Tweeter shootout

[Timber_MG]

I have arranged for a shoot-out of tweeters in Pretoria in about 2-3 weeks time (date still to be finalized)

The comparison will be between a compression driver loaded wave guide, a dome tweeter and a ribbon tweeter all mated to a 4” midrange driver and a still to be decided bass enclosure. The system will be driven fully active and might even turn into a 4-way if I decide to lug my subs along (2 Eton 6,5” Mid-basses it looks like at the moment). There is also a chance that there might either be a Pair of 15” Tannoy Dual Concentrics or some other interesting kit on hand to compare (like maybe a 12” + 1” wave guide prototype and if not the mini-PA to get back at the neighbours)

If there is enough interest, this could be made into a more formal event. At the moment it looks like Hennie, a friend of mine and myself and likely one or two enthusiasts not connected to the forum. So all interested parties in the Pretoria area please stand up, a meet up with fellow enthusiasts can be a laugh. I will get back to the forum if enough people express interest.

The Listening would take place under single or double blind conditions (i.e. speakers hidden behind an acoustically transparent cloth with an uninvolved party switching outputs on the loudspeaker controllers to switch tweeters each with their own optimal settings.

Any thoughts? mail me at audionut zZz tuks ZzZ co ZzZ za.

Martin

[Viagara]

This would be really interesting, but a bit too far for me

I have read a bit about compression drivers lately and it has grabbed my interest. I am thinking of building some speakers just for the kicks, but will see.

[kay]

I might be interested, depending on the final date - in the middle of exam season right now

[Hennie]

Timber,

Maybe it is a good idea to lug the subs along and give it wider appeal - some members may be interested getting an impression of a fully active system with digital crossover as part of the event.

I would be extremely interested in a comparisison of a 12" midbass /  12" waveguide system against another good reference, even if that is done later. A comparison between a 1.4" and 1" compression driver on waveguides would also very valuable to me personally, but let us take it one step at a time because your plate is probably full already.

Just shout if you need CD's or DVD's to include in your tests.

I would also like to listen to a few familiar tracks after the tests.

[Timber_MG]

I don't know whether Nick would allow me to play the subs to an extent where one can even see the cone move ;-). I would need to arrange for a bakkie in the case of moving subs and other kit as I don't own a car capable of moving the kit. A sealed, side-firing 10" eton would be an alternative.

I am just as interrested to hear the comparison of 1" vs. 1.4", but the problem is that one needs to switch very quickly as the audio memory is quite short (quite easy with the tweets mentioned as I can configure them as to only require muting some outputs on the DCXs) but I would need four waveguides for a proper comparrisson of 1" vs 1.4". The 1.4" could cross very low on the right size waveguide, potentially 700hz at high output for home use if the round-over diffraction isn't too bad. I don't expect too large a difference to be honest, though the 1" will have a touch more air for us younger folks.

I think we could set up a test CD with some short snippets, as listening tests are waay to tedious to spend more than an hour or so when done properly. Afterwards I am sure (neighbours allowing) that most people in attendence will want to play some music of various genres while someone ducks and evaluates results (roughly, I am not a statistician, but I can ask a friend who is one to help if need be)

Lets first see how much interest we can gather and then see. If there are only a handful of people I would make it very straight forward.

One could also evaluate listener consistency if one wanted to put some pressure on by having repeated tests ;-). If it is small group it would be more of an informal meeting anyways, which might be a good idea for a first meeting.

Kind Regards

Martin

[Hennie]

Timber,

I think meeting your primary test objectives is fine by me.

Depending on turnout I'm happy to flick switches or whatever's required but would of course like to eventually listen too.

[Timber_MG]

I would listen first. I don't think that the 1" will have an issue with a 1kHz cross in the home. This is sufficient in my book and 700Hz requires a waaaay larger waveguide where aperture diffraction starts to become another problem too (it could creep into the 7-8 kHz region)

I don't have a huge issue with crossing the 12 1.2-1.3kHz at all. In fact it is crossing it lower propotionally that what most 6" drivers are crossed.

I am about to start work on a large waveguide this week. If there is sufficient interrest I might make a mold and have some made up (or knock them up myself). If I can let a set of four 1.4s go I would considder letting them go as a batch. I would however ask of those who take them, that the applications are up to scratch of what such a device deserves regarding termination and round-over (non-trivial if you want to cross 700hz) becasue it would be a shame to have such a wide-band CD device be riddled with problems in the time domain when used to its potential.

[chipwelder]

Are you going to allocate the different chair locations a value or a spatial ID / location, so that one can analyse/model the difference the seating position distance from and axial deviation makes to the preference.

Also could the subject indicate his general preference for driver type beforehand AND to what he most often listens to: ribbon/dome/waveguide, if we compare both of these with his final choice we might get a clue whether we all just hear different (have different values/criteria) or if there really is a best...

The same goes for the music - what music do you prefer/use for reference purposes - amplified / unamplified / electronic / Rock / Pop / Jazz / Blues / Classical, tick all applicable options.

I could probably do horizontal spatial analysis - i.e. give an axial and distance value to each listening position, of each speaker -  if we set it up almost just so... could be fun... or hard work, depends on what you'd like to find out...

What acoustically transparent material are you going to use? I would like some - I haven't been able to find anything that doesn't kill the tops...