Just for FI....

[jonbearsmt 919]

Fs: 00.0 Hz | 00.0 Hz

Re: 0.7 Ohms/coil | 1.5 Ohms/coil

Qms: 0.00 | 0.00

Qes: .00 | .00

Qts: .00 | .00

Mms: 000g | 000g

Cms: 0.00mm/N | 0.00mm/N

Sd: 1210cm^2 | 1210cm^2

Vas: 00.0 l | 00.0 l

Spl: 00.0dB 1W/1m | 00.0dB 1W/1m

Bl: 00.0 N/A | 00.0 N/A

Xmax: 16mm * | 16mm *

Rms: 2000W * | 2000W *

Sealed box: N/A cuft | N/A cuft

Ported box: 5-10cuft | 5-10cuft

Sub OD: 18.500

[BKOLFO4 29]

First one does not have it listed, the second one is 89.4 or 89.6 depending on the coil config.

Spl: 89.4dB 1W/1m | 89.6dB 1W/1m

edit - was the old BTL listed in the 95 dB range (from the bladeice website)?

Edited June 11, 2008 by BKOLFO4

[jonbearsmt 919]

First one does not have it listed, the second one is 89.4 or 89.6 depending on the coil config.

Spl: 89.4dB 1W/1m | 89.6dB 1W/1m

the first one was the btl 18 and the second was the ssd 18.

[BKOLFO4 29]

I think the Fs is much lower for the SSD, so in the correct box, it may peak lower and sound much louder playing music. . .that would go back to a BIG part of loudness being install dependent, which could be the difference you heard in your comparison above.

Comparing the loudness of two system, even at the same power level, is more than just the sub's efficency rating. Heck, the same woofer in two different installs and/or vehicles with the same amount of power will more than likely end up not being the same loudness.

The point is the higher efficiency of the BTL shows that while it will handle more power, it does not have to be driven with it's full RMS to easily be louder than other Fi subs at lower power levels when installed correctly.

Edited June 11, 2008 by BKOLFO4

[todd.brust 29]

Nice to see ya around Mike. The whole effiency thing always gets me wondering. High effiency pro audio speakers for SPL? Just a thought I wouldn't mind seeing it elaborated on!

[audio-neon 34]

Nice to see ya around Mike. The whole effiency thing always gets me wondering. High effiency pro audio speakers for SPL? Just a thought I wouldn't mind seeing it elaborated on!

This is exactly what the new Street A rules are making some of us dB draggers look into.

[todd.brust 29]

I take it they want to ban it because of certain advanatges it may give to a competitor?

[95Honda 486]

No apologies BigJohn, that's not why we are here buddy..

And believe me, I am not suggesting everyone buy a BTL and run it off deck-power, I just wanted to point out the fact that the BTL will get louder at the same power as all the other subs due to its efficiency being the highest.

Additionally, efficiency isn't the highest only at 1w, it is measured at 1w most of the time because #1, that is where the industry has set the driver sensitivity standard (1w/1m) and #2 this is where the driver is the most linear. If you could see driver efficiency vs power, you would see how much more un-linear and in-efficient drivers get as you increase power. The efficiency curve really takes a nose dive at the thermal limits of the driver.

You also have to remember that the RMS or thermal rating of a subwoofer has absolutely nothing to due with the amount of power a sub requires. All this rating is usefull for is telling the user that at XXX amount of wattage, you will begin to have thermal breakdown of the driver (glues fail, VC wire melts, formers come apart). The other driver parameters (Vas, Xmax, Qe, Qt, Spl, Bl) and much more indicitive of how much power you will need, and the most important factor 99% of the time is the chosen enclosure alignment... Sometimes we forget that a driver may need 100 watts to reach it's peak output in one box, and 200 watts for the same driver to have the same output in another box....

Why not pro audio drivers? I have wondered this alot myself. I really think in the past it really hasn't been super popular because of the fact that the real efficiency of the pro audio drivers (even 18" subs) is higher in the frequency range than you would think. Most 95-97db rated pro audio subs are only this efficient 100Hz or higher, not down around 40-60Hz where you would really want for music, in most cases they are only as efficient or even less efficient as some car audio subs down low. But, there are some exceptions, last year I built a set of 20ft subs with dual 18s in each box for a movie theater. I used the Aura NRT18s... These things are about 96db efficient, have 15mm of xmax and an Fs of 25 Hz.... They also have 4" Voice Coils and some serious suspention... Absolutely insane low end.... I remember talking to Marshal (Black00) about these when I was working on this project, and believe me, we were really thinking these could do some seriously mean #s in a car, with very low amounts of power... The problems we saw were that #1, these only had 8 ohm coils, so you would have to start re-thinking your amplifier stratagies unless you could get some custom coil configs, #2 these things are $1000 each.... #3 well, we never got to #3...... Anyway, you get the point....

I hope this is usefull information for you guys.

-Mike Edgar

[Adrian_D 520]

funny tho.. i have yet to hear anyone that owns a btl that DOES NOT FEED IT OVER 2k....

or any big sub like that.

Don't take me the wrong way. I'm a guy who has a pair of XXX18s and 5KW rms in my living room..

HA, I suspected you were that 95Honda

BTW, my xxx18 works awesome on only 500w

[audio-neon 34]

I take it they want to ban it because of certain advanatges it may give to a competitor?

Basically what they did was make street A a vehicle dependent class. You really need a yugo, crx, rabbit etc to even think of going to world finals now. 1 amp only... car off etc. You can only realistically see 3 maybe 4k watts in this set-up.

Pro-audio drivers and really creative box designs are the only way those of us with trunk vehicles can hope to do well at the regional level.

[95Honda 486]

Exploiting efficiency can be the name of the game..

A few years ago I was trying some different tuning combinations and came up with a 143db Termlab score on the windshield in my 78' Bronco with 154 watts..... It was all about a super efficient box alignment... This was done with 8 RE 8" subs or about 19 watts per woofer........ Black00 made the TL measurements..

I was only thinking what I could have done if I would have actually used some real efficient drivers.....

Edited June 12, 2008 by 95Honda

[audio-neon 34]

Exploiting efficiency can be the name of the game..

A few years ago I was trying some different tuning combinations and came up with a 143db Termlab score on the windshield in my 78' Bronco with 154 watts..... It was all about a super efficient box alignment... This was done with 8 RE 8" subs or about 19 watts per woofer........ Black00 made the TL measurements..

I was only thinking what I could have done if I would have actually used some real efficient drivers.....

I only have the ability to use 3 8" drivers, 2 10" or 1 12" drivers. To push 150+dB's out of a trunk would require a super efficient box, and 2 really efficient woofers.

[Adrian_D 520]

Exploiting efficiency can be the name of the game..

A few years ago I was trying some different tuning combinations and came up with a 143db Termlab score on the windshield in my 78' Bronco with 154 watts..... It was all about a super efficient box alignment... This was done with 8 RE 8" subs or about 19 watts per woofer........ Black00 made the TL measurements..

I was only thinking what I could have done if I would have actually used some real efficient drivers.....

Please go on, things like this are very interesting.

EDIT : Any chance you have Y! messenger ? I'd like to talk to you about a couple of things

[95Honda 486]

Sorry I don't have any IM.

email any time you want though.

[email protected]

I am in Germany though, so the hours are a little different.

-Mike

[Adrian_D 520]

Sorry I don't have any IM.

email any time you want though.

[email protected]

I am in Germany though, so the hours are a little different.

-Mike

Thanks bro.

10:24 AM in Germany

I'm only 1000km's further east

[dondie 0]

My take on this is this:

The most efficient among the FI lines, given the factor of 500 watts on each sub is the SSD. All because of its rating it can sing at its own level of likeness. The BL, Q and BTL however will still move the cone with 500 watts but will not perform as well because it was not build for that small amount of power.

Again it will sing but not that well.....so to answer the querry of EFFICIENCY, its the SSD (at 500 watts)

[stealth 113]

off topic but, higher efficiency subs get louder out of a larger box. lower efficiency does better in a smaller box. with tuning between 20-40hz. visa versa for tuning 50-80hz.

Edited June 12, 2008 by stealth

[MikeS 0]

Exploiting efficiency can be the name of the game..

A few years ago I was trying some different tuning combinations and came up with a 143db Termlab score on the windshield in my 78' Bronco with 154 watts..... It was all about a super efficient box alignment... This was done with 8 RE 8" subs or about 19 watts per woofer........ Black00 made the TL measurements..

I was only thinking what I could have done if I would have actually used some real efficient drivers.....

I only have the ability to use 3 8" drivers, 2 10" or 1 12" drivers. To push 150+dB's out of a trunk would require a super efficient box, and 2 really efficient woofers.

I got to listen to Mike's 8 RE's in his Bronco. It was roughly a enclosure of around 5-6 foot internal volume...(he knows the exact volume and alignment) It had multiple ports, and you could plug some of them to tune lower, or run them all open open for SPL.

I was scratching my head when he told me it was a 4 ohm load with a 150 watt Alpine amp. I think he had it tuned lower for music when I listened to it.

Efficiency can be your friend.......especially in the home audio world.

To say speakers/drivers in general are inefficient, well maybe the generalization can fly in the car audio world. But high efficiency loudspeakers have been around for a good 80 years now.

When you only have a couple few watts to work with, you need a real efficient loudspeaker.

A 50 watt commercial home tube amp in the mid fifties was about as much power as one could find without having to be a insane DIY dork and resort to building some sort of audio amp with the higher power transmitting tubes of the time.

I have a pair of 104db sensitivity loudspeakers. They can boogie with one watt.

The FI subwoofer is 95db efficiency?

Mike

[95Honda 486]

My take on this is this:

The most efficient among the FI lines, given the factor of 500 watts on each sub is the SSD. All because of its rating it can sing at its own level of likeness. The BL, Q and BTL however will still move the cone with 500 watts but will not perform as well because it was not build for that small amount of power.

Again it will sing but not that well.....so to answer the querry of EFFICIENCY, its the SSD (at 500 watts)

Actually, no, this is the mistake being made.

At 500 watts the BTL is more efficient than the SSD (and Q and Bl etc) and will play louder. The BTL is more efficient at 1 watt, 10 watts, 500 watts and 1000 watts, etc.....

But I think we are beating a dead horse at this point.... Some will get this, some won't... Take it for what it is.

[95Honda 486]

off topic but, higher efficiency subs get louder out of a larger box. lower efficiency does better in a smaller box. with tuning between 20-40hz. visa versa for tuning 50-80hz.

Well yes... and no..

All vented alignments gain efficiency with size, but this efficiency comes at the expense of bandwidth (greater ripple in response) or, in simple terms, the box gets real peaky...

The correlation between "small box woofers" and low efficiency is, that when a subwoofer is designed, the designer can lower the Vas (all else being somewhat equal) to allow the driver to achieve a lower target F3 in a smaller box, but the efficiency of the subwoofer also drops. This doesn't mean that the subwoofer works best in a small box, it means that the designer sacrificed efficiency to design a driver that will still achieve a low cut-off point in a small box, and they do this by making the driver less compliant (small Vas/stiff suspention) a good majority of the time. But the downside to this is a loss of efficiency. So, to combat this, you design a driver that can handle a ton of power and you overcome the efficiency problem with brute force.

If you can see the connection here, now you may know why the big 18" prosound drivers that are fairly efficient have a pretty large Vas most of the time and need a big-ass box to realize thier full potential... This is one area where designers find ways to gain efficiency. And they tend to not worry about box size so much because these are going on stage, not in a small tire well.

[Aaron Clinton 2,372]

with 500 watts I would not run a BTL...I would run an SSD

Thats why they have different RMS ratings. I would even venture so far as to say with 500 watts the SSD would get louder then the BTL due to the way the sub woofers are intended to be used.

Ding, nailed it again....

WHAT THE HELL IS GOING ON HERE,..... HE JUST SAID THE EXACT OPPOSITE OF YOU AND YOU SAID HE MADE YOUR POINT

His point is the perception that the BTL has of needing 2k watts to function, and Hayes feels that the lower power handling less efficient woofer would be louder.

[KU40 173]

I think the space within a car audio environment is really the driving force behind car sub manufacturer's designs. You have to keep the box relatively small and not many manufacturers want to give up low end (for many different reasons, including consumers who specifically want a low end monster, having a flat response down to 30 hz or whatever for sq guys, etc.), so that means efficiency has to suffer.

But if you could get a big van or something and have enough room for maybe 2 of those 104 db/watt efficiency drivers and the boxes they need (what like 20 cubes?), those would take the place of maybe 10 "normal" drivers. So even with a $1000 price tag they may be worth it if you consider the alternatives.

[DevilDriver 28]

The BTL is the most efficient driver and at any power level, it will be the most efficient driver. Efficiency, in the simplest sense, is the ratio of input vs output, ie. in a highly efficient system, there will be more output for a given input.

So what affects efficiency? In a very general sense, we are looking at two primary factors: mass and BL (or for comparison's sake, BL^2/Re). We know mass will not change at 1 W or 10,000 W. We know the B (flux density in the gap) will not change (within reason). And the L (length of coil that cuts the flux) will only significantly change once we approach Xmax. The BTL's coil also happens to be capable of handling more power before the resistance increases, so we know the BTL will be most efficient at any power level.

Now....does this necessarily transfer to loudness? First, we need to look at the bandwidth (range of frequencies) that the subwoofer will be covering. Yes, the BTL is more efficient than the Q, but will it be louder at 20 Hz for a given input? There are many factors and, at the risk of oversimplifying, the answer is no. This is the tradeoff that is Hoffman's Iron Law (look in the Tech Area on this site). However, through most of the bandwidth that is typical of a subwoofer, the BTL will, in fact, be louder than any other Fi driver. No speaker "needs" a certain amount of power.....the only time you need more power is if you're not satisfied with the output you already have.

So why not just buy the BTL? Well, there are different applications for each driver. Some drivers are more linear than others (generate less distortion), some drivers have better low frequency extension, and some drivers will meet your needs at a much lower cost than buying the big boy BTL.

[jonbearsmt 919]

My take on this is this:

The most efficient among the FI lines, given the factor of 500 watts on each sub is the SSD. All because of its rating it can sing at its own level of likeness. The BL, Q and BTL however will still move the cone with 500 watts but will not perform as well because it was not build for that small amount of power.

Again it will sing but not that well.....so to answer the querry of EFFICIENCY, its the SSD (at 500 watts)

buddy... did you read the past 5 pages?

[jonbearsmt 919]

with 500 watts I would not run a BTL...I would run an SSD

Thats why they have different RMS ratings. I would even venture so far as to say with 500 watts the SSD would get louder then the BTL due to the way the sub woofers are intended to be used.

Ding, nailed it again....

WHAT THE HELL IS GOING ON HERE,..... HE JUST SAID THE EXACT OPPOSITE OF YOU AND YOU SAID HE MADE YOUR POINT

His point is the perception that the BTL has of needing 2k watts to function, and Hayes feels that the lower power handling less efficient woofer would be louder.

i now understand that