Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

[GM]

From Iwan Arjanto's FB photos: Iwan Arjanto | Facebook

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[Ro808]

 

[phase_accurate]

And where exactly do you place your listening chair in that horn ?

Regards

Charles

P.S.: Very nice build.

 

[silverprout]

a long horn which simply provides better loading, especially down to the resonance region of the driver/horn combo. You can see this effect by simply doing a free air impedance shot and then mounted to the horn.I am quite sure that the driver itself prefers a long horn, especially if you wnat to go down as possible, but what I found is that most long horns are no more constant directivity.

Can you help me please, here is a measurement of a DE250 in a JMLC700 (green) and a Fane FH450 (red).
There is a problem with the phase at 1.1K

 

[phase_accurate]

 

[silverprout]

My microphone is perhaps defective, i should probably knock it few times on my table in order to fix it !

BM750
Tractrix 280 (blue)
Tractrix 320 (green)
Tractrix 350 (red)

 

[cspieker]

Can you help me please, here is a measurement of a DE250 in a JMLC700 (green) and a Fane FH450 (red).
There is a problem with the phase at 1.1K

Are you talking about the "wrapping"? I don't see anything wrong with the phase. Since 180 and - 180 are the same thing, it "wraps" the graph simply to save space.

 

[camplo]

I've been on pintrest looking for inspiration, I'm probably going to end up with a fricken rectangle with a horn on top. I should at least try to round the baffle edges.

There is a type of enclosure where the ports or many slots, I forget the name...I seen another enclosure where the guy used several longitudinal slots on the sides for the port. At least, the first instance its a known enclosure style that supposedly has increased performance. I'll figure out the name in a second.....its dinner time.

 

[GM]

I presume you mean the Onken, a specific alignment of a type of Jensen Ultraflex [fig.2]: http://www.dcaudiodiy.com/jensen_imperial/page_14.jpg

GM

 

[GM]

The TD15M just barely meets the Av = Sd ideal w/6.34 Onken alignment.

For 'best' = 5.7 alignment = ~ T/S max flat, vents will need to be < Av= Sd, but still 'good enough' to get some of the Onken's Fb boost: HiFi Loudspeaker Design

GM

edit: comparing these two except with a single large vent, which can be easily retuned, the smaller 6.34n seems a better choice overall unless of course you want the multiple vents for their industrial 'look'.

 

[camplo]

I think you just said a single large vent is suffice. I really don't like the look of the onken alignment with square slots., I was hoping the same could be done with multiple round holes.

 

[Ro808]

Onken... or whatever floats your boat.
The French love those Jensen/Altec inspired cabs.

 

[Ro808]

I believe GM prefers corner loading and therefore a cab similar to this:

 

[Ro808]

2x Altec.
Double front port vs. Onken style, or more specifically: vented FLH.

 

[Ro808]

This is the other Jensen design with the vents at the front, that you see more often:

Such cabs are more difficult to build compared to good ol' BR cabs.

 

[diyuser2010]

Camplo, it may be beneficial to you to read the JBL AES paper on loudspeaker ports, entitled:


"Maximizing Performance From Loudspeaker Ports"
AES E-Library >> Maximizing Performance from Loudspeaker Ports


Also: http://www.bodziosoftware.com.au/PORTS.pdf


AES E-Library >> Nonlinearities in Loudspeaker Ports

 

[GM]

I think you just said a single large vent is suffice. I really don't like the look of the onken alignment with square slots., I was hoping the same could be done with multiple round holes.

Round is most efficient and a single large vent will be shortest length with the [potential] downside that its harmonics will be the strongest, so sometimes need to be 'critically' damped whereas with multiples like the Onken tend to be resistive whether you want them to be or not and yes, they can be round. The patent prototype BR: US1869178A - Sound translating device
- Google Patents

Their combined harmonic structure causes what I consider excessive comb filtering with the driver, making a mess of the critical lower mids, though many folks prefer this euphonic distortion, so go figure: https://www.stereo.net.au/forums/ap...daddad6c53c3c7d23ea37f05b5b241d1476ed7a9b9253

GM

 

[GM]

I believe GM prefers corner loading and therefore a cab similar to this:

Indubitably I does!

 

[Ro808]

A recent AES paper on port modeling.

 

[Ro808]

And a paper by Salvatti et al. with reference to Vanderkooy.