passive subs

[DrDyna]

In your case, with the restrictions you have in place, my personal opinion would be that you need to have separate left and right subwoofer drivers, 8 ohms if you can. That'll give you the best possible compatibility rate with a wide variety of amplifiers and make it a little easier to design the subwoofer crossover.

Just my opinion.

[Michael Chua]

How about something like the JBL SB-5 (Triple Chamber Bandpass). Doesn't need to be isobaric. Two woofers will do.

[sreten]

Originally Posted by Too Tall

I guess it will help if I explain the project.

This project is for retail sale. This is not a one-off for my
garage, We need to keep an eye on cost and price point.

Hmmm.....

If you need to ask here it seems you are way out of your depth.

Your clueless and so is your customer, not a good combination.

Your requrements are clueless, you are bound to fail.

rgds, sreten.

The top speaker is a 1” compression driver and a 5-1/4” woofer.
Coaxial and no horn.

Any idea what utter nonsense the above is ?

[DrDyna]

Originally Posted by sreten

Hmmm.....

If you need to ask here it seems you are way out of your depth.

Your clueless and so is your customer, not a good combination.

Your requrements are clueless, you are bound to fail.

rgds, sreten.



Any idea what utter nonsense the above is ?

I love sreten man, he has the bedside manner of a sledgehammer! I wish you lived closer to me, I think we'd have a blast with a case of beer and some old LPs

Party on brother!

[Too Tall]

sreten;2890656]Hmmm.....

<<<<<<<<<
If you need to ask here it seems you are way out of your depth.
<<<<<<<<<

Well I have been at this long enough to know when I need to ask for information.
I also posted on Pro Sound LAB (Live Audio Board).

Though I spent many more years on the old Bass List, before this place was created I found many people there who had more than a clue.
I expect there are quite a few people here that I could learn from.

<<<<<<<<<
Your clueless and so is your customer, not a good combination.
<<<<<<<<<<

LOL
Opinions vary, but few people have jumped to that conclusion (Lately).

<<<<<<<<<<<<<<<
Your requirements are clueless, you are bound to fail.
<<<<<<<<<<<<<<

My customer has been running a regional sound company and other related sound tasks for decades and has the respect of the live sound community.

We both knew this search might not be successful, but it was worth checking out.
Too Tall

rgds, sreten.

[weltersys]

Originally Posted by Too Tall

Well I have been at this long enough to know when I need to ask for information.
I also posted on Pro Sound LAB (Live Audio Board).

My customer has been running a regional sound company and other related sound tasks for decades and has the respect of the live sound community.

We both knew this search might not be successful, but it was worth checking out.
Too Tall

Too Tall,

Forget the transformers for bass, they will cost more than a 12", and be heavier.

While I agree with most of sreten’s points, most bass is still mixed center live or on recordings, a passive sub could be used from one side of a stereo system with no problem for most music, assuming the 5.25” can play well down to around 100 Hz. If it can't, the sub is a woofer anyway.

Since the 12” is presumably of at least the sensitivity of the pair of 5.25” midrange and a proper passive crossover presents a relatively uniform impedance between the bass speaker and midrange speaker, no problem on the side loaded with both.

The side with the top cabinet only may present a tricky load for some amplifiers, though from experience many passively crossed woofers are burnt up in pro use, leaving the mid/high functional and I have not heard of amps blowing up from that scenario.

As far as the HF driver on the coax, is that a 1" diaphragm or exit size?
A one inch exit would indicate a fairly large voice coil for a 5.25", and reduce cone area, both reducing sensitivity, I could see how one decent 12" could kick over the pair of 5.25".

That said, with most live applications wanting 10 dB more LF than mid frequency, matching a pair of 12" subs with a pair of 5.25" makes more sense, and the subs then can be used with pole mounts to put the top boxes on.

Art

[mdocod]

Gotta love Sretens special appreciation for mediocrity.

[Too Tall]

Originally Posted by weltersys

Too Tall,

Forget the transformers for bass, they will cost more than a 12", and be heavier.

This may not be so.
The 12” driver costs over $300 and in this case the extra weight may not be an issue.

Originally Posted by weltersys

While I agree with most of sreten’s points, most bass is still mixed center live or on recordings, a passive sub could be used from one side of a stereo system with no problem for most music,

assuming the 5.25” can play well down to around 100 Hz. If it can't, the sub is a woofer anyway.

This may be the biggest problem.
If the mids do not reach far enough down then your ears will tell you where the sub box is.
When this happens the usual setup has two subs and they are placed near each top box.

Originally Posted by weltersys

Since the 12” is presumably of at least the sensitivity of the pair of 5.25” midrange and a proper passive crossover presents a relatively uniform impedance between the bass speaker and midrange speaker, no problem on the side loaded with both.

He knows that most of the bass info is mixed down the middle. That said I do not know if he is willing to “cheat” even that little bit.

Originally Posted by weltersys

The side with the top cabinet only may present a tricky load for some amplifiers, though from experience many passively crossed woofers are burnt up in pro use, leaving the mid/high functional and I have not heard of amps blowing up from that scenario.

All the drivers are top shelf pro drivers.

Originally Posted by weltersys

As far as the HF driver on the coax, is that a 1" diaphragm or exit size?

1” throat.

Originally Posted by weltersys

A one inch exit would indicate a fairly large voice coil for a 5.25", and reduce cone area, both reducing sensitivity, I could see how one decent 12" could kick over the pair of 5.25".

That said, with most live applications wanting 10 dB more LF than mid frequency, matching a pair of 12" subs with a pair of 5.25" makes more sense, and the subs then can be used with pole mounts to put the top boxes on.

Art

Thanks,
I still hope to find a transformer that will combine the two signals at speaker level. If that is the best way to go.

[DrDyna]

Originally Posted by Too Tall

I still hope to find a transformer that will combine the two signals at speaker level. If that is the best way to go.

Best...very subjective. In my opinion, I wouldn't consider it to be the "best" solution.

If you're building, or trying to build a commercially viable speaker, it would be best to build something typical if you're looking for bass response rather than try to build some kind of single subwoofer that uses transformers and wizardry to be compatible with the vast majority of amplifiers.

If you want something marketable, build a pair of 3 ways that go down low enough to be good...or do small 2 ways with a sub for each one.

Remember, the more atypical you build this thing, the harder it's going to be to make a system that's widely acceptable for consumers.

[Too Tall]

[QUOTE=DrDyna;2890979]Best...very subjective. In my opinion, I wouldn't consider it to be the "best" solution.

By “best” I hope not to have a system that will fry eggs in the morning.
I want to keep all the energy in the drivers moving.

Originally Posted by DrDyna

If you're building, or trying to build a commercially viable speaker, it would be best to build something typical if you're looking for bass response rather than try to build some kind of single subwoofer that uses transformers and wizardry to be compatible with the vast majority of amplifiers.

He is doing this to satisfy a specific nitch. This is not a mass market design. It runs off what you can get out of that tiny 5” coax.
With an added low end driver he can get serious bandwidth without putting the mid in a big box to get as much low end as possible.

Originally Posted by DrDyna

If you want something marketable, build a pair of 3 ways that go down low enough to be good...or do small 2 ways with a sub for each one.

Again, he has a market identified. My guess is he has customers who want this specific design.

Originally Posted by DrDyna

Remember, the more atypical you build this thing, the harder it's going to be to make a system that's widely acceptable for consumers.

I am looking on something a bit larger.
Use the coaxial 5” and add a plain 5” woofer.
Myself and a friend did a “Flagship” home audio design using dual Peerless 5 ¼”, a 1 5/8 “ soft dome high mid and a JVC ribbon super tweeter.
The dual 5” gave it some extra output where it needed it most.
For a sub we used a Dynaudio 12” and a 15” passive radiator.

This will be similar, but all Pro drivers.

My trouble is I have a set of Acoustat 3 sitting in my living room.
Hard to find room. LOL