PaulD

ok, cool. I know I can replace the PDX 2.150 with a 4.150 pretty easily without really changing anything. I don't want to add lots more power because the car is pretty much stock and trouble free. Adding lots more power = bigger batteries, bigger alternator, bigger power wire ...... too much for the daily driver.

TMI dude ..... Either sealed or IB in an '01 Accord Coupe (2 dr). This is an SQ only setup, so it will only being playing up to 40 Hz or so. How well does the bass come thru from the trunk, because I have no pass thru between seats.

would 300 watts (the back half of a PDX 4.150) be enough to run one of these ?

They had one on the shelf at the Audio X show last month. It was a 15" and Nick said it weighed like 65-70 lb or so, I tried moving it and I was afriad to try and pick it up it was so heavy ..... and I am used to lifting 45 lb weight plates all the time. I hate to think of the bracing the box will need just to hold the weight of these things.

A bigger battry will put a bigger load on the alt IF it's allowed to be discharged

Sounds like his alternator belt is squealing, once the battery is recharged from starting the car the noise will stop because there is so much less load

what kind of car does it go to ?

1) do I have to connect the 2 inputs like in the diagram, or can I just use one ? 2) I am assuming the 2 speaker outputs are in parallel, so connecting a 2 ohm load to each set will result in a 1 ohm load to the amp .... ??

ok, can someone remind me of how much airspace a Mag 15D2 takes up. I think I estimated 600 in^3

well, it wouldn't let me edit ..... When the FTC laid down the law about stereo specs (1974 I think), they were asked about car stereo equipment. Their response at the time was - car stereo is car stereo. Meaning the best you could get was a cassette or 8 track player and a 12.5 watt/channel amp. Not much there to regulate. I would also like to see more standardized spec ratings but the problem is what you saw with the new CEA rating scheme. The cheapo companies so watered down the way ratings are done that many of the specs are nearly worthless.

Actually if you take the experiment from the opposite direction, it means the extra power capability will increase the speed of the driver - not necessarily the amplitude, remember the max amplitude of the speaker in this case is really the Xmax and is fixed. Efficiency can also help, unfortunately it seems that all too many efficient drivers are not too good sounding. I like these topics being discussed in this area, good stuff.

a big amen to that one ....

interesting stuff,although I'm not a basshead either On the SQ side, I have an interesting experiment for you to perform (or at least tink about). Take a length of transformer wire, it's coated so it won't short out against itself, and make a tightly wound coil with about a 1" or so tube down the middle - then attach the ends to an ammeter with an analog needle. Find a magnet that will fit in the gap tube) and slowy run it in and out, you will notice the ammeter (current meter) will start to move some. Now move it thru a little quicker, you will notice the needle will deflect a lot more, the faster you move it thru the higher the peak current reading will be. Be careful not to peg the meter to hard on this experiment. Lessons for SQ ....... if you want powerful dynamics and sharp transient response, what you really need it LOTS of power, at least 2 - 3 times the max RMS of the speaker and just watch the gains. Note that this logic applies to mids and tweets too. WARNING ... my power recommendations do NOT apply to bassheads who play electronic music with liitle or no headroom at full volume, the only thing you will get from it will be blown speakers.

I have never seen this bassrace in person, I might have to go to one close by just to see it in operation

I guess this is why most of the SQ based fiberglassed boxes are sealed, they don't want to rebuild them every weekend. I guess my problem with tuning to 34 Hz (ported enclosure) is that the sub will be unloaded below like 30 Hz ...... that won't kill it without a fairly steep sub bass filter ?