follow up on ZA 14 vs Fountek

[Deward Hastings]

Re: follow up on ZA 14 vs Fountek

now, this is what happens then you put padding on the walls. a fundamental standing wave is still there (equal in length to the longest dimension, about 11 inches in this case) but lower in magnitude. Padding is only so effective.

Padding "on the walls" is much less effective at midrange frequencies than the same absorbing material more "in the box". Rigid fiberglass or rock wool batts criss-crossing the box are far more effective than loose batting. But there is one of those connundrums that appear so often in audio design . . . if you want the same frequency response and freedom from resonance that you get on a test baffle then you have to *really* stuff the box and absorb *all* the back wave. But if you do that the apparent output will fall, and the box will no longer function properly as a reflex enclosure. You can only extend the bass response (in a ported enclosure) by dirtying up the midrange. People compromise by adding as much stuffing as they can without disrupting the reflex action, but that's never enough to completely absorb the backwave and clean up the mids. There's no completely satisfactory solution (short of going to a fully closed box and extending the bass some other way). The loudspeaker industry survives because people have come to expect, and even prefer, the blurred and muddied sound of under-damped boxes. It is also (part of) why OB and dipole (non)enclosures sound so startlingly "different".

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

agreed, always a set of trade offs like anything else.
let me see if Owens Corning 703 will do the trick.
The graphs that I posted may be of use to some. If you are seasoned speaker builder, this info is probably something that you've been through before. This is just an open project. On the other hand I've been asked if the port automatically prevent mid range from leaking (what?? why?)

[Deward Hastings]

Re: follow up on ZA 14 vs Fountek

On the other hand I've been asked if the port automatically prevent mid range from leaking (what?? why?)

Too much looking at ray diagrams, maybe (and in that context understandable). If the reflected "ray" of sound doesn't hit the port opening it can't get out (that way)? A beginner may not "get it" that pressure waves in the box don't work like that, or that the driver cone is transparent to (moved by) reflected pressure waves also. A mistaken understanding of mechanism can lead to (will often lead to) a mistaken expectation of result . . .

[DoubleTap]

Re: follow up on ZA 14 vs Fountek

and ZA14/vifa

This combo looks like it'll be a bit forward sounding based on your sim ...

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

This combo looks like it'll be a bit forward sounding based on your sim ...

You mean because of the crossover point is not low enough and summed up response at the listener position may have a pick around 2k? May be I should bring the point 2 or 3 db lower.
Anyways, got 2.7 coils today. Listening impressions and verifications will be coming soon. :p

[DoubleTap]

Re: follow up on ZA 14 vs Fountek

You mean because of the crossover point is not low enough and summed up response at the listener position may have a pick around 2k? May be I should bring the point 2 or 3 db lower.
Anyways, got 2.7 coils today. Listening impressions and verifications will be coming soon. :p

I said that because it looks like you have an extra db or 2 in the 400-800hz range ...

I should qualify, my idea of 'forward' is when vocals come forward in the soundstage and sound in your face. My experience is that happens when you have a hair of extra energy in the mid-upper vocal range. It can be alright when vocals do that, but since brass can be in the same range, when it does that, it can be painful.

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

Small update. Both systems are together and playing. I haven't had time to seat down and listen critically but from the first few hours both sound quite nice. I've listened to the ZA14 pair to look for that forwardness in the vocals and rather noticed chestiness in the male vocals. Crossover was changed slightly. I don't hear any problems at this point. I can't say that I am terribly exited about this Vifa tweeter. ZA14 and FW probably deserve OW1 or 2905. More to come later. I'll be setting a switch box (which I have, Bryston) for comparison.
Later.

Oh and while I have Owens Corning 703, it is not in the speakers yet. Sorry.

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

ZA14 based system actual measurements.

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

merged response: 1meter+ near woofer/diffraction+port

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

CSD taken about 20cm on tweeter axis.

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

all done. all in my home for listening impressions. both systems sound nearly identical.
Oh, thanks for a good advise Peter, that Owens worked well. Not a black hole per say but pretty effective. I did get a case and making some sound absorbers for my home listening room.

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

and now the listening begins for what it's worth.

[DoubleTap]

Re: follow up on ZA 14 vs Fountek

Gorgeous work my man, both sets look amazing! I love how you spliced the veneer on the chamfers for the Zaph pair, the way the grain lines up is very classy.

[critofur]

Re: follow up on ZA 14 vs Fountek

...I also find stuffing such as accustuff only marginally effective in the ported loudspeaker...

There is a wide range in the effect of different types of stuffing.

[r-carpenter]

Re: follow up on ZA 14 vs Fountek

Gorgeous work my man, both sets look amazing! I love how you spliced the veneer on the chamfers for the Zaph pair, the way the grain lines up is very classy.

Thanks! These were allot easier to make then your curved-front 2-ways though.