Greets!
Maybe we'll get some drivers to compete with Supravox, etc., except with mass quantities of Xmax:
http://forum.carstereos.org/officia...-effect-on-the-mobile-adire-market-59904.html
GM
Maybe we'll get some drivers to compete with Supravox, etc., except with mass quantities of Xmax:
http://forum.carstereos.org/officia...-effect-on-the-mobile-adire-market-59904.html
GM
I am a bit concerned that the Hemp Acoustic drivers will start to exhibit the SPL ratings typical of XBL2 designs (mid to upper 80's). That would be unfortunate, IMO.
I am very interested in the smaller FR drivers. I'm hoping they will be whizzerless.
Given the parties involved, I'm hopeful things will be positive.
Paul
I am very interested in the smaller FR drivers. I'm hoping they will be whizzerless.
Given the parties involved, I'm hopeful things will be positive.
Paul
Greets!
Efficency and XBL^2 aren't mutually exclusive, I imagine it's just more expensive to 'have your cake and eat it too'. I'm more concerned about the lack of protection against bottoming that the XBL^2 CSS FR125S exhibits, so I assume there will need to be some trade-offs WRT maximizing excursion Vs the ratio of Xmax to Xmech.
Maybe DW can find some time to elaborate.
GM
Efficency and XBL^2 aren't mutually exclusive, I imagine it's just more expensive to 'have your cake and eat it too'. I'm more concerned about the lack of protection against bottoming that the XBL^2 CSS FR125S exhibits, so I assume there will need to be some trade-offs WRT maximizing excursion Vs the ratio of Xmax to Xmech.
Maybe DW can find some time to elaborate.
GM
Hopefully these new drivers will not all be $100+ priced. On one hand I'm happy to see Adire's business flourishing, on the other I'm sad to see Adire is going mobile only... I guess thats where the $$$ is. I have some credit on my account with them, I guess I better get in touch and see what I can still apply that to.
Here is how XBL^2 can do high efficiency:
http://www.audiocircle.com/circles/viewtopic.php?t=25792
I wouldn't count on them being cheap.
http://www.audiocircle.com/circles/viewtopic.php?t=25792
I wouldn't count on them being cheap.
Doesn't an extra driver add 3db? Also, as it talkes about later in the thread, Dan Wiggins often designed BSC into the driver curve. If you add BSC to an FE206E the efficiency doesn't look as nice. And even if the efficiency is a little lower, the output capabilities of a FR in a simple BR will rival conventional multiway speakers, something I haven't seen accomplished before. Evidentally XBL^2 will lower distortion significantly as well. For those that want a really high efficiency high end 8" there will always be drivers with 1/2mm of excursion.
For my needs (95db tops in a small-medium room) the current offering is perfect. I'm curious to see what substantially more excursion and/or a lack of whizzer will do.
For my needs (95db tops in a small-medium room) the current offering is perfect. I'm curious to see what substantially more excursion and/or a lack of whizzer will do.
I should be clear, lest I sound grumpy. I'm not trying to knock on anybody's opinions or approaches. It seems to me that Hemp Acoustics is trying to add something unique to our options. If you want a 206ESR, a 208ES or a Lowther, those things already exist.
When you think of price, look at the size and complexity of that motor. It ain't made in Asia, and neither is the cone. The whole thing is assembled either in the US or Canada. The firms involved aren't large. I don't have a problem with Asian manufacturing; I prefer it for budget pieces. That isn't where this company is headed though.
These promise to be something different. I happen to think the current 8.0DIY is something special, and others agree. If the new drivers follow in the same vein, many will find them to be special as well.
p.s. It occured to me that an additional driver can add 6db depending upon whether efficiency is spec'd in watts or volts.
When you think of price, look at the size and complexity of that motor. It ain't made in Asia, and neither is the cone. The whole thing is assembled either in the US or Canada. The firms involved aren't large. I don't have a problem with Asian manufacturing; I prefer it for budget pieces. That isn't where this company is headed though.
These promise to be something different. I happen to think the current 8.0DIY is something special, and others agree. If the new drivers follow in the same vein, many will find them to be special as well.
p.s. It occured to me that an additional driver can add 6db depending upon whether efficiency is spec'd in watts or volts.
pjanda1 said:
The 2nd driver adds 3 dB, if you wire in parallel and your amp puts out more power into the lower impedance (most tube amps are excluded from this) then you can get another 3 dB.
The RAW 6 is a very nice looking driver, the MTM needed some work -- but knowing the complexity of the XOs involved in most RAW stuff there is lots of room for development.
Terry O's RS 40-1197s handily outperformed the quickly assembled prototypes thru the midrange.
dave
Hi all,GM said:
Yeah, I can add a few things, since I'm a bit familiar with the technologies and the venture...
XBL² is NOT a low efficiency design; you can get as much efficiency from an XBL² driver as you can with other motor designs. And it's not even more expensive! It's strictly a function of what you want.
Up until now, most customers and designs have focused on the lower end response - looking to get a LOT more clean output down deep. And typically out of smaller boxes. Well, Hoffman's Iron Law rears its ugly head - you want deeper extension in a smaller box? Efficiency drops. No choice.
For subs, the big push has been in car audio. The trend there is to go with smaller and smaller boxes (because of the ever-shrinking car size), and bigger and bigger amps. The result is a driver like our Brahma, where the 10 inch dual 2 Ohm driver mounted in a 21 liter ported box will have an F3 of 25 Hz! Amazingly deep output in a tiny box. The downside is the resulting 80 dB efficiency. Of course, with a 1000W amp, that kind of becomes less of an issue...
Even with a few of the wide-range drivers out there (like the FR125S), efficiency is about where a lot of other midranges are, but you get a LOT more bottom end. What other 4" woofer has the sub-200 Hz capability of that driver?
Of course, you also get the issue with bottoming, where you can physically push the suspension to its limits with little power. It's easy to bottom ANY small driver if you can get it to play low enough; up until now, the small guys didn't bottom because the motor didn't have the capability to support the depth extension in a flat SPL manner. Now they do. And so we run into the bottoming issues...
Is this a limitation? IMHO, no. Would you rather have 95+ dB output from 150 Hz to 20 kHz and no bottoming, or 95+ dB output from 60 Hz to 20 kHz with the ability to bottom the driver? That's what it boils down to - how that extra stroke leans on the rest of the system.
I've used small full-range drivers quite a bit in the past, and while the other options out there are good, I don't think any of them really come close to addressing the bottom 50% of music in terms of power - the stuff below 150 Hz. The FR125S definitely can... It just means there needs to be a bit more design consideration for the entire system when using it.
There are two types of efficiency: small signal, and large signal. At rest, or with very little motion, many drivers are highly efficient. The question becomes how does that efficiency hold up over stroke? If your 5" driver is 95 dB efficient at 0.5mm of motion, but 91 dB efficient at 2mm of motion, then when peaking at 90 dB SPL at 2 meters away, with a 100 Hz signal the driver is actually averaging 92 dB efficiency. That is the average efficiency over the required stroke.
I personally focus on making a driver with a CONSISTENT efficiency, so that it will maintain a flat frequency response over SPL; most drivers will actually lose higher frequency output as the lower frequency output increases. On paper, and with small (under 1V) singals, you may have more efficiency. In the real world, however, efficiency will drop on average. And of course, in addition to mucking with the frequency balance versus SPL, this is also a form of compression - highly prevalent, always present in most home speaker systems.
Anyway, back to efficiency... Designing for higher efficiency means you will - for a given cabinet size - trade off low end extension. Period. No way you can have both. If you want extension to 60 Hz in a 7 liter box, you are theoretically limited to no more than 86 dB efficiency, max.
That said, there are quite a few high efficiency designs out there. I know one source making a 100 dB efficient woofer with 20mm of linear excursion. And no, I can't tell you who it is - contracts and all... But there are quite a few higher efficiency designs on the market.
We are looking at some high efficiency drivers for the Hemp line. It's what they do, and its what we'll work with them to do. High efficiency, high stroke designs will be coming. I personally would like to do a full range unit with 96-97 dB efficiency and 9+mm of linear stroke. Target a 1-1.5 cubic foot box, with an F3 around 80 Hz (theoretical limit for that efficiency range in that range of box sizes). It's not full range - wide range, perhaps, but not full range!
To do full range, we'd need to look at lowering the efficiency into the 90 dB range. That would allow extension to the 40-45 Hz range. A lot better for most music!
Actually, I guess perhaps some questions are in order - you guys want to give some input into a driver design? I'd really like to know the following:
1. What is your definition of high efficiency?
2. What is an acceptable box size for, say, an 8" woofer?
3. Bass reflex, sealed, or horn loaded?
4. How deep does a full range speaker have to play?
With some answers, I can narrow in further on a design. Note that I will cull out the obviously impossible designs (95 dB, sealed 1 cubic foot, with extension to 40 Hz). I think I'm a good engineer, but I can't break the laws of physics!
Dan Wiggins
Adire Audio®
Dan,
I'm excited to hear that you'll be pursuing the higher efficiency drivers, and look foward to the results. I'd personally love to see a high-efficiency version of the FR125 (95-97dB?), that'd be just peachy for a slender floorstander fullrange for HT or small rooms, 80Hz bottom end would be just fine, assuming a sub is used..... that'd give you maybe 60-100 litre cabinet size to work with, plenty to get that sort of bottom end I'd think. Flea power home theater anybody?
I'm excited to hear that you'll be pursuing the higher efficiency drivers, and look foward to the results. I'd personally love to see a high-efficiency version of the FR125 (95-97dB?), that'd be just peachy for a slender floorstander fullrange for HT or small rooms, 80Hz bottom end would be just fine, assuming a sub is used..... that'd give you maybe 60-100 litre cabinet size to work with, plenty to get that sort of bottom end I'd think. Flea power home theater anybody?
Yes; no whizz.
The whiz on the V.1 is fast being left in the ditch by the hemp cone, as it bakes, now ~150 hours(?) ... Lose the whiz for a WB 97db, as above 9-10KHz. Mmmmmmmmmm
Dan -- If you make a high Q 8, it will stand alone. Build it and they will come. You could conceivably knock Visaton B200 out, just as they are making significant inroads.
The whiz on the V.1 is fast being left in the ditch by the hemp cone, as it bakes, now ~150 hours(?) ... Lose the whiz for a WB 97db, as above 9-10KHz. Mmmmmmmmmm
Dan -- If you make a high Q 8, it will stand alone. Build it and they will come. You could conceivably knock Visaton B200 out, just as they are making significant inroads.
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