Help needed! Where to start with open baffle speakers

[SW1X]

It's quite obvious you know nothing about crossover design.

Obviously, you do know a lot and you know much better than me.

[bumpy]

There's absolutely wrong with mating a sealed bass driver with an open baffle midrange. Done properly, you wont hear the joins.

Its true what you say, but you no longer have an open baffle speaker. The lower frequecies are coming from a sealed box, so gone are the attributes that open baffles offer, such as an open non boxy sound and a vast reduction in room resonances.

[fatmarley]

Referring to flagship designs of some manufacturers does not prove anything nor offers any substance- your experience does.

S

It proves that all high end manufacturers have very different Ideas of what makes the best speaker. There are so many variables Involved In loudspeaker design, that to say your way Is the "least compromised" Is just your subjective opinion and carries no weight at all.

[fatmarley]

Argue your principles by all means Matt. But avoid personal comments like this! Thanks.

Ok, sorry Geoff.

I'll go back to that post and ask a sensible question.

[fatmarley]

3. Build a simple 1st order or max second order filter. Experiment with different caps and choke values to get the feeling.


S

Is that first order electrical or acoustic?

[walpurgis]

Is that first order electrical or acoustic?

Depending on interpretation, surely these are similar?

[fatmarley]

Depending on interpretation, surely these are similar?

No, they are two very different things.

[walpurgis]

I don't claim to be any kind of expert with crossovers, but have designed and built a few over the last forty years or so (probably not great ones ) and the words 'acoustic' and 'electrical' have been interchangeable in my experience in this context.

[fatmarley]

I don't claim to be any kind of expert with crossovers, but have designed and built a few over the last forty years or so (probably not great ones ) and the words 'acoustic' and 'electrical' have been interchangeable in my experience in this context.

They're definitely not Interchangeable.

[Macca]

As the OP who started this thread, I did not expect it to generate such a lively debate. Clearly there are many here on AoS with lots of knowledge...and diverse views!

I'm not ashamed to say this, but most of what you guys are saying has gone totally over my head, but hey, that just shows how much I have yet to learn.

Reading your various posts, I did have a few (more basic) questions:

1. given the wide range of driver/tweeter manufacturers out there - eminent technologies, fostex, seas, scanspeak, vifa etc., is there a combination of woofer and tweeter that goes well in an OB set up (without breaking the bank)?

2. for a first timer like me, should I start with just one woofer and one tweeter for each speaker or have more? (I recognise the answer might have a lot to do with the size of my room and acoustics etc.)

3. should I build my own X-over or buy a ready made one and tweak it? Or maybe no X-over at all and do what Slawa suggests, base on field coil drivers?

My room is about 18ft x 30ft although I sit facing the short length. Walls are fairly bare and ceiling around 15ft high. Floor is suspended wooden slats but largely covered with rugs. So quite a few hard surfaces, but quite airy.

Slawa - glad you joined the thread. It was seeing pictures of one of your OBs for sale on HiFi Wigwam last year that piqued my interest in OBs. Then talking to my friend Dave earlier this year gave me the encouragement to take the plunge. So you are the genesis of this project of mine. Would love to speak to you in person one day and maybe hear your OBs.

Thiha

You have a big advantage with that room but the best way to use an open baffle speaker is to have it firing down the length of the room, not across the width.

The big problem with open baffles is bass cancellation. Bass units go in boxes for a reason, because if you don't put the bass in a box you get cancellation from the return wave and.... no bass or heavily curtailed bass. With 30' to play with you can have the bulk of the room behind the speaker, giving the bass wave a chance to dissipate down the length rather than return. Unlike most rooms you should be able to get pretty good bass from an open baffle by setting them up like that. Have 15' to 20' of the room behind the speakers.

In general terms re open baffles, people do claim that bass sounds more natural etc without the box. I'm not so sure. The various monitoring speakers in studios are not open baffles. Recordings tend to be mixed to sound good on these speakers - not on open baffles. If you listen to a lot of music that has a lot of bass energy below 40 Hz (dance music, electronica, organ and so forth) then I wouldn't recommend going for an open baffle. At least not for the bass. The are not intrinsically better, they are, like all speaker designs, just another set of compromises.