Well, the drivers are decided now, at least for my current set of projects. I'll just go ahead, measure, design and build. And if there's any desire to replicate any of the designs, I think it makes most sense to stick with drivers available from diyaudiocart and theaudiocrafts. Bajaao.com used to sell good drivers, but their range has shrunk a lot now.
Designing a 2-way bookshelf speaker
- Thread starter tcpip
- Start date
rajesh srinivas
Active Member
which drivers have you settled for??/
The Peerless India drivers have arrived from diyaudiocart.
The one on the left is the 6.5" midbass driver for the TM. The stamped steel frame is quite good. The silver coloured cone has a black dust cap.
The 5.25" midbass driver in the centre is better finished, as expected from its moulded polycarbonate frame. These will go into the MTM design.
To the right is Peerless India's best tweeter, their TL26 silk dome made famous by the GR Research kits. These tweeters will go into the TM design with the 6.5" midbass drivers.
The Tympany tweeters are coming from somewhere else, so that package will probably arrive today.
Let me see how soon I find the time for T/S parameters measurements now.
The one on the left is the 6.5" midbass driver for the TM. The stamped steel frame is quite good. The silver coloured cone has a black dust cap.
The 5.25" midbass driver in the centre is better finished, as expected from its moulded polycarbonate frame. These will go into the MTM design.
To the right is Peerless India's best tweeter, their TL26 silk dome made famous by the GR Research kits. These tweeters will go into the TM design with the 6.5" midbass drivers.
The Tympany tweeters are coming from somewhere else, so that package will probably arrive today.
Let me see how soon I find the time for T/S parameters measurements now.
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The Vifas have a poor offaxis response. On axis they have good detail, sound is crisp but it has an inherent peak between 3 and 4.5 khz and power handling is mediocre.
It can get fatiguing if not tamed with a couple of notch filters.
I had bought four and the peak I mention above was not consistent.
Build quality is average, but because of its design, you need not flush mount it.
Though the f/s is around 840 hz, I would not recommend crossing it anywhere below 3/3.5khz.
It can get fatiguing if not tamed with a couple of notch filters.
I had bought four and the peak I mention above was not consistent.
Build quality is average, but because of its design, you need not flush mount it.
Though the f/s is around 840 hz, I would not recommend crossing it anywhere below 3/3.5khz.
Ya, I can see what you mean. The fall-off off axis is quite strong.
I'll see what the SPL curve looks like on the baffle, with a 5.25" on either side (which will add a few small peaks due to reflections off of them). If it sounds bad, I'll try to cut the peak.
I think it's going to be ok in the power department for this specific design. It's supposed to be a small MTM for small Indian rooms, see? I imagine some people will just stand them vertically, one on each side of their TV, and listen to them from 6-7 feet away in a 12-foot room. You don't need even 5W through the tweeter for such setups.
I'm using this in a budget design which should be easy to build and give excellent sound for the budget, for small rooms. I think the build quality will be comparable to the other drivers I'm using here.
Looking at the construction and front plate, I can't see how you can avoid flush mounting it.
For my modest power application in this design, I think the power handling won't be an issue, and I intend to do 4th order anyway. So I think I may look at something closer to 2.5k. It'll finally depend on the on-baffle SPL curves of this driver and the midbass units.
If I was building large floorstander MTM like the Asawaris, I'd not use this tweeter, and some of the reasons would be as you have mentioned. Even the SB Acoustics SB26STCN, with its small faceplate similar to this one, would probably be a better tweeter for such designs. But this one is a budget design for modest power handling in smallish Indian rooms, so this will be a good fit, I think.
Its face plate is kinda recessed, so that will reduce the edge reflections and diffraction considerably.
I had also observed it practically.
But again there is no harm in flush mounting it either.
No, the problem is that the face plate ends in a sharp edge or "step" all round. The fact that it has a very shallow waveguide-like depression won't take away the impact of the edge. So, the edge reflection will be quite sharp. It should be carefully flush-mounted like most other tweeters.
The only drivers which don't need flush mounting are those which have a front plate which tapers down to the baffle, blending with it in a smooth surface. The step at the edge of the front plate should not be there.
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Yes, this generally works very well. But it doesn't look good, and I want these speakers to look smart. [emoji2]
How about lining the entire baffle adjacent to the tweeter with 2 to 3mm thick suede leather? You can shave off the baffle material by same thickness so as to give a two toned look. Alternatively, you may cover the entire baffle with swede leather for uniform look.
Am lazy, and I don't see the benefit I'll get from this extra effort. Just simple MDF baffles with rounded edges (I have a 25mm radius for my rounding, which is more than what most designers seem to do) and nicely flush-mounted drivers is enough.
And there's another reason. I'm trying to maintain a consistent set of design choices here. I want to deliver a carefully designed speaker with inexpensive and probably mediocre drivers, which is easy to construct, smart looking, and excellent value for money. I don't think suede leather front baffles fit into this target positioning. I'm also not doing curved side panels, Corian front baffles, or other higher-end construction techniques. I'm not doing an experimental design or a far-out ultra-tuned design here.
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I believe you. But even if I am surprised, I will not be incorporating either material into the current designs. [emoji5]
BEGINNING OF OT
My gut feeling says that suede leather would perform better. May be you can experiment to prove me right/wrong.
END OF OT
keith_correa
Well-Known Member
Good thinking, because though the effect will show up in squiggly lines, it will be near inaudible.
IMO, not worth the effort unless one wants to get anal about it.
Matches my thinking exactly, but I am afraid to be frank, having had a lifetime of being told that I'm too frank.
hyeah: I have the same feeling about whether, say, 95% listeners will hear a difference between the inexpensive Vifa tweeter I'm using and the better but similar looking SB Acoustics SB26STCN, unless they do side-by-side A-to-B tests.Having built a few pairs of speakers under a good guru, I've realised that some of these things which people like to worry about are not audible to most listeners, while things which are audible are often ignored. In the latter list are enclosure rigidity, accurate crossover design, etc. I guess each designer decides what he considers important, and I'm doing the same.
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keith_correa
Well-Known Member
Ha! I've been told numerous times too to keep my bluntness to myself but you can't teach an old dog new tricks and moreover this old dog refuses to learn!Matches my thinking exactly, but I am afraid to be frank, having had a lifetime of being told that I'm too frank.
Absolutely right!
That's not to say what the designer decides is important is "right"! It may be important to the designer but what good is it unless it sounds better. I've implemented numerous so called "tweaks" which were supposed to give me "A-ha!" moments according to people who implemented them - instead I experienced WTF moments.
hyeah: Buy from India's official online dealer!
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