Search found 453 matches

by rowuk
Sun Aug 13, 2023 7:49 am
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

I am happy that we got such a response on the “constrained layer” principle. Moving the resonance of the box material up makes it easier to damp but, increasing mass can increase stored energy, so like most things in life, you just have to strike a balance. In my case, the curved sides probably also...
by rowuk
Thu Aug 03, 2023 7:10 pm
Forum: Solid State
Topic: DIY Transistor Amp Using NVA Boards
Replies: 435
Views: 178477

Re: DIY Transistor Amp Using NVA Boards

I've heard many 1000s of systems over the years but exaggerated articulation due to excessive damping is a new one on me.. My speakers too seem to perform equally well with any type of amplifier, the quality of the amplifier being the overriding factor I do not read much about "articulation&qu...
by rowuk
Sun Jul 30, 2023 6:55 pm
Forum: Solid State
Topic: DIY Transistor Amp Using NVA Boards
Replies: 435
Views: 178477

Re: DIY Transistor Amp Using NVA Boards

It was Chris's idea. A 8.2mH in series with the Supravox, and a 0.47mh in series with the Lowther. In both cases to roll off the drivers before the response gets ragged and to improve the match to the next driver up in frequency. A unexpected effect has been to make the speakers play nicely with bo...
by rowuk
Sun Jul 30, 2023 4:05 pm
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

Thanks Rowuk, some food for thought. I've never seen bamboo ply but googling it, it's the same price as birch ply, £220+ a 8x4 sheet - the price of sustainability I suppose. I've sometimes wondered about expanding foam rather than sand. It should fill all the voids if done carefully and wouldn't se...
by rowuk
Sun Jul 30, 2023 3:55 pm
Forum: Solid State
Topic: DIY Transistor Amp Using NVA Boards
Replies: 435
Views: 178477

Re: DIY Transistor Amp Using NVA Boards

Thats my view too, a smaller efficient speaker with a large enough magnet can be completely self damped, as the magnet decreases or the cone gets larger, the self damping starts to decrease. In most cases this is clearly audible as the leading edges of notes start to become softer and less accurate...
by rowuk
Sat Jul 29, 2023 11:18 pm
Forum: Solid State
Topic: DIY Transistor Amp Using NVA Boards
Replies: 435
Views: 178477

Re: DIY Transistor Amp Using NVA Boards

I would not expect a single ended valve amp to be optimum for a low efficiency speaker. I believe that the secret is the total amount of "control". Efficient speaker drivers have less "compliance", meaning more return force through mechanical means. For any given system the retur...
by rowuk
Sat Jul 29, 2023 9:24 am
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

I don’t think that anything is generally “best”. If my goal is to reduce the contribution of the box material, that can be accomplished by raising the material resonance above the range where the bass driver plays. This makes it easy to damp (B&W matrix or my braced curved walls). We could also ...
by rowuk
Fri Jul 28, 2023 9:39 pm
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

Short answer: Yes, cork makes a substantial difference, is cheap and works well with curved sides and white PVA glue. No special tools were required. Jigsaw, drill, hand belt sander, router, knife. Oh yes, also an industrial vacuum cleaner. Long answer: I have experimented with sand filled, lead she...
by rowuk
Fri Jul 28, 2023 5:42 pm
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

The inside is 120 liters big. The Fane woofers have a Vas of 56 each. The horn is mounted so that the tweeter mentioned above will be at ear height.
by rowuk
Fri Jul 28, 2023 5:38 pm
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

Here is the top that was made by gluing the off cuts and making a lot of sawdust. img_2603.jpg Here is a picture from the side and back without the drivers. img_2636.jpg The finish on the side is a dispersion paint from Alpina. It is called "Sturm-Optik Anthrazit" here in Germany.I put a l...
by rowuk
Fri Jul 28, 2023 5:30 pm
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Re: Quite possibly my last speakers

I started by cutting and milling the edges of the front out of 1" Bamboo multiplex. Then I glued and screwed the frame slats as shown below. The glue is a standard PVA white glue from Ponal (White bottle in the background). It is not the express drying version. img_2543.jpg Then I glued and scr...
by rowuk
Thu Jul 27, 2023 9:24 pm
Forum: Speakers
Topic: Quite possibly my last speakers
Replies: 43
Views: 13327

Quite possibly my last speakers

Faital HF146/250Hz horn 2x Fane Collosus 12" Neodymium MiniDSP HD for development RH307 Super Amp RH84 Revision 2 Amp 2.5 system with the lower woofer cut off above 120 Hz. Horn is crossed over at 400 Hz Still to come is the Karlsson K-Cube tweeter: https://i.imgur.com/1CHppdf.jpg If there is i...
by rowuk
Mon Jul 03, 2023 3:01 pm
Forum: Speakers
Topic: T/S parameters valid for normal listening levels.
Replies: 32
Views: 12212

Re: T/S parameters valid for normal listening levels.

When we are talking about Thiele/Small, we are basically ONLY talking about the lowest frequencies that a driver can produce. The "audibility" of a moving target at that lowest octave should not be a huge problem unless we are overdriving the voice coil at a frequency where the box is limi...
by rowuk
Mon Jul 03, 2023 2:54 pm
Forum: Everyones Projects
Topic: DSP and not DSP
Replies: 38
Views: 11143

Re: DSP and not DSP

and that a simple single buffer will flip phase. Not true, a cathode|emitter|source follower will not alter phase. I stand corrected! DSP below 100 Hz could work well if the subwoofer was n milliseconds closer to the listening seat. For instance right behind the listening seat and the stereo pair n...
by rowuk
Sun Jun 25, 2023 6:29 pm
Forum: Everyones Projects
Topic: DSP and not DSP
Replies: 38
Views: 11143

Re: DSP and not DSP

Thanks rowuk, interesting stuff to mull over. Particularly that you couldn't find a valve buffer to your liking. The second half of an Aikido drives most stuff, did you ever try one? Just curious. I said that I could not find an exceptionally "neutral" valve buffer (including the Aikido)....