Fi BL or BTL?

[mwoehr 1]

I've always thought the SQ of the BL and BTL were kinda iffy and more geared towards SQ. However I notice that the BL and BTL both have daily options and the new BTLs always have a high Xmax option now. Do these subs have decent SQ? I friend of mine is looking for a pair of 12s ported or a single 15 ported being powered by a 2500 watt Kicker zx2500.1 amp that'll get very loud and have decent sq. I like the look of either of these for him but want to know more about their sq.

[JimJ 11]

I think your friend is confused...

[mwoehr 1]

I think your friend is confused...

How so? He wants a sub that is loud that sounds decent. What's confusing about that. From what I hear on this forum the BL's do sound decent and get loud. Both the BL and BTL have a Daily and a SPL option. He wants something for a loud daily driver that'll sound decent.

[Duran 387]

I think your friend is confused...

How so? He wants a sub that is loud that sounds decent. What's confusing about that. From what I hear on this forum the BL's do sound decent and get loud. Both the BL and BTL have a Daily and a SPL option. He wants something for a loud daily driver that'll sound decent.

Daily doesn't mean it will sound good, it means that there is a bigger gap between the magnet and the voice coil, it is more forgiving than the SPL option which is a VERY small gap. You only use the SPL option for a one note burp, play music and you will be sorry.

[RobClay 20]

then go with the bl's if, if he gets the btl's just consider that he'l have to spend alot of money on electrical to power his amps correctly

[JimJ 11]

The BTL will work, but it'd be helpful to know what his definition of "decent SQ" is.

[Duran 387]

then go with the bl's if, if he gets the btl's just consider that he'l have to spend alot of money on electrical to power his amps correctly

Its actually a toss up though, if you want to get louder with the same power get the BTL. Given the same amp, lets say a Sundown SAZ 1500D hooked up to a fully loaded BL, yes it will be loud, take the same amp and put it on a BTL, it will get even louder. But do you want to pay extra for a few tenths of a dB? Most people will say no, but I think its smarter to get the BTL and then that will leave room for improvement.

Edited October 25, 2008 by Duran

[RobClay 20]

then go with the bl's if, if he gets the btl's just consider that he'l have to spend alot of money on electrical to power his amps correctly

Its actually a toss up though, if you want to get louder with the same power get the BTL. Given the same amp, lets say a Sundown SAZ 1500D hooked up to a fully loaded BL, yes it will be loud, take the same amp and put it on a BTL, it will get even louder. But do you want to pay extra for a few tenths of a dB? Most people will say no, but I think its smarter to get the BTL and then that will leave room for improvement.

good advice and yes the btl is fi's loudest sub but like he said 2 12 btl's. ull need some powerful amps to run their 2000w rms and some good electrical

[Duran 387]

then go with the bl's if, if he gets the btl's just consider that he'l have to spend alot of money on electrical to power his amps correctly

Its actually a toss up though, if you want to get louder with the same power get the BTL. Given the same amp, lets say a Sundown SAZ 1500D hooked up to a fully loaded BL, yes it will be loud, take the same amp and put it on a BTL, it will get even louder. But do you want to pay extra for a few tenths of a dB? Most people will say no, but I think its smarter to get the BTL and then that will leave room for improvement.

good advice and yes the btl is fi's loudest sub but like he said 2 12 btl's. ull need some powerful amps to run their 2000w rms and some good electrical

That's the beauty of the BTL though! You could have 1000 watts RMS between the both of them and clip the hell out of them and still be fine.

Edited October 25, 2008 by Duran

[dbjunior 0]

just because a sub is rated at 2000w doesnt mean you need 2000w you could power it with 500 if you want but with the power you have 2 12bl's or 1 15btl. the 1 btl would be cheaper an depending on box can get really loud and sound decent as far as an spl sub is concerned

[lee 2]

I am a firm believer that if you're not going to give the BTL up to atleast close the rated power, you are wasting your efforts. The suspension is so stiff on it that anything under 1500wrms wont do it any justice. However the kicker 2500 would be good for a 15''btl imo. What is your description of SQ? Just curious. I have a feeling most people don't really understand what SQ is, in terms of a vehicles environment.

[///M5 2,833]

Depends on your definition and the box.

[seanbw 1]

i feel like this thread has been addressed a thousand times but correct me if i'm wrong. isn't this the whole reason there's an efficiency rating in the t/s parameters?

[dbjunior 0]

efficency ratings are worthless in ported applications

[seanbw 1]

efficency ratings are worthless in ported applications

i'm confused then... watt for watt the btl will not have more output than the bl in that case? what does the efficiency rating pertain to?

[95Honda 486]

Efficiency ratings apply in every enclosure application. This rating tells you how much output a given driver will have with a certain input.

Watt for watt, the BTL is the loudest sub FI makes because it is more efficient, in the right enclosure, of course..

Yes it would be kind of strange to buy a BTL and send it 100 watts, but it would still be loudest driver you have with your 100 watts..

Just because a driver has stiff suspention doesn not mean it needs alot of power. The suspention is just one of the components thta make up the driver charactoristics. For example, if you have 2 drivers and one has lower compliance (this is the definition of "stiffness") but the other has increased motor strength, the other driver may still have increased cone travel at the same power output.... Same case with a BTL, just because it's suspention is stiff, doesn't mean the cone won't move as much. In fact, it will more than often move MORE because of the increased motor strength... This is how it is more efficient, if the cone wasn't moving more, it wouldn't be ass efficient. But again, this is all on the box and frequency being played.... But hopefully this helps some understanding here...

Yes, this has been covered before, alot. But it is good to see a few guys remembering/understanding this...

Now there is also a flip side to this. With all other parameters being equal (same motor, cone mass, etc) when you decrease compliance (say add spiders) you do a few things. Generally speaking, you increase Fs, increase mechanical power handling and you decrease the Vas of the driver. Now, efficieny and Vas are directly proportional, so buy decreasing compliance, you decrease efficieny at the same time. But there is a lot of factors that play into this. For example, if you had a BTL 18 and only had 1 very compliant spider, it would be much more efficient than one with stiff suspention, but the downside is that since Vas may have gone up so much, you now would need a much larger box to get the same response, additionally the mechanically handling would be very poor. You may gain a few db or so within it'susable power handling range, but anything more than say 100 watts may send the coil into the backplate of the motor or bottom out the triple joint... Adiitionally the drastic change in mechanical Q may render the driver too peaky for music. So basically, the engineers at FI choose the best ratio of compliance to motor stregth (and yes alot of other paramters) until they got a driver that was efficient enough and had enough mechanical handling to be thier loudest sub. If there was a class that was say 100 watts and a single 18" driver ONLY, you may see a driver design like something I have been talking about here, but of course there is not, so there isn't really a driver designed like that. But hopefully this helps with the understanding of compliance, efficiency, etc....

[seanbw 1]

in respect to sound quality like the guy was asking, wouldn't having a longer linear throw and a lower resonance frequency be more important to sound quality in a woofer than motor force and suspension stiffness? i think the bl and btl will be similar in sound quality whereas if he was comparing either to a tempest-x or something with xbl^2 it would be a different story.

additionally, thank you for clarifying the meaning of efficiency again 95honda, i know you probably feel like a broken record at this point