Fane 15" full range speaker

[Cressy Snr]

I intend on making a pair of these for my wifes living room system.
I will also get the benefit from them as well.
Any further information available to support the methods of cabinet bracing suggested would be appreciated, I'm ripping down 25mm Plywood this week for the boxes.

Hi John,
With a cab of this size I would put in three braces. (five pieces in all)
The first would be a single longitudinal brace, top to bottom of the cabinet. You need to fill it with holes (three inch holesaw is ideal) and offset it by 12.25mm from a top to bottom centre line drawn on the inside of the back panel. Just draw a centre line and put the brace edge on that line. This will give you automatically, the right offset.

Additionally, with the longitudinal brace, you need to make a cutout in it so the driver will go in. The rear of the driver magnet is up against the brace when fitted into the cab. Also take care that the brace does not block the hole in the rear of the magnet.

The vertical brace connects the front, back and top and bottom panels and is the most time consuming to make and fit but it is worth the trouble.

The horizontal braces are much easier. I would make two small ones to fit either of the vertical brace, one running just above the horizontal centre of the driver, above the hole in the magnet and another two half way between the first one and the bottom of the cab. The top two can be six inch wide holey rectangles that run past the rear of the driver without being shaped around it but the bottom ones can be the full depth of the cab, as there is no driver in the way to make things difficult.

That lot should make the cabs rigid and relatively inert.

Hope that helps.

[chris661]

There are better ways to cure the problem if you are stuck with it, increase mass and stiffness. I can prove it to anyone with an open mind. Though if the speaker was packed full of daft crossover components then nothing would save it (the music).

Changing the mass and/or stiffness of the walls of a cabinet will do nothing to the standing waves that form as a function of the reflections inside a cabinet. This is literally Physics 101. I know this, because I've taken it. You obviously slept through that lecture.

Since you're clearly the expert on all things speaker-design, tell me, how would you go about making a compact PA speaker that's suitable for live music 50 or so people with useful bass extension when mounted on a pole?
I've managed it. Can you?

Chris

PS - Ant, if this is cluttering up your thread, I'll split it off - just say the word.

[Dr Bunsen Honeydew]

Chum - you just want conflict, sorry mate I wont oblige. Show me where I said I am "clearly the expert on all things speaker-design", I have opinions and LOADS of experience. You are absolutely wasting your time quoting physics or charts at me, I will just laugh. There are very few things important in domestic audio design. Your ears, Your brain, Your music, Your room, and that formulates Your opinion. We seem to be at cross purposes unless I am mistaken this forum is about Hi-Fi not pro gear, that is a different set of compromises, and they don't usually see eye to eye IMO.

I am quoting my experience that goes back to working for Acoustic Research (UK) from 1972. My ideas started with trying to find out why the new range designed by new designers after Ed and Roy left and the knob heads in suits from Teledyne took over were relatively so bad. Everything I have done has been on a long learning curve ever since. I have learnt that people try to do too much, they take things for granted (like putting in wadding). There is too much trying to shut the door after the horse (music) has bolted. For once I see someone who is *IMO* getting the balance right in Steve and his Fanes, and before I was going on instinct, now on experience having heard them at Owston, and if they work there they must be good as the place is shit acoustically. Nothing to my ears sounded any good but Steve's corner, even more so when Thermionic's thingy got involved with it. I could have sat there all day listening to it, and apart from the big reds, everything else made me want to leave the room.

[Dave the bass]

unless I am mistaken this forum is about Hi-Fi not pro gear,

You are mistaken.

Have a look at the Forum header. "audio-talk, The place to discuss anything involving sound".

[Dr Bunsen Honeydew]

They don't follow the same rules, so unless you say to which you are referring so the confusion that happened here will happen again. I perfectly understand why he does it his way for pro gear.

[chris661]

Chum - you just want conflict, sorry mate I wont oblige. Show me where I said I am "clearly the expert on all things speaker-design", I have opinions and LOADS of experience. You are absolutely wasting your time quoting physics or charts at me, I will just laugh. There are very few things important in domestic audio design. Your ears, Your brain, Your music, Your room, and that formulates Your opinion. We seem to be at cross purposes unless I am mistaken this forum is about Hi-Fi not pro gear, that is a different set of compromises, and they don't usually see eye to eye IMO.

I am quoting my experience that goes back to working for Acoustic Research (UK) from 1972. My ideas started with trying to find out why the new range designed by new designers after Ed and Roy left and the knob heads in suits from Teledyne took over were relatively so bad. Everything I have done has been on a long learning curve ever since. I have learnt that people try to do too much, they take things for granted (like putting in wadding). There is too much trying to shut the door after the horse (music) has bolted. For once I see someone who is *IMO* getting the balance right in Steve and his Fanes, and before I was going on instinct, now on experience having heard them at Owston, and if they work there they must be good as the place is shit acoustically. Nothing to my ears sounded any good but Steve's corner, even more so when Thermionic's thingy got involved with it. I could have sat there all day listening to it, and apart from the big reds, everything else made me want to leave the room.

I don't want conflict as such, but I do want an explanation of why you think interior panels must be steel-plated (which will cut down on cabinet resonance - a good thing - resonant panels introduce a load of time-smeared energy, which messes up transients), and yet completely neglect all the sound that's going to bounce around inside the cabinet before exiting through the cone (which will introduce a load of time-smeared energy, messing up transients). You're sorting out one, but not the other, while they both have similar effects.

I find the cleanest sound comes when you do both - make the cabinet solid, and apply absorption. That way, you only hear what's coming off the front of the cone without any additional time-delayed mess in the midrange.

With regards to graphs, I think they're very useful when you keep them in context. For instance, I had some horns a while back that sounded very good, except for on one piece of music where a particular vocal hit a particular note and there was a very harsh harmonic - enough to make you wince at normal listening levels. The problem was a very narrow spike at about 7kHz, and getting rid of that spike solved the problem completely. Graphs don't tell you if something sounds good, but they really do help with problem solving.

Chris

[Dr Bunsen Honeydew]

There are no explanations beyond your ears and your music, go back to them and you may be surprised at what you change. All I do is use my ears and my music, and it gives me *ways* to do things often involving very lateral thought referred to convention. People have a choice, listen or ignore, do you really think I give a toss which. My pursuit is the pursuit of music and truth *for me*, as has been shown both in the now hundreds of reviews from users at HFS and the 10's of people who have tried my speaker mod ideas, and NONE have gone back and removed the mods, they 99% agree with me. So for me the proof of the pudding is in the eating, everything else is BULLSHIT!

I have a set of speakers here with the mods for loan, do you want to try them.

BTW I have found ceramic tiles to be nearly as good as well, and not so heavy.

[chris661]

There are no explanations beyond your ears and your music, go back to them and you may be surprised at what you change. All I do is use my ears and my music, and it gives me *ways* to do things often involving very lateral thought referred to convention. People have a choice, listen or ignore, do you really think I give a toss which. My pursuit is the pursuit of music and truth *for me*, as has been shown both in the now hundreds of reviews from users at HFS and the 10's of people who have tried my speaker mod ideas, and NONE have gone back and removed the mods, they 99% agree with me. So for me the proof of the pudding is in the eating, everything else is BULLSHIT!

I have a set of speakers here with the mods for loan, do you want to try them.

BTW I have found ceramic tiles to be nearly as good as well, and not so heavy.

It might be a coincidence, but I (and many others in the professional audio industry) happen to like it when a system is flat, and we'll usually tweak it to get as flat as possible.

The speakers that went to Owston a little while back needed quite a bit of power IIRC, so if you're happy for them to be powered by something fairly large, I'd be interested in a demo set. I'm not going to try to blow them, and will reduce levels if they're sounding stressed in any way.
Full disclosure - there will be measurements. With your permission, I'd also like to see if adding absorption changes much. I have a suspicion that a heavily-doped midbass driver like the ones you use won't allow much sound from inside the cabinet to escape. Thinner/lighter cones will clearly allow much more sound out.

I'll be moving house soon, but will be in touch when that's all done.

Chris

[JohnG]

I,ve just done a cutting list for 25mm Marine Plywood.
The Dimension for the Longitudinal Brace is now on the Plan as 765mm, not the 465mm shown.
I've also changed the hole quantity, worked on the dim of 25mm from the top edge of the brace, with 50mm between the holes, this allows for 6 holes on the longititude. So approx 12 holes in this baffle.
Any corrections to offer, let me know, as I will be cutting tomorrow.

[Cressy Snr]

Looks OK to me.

[Ant]

Made some gains with these lately, extra bracing helped matters making the panels less resonant, also these are more finicky than the 12" ones wrt positioning.
The usual advice is to position speakers as far apart a the distance is from your seat to them.
I had them closer together than that by about 16". Moving the right hand on further to the right by that 16" has made things alot better in terms of imaging and soundstage. With them flat with no toe in (or out) they are much nicer, and just sat on the floor instead of on the 3" tall bases seems abit better.
They want putting on some small risers with spikes on so I can level them up.

[Ant]

finally got around to making them look presentable. i was going to veneer the top, but the black is growing on me

Fane 15" sealed box speakers by anthony cresswell, on Flickr

Fane 15" sealed box speakers by anthony cresswell, on Flickr

covered in some faux suede material

[Ant]

Put the old speakers back in while I got them prettied up, played three Tracks. Didn't play any more, and got a move on with getting them done.
Imo, there is simply no substitute for cubes. These are effortless, the Mets with the 6" driver and port sounded constipated in comparison. And the Mets are good. But they don't do what these do.

[Ant]

Bashed some big holes in the cabs this afternoon.
Found some info on aperiodic loading on diy audio projects, then followed some links on the page. Read a 50s paper by e jordan and a few others. A basic guide was to cut a vent in the cab that is 10 square inches for every cubic foot of cabinet volume, mine are just short of 5 cu ft, so a hole 5" x 10" was hacked out of the cab.

I didnt want any real bass reinforcement so i put the hole in the top instead of the conventional place of at the base on the front or side somewhere.

Glad i did, as it seems to give a pseudo semi onmi effect as its venting upwards, the imaging is better and the height of the soundstage is also much better

Duck taped some 3mm compressed wool felt onto the inside of the vent and then dropped in some 25mm wool felt sheet into the vent to form the membrane. This needs adjusting to taste, as it is, its not far off so ill do some tweakery when i get around to it

The effect of this hackery has opened the speakers right up and smoothed the response right out. It seems to have also extended the bass response a little further down

If i read the info right, it will have flattened the impedance spike around the resonant frequency of the driver out somewhat.

What it seems to have done from my point of view is let little nuances out of the box so to speak.

Need to get some mesh of some sort and do it properly

Interesting

[Cressy Snr]

Heard them this afternoon. They sound great. Aperiodic loading works really well with both the 15 and the 12in drivers.
I converted my 12in cabs to aperiodic a while ago and have never looked back.