HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

The original 4 sides tapered OmniMets are back my system at the moment, as the Flatties are being sent out on loan, later this week. Very little difference between the two configurations, apart from the fact that the Flatties are much easier to build.

Seeng as the original OmniMets, Huey and Dewey, are back in the system, due to the Flatties being on their hols at Quarknosis' place, I thought I'd have a little see if the Omnimets could be tweaked up a little.

Here we see a bit of judicious application of some white tak at the junction of the dustcap and cone, of the main Faital Pro 6PR110 driver.

The results are very nice. The white tak took out a bit of peakiness in the upper mids.
Musically, they are now just about as good as I can get them.
Note the nice, smooth, in-room response right across the lower mids up to the treble:
This third octave analysis is taken from the listening position, between the speakers and we can see the bass rolloff caused by the speakers being in different acoustic environments. The LH speaker has no wall behind it, only a diagonal staircase. This will be sorted when the wall is reinstated next year. Nevertheless they still sound great despite the less than ideal situation in which they find themselves.


"Recessed midrange, flabby bass?"

SteveTheShadow wrote: ↑Sat Jul 08, 2017 5:40 pm Here we see a bit of judicious application of some white tak at the junction of the dustcap and cone, of the main Faital Pro 6PR110 driver.

Mmmm I've seen that mod somewhere before, can't think where...

Indeed
It'll end up replaced by black-tak in the near future. Need to order some next week.

I might give that white tack tweak a go on a pair of speakers i own. Kevlar 6 & 1/2 inch mid/bass. Do they do yellow tack ?

Stu

Probably not.

OK. It has been just over a week since I brought the Flatback Banned speakers back from Paul (Quarknosis) place, and have been tweaking the speakers up, mindful of Paul's constructive comments about them.

By judicious use of installing a fixed L-Pad, to keep the tweeter impedance the same, so as not to disturb the crossover, I have shelved down by 4dB, the region from 1K onwards.

Everything has calmed down beautifully and I'm not "seeing" the tweeters now. Eva Cassidy sounds awesome and sits on the stairs once more, like she did when Paul B off Audio-Talk, came round last year and I still had the big 5ft Metronome speakers.

The shelving down of the treble region has had the effect of bringing up the midrange a bit, giving more body to the sound, making the semi-omni presentation a bit less ethereal and more grounded. This omni business is a delicate balancing act; not straightforward, but then I like making things hard for myself... well I think I do. Maybe I should just conform and stop being one of those poncy, poofy, arty-farty, highly strung creative types.

I think the raised treble region was swamping the upper range output from the bass/mid driver, and affecting the direct to reflected sound ratio in a negative manner. Now the things seem to fill the room a bit more effectively; all learning that can be applied to the bigger ones on the other thread.

Here's the in-room analysis with the bass end sorted by, tuning the port lower and the tweeter range tilted down.



I'm not going to realistically get it much better than this. A bit of bass coloration has disappeared, the very bottom has joined the rest of the bass range, so it now does reggae to a good standard, and the project sounds pleasingly musical.. The speed it had has not been lost, but there's a bit more finesse across the musical range, with more midrange subtlety.
Just shows you what can be got out of an efficient 6" pro midrange driver and a decent tweeter, if you are stupid enough to try

Thanks for listening to the speakers and offering consrtuctive comments Paul. These comments have enabled the maximum bang for the buck to be extracted from the Flatties. They wont shift air like your IMFs of course, but at least now they will actually reproduce those low frequencies.