95Honda

Gainmatching hurting the subs is an absolute myth.. I still don't know who made that one up.... You can drive one coil with 100 watts and one coil with 200 watts... It doesn't matter, all power is additive if in phase.... If it isn't in phase you have combining loss, and this also doesn't hurt anything. Period. You don't need anything fancy to do this, if you want, play a test tone and just make sure the voltage from each amplifier's output is the same. It could be any tone, at any frequency at any level, that part is arbitrary.... And the only reason you would match the amplifier's output is to be sure one doesn't run out of steam before the other....

If SQ is truly your goal, the Aura subs with underhung motors have less distortion than almost anything else you can buy.... The just cost almost $1000 for 15" The NRT 18 is a prosound woofer, but if you had room for an 8ft3 box, that would probably give you more low distortion bass with only a few hundred watts than you could get anywhere... Again, for about $1000 a pop.... 05' and earlier XXX subs (no longer made) Adire Brahma (no longer made) Those would be my top 3 picks of anything at any price, if SQ was truly the only goal.

Err, I think you misunderstood the white paper. Bob makes it clear his alignment is very inneficient, hence his 2700 watt amplifier... He also personally told me this about 13 years ago when he demonstrated the first prototype of this sub to me and a few others (Dan Wiggins was there, LOL)....

I think most of the disrespect was in the fashion the OP was written....

100% of the port can be outside the box, it doesn't make one difference at all... It actually makes things easier because you don't have to account for the port displacement with you box design...

There are a ton of online calculators... There are some even on this site... Just plug in your numbers and go....

Yep, they will absolutely fail with too much heat.... I built a Nalson Pass single-ended class A amp about 10 years ago and a fried a pair of FETs while seeing how much power I could get out of that design.... They fried from the heat alone of bias, there wasn't even music playing when they cooked... And if you have bad drivers, you will keep replacing output devices. Also, matching can be an issue.... You get all kinds of wierd things here, especially uncontrollable DC offset on the output.... Come to think of it, the ONLY time I ever just replaced the output devices without checking anything else (and was succesful) was when I accidentally shorted the remote input to the speaker output connections (they are on the same barrier strip) on a PPI A600 about 15 years ago..... I knew excatly what I had done and that was the only reason the approach worked....

Alright, you really want to use those 6.5"s What tweeters did you pick and have you decided and/or researched if you will go active or passive? As soon as you make a choice, you can get help with your execution. The overall impedance you will have (2 or 4 ohms) is pretty much a mute point, or in other words, it won't matter at all.... You gain almost nothing by running an average 2 ohm set over a 4 ohm set....

Guys please. No more swearing at people in this thread. If you want to help the OP good, if not, leave it alone.

Soldering all your life and fixing amps for a living are 2 diffrent things. Mosfets blow for a reason. When it's not excess heat it's some part in the control / drive section. I can't even tell you how many times on went on wild goose chases replacing semiconductors only to have them fail again 20-30 minutes later back in the day before I really understood this stuff... Especially with Class D......

I am trying to help, but yes, please don't talk to people like that.

But, whatever man.....

I don't know how you save any money by running them at 2 ohms... Do yourself a favor, research passive and active crossovers, mill around the ideas for a few days and then post a question.. Please, do us all a favor and and quit writting words like "cud" "shud"... It makes you sound stupid, but I don't think you are... But when you are looking for informed, well thought out answers, at least attempt to post your questions that way...

Tang Band comes from a land where there seriously aren't many rules at all as far as advertising.... This is why you can get an 8" woofer with 12mm of one way throw for $40..... I take what I can get from those guys... I have bought 2 maybe three pairs of "beryllium" tweeters in the past... I think a pair or 2 from Focal... I never even pondered what the dome material was really made of.... They may have been aluminium for all I know LOL....

Ughh..... Yes, 2 of them would be 2 ohms.... When you do run them at 2 ohms off your amp alot of things happen. Your amp runs hotter, is less efficient, has more distortion and losses dampening... All of this at the gain of a db or so. I don't like doing this..... I would run each 6.5" on it's own channel instead of combining them... What kind of crossover are you going to use? I assume active on these if you are running 2 ohm, or are you designing some passives? Remember if you have passives already that are for (1) 6.5, they will cut the lowpass frequency in half if you run a pair at 2 ohms....

Pay to get it fixed then sell it. There isn't a single product made by Audiobahn that didn't have cosmetics as the #1 goal...

"Cud" isn't a word... They are 4 ohms, you can't change that....

I think it is the cost... The motor is the most expensive part of the driver. The steel is the what really hits you in the pocket book these days... It really is a tough sell... Also, don't forget that alot of the goals you are talking about are easily achieved with some of the current drivers on the market now. Getting low in small box can be done by either cuting efficiency or adding substantially to motor cost... I think the real benefits of what you are thinking about are the drops you will see in non-linear distortion from a driver that behaves equally both in forward and rearward stroke.... That would be my target goal for something like this....

If it is a 1200 watt amp at 1 ohms it swings 35VRMS If it is a 1200 watt amp at 2 ohms it swings 50VRMS It will swing the same voltage at 3 ohms, or a little more due to the power supply capacity and output stage losses.... This will also be the same voltage fully clipped or unclipped, it is the rail limits.... If anyone tells you what they clamped it at, that doesn't help you.... That will all depend on thier vehicle electrical and if they really know they are checking it at 3 ohms.....

2 3" ports have no where near the surface area of a single 6" port (they actually have about half) and may give you compression problems on the bottom end with that sub at full power (is this an LMS 15"?) 5" of clearance would be perfectly fine, 3" may introduce some weird tuning issues, but it won't really add much in terms of compression... Less than 2" is where you would run into problems....

Yep. That's why I said at least 700. At least in unregulated power supplies, right? I thought regulated power supplies were a little more strict on doubling as impedance halved. Even the regulated ones usually don't have the nuts you need to double power...

Also, don't forget that pretty much all car audio amps don't have the power supply to double wattage any time they half impedance... So a 1200 watt amp at 1 ohm is usually a 7-800 watt amp at 2 ohms and a 4-500 watt amp at 4 ohms..... In other words, power loss as you raise impedance isn't as bad as everyone makes it out to be...

It will probably sound better, last longer, be easier on your amp and smell better at 2 ohms anyway....

You don't need personal experience, it is almost meaningless.... It is like asking what is the best color of a car... Seriously, do your homework, design an efficent SPL box and go at it.... That is the best personal experience you will ever get...

I have made maybe a 100 or so orders with Mouser and Allied Electronics over the years... I have never had a problem.. Also real good luck with Michael Percy for high-end stuff and MECI for surplus caps, heatsinks and transformers....