95Honda

A cap in series isn't a linkwitz transform. It is a highpass filter that slightly moves the response curve to the left and gives a 5th-6th order roll-off. Infinity used to do it alot in many of their speakers in the 80's and 90's. Also, did you mean 1.2uf (microfarad) or did you mean 1.2mf? (milifarad) 1.2 microfarad will roll sub of around 5Kz, 1.2 milifarad around 20Hz. Don't put a 1.2uf(!) cap in series with the woofer.... And if you are talking about a 1.5milifarad cap, good luck finding one! You'll have to put a few huge electrolytics together (but they may not handle the power) or an ass load of film caps, that will be some serious$$... A linkwitz transform will be an Eq circuit that is the inverse of the roll-off below resonance. So if you are down say 12db at 20 Hz, it introduces 12db of gain at 20Hz and so on and so on. This is normally used in a sealed alignment that operates entirely under resonance. It takes an ass-load of power to get loud low with it also... It is an active circuit before the amplifier. I used a linkwitz transform with one of my XXX 18s in a .5ft3 sealed alignment with 2.5 KW. It worked OK, but you loose alot of output compared to a more efficient, larger alignment...

No. Clean power has nothing to do with it. A clipped signal has never hurt anything. If you are listening to FM radio, you are listening to clipped signals. Too much average power is what destroys a driver. This concept (lack of understanding it) is what gets people in trouble. It is a missconception to think you are delivering a full amplifier's power into a subwoofer on a continuos basis. Without constantly knowing all variables (impedance, drive voltage, signal, back-EMF, etc) in real time, you have no idea what amount of continuos power you are actually driving the subwoofer with. Most people believe they are "giving thier subwoofers more than RMS" when in reality they are not. RMS thermal ratings are provided by the manufacturer for a reason. To let you know the thermal limitations of the voice coil in it's given motor assembly.

Depends on what level the tone is recorded at. If you have play a song that has a higher level than the tone (possible 99% of the time) you will have more power output. Additionally (even with cooling) you have enough power on tap to thermally damage the subwoofer, without any clipping. With a heavily clipped signal, that amplifier will put out well more than enough power to cook the driver. Don't mistake the driver being cooked from the clipping, it is just the fact that the amplifer can produce more continuos power with a clipped signal, the clipped signal in itself is no different to the driver than an unclipped one. So in reality you have more power than the your driver is thermally rated for. Your right hand is going to determain how long it (the driver) lasts...

Didn't take it that way at all. Just trying to help you get this figured out. I think it is a lot more simple than everyone is making out to be.

It has been explained precisely here: The only thing that will burn up servicable tinsel leads is too much power. The type of signal doesn't matter here as long as we are in the audio realm. Now, if the lead is damaged in any way the potential for higher resistance (at the damaged point) occurs. When you have higher resistance you get voltage drop. When you get voltage drop you get heat. When you get heat you get more voltage drop. So on and so on until something fails. Not trying to create an end-all answer, but that pretty much is it. Now, it could be a manufacturer defect or incorrect use, but this ^^ is it.

You can set up your gains however you like with a DMM or an O'scope. Problem is, if you change anything, and I mean anything in the signal chain, it is all a mute point. If you set for visible cliping with an O'scope then you have to be 100% sure that is the same signal you play after you calibrate. I.E. if you set it with a sine wave, it is only good for a sine wave at that exact level. Music is much more dynamic than a sine and it is tough to see visible clipping with music. If you set with a DMM you need to know the exact impedance. You can't do this with a single DMM. And even if you know the exact impedance, you have a tolerance given by the manufacturer for output power that cannot be used with confidence for setting up a clipping threshold. Also, a small amount of clipping doesn't hurt a thing. In fact full clipping doesn't hurt anything as long as you stay under the manufacturers thermal ratings (assuming the ratings are not inflated). You need to fully realize how this works though... So in a nut shell, don't turn the volume knob up too far, this will keep you from blowing things up. If you can't follow this, trade your amp in for one that is no more than 1/2 the RMS rating of the subwoofer and never worry about a thing...

Wherever you tune your are going to see a drop in response below resonance. It will be somewhere around 24/db per octave (so if response starts to drop at 20Hz @ 90db it will be be 76db by 10Hz) and you will need to mirror the inverse of this with your SSF. So if it were textbook you could just apply a 24/db per octave highpass filter that starts rooling off right below your resonance point. Or, just pick a highpass filter like a Harris F-Mod that is roughly the same (or slightly less than) cutoff of your enclosure tuning. Or tune real low liek we said (teens) and don't give it a ton of power and be happy with it. Or go sealed and never worry about it...

I wouldn't neccesarily say that. Most amplifiers have pretty flat voltage gain in their usable bandwidth, and unless the load is crazy, power is pretty flat. At least within a db or so....

The only thing that will burn up servicable tinsel leads is too much power. The type of signal doesn't matter here as long as we are in the audio realm. Now, if the lead is damaged in any way the potential for higher resistance (at the damaged point) occurs. When you have higher resistance you get voltage drop. When you get voltage drop you get heat. When you get heat you get more voltage drop. So on and so on until something fails. Not trying to create an end-all answer, but that pretty much is it.

SSF = Sub Sonic Filter. It is a highpass filter. In alignments that do not provide enough loading to the driver below resonance, this filter reduces output to prevent mechanical failures.

^^agreed. I wouldn't waste any time with this other than looking at output waveform. I have yet to see anyone on this or any forum set a gain objectively with an O-Scope... Also, depending on that Scope (not sure wich one that is) it may not read RMS voltage, may just read Pk or Pk-Pk, so take that into consideration...

Yes SSF like M5 said. I ruined a pair of Tumults (triple joint failure) in boxes tuned in the high teens for the simple reason I didn't have a SSF. And I was watching "The Polar Express" of all things... And these were drivers with almost 3" of linear stroke...

Design your box with the goal of low end extension and tune around 20Hz if you can. This will make for a bigger box, but you will have a flatter response with less ripple and better low end extension. You have enough power that the overall alignment efficiency won't be a huge deal. I haven't looked at the SA12 T/S parameters, but most "car audio" subs will work fine as long as the Fs isn't absurdly high and they have a usable Vas (usable that the box will be large enough to accomodate an appropriate size vent and not have a huge bump in response)...

You have no idea what the impedance is, so your 50 VAC measurement doesn't tell you a thing about output power. A 1/2 octave below tuning may be too low depending on the Q of the SSF, may want to experiment a little.

I have made them as much as 12:1 and they still worked (and measured) correctly. You will be OK.

When it comes down to it, they will both be very similar in output.

I have owned about 10 drivers with that motor (Tumults and XXXs). I have a pair of the 18s sitting in my basement right now waiting to be installed in the H/T. Awesome drivers...

OK, I don't get it... Are you trying to figure out your substage?

Actually, a slightly rougher surface may/will promote better airflow than a smooth one. This can be a missconception... B&W starting working with this principle with thier cabinet vents a few decades ago. It works well for them and has been adopted by several other manufacturers...

I feel for you guys over there. I just spent 4 years in Europe. I can't tell you how many orders I placed back to the US for car audio gear for the locals because of the shit selection and ridiculous pricing over there... Good luck man... If you can find an American military friend he can order any FI product for you at US prices and US shipping... Just food for thought...

Cresendo arrived. Just waiting on the Mayhem and Audio Control LOC...

The voltage at the battery and amplifier will never be the same. This why you use sufficent enough gauge of wire, in order to minimize this....

A round 8" carboard tube is more rigid than a similar size square vent made of 3/4" MDF. Remember, it is round....

New H/U in and everything sounds awesome... The Leviathan is a great amp. He got the bass bug now, I am building a box for a Mayhem 15 for his 4-runner. Power is Cresendo 3500... Stay tuned..

Are you refering to a 6th order bandpass?