Possible New LLT project

[Warmon]

a1161979 wrote:

Do you have any enclosure plans for the new default LLT driver yet steve

If you want to get one, better hurry - pre order sale ends tomorrow...

[SteveCallas]

Sorry, I've been very busy this week. The Maelstrom X works well in anything from 400-700 liters. Tell me what size you want to go and I'll tell you what port length and tuning looks best for that volume.

Regarding the FiCar IB18, how can a driver designed for IB (a giant closed box) perform well in a vented system?

The characteristics needed for a good IB and LLT driver are similar - high Vas, lowish Bl, low Fs, lots of displacement.

[mdrake]

The characteristics needed for a good IB and LLT driver are similar - high Vas, lowish Bl, low Fs, lots of displacement.

Why a low Bl, I thought Bl, helped stop and start the woofer "magnet strength"? I always always under the impression that a higher Bl was better because it help give the woofer better transient response,especially when using a larger cone. Am I missing something?

Matt

[SteveCallas]

You need a loose suspension in order to achieve the ideal FR rolloff that mates well with a <15hz tune. A tight suspension, even in an infinitely large enclosure, will result in a very peaky range around tuning. Also, since a LLT or IB offers little no no resistance to cone movement, the magnet strength becomes less important. High Bl is much more important in small sealed subs, as that magnet strength is needed to compress the air inside the enclosure.

[mdrake]

You need a loose suspension in order to achieve the ideal FR rolloff that mates well with a <15hz tune. A tight suspension, even in an infinitely large enclosure, will result in a very peaky range around tuning. Also, since a LLT or IB offers little no no resistance to cone movement, the magnet strength becomes less important. High Bl is much more important in small sealed subs, as that magnet strength is needed to compress the air inside the enclosure.

I just now saw that reply. THANKS that was a VERY helpful explanation!!!!!! To many years in car audio.

Matt

[kstich]

Hi Steve,

Sorry for re-opening this discussion, but I just got a Maelstrom_X and wanted to run the LLT alignment by you. I have read your LLT Explained thread. Thanks and great job!

Here is what I have modeled so far:

Volume: 424.8 L
Tune: 16 Hz
Port Dia: 8"
Port Length: 29.27" (one end flanged)

This appears to give relatively flat response to below 20 Hz without being too large. When I put the volume and tuning into the sonosub.exe program, the port length calculated is very close 29.75".

I modeled another larger ESB3 alignment and came up with 679.6 L tuned to 12 Hz, but that is awfuly large, and the -3 dB point is higher. I am leaning towards the 424.8L sonosub. What are your thoughts on these designs? Thanks in advance...

[SteveCallas]

Looks really good - I would increase port length to 36" though to knock the tune down a bit lower. Remember there will be room gain, so you don't want an anechoic response that stays naturally flat all the way down to tuning when tuning is below ~25hz