[DT]

Thanks. I did a little measurements, and the Sundown really not all that mammoth (2" x ~9" x ~18"). It's at least very thin.

Do A/B class amps tend to get hotter or cooler, or is that independent of class and more just the specific vendor and construction?

Any insight into the components above? I know you're a big proponent of active setups, but I'm OK with passive for now.

ace123

If you do the sundown, you will have the option to go active on the amp with just a high pass filter on the midbass from your head unit. it's easy--just use the filters. that's it. you may also have significantly reduced signal loss if you go active vs passive as you are changing the preamplified signal (i think that's how it works--that's how i would design it) instead of the post-amplified signal. i've heard speculative numbers of 3dB difference, which is equal to doubling the power of the amplifier. but it's completely up to you.

the sundown is a bit thicker than 2" but less than 3 IIRC. (I have that amp.) I thought it was like 2.56" thick? it is large, but it's not terrible, that's for sure.

Class A/B amps will essentially always produce more heat than class D because they inherently use significantly more current and have significantly lower efficiency, but a good design will dissipate heat well, so it can be a non-issue. you can't throw it in between styrofoam insulation panels and call it a day though or it will roast. most heat problems are due to that kind of effect--miserable, insulated location--or more commonly IMO, running an amp at too low a load, ie running a 2 ohm stable amp at 1 or 1/2 ohm. i can explain that if you aren't familiar with it, but you won't have that issue with door speakers; subs are usually where people do that.

ace123

and compare the specs on the pdx vs the sundown. i think the S/N ratio was >90dB on the sundown vs 76dB on the pdx? don't quote me, check it out. that will tell you a lot.

alpine has a next gen pdx coming out that is supposed to narrow the gap in SQ, but the sundown will still beat it for quality, and that next gen amp will probably cost full retail price. and you're still stuck making the same trade-off.

Neutered Sputniks

I wrote a post up somewhere that explained the biggest issue with Class D amps as full-range amps. It has to do with switching frequencies (and their resonances). So regardless of what they do, there will always be more noise with a Class D amp over the full range than a Class A/B.

[DT]

OK!

Ordering the Knukoneptz kit in just a few minutes. I saw there was a kit that was like $7 more than the one I posted above, ($58 vs. $51) had one grade higher RCA cables, figured for that small amount, why not!

There were a couple of cheaper Knu kits, like around $40 but they were out of stock, and though I could probably have scored them through a vendor, figured the "top of the line" kit was still pretty reasonable.

I've been ruminating over the MBQuart 4125 as well. I didn't realize till just recently it's actually an A/B class amp too. Several folks have been highly complimentary about the MBQ amps. One guy did a full tear down and was extremely positive about the internal components.

I can buy the 4125 new, all day for ~$175 which seems like a heck of a deal. Here's the full specs:

Discus Series 4-Channel Class AB Car Amplifier
RMS Power Rating:
4 ohms: 125 watts x 4 chan.
2 ohms: 250 watts x 4 chan.
Bridged, 4 ohms: 500 watts x 2 chan.
PWM (Pulse Width Modulated) MOSFET power supply
Remote bass level input (remote level control sold separately)
LED power and protection indicators
Tuned Bass EQ (0-9 dB bass boost at 45 Hz)
Bridgeable operation
Soft start sound
Preamp RCA outputs
DC, short, thermal, and overload protection circuitry
Unbalanced RCA inputs
Switchable 2-channel/4-channel input modes
Damping Factor: >180
Variable input level control: 0.2V-0.6V
Variable high-pass filter (10-1200 Hz, 24 dB/octave)
Variable low-pass filter (30-150 Hz, 24 dB/octave)
Frequency response: 10-20000 Hz
Dimensions: 15.75"L x 9.45"W x 2.7H

I'm also just about sold on the Hertz HSK 165. I saw a guy who had a component "want list" and it's basically the exact same as mine. Seem like a great solution for the price (can be picked up for $200 new).

ace123

I don't have experience with either, but the spec sheet looks fine on the MB amp at least. I found the same thing as you on the Hertz speakers--the HSKs generally get very good reviews for the price range they compete in. It sounds like one of many decent ways to get the S2000's stereo sounding good.

Also, my headunit has auto-EQ and TA, and while the woofers have a very flat response in controlled environments, the S2000 as an environment really seems to screw things up. The EQ makes a lot more difference than the level of compensation the woofer itself would/should need based on the specs--it does a lot of compensation for the car's poor acoustics. The point being, if I were you, I would give Imprint a very serious look. Check out the threads on the subject--our car acoustics are all over the map. It should make a big improvement.

Anyways, let us know how you like it!

[DT]

Thanks! I was sitting downstairs last night and told the wife I had to run these options past my car audio consultant from the S2000 board

I ordered the Knu wire set (the K44 with the slightly better SS RCA). I might be able to start with some initial wiring this weekend, figured I'd start with the power and review the couple of recent install threads.

I'm kind of on the fence about a 4125 vs. a Sundown 100.4. There's been a few lightly used Sundowns recently, about $100 more than a new 4125. Not sure I'm going to get much more out of the Sundown, even if it is "better", but at the same time - like the wiring - we're not talking about a massive difference in the grand scheme of things.

I saw SSA is doing a special on their 10" DCon which is supposed to really be geared toward my application (ultra clean, small enclosure, 300W):

http://www.soundsolutionsaudio.com/store/p...%7B47%7DS4.html

Neutered Sputniks

I would go with the Sundown.

Sundown is geared purely for SQ, MBQ is geared to sell to kids who don't know better


SI is taking pre-orders on the new BM. $175+shipping till the end of this month (scheduled to ship mid to late Feb). 12", 400W, .5cu ft enclosure (yes, that's right, .5cu ft) and you won't be able to match the SQ with anything with similar specs.

[DT]

Thanks for the continuing great input.

I saw your post about the SI - I was floored with the amazingly shallow depth for a 12" sub.

Space conservation is still high on my list of priorities. With the small mounting requirements, does that let the SI sit somewhere out of the way?

Neutered Sputniks

I'm waiting to get my BM...once I have it, I'll be designing a fiberglass enclosure to put the sub where the spare tire usually mounts - That gives you the ability to hide it with the carpet, have a 12" sub, while not losing any real trunk space