Hi,
While speculating about various possible designs for a DIY subwoofer, I began wondering whether it would be possible to horn-load a port in the same way one can horn load a driver (see attached pic).
However, I can't get my head around whether the port would function correctly if its mouth were loaded by a horn. Does anyone have a good idea of why this might or might not work?
And, if it were theoretically possible, could it be modelled in hornresp?
Many thanks 🙂
A
While speculating about various possible designs for a DIY subwoofer, I began wondering whether it would be possible to horn-load a port in the same way one can horn load a driver (see attached pic).
However, I can't get my head around whether the port would function correctly if its mouth were loaded by a horn. Does anyone have a good idea of why this might or might not work?
And, if it were theoretically possible, could it be modelled in hornresp?
Many thanks 🙂
A
Attachments
I believe what you've described is commonly known as a "Big Vent Reflex" (BVR) and yes, they can be modelled in Hornresp. Use the "compound horn" option, and use S1 to S4 to describe the vent and the attached horn.
Very interesting Brian, thanks! Do you have links to any further info on this type of design? I googled but didn't come up with anything illuminating.
And do you know what the benefits/drawbacks are supposed to be?
Cheers,
A
No links offhand, unfortunately. I prefer offset TLs, which are pretty close in layout.
Benefits = less vent compression
Drawbacks = like RLHs, midbass response might be uneven, e.g. with a big notch where the output of the vent is out of phase with the output from the driver.
BVR were popular in the days of Abraham Cohen and with short path, seen in some musical instrument cabinets to get some "hit"
here's one way (If i did it right)
https://i.imgur.com/u58Oqpp.jpg
and a practical example built by RCA-Fan (Bill Woods of Yorkville Sound and Acoustic Horn)
RE: half horn plans - RCA-fan - High Efficiency Speaker Asylum
here's one way (If i did it right)
https://i.imgur.com/u58Oqpp.jpg
and a practical example built by RCA-Fan (Bill Woods of Yorkville Sound and Acoustic Horn)
RE: half horn plans - RCA-fan - High Efficiency Speaker Asylum
In my accidental venture into "Big Vent Reflex" (BVR) named the Domino DFLH (Ducted Front Loaded Horn) the midbass had a hole around 260 Hz:
Lab 12 Domino DFLH
Oddball design..
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Hmm... that doesn't appear to be a BVR. With a BVR, one side of the driver is not loaded by a horn, box or vent.
My mistake, missed that the OP's diagram depicts the driver exiting on the left as a direct radiator.
Usually, that type of design would have the horn and driver on the same cabinet face, as in the JBL 4520 or 4530.
The Domino DFLH is a different design type entirely.
Attachments
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If you look at the picture you can "see" the port as the beginning of the horn's throat. In fact it looks as the port ceases to be a regular BR port - with a free end to the open space outside - due to the loading of the rest of the horn.
So I feel that this concept has become a backloaded horn...
Then rises the question: when exactly do you have a BVR?
Andre
here's an excerpt from Abraham Cohen's "Loudspeakers" - - a short positively flared port can provide a bit of "hit" vs a regular duct port but also generally has a recessed response after that small rise
High Efficiency Speaker Asylum
High Efficiency Speaker Asylum
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Thanks Art, very interesting. I’m not sure I understand what’s going in with the Domino though. The JBL 4520/30 are pretty classic rear-loaded horns in my estimation. How is the Domino different?
Cheers,
A
A BLH is large, long enough [in whatever pi space] to load down to the alignment's corner frequency without excessive 'ripple' due to reflections back to the throat same as a FLH, but the vast majority of so-called BLHs have a TL's 3rd harmonic dip with its consequent HF 'ripple', so in a 'fit of frustration' one day said let's call them for what they really are: 'big vent reflexes' [BVR], AKA 'scoop bin', i.e. the pioneer's ~1/8 WL 'port horn' Freddi posted.
No way to know for sure what the OP's is without dimensions, but odds are it's a BVR.
GM
Andreasmaaan,
The Domino DFLH is a standard sealed compression chamber front loaded horn with ducts connecting near the throat area of the horn itself to near the mouth area.
It really has nothing in common with your OP, my perception of your design was mistaken, and my recollection of the D DFLH design was also off.
I don't think it is possible to model the Domino DFLH in Hornresp.
Quite different from the JBL 4520/30, in which the back chamber is connected to the horn, a "horn loaded port", or "big vent reflex", either of which can be modeled in Hornresp.
Art
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got reminded of this:
TAD speakers
TAD speakers
An externally hosted image should be here but it was not working when we last tested it.
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