4 way passive with mid/hi horns help

[wwwn]

Hi,
I need advice for my new 4 way project.
The idea is to use 12' bass (95db/m, 30-160Hz) in compression box, 6' bass / lomids (88db/m, 160-1500hz) compression box also,
exotic RCF tw101 tweeter with horn for himids/hi (103db/m, 1500-10000hz) and selenium bullet twitter
st-302 for hi (108db/m, 10k-20k).

Plan is to use first order 4way series crossover.
I 'll put tweeter in a smaller box on top of the whole system 15-20cm from the front over RCF horn.

Is it OK?

The problem is to align acoustic centers of RCF horn and bass / mid speaker.
Namely, the horn driver is about 20 cm inside of the box-horn as well as its acoustic center.

Would it be a good solution to make a similar horn for the bass / mid speaker? This would probably obtained
this speaker(apr 88db/w) to be louder because it is more than 15dB quiter than the horn.
Next, design would be uniform in that case.
Should hole on the new mid/bass horn towards speaker be in measure-diameter of whole speaker (easier for mounting externally ),
or the greater part of that mid/bass horn should cover loudspeaker cone?

Sorry for english

[picowallspeaker]

Hi
your english isn't very bad , although in the last period seem that things are upside down
Just to say that ... perfect alignment of the acoustic centers doesn't
guarantee perfect in-phase output of the drivers .

this speaker(apr 88db/w) to be louder because it is more than 12dB quiter than the horn.

oooh , now I got it : no ,wait , how can it be louder if it's quiter

[wwwn]

Originally Posted by picowallspeaker

Hi
your english isn't very bad , although in the last period seem that things are upside down
Just to say that ... perfect alignment of the acoustic centers doesn't
guarantee perfect in-phase output of the drivers .

oooh , now I got it : no ,wait , how can it be louder if it's quiter

Probably, because of horn? Or this is not that case?
Anyway, I will put resistors to eqalise levels of drivers...

[picowallspeaker]

The horn just matches the air in the vicinity of the diaphgram of the driver ,it's an acoustic load ,and the (compression ) driver is designed to be matched with a horn . The different size of horns and geometry and angle makes change in the minimum frequency until the horn functions ( horn mouth diameter ).
Also directivity is determined by it ,and also the gain in sensibility in a broad range of frequencies .
For good matching it may be advisable to find a higher sensitivity mid-bass , at about 94-96 dB
Of course you may add a front horn to it ,but everything must be 'integrated'
(bad mathematical word )with an eye to the directivity of the whole speaker , i.e. position from the audience .
But many along the Forum are very into it , so just ask ...

[wwwn]

Hi picowallspeaker
Do you know what apr. measures this bass/mid horn should have(for 160-1500hz)
Now, plan for box is 41cm wide x 32cm depth...

[picowallspeaker]

But the horn doesn't amplify ! You would have just some decibel gained by
the change in directivity obtained by different acoustic load
(someone correct me if ..and I should be...wrong )
so it's better to look for an higher efficiency driver .
Then the horn should match the directivity of the upper (treble) horn .
A little closed back -a chamber- behind the driver , and about 45° laterals and a little vertical exponential expansion ...it should cover , the throat , half of the surround of the driver , to take advantage from the only center emission ( more pistonic motion ) of the membrane .
I guess

[wwwn]

Since 12 ' bass driver has a range of 45-5000Hz and sensitivity 95db/m, maybe i should go 3 way with 1,5/10k crossover? In that case, will i lost bass punch obtained with dedicated hi-bass speaker placed in smaller box?

[wwwn]

Does the horns make loudspeakers more effective in some way?
I have 86db speaker for upper bass range/lo mids, but other speakers are more louder - woofer 12-95db, mid/hi horn 103db, super tweeter 108db.
Should horn on this 86 db speaker make it louder? I don't know parameters for that loudspeaker but it is with rubber ring around cone, apr 86db sensitivity, 20cm diameter. Is it possible to make some kind of horn to match it with RCF mid/hi horn 103db and to put short pipe for upper bass reflex around 150-250hz? Its range should be 156hz to 1500hz?

Anybody please?

[rvrazvan]

Try a compression driver from 1.5 k down .
i have my eyes on a monacor PA drivers (ku-516). Goes down to 160hz so i guess i can be crossed around 300hz or so

[wwwn]

Originally Posted by rvrazvan

Try a compression driver from 1.5 k down .
i have my eyes on a monacor PA drivers (ku-516). Goes down to 160hz so i guess i can be crossed around 300hz or so

My system is for home use and i want punchy, well defined bass.. That's why i am thinking about 4 way design. Second, intention is to go with 1 order crossover. Now there is tw101 compression driver with mid/hi horn (800-16000 range) for 1500-10k band.