Cross-over slopes/frequencies for Oris 200 & Bass (BD-Design)

by GC, Saturday, February 12, 2005, 13:00 (6985 days ago)

Anyone here share experiences with other slopes/frequencies on their set-up?

I'm playing around with mine at the moment, and will include rolling off the Oris as well (by changing a capacitor value in the Oris SET amp).

I'm also particularly keen to hear about crossvers used with dipole bass system as this is my own set-up.

Bert what are you using for your new Quasar system? BTW it looks really great! Have you tried using the bass end with an Oris 200 on top? That would give a setup really similar to mine!

Kind regards to all,

Jonathan

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Cross-over slopes/frequencies for Oris 200 & Bass

by GC, Monday, February 14, 2005, 17:16 (6983 days ago) @ GC

Hi Jonathan,

It seems that I have to answer this topic again... :-(

I'm also particularly keen to hear about crossvers used with dipole bass
system as this is my own set-up.

A dipole needs EQ due to the roll-off in the bass. This can partly be done within the filter by stretching the crossover points. The first section could be used (6dB) to EQ the respons in the deeper bass and the second to filter at the actual crossover point where the mid-high takes over.

This only works with a very small baffle though where the width/placement determines/influences the higher crossover frequency if the EQ is used as described above.

Bert what are you using for your new Quasar system? BTW it looks really
great! Have you tried using the bass end with an Oris 200 on top? That
would give a setup really similar to mine!

I use a two stage passive line filter where the first stage is the EQ and the second one is the "tuning" stage. This only works optimal with the speakers placed free in the room though, placing them in the corner or even close to a side wall changes the frequency respons a lot (stronger lower midrange with probably a steep dip also...)

I haven't tried the Oris 200's with the open panel and I don't think I will simply because the nature of a front loaded driver is completely different from the open panel basses. In my experience this will always give problems when trying to blend the two systems together...

I prefer to use similar systems, one of the major reasons why the Oris Ultra And the Oris "Swing" work soo well.... :cool:

Ciao,

Bert

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Front horns and bass dipoles

by GC @, Tuesday, February 15, 2005, 19:59 (6982 days ago) @ GC

Hi Bert,

I had a reply planned based on your first reply then couldn't find your site at all yesterday!

I haven't tried the Oris 200's with the open panel and I don't think I
will simply because the nature of a front loaded driver is completely
different from the open panel basses.

I think you are overlooking some fundemental factors regarding the acoustics of the average listening room!

The behaviour of the average room is very different at varying frequencies, which demands a speaker approach that suits the challenges the room provides. In typical rooms, around 200Hz and upwards the room falls into the "reverberant" range. This is where mid/high frequencies have to be controlled in order to avoid a mess of those frequencies reflecting about the place and causing diffuse imaging, phase problems and generally weird effects! Some people of course like this, and that's their preference and choice. But in my experience you have to have a very symetrical room for this to work even close to its best potential (but is still not my cup of tea!).

The 200hz area and downwards are where the resonant range starts and where all kinds of problem occur. Most bass systems excite those frequencies, causing dips or peaks up and down the room. Dipoles as you know excite resonances by far the least, and that's why they work so well.

So to my simple mind a horn/directional approach for the reverberant range, coupled with a dipole for the resonant range is actually a very elegant way to go. And the Oris 200hz has just the right cut-off to achieve this!

In my experience this will always
give problems when trying to blend the two systems together...

I don't see where the problems are?

You said in "your experience" does that mean you have tried front horns/dipole bass in the past? If so can you provide the details?

Kind regards,

Jonathan

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Front horns and bass dipoles

by GC, Tuesday, February 15, 2005, 20:51 (6982 days ago) @ GC

Hi Jonathan,

The 200hz area and downwards are where the resonant range starts and where
all kinds of problem occur. Most bass systems excite those frequencies,
causing dips or peaks up and down the room. Dipoles as you know excite
resonances by far the least, and that's why they work so well.

Yes, if placed properly then you can overcome some of the problems having the 1st harmonics less excited but you can also create other problems when placed on the wrong spot. Nothing is perfect....

I am also not sure if it is the open panel principle that is the advantage perhaps it works better because it rolls of in the bass so that it seems to give less problems? In my book the only advantage of an open panel (if build properly) is the open boxless sound...

You said in "your experience" does that mean you have tried front
horns/dipole bass in the past? If so can you provide the details?

No experience with dipoles and horns but with all kind of other related things. Its hard to write down all experiences but think that most things do not combine optimal due to the different materials used, different directivity characteristics used, different sensitivity, etc.

It is very well possible to create a good sound though, even when using different characters but it will never be optimal.

If the open panel with the Oris horn works soo well then why do you have problems or raised questions about optimizing the filter?

Since I have the Ultra system (and the new "Swing" system) I never had a problem to get the filter right.... with the other Oris systems I always have had doubts for a long time (tuning in between) before I found the integration optimal in my room. Same feeling while listening to other systems trying to combine different "systems".

This gives me the feeling that I can say that using similar systems (horn-horn, baffle-baffle, cone-cone, etc.) brings the most optimal integration.

Ciao,

Bert

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Front horns and bass dipoles

by GC @, UK, Thursday, February 17, 2005, 10:59 (6980 days ago) @ GC

Hi Bert,

I am also not sure if it is the open panel principle that is the advantage
perhaps it works better because it rolls of in the bass so that it seems to
give less problems?

No, dipoles "minimally" excite the rooms main resonances, whilst most other systems "maximally" excite them. Its all just fundemental acoustics - you can read more on this on Siegfried Linkwitz' site on the theoretical side.

I've taken lots of measurements, as well as listening subjectively and there is no doubt. Flat measured bass from dipoles is much cleaner and "free from the room" than other bass systems.

No experience with dipoles and horns but with all kind of other related
things.

If you've not tried it then you can't really say categorically it's not the most optimal way! These things always differ to a degree of course in other rooms.

but think that most things
do not combine optimal due to the different materials used, different
directivity characteristics used, different sensitivity, etc.

Again you are missing the point about room acoustics.

What do you mean "different materials used"?

Sensitivities can be matched easily that's not a relevant factor.

If the open panel with the Oris horn works soo well then why do you have
problems or raised questions about optimizing the filter?

I don't have problems in terms of "it sounds horrible". But as in all things we are all trying to make improvements, and I'm (and I am sure like you!) never fully satisfied with things!

I just wanted others to share their experiences that's all, and especially those with dipoles.

integration optimal in my room. Same feeling while listening to other
systems trying to combine different "systems".

Using your own terminology front horns and bass reflex boxes are actually "different systems"! I really don't understand why you feel that combining a front horn, with a bass reflex is neccessarily an optimal acoustic match?

This is good debate, its useful stuff!

Kind regards,

Jonathan

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Front horns and bass dipoles

by GC, Thursday, February 17, 2005, 11:24 (6980 days ago) @ GC

Hi Jonathan,

No, dipoles "minimally" excite the rooms main resonances, whilst most
other systems "maximally" excite them. Its all just fundemental acoustics
- you can read more on this on Siegfried Linkwitz' site on the theoretical
side.

Okay, I won't argue about the fact that dipoles exite the room less but I remain convinced that the character is also a major factor in the perceived sound... :-)

If you've not tried it then you can't really say categorically it's not
the most optimal way! These things always differ to a degree of course in
other rooms.

Most important about a speaker system is that the sound should be correctly radiated from the speakers themselves. If there is something less optimal then you'll always hear it back at the listening position.

Rooms can destroy or even improve things but with an optimal radiating source the results at the listening position will always be better...

What do you mean "different materials used"?

Paper cones with metal dome tweeters, ESL with dynamic woofers as clear examples. Even small differences are audible.

Sensitivities can be matched easily that's not a relevant factor.

It is a relevant factor because higher sensitive systems have a stronger motor to begin with where less energy is wasted in warmth (warmth reduces dynamics, speed and detail). All parts in the system should have the same tonal character and behaviour, if not then you'll hear that.

I can drive over 200km/h with my Opel but driving the same speed with a Viper is something else.

I just wanted others to share their experiences that's all, and especially
those with dipoles.

No problem with that! That's why we have this forum... :)

Using your own terminology front horns and bass reflex boxes are actually
"different systems"! I really don't understand why you feel that combining
a front horn, with a bass reflex is neccessarily an optimal acoustic match?

No, a front horn with a front horn loaded bass (closed, reflex or even a real horn but then the timing problem disturbs too much...)

Ciao,

Bert

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Front horns and bass dipoles

by GC @, UK, Friday, February 18, 2005, 13:31 (6979 days ago) @ GC

Hi Bert,

Most important about a speaker system is that the sound should be
correctly radiated from the speakers themselves.

What do you mean "different materials used"?

Paper cones with metal dome tweeters, ESL with dynamic woofers as clear
examples. Even small differences are audible.

Agreed, absolutely. That's the key reason that I wanted bass drivers with paaper cones to match the Oris drivers. But were you were infering something that was related to dipoles vs. other bass system?

Sensitivities can be matched easily that's not a relevant factor.

It is a relevant factor because higher sensitive systems have a stronger
motor to begin with where less energy is wasted in warmth (warmth reduces
dynamics, speed and detail). All parts in the system should have the same
tonal character and behaviour, if not then you'll hear that.

Again very much agreed. I was saying it is irelevant to our discussion on the types of bass system.

No, a front horn with a front horn loaded bass (closed, reflex or even a
real horn but then the timing problem disturbs too much...)

I've got you - you were talking about the Oris reference, I see now!

How low does the Oris 150 load the 15" down to? Surely a horn flare and therefore cutoff is the same whether it has an 8" driver or a 15" driver.

Regards,

Jonathan

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Front horns and bass dipoles

by GC, Friday, February 18, 2005, 14:04 (6979 days ago) @ GC

Hi Jonathan,

paaper cones to match the Oris drivers. But were you were infering
something that was related to dipoles vs. other bass system?

The directivity differences and character have their influence.

How low does the Oris 150 load the 15" down to? Surely a horn flare and
therefore cutoff is the same whether it has an 8" driver or a 15" driver.

It loads down to 80Hz but not as effective around 220Hz. The way the horn is tuned to the BD15 driver results in a 6dB roll-off from 220Hz down to 30Hz and adds directivity (gradual) from 80Hz and up.

With the used 12dB filter (actually about 9dB effective) the response is flat up to 200Hz where it rolls-off with about 18B/oct due to the mass roll-off of the driver and the filter.

Another advantage of the added horn in front of the bass is that the character in the crossing area (the overlap between both the bass horn and the mid-high horn) is identical. The bass horn also gives extra "loading" to the mid-high horn so the real crossover frequency of the system is around 200Hz. The standard Oris systems crosses around 220-240Hz...

Ciao,

Bert

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