Conical Horn with Markaudio Alpair10 FR

[Henkjan]

I mentioned it already in some other threads, I have put the Markaudio Alpair10FR in a conical horn. and it is that good imho that it deserves its very own thread

this combination is bull's-eye in any way, for it combines the lively sound of a horn, the 'pure' sound of a full range without any corrections, and the tonal accuracy and true full range, flat response usually only found in good multyway speakers.

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

some quick measurements... under 400Hz is nearfield (2"), under 100Hz I deleted the graph for I was too lazy to include the horn output.
some slight non-flatness above 4kHz which might be diffraction (again, lazyness causes the lack of off-axis measurents) but in any case do not colour the sound in any way

and a sketch:

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

and guess why I have not made a proper drawing

 

[EUVL]

No BSC, no notch ?
Looks great.


Patrick

 

[Scottmoose]

Given that the majority of the horn output will be below 100Hz it's a shame it hasn't been shown, as the graph is effectively giving very little, if any, information about how the cabinet is behaving.

 

[Henkjan]

No BSC, no notch ?

no, just the driver and a horn

Given that the majority of the horn output will be below 100Hz it's a shame it hasn't been shown, as the graph is effectively giving very little, if any, information about how the cabinet is behaving.

yes, I know. when I fix my own measuring gear I will do some close range of driver and port, for normal measurements will only represent my listening room. I could dig out the sims if you are interested?

based on my ears, I would guess that f3 is somewhat below 50Hz

 

[GM]

For the moment, stick the mic ~ 1mm ~centered inside the port and horn mouth to get a near-field measurement to take enough of the room's effect out of their respective response.

GM

 

[_henry_]

Henkjan,

Did u try Jim's style ML-TL? if no need for bsc for this conic horn it will be superb.

 

[Henkjan]

For the moment, stick the mic ~ 1mm ~centered inside the port and horn mouth to get a near-field measurement to take enough of the room's effect out of their respective response.

I know the theory, the prob is that I need to fix my own measuring gear first...

if no need for bsc for this conic horn it will be superb.

there is no need for a bsc with this horn

Did u try Jim's style ML-TL?

no, already suffering from the "too many projects, so little time" syndrom.

 

[_henry_]

henkjan, any updates on your conical horn?

im sure u're enjoying too much

 

[Henkjan]

sorry, no updates yet... I did buy all the stuff I need to get my measuring gear working again (mic, USB-preamp, usb hub) so when i find the time and courage to install everything, I will post it here...

 

[madawasca mike]

clarification from newbi

The shaded area at the top left of the right hand view, I take to be the driver mounted. I just wondered since it's shown as a box if that is what is meant or does it simply represent the driver installed onto the baffle.

And lower down on the right above the opening, I take the squiggly
red lines to be suspended dampening held in with a mesh?

I have order the Alpair 10's and hope to make this my first build.

 

[Henkjan]

Re: clarification from newbi

The shaded area at the top left of the right hand view, I take to be the driver mounted. I just wondered since it's shown as a box if that is what is meant or does it simply represent the driver installed onto the baffle.

And lower down on the right above the opening, I take the squiggly
red lines to be suspended dampening held in with a mesh?

I have order the Alpair 10's and hope to make this my first build.

yes that is the position of the driver, so port is at the back (yes, this is important). the shaded grey area is meant to represent where the walls of the cab are lined with felt (8mm thick approx).

the red lines just above the port is damping material (about 50 grams of BAF (the white stuff)). in my case it just stayed in place by putting it there. so the other 50 grams are evenly distributed where the other red lines are, so a bit behind the driver, and some in the top

looking forward to hear your opinion of this design, I hope you like it as much as I do.

 

[madawasca mike]

further clairfication and thanks

That's is most helpful and we can begin our project. I am still a bit unsure how the sonofil stays in place in the upper portions of the enclosure since it seems to defy one or the other of Newton's laws. Or
does it get glued?

We hope to also make a smaller pair for a recording studio application at the same time using a MarkAudio design.

I will definitely report back about how it goes.

 

[Henkjan]

Re: further clairfication and thanks

..... I am still a bit unsure how the sonofil stays in place in the upper portions of the enclosure since it seems to defy one or the other of Newton's laws.

I used staples to keep it there, but some glue (spray-on) might also do the trick
(I guess that Acousta-Stuf Polyfill will be the equivalent available on your side of the pond of Sonofil )

 

[madawasca mike]

About ready

Thanks, kinda figured as much, but good to have confirmation. Now I need to find the time.

 

[Henkjan]

Re: About ready

....Now I need to find the time.

if you find any, can you send me some?

 

[madawasca mike]

start clock

Well for the record, the drivers just arrived yesterday. So now the guilt will stare me in the the face. As for creating time, I think the whole point of the exercise is to create from material reality (wood metal glue) a way to have the ensuing music either stop time or expand it. Or possibly both. Maybe I'll name my project Alchemy!

Do you have a preferred internal wiring that you used in your build?

 

[Henkjan]

Re: start clock

Do you have a preferred internal wiring that you used in your build?

nope, I used plain 1½mm² OFC copper, the cheap stuff that I had laying around but feel free to invest in some nice silver wire if you think that will make them even better

 

[elac310]

Hello Alpair 10FR users,

For your info, I've launched a thread on listening experience (and only that) with this speaker at http://www.diyaudio.com/forums/showthread.php?s=&threadid=139388

Feel free to feed it in due course with your own listening experience !

 

[JC Fardo]

Henkjan

Thanks for sharing Conic. Did you flush mount the driver. That 9mm flange are really thick

Thanks

JC

 

[Barnhouse]

madawasa mike...has the guilt got the better of you yet? Interested to know how they sound and your building/tuning/room placement experience.

Going to order some 10s with the intention of building Dr Jim's MLTL or pushing the boat out and going for this one which is probably at the limit of my woodworking skills. Kinda attracted to the horn it as it raises the height of the driver to about where I want it and interested to find out what efficiency benefit it might bring. May mate with a sub for the very bottom end but am a bit anti-sub has never managed to get them to sound "real".

A virtue one will drive them until I have a chance to experiment with some tubes.

Any and all views welcome.