectations in all respects.I would like to thank Leland Crooks for supplying the raw materials for the builds, as well as BFM for an outstanding design. I have used these cabs for DJ work over the summer with a QSC 1850 and passive xovers I am throughly impressed with the sound quality as well as the value for dollar.

http://www.flickr.com/photos/30933200@N05/2900953142/
http://www.flickr.com/photos/30933200@N05/2900952946/
http://www.flickr.com/photos/30933200@N05/2900952774/

I am unsure about inserting actual photos into posts and all I can do is hope that these links to flickr pix work.
A helping hand would not be unappreciated.

where do you position these around the venues?
I didn't even know there was a Omni sub, I thought it was a just the tallboys? well learn something new everyday.

Very nice looking, clean and sleek.
(I found it. Its last words in the advertising, first paragraph.)

[Chris_Allen]

I didn't even know there was a Omni sub, I thought it was a just the tallboys?

That's a good point, neither did I!

Wonder how they compare against a T30 since they can't fit a 3015LF and they look a similar size and a much simpler build.

[DJDAVE]

Is that the LOWBOY. I built the standard O15 as a sub because I liked the dimensions of it. It would sit right in front of my DJ table with out taking hardly any room in front which is where the dance floor usually is. I wonder how they would compare in sound?


Anyways, Thats a awesome looking build. I could never get away with painting my speakers due to my poor building skills. I'd love to hear how your system sounds.

[Mark Coward]

I have used these cabs for DJ work over the summer with a QSC 1850 and passive xovers I am throughly impressed with the sound quality as well as the value for dollar.

Nice work, did you just use the same O15 500hz Lowpass in the subs?

[Scott Brochu]

You can build it with midrange and tweeters for a full range high efficiency single box system, with or without tweeters for electric bass, or woofer only for a sub suitable for either PA or backline use.

^^^^^^I found that on the advertising page for Omni 15^^^^^^^

[Mikey]

Wonder how they compare against a T30 since they can't fit a 3015LF and they look a similar size and a much simpler build.

The O15 Sub was discussed at great length in a thread quite some time ago. Many pros and cons were weighed, and the general concensus was that it would be good as a stand-alone, such as for bass guitar or keys, but fully horn-loaded cabs win-out above that, for many somewhat obvious reasons. Judging from these pics, it looks like tarduare probably used the O15 Sub dimensions from that thread, which also includes one extra piece of wood to keep the horn depth the same while making the cab deeper.

[MYork]

Do the subs and TB15 complete cabinets both have 15" drivers? How do you crossover the frequencies and connect the cabinets? MY

[Mark Coward]

Do the subs and TB15 complete cabinets both have 15" drivers? How do you crossover the frequencies and connect the cabinets? MY

I asked the same question, assuming that he used the same 500hz LPF from the plans since he mentioned using a single amp to power the rig. Hopefully he will reply eventually.

[Mikey]

My guess would be that he biamps between bass and mids. Otherwise, he'd need different passive crossover components when adding the subs, due to the impedence going from 8 ohms (1x15) to 4 ohms (2x15).

[Mark Coward]

My guess would be that he biamps between bass and mids. Otherwise, he'd need different passive crossover components when adding the subs, due to the impedence going from 8 ohms (1x15) to 4 ohms (2x15).

Nope, read his post again:

I have used these cabs for DJ work over the summer with a QSC 1850 and passive xovers

If both the O15TB and the O15 sub have internal passives in each they would be the same, 8 ohm per cab and paralleled for a 4 ohm load. I was just curious if he might have changed the frequency on the sub from 500hz, I'd considered a similar setup and was thinking about around a 100hz - 150hz LPF on the sub. Many 2x15 full range cabs have a passive crossover on the bottom 15 as a sort of built-in "sub."

tarduare, let us know as inquiring minds want to know

[Mikey]

My guess would be that he biamps between bass and mids. Otherwise, he'd need different passive crossover components when adding the subs, due to the impedence going from 8 ohms (1x15) to 4 ohms (2x15).

Nope, read his post again:

I have used these cabs for DJ work over the summer with a QSC 1850 and passive xovers

Hmmm, yeah, missed that. Definately raises some questions.

If both the O15TB and the O15 sub have internal passives in each they would be the same, 8 ohm per cab and paralleled for a 4 ohm load.

The two 8 ohm drivers in parallel would be a 4 ohm load, but the two crossover components in the woofer circuit would have to be changed in order to accomodate the 4 ohm load while maintaining the 500hz crossover frequency ... the 20uf cap would have to be 40uf, and the 5mh coil would have to be 2.5mh. The logical way to accomplish going with/without the sub would be to use two 20uf caps and two 2.5mh coils ... 1 cap + 2 coils for 8 ohm woofer, 2 caps + 1 coil for 4 ohm woofer, with a switch to accomodate that.

I was just curious if he might have changed the frequency on the sub from 500hz, I'd considered a similar setup and was thinking about around a 100hz - 150hz LPF on the sub.

You'd succeed in losing sensitivity and gaining nothing. The O15Sub will only go a couple of hz lower than the O15, due to the slightly increased volume by omission of the mids and highs. Otherwise, the driver, horn and vent are the same.

Many 2x15 full range cabs have a passive crossover on the bottom 15 as a sort of built-in "sub."

They "rob Peter to pay Paul". It takes some lows out of the top 15, for a tiny bit more mid clarity, but in doing-so, decreases over-all low-end sensitivity (due to loss of low-end coupling between the drivers). IMO, it's sorta like cutting off a guy's balls so that he can hit one note higher ... not worth the trade-off. I've heard JBL's attempt at it, and I really feel sorry for the poor eunuch cabs. Maybe others work better (?).

[Mark Coward]

The two 8 ohm drivers in parallel would be a 4 ohm load, but the two crossover components in the woofer circuit would have to be changed in order to accomodate the 4 ohm load while maintaining the 500hz crossover frequency ... the 20uf cap would have to be 40uf, and the 5mh coil would have to be 2.5mh. The logical way to accomplish going with/without the sub would be to use two 20uf caps and two 2.5mh coils ... 1 cap + 2 coils for 8 ohm woofer, 2 caps + 1 coil for 4 ohm woofer, with a switch to accomodate that.

You're over thinking it, the crossovers would be in each cab, you parallel connect their inputs so each is an 8 ohm circuit. It's no different than simply running two O15's in parallel, or any other cabs with internal passive crossovers.