HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

I am going to try and make an appearance at Owston on the Saturday. Is it acceptable to turn up for a few hours with no kit then bugger off ?

Perfectly acceptable, just add your name to the Owston thread on AT.

Ok, will do. Thanks Steve.

I know it is early days and these were built to get a speaker that would work at Owston, BUT any idea as to how they compare with the semi omnis.

Dr Bunsen Honeydew wrote: ↑Sun Apr 29, 2018 11:04 am I know it is early days and these were built to get a speaker that would work at Owston, BUT any idea as to how they compare with the semi omnis.

They are very good. The soundstage compared to the semi-omnis is nowhere near as expansive, but the musical details are all there, and because of the big driver, the weight of sound is better.
The best thing about them, compared to the semi-omnis is the bass performance, which is even, fast and boom free.
This performance IMO is down to the sealed box loading. The transmission line loaded semi-omnis now have totally false bass in comparison.
I know that you've been trying to get this point across for a long time, and have been up against a wall of indifference, but unless you actually hear for yourself, the superiority at the bottom end, that a properly engineered, sealed box has over ported bass, then you won't get it.
The theorists would argue that modern drivers are not engineered for sealed box loading, but you don't look at hi-fi drivers; complete waste of time unless you are prepared to dope them. What you do in fact do, is look at pro drivers instead. Granted, with sealed boxed pro drivers, you are going to end up with big boxes, which is not an acceptable situation in most homes, but the results, if you can get away with the size issue, are excellent.

Failing that of course you can Doc mod an existing speaker or buy some Cubes.

So the semi-omnis will need a rethink as I can no longer stand ported bass. The ones I built are good, very good in fact, and have the fantastic window to the studio space, but they are a mish-mash of too many influences. Again as with everything now, a fresh look, is needed keeping simplicity at the forefront of my thinking. A new, simpler semi-omni design will be in the planning stage once I get the full-rangers finished.

As with Stu, the building of the DIYNVA and the building of the full range drivered, sealed boxes is forcing me to unlearn most of what I thought I knew and embrace the KISS approach to getting the best music making from a sound system.

Here is another boring set of measurements:

Response 1:
taken at 1m on axis, looking straight down the barrel at the dustcap:

Note the rising response, but it's fairly even apart from a peak at 8KHz, which is exactly like the Fostex FF225WK without damping ring.


Response 2:
taken 1m at 30deg off axis, which is representative in my room of listening in the near field, with the drivers pointing straight down the room.
Useful treble is maintained up to 16KHz (Fane claim 17KHz, which is probably about right)
Granted, it does roll down at that listening angle, but it is still a very good listen.


Obviously there may be a point somewhere in between, where the FR gets nice and flat. Nevertheless, these drivers do project a very useable, wide soundfield.

Stage two of the finishing process:

Walnut veneer has been applied.
It'll be left until tomorrow to settle, after which the front cabinet corner beading will be applied.
Two brass parallel strips with a small gap between them, will be fitted around 3" below the driver, then the cab will be finished with several coats of Danish oil.
Once the tapered legs (due Tuesday) are fitted, the retro feel will be complete.

Which amp is going to Owston with these.

Both the valve amp and the DIYNVA will be going.
They both work well with the speakers.

I have found I can get there on advance booking for about £50 return, which day is best?

Obviously by train I am not bringing anything unless it goes in a carrier bag.