Look, when I installed my first Amp (over a decade ago now), my friend who was helping me informed me of these two rules:

1) It will never, ever, work right the first time you turn it on. Never. Not even that one time.

2) There will be blood.


To this day, even after all the installs and changes I've made...I find these still hold true...


Ace, you're running passive?

 

I've proven those every time I touched anything! I just try to make sure the mistakes don't break anything expensive and get worked out rather quickly. Or at least understood rather quickly and worked out on a prioritized basis...

I'm running active. Right now it's all done at the head unit. It runs a 3-way active setup (tweeter, mid, sub) with selectable -6/-12/-18/-24dB/octave slopes at quite a few points; the points are at about 1/3rd octave steps apart. People at DIYMA have generally come to the consensus that this set sounds the best crossed over around 3kHz. My HU can do 2.5, 3.15, and 4kHz points, so I just set both at 3.15kHz@-12dB/octave and figure I'll change it up some over the next few days after I get used to the sound. (Honestly, with the analog crossovers on the SAX-100.4, I'm not sure if I could get it any closer than 1/3rd octave from where I think they are.) The midbasses are at -12dB/octave@80Hz, and it goes up to 100Hz for some tracks when I want it loud or it can get a little muddy. I'll have to eventually add a sub to fix that.

I might let the amp do the work after I play with the crossover points enough to decide what I like, but getting the HU set up with crossover points and a rough (auto-EQ and TA) tune took about 10 minutes, and it takes about 3 seconds to change crossover points to whatever I want to try. For tuning, you can't beat that for flexibility and ease IMO. I really like this HU for that reason.

Also, a lot of people at diyma bought this 720prs set for the midbass only and dumped the tweeter. I figured if after I've had it a while I decide I don't like the tweeter, I'll deal with it until I see a great $600 pair at a fire sale price. Then I can eventually do the same for the woofer, but I'll probably get a sub before either one, and I might get a flashpro or exhaust parts before that... decisions decisions...

 

Trust me, upgrade to the SEAS tweeters on Madisound.com.

$70 for the pair, shipped. And they'll blow away most tweeters in $600+ sets.

What's your HP for the tweeters, LP for the woofers set at?



ETA: If you're up for fiberglassing, the ScanSpeak 5 1/2" Revelators are $220/ea from Madisound...so for $500 or so, you could have an amazing sound system.

 

[QUOTE=Neutered Sputniks,Jan 13 2010, 01:35 PM] Trust me, upgrade to the SEAS tweeters on Madisound.com.

$70 for the pair, shipped.

 

1st, I would turn off the xovers on your SAX. No need for 2 xovers...

Here's what I have my xover points set at (with no clipping, no distortion at max power/volume - to show why you should go with the SEAS tweets/ScanSpeak Revs/SI sub):

LP (sub): 100Hz/-12dB (500W on a 12!)
HP (mids): 100Hz/-6dB (on 5 1/2's!)
LP (mids): 3.15Khz/-12dB
HP (tweets): 2.5Khz (on tweeters!)

I could run the LP on the Revs a bit higher, but there's no real reason to do so.

 

Oh, they certainly are off! That's what I meant when I said it was all run by the headunit. No sense adding slopes to slopes, at least without thinking about it. But the thought of adding a -6dB@100Hz LPF to a -12dB@40-50Hz (for 18dB@40-50Hz) to the mids has crossed my mind, and I might experiment with that later...

But it totally depends on the source--I'm finding that I can play Chevelle about 10dB louder than Muse with the crossover at -12dB and 80Hz. On Muse I have to bring it up to 100Hz before really letting the speakers rip. Of course, I'm talking deafening volumes. The speakers perform beautifully at normal volumes. I'll need to exercise a little self control or I'll start to endanger my hearing. The mids really have great control and precision, which I really appreciate.

100Hz/-6dB on 5 1/2 mids!! That's good! Obviously it depends on the music and volume, but I certainly wouldn't be able to set mine there if the speakers lost an inch of diameter. Those are impressive!

The pio tweets are set by the passives at 2kHz, but the frequency response isn't as clean as even the cheaper seas tweeters. Most that switch to the entry ones though say the great off-axis response and other characteristics of the pio tweets offset some for their flaws, so it sounds like it might not be worth upgrading unless I step up to the nicer set. Then again, the neos are so cheap it might be worth it just to try.

And I just moved the tweeter up to 4kHz, leaving the mids HPF at 3.15kHz. Having a ~1/3rd octave step sounds better with the -12dB slope--it makes perfect sense mathematically. But at high volumes, the tweeters can still get a little screamy with rock... hmm... I really do like these woofers though.

 

How's the system? Bump for update

 

Well, no progress at all, but I can at least say what I do and don't like about it.

I work full time while going to grad school, and I'm only taking one class this semester. I started documenting my time spent, and it's been taking around 20-25 hours per week. It's the same for all my classmates--this teacher is a work nazi. I was taking two classes last semester and had less to do. We're aiming to buy a house sometime from July to December, and I reduced the courseload so I would have time to do research--and I haven't even caught up enough to wrap this project up from Christmas break! I still don't even have half the bolts in the doors or the amp mounted down...

On the install, I've noticed that the driver's side tweeter is a bit too far back with the spacers I used--it should be about 1/8" to 1/4" shorter than I did it. The door panel bulges a bit. Not a good thing, but it's not going to hurt anything either; I'll fix it as one of the first things when I finally get some more time. The passenger side has plenty of clearance.

I've still got a ton of work to do to finish it. But I can at least give a short term audio review.

SYSTEM REVIEW

The sound is really great. I love it. It's worth the time, effort and money if you appreciate good music and have a commute. In total, I spend about an hour to an hour and a half driving every day, so I really get some benefit out of it. My wife, who has untrained ears, says it sounds different from a typical stereo in the way she would expect a recording studio to sound different.

But the things I really LOVE about it are how loud and CLEAR everything is.

IMO, a good equalizer--certainly not just 3 or 5 bands--is a must with this level of investment. It settles things out just a little better, but an audible, perceptible little bit better. Time alignment is nice too-similar in effect.

HEAD UNIT

I really like this head unit. The auto time alignment and auto EQ are really great--6 minutes and your system sounds pretty close to dialed in. Then to get it fine tuned to your ears and tastes, all the adjustments are right there, quick, easy, intuitive, and digital--meaning I'm not guessing 80Hz is somewhere between 20Hz and 200Hz like on the amp--I pick 80. Then I switch it to 63 or 100 and see if it's any different. And it is. And I amplify or attenuate any frequency to dial it in--1dB increments, ~1/3rd octave resolution, which is right on the threshold of what I can actually use vs what I want to believe I can use and get real benefit from. I REALLY like this headunit. For those that want all the tech features though, it's somewhat minimalist except for audio controls. Perfect for me, but not if you want the most seamless and easy bluetooth, iPod support, etc etc. And I really wish it supported lossless compression. Otherwise, it's a really great head unit. It provides a lot of control, good clean signal, low noise, IMO it's nice looking, and it's easy to use and get the most out of.

And with the HU, amp, and etc, there's not a lot of static noise, which was important to me.

AMP
- very little review due to an issue

The amp is very good. It provides a lot of very clean power and is very low priced considering the specs and sound. It has somewhat more power than I use--not a ton, but I have some headroom--which is exactly how it should be IMO.

I've got a bugger of a transient issue though and haven't figured out if it's the amp--I'm pretty sure it is. The issue: About one time in 20, I get nothing but noisy Nintendo-esque sound when I turn it on. Remastering the track to the Nintendo console's sound is really the best way to decribe it. I just turn everything off, wait about 5-10 seconds, and then turn it on again and it's fine and back to normal. But I absolutely hate issues like that. Also, during the brief moment when the HU is sending music and the amp is still powering on, I hear garbage signal for a moment as the amp is powering up--the same kind of Nintendo garbage--so I wonder if / suspect the problem is a power/ground to the amp issue. I suspect the ground is the problem since I still have an alternator whine that I haven't fixed, among all the other unfinished install issues.

Once I fix that I hope/suspect this issue will be gone too, but I don't know for sure. If it weren't for that flaw, I'd be shouting on the rooftops to buy this amp. It really sounds great. Lots of clean power for a low price, and it does have plenty of warranty time if it's actually a defect. But I want to figure this out.

SPEAKERS

These speakers really make vocals, acoustic tracks and jazz sound haunting. They often make the hair on the back of my neck stand up. I now filter music a lot by recording quality. If they use poor quality synthetic sounds, I can hear the difference--all the harmonics are gone, and it sounds much poorer with these speakers becuase they are accurate enough to communicate it. I can see how they could be better (esp the tweeters), but these are really pretty damn good. For the money, they're great. I also see why people say the speakers are the most subjective part of the system and arguably the most important. I agree. They color the sound more than anything else. I love how punchy they can sound, not just bass, but in every frequency. Very accurate, clear, and crisp without being harsh--except the tweeter. The tweeter is too loud at ~3-4kHz and can get a bit screamy in that range when pushed hard with rock music, so I can't just attenuate it once for all volumes and music types and then always be happy. And the tweeter sounds excellent with acoustic tracks, female vocals, jazz, etc. It's just poorly suited for rock--particularly distorted guitar. It sounds funny to say, but I'm amazed at how clearly distorted guitar and other distorted sounds are represented too--I can tell I've been used to inaccurate speakers. And then when they switch the distortion off and keep playing, when they play a drum solo, if the band uses a brass instrument, etc., the speakers really shine.

The thing I'm most surpised about: I can say I've never heard 6.5"s that can produce quite as much bass volume as these do. But it's clearly less than a mid-range single 10" sub with a decent amp. It's about what I would expect out of a good pair of 6x9s with the same power. And I must add that I've never listened to significantly higher end speakers, so I'm sure there are plenty better out there. But I don't miss a sub as much as I expected. It WOULD sound better with one in the system. Probably a lot better. And if I listened to much rap/hip-hop, I would need one, no question. But I don't hate that I don't have a sub, which surprises me. And when I get one I'm sure I'll love the range and be disappointed with the slop--larger subs are usually somewhat sloppy with extremely fast, puncy beats, and these speakers really sound like the drums are supposed to sound--very composed and responsive.

CROSSOVERS / SETTINGS

I still haven't figured out where I like the crossover slopes the best. One minus of these speakers: This set needs some attenuation in the ~3-4kHz area to play rock well or it sounds like grinding nails in my ears when the band beats on guitars with the distortion up. At the moment I'm getting the attenuation through crossovers, using a 12dB HPF@3kHz and a 12dB LPF@5kHz, but I'm not sure I'll keep it there. I think a 1/3rd octave step might sound better; that's what I've had it (plus attenuation at the ~3-5kHz zone) at for most of the time. The auto-EQ doesn't seem to compensate for nonlinearity when the volume is boosted beyond the EQ's test volume, and that's what I'm fighting. And it probably sounds better without any attenuation for more natural tracks, so it's not as bad as I make it sound. It's just not perfect with one setting for all genres.

On the LPF, I change it up depending on the track. I use at least a -12dB@80Hz crossover, but there's a big caveat: the auto-EQ on my head unit boosted the low end of the range to compensate for the natural falloff of the frequency response of the speakers. So I'm cutting ONLY 12dB/octave vs what a subwoofer would play, not -12dB/octave superimposed atop the -6dB/octave at 100 120 or 150Hz that the 6.5s have through their natural response. So it's a considerably more aggressive setting than it sounds like, and I often change it to a) -18dB@80Hz, b) -12dB@100Hz, or c) -6dB@125Hz. What sounds best depends a lot on the genre and track content--option c) sometimes sounds the best by a margin and other times it sounds terrible. And if I cut the volume in half (set the volume to half, so like 20dB down), I can play most music with no filter and have no distortion. What I may eventually settle on doing is set the Sundown to ~80Hz (-12dB) and then sometimes superimpose -6dB at whatever frequency I want for that music using the headunit.

Or I might just break down and get a sub...
I just don't want to spend more money, and I hate the idea of having a big chunky heavy sub in the car all the time! This one big amp is enough!

 

Well, after finally getting sick of having the amp wedged between tools to keep it from sliding around, I bolted it down. I was planning to make an MDF sandwich for it and carpet the top, but at Lowe's I felt how heavy the MDF was and decided I would rather not have it in my trunk. Instead I took an easier route and drilled holes in the spare tire piece. I bolted the amp with 4x #8 zinc bolts using nylon washers to keep from scratching the amp. (Zinc was used as it is unlikely to galvanically corrode with aluminum.) The bolts do penetrate through the bottom and are probably scraping up the foam. I don't care much about that, so no big deal there. It accomplishes my goal: I can move the amp out of the way if I have a flat tire and need to use the well.



Since all I had done was bolted it down, I had some time to spare. I decided to attack two of the other problems I had left unaddressed: The tweeter fitment and coating the MDF spacers. Actually, it was really just one problem I was addressing: I refused to put all the bolts back into the door until, at a minimum, the tweeter fit and the spacers were done so my door panels would fit correctly and I could leave them alone for a few months without thinking twice about it.

I still might cut up the factory tweeter covers and apply an acoustic coating to let the sound through better--I am confident that will sound better--but for now I don't want my door frame getting scratched up any more. Also, I might add the dynamat I bought to the doors in some quantity--maybe reduced, maybe not. But here are the speakers getting sprayed with black epoxy. They look poor but do their job. Keep in mind I'm an engineer, so I know all the theory on how to do these things, but that doesn't mean I can so much as turn a wrench.



Next, all I had to do to get the tweeter to fit correctly in the driver's side door was to trim the mount. It was quick and easy. I wish I had realized this earlier. If you follow my install for tweeters, do this first and everything will fit correctly.



And on the sound, it sounds very good excepting the fact that I can hear but not feel bass. The addition of a subwoofer really adds a dimension when you feel the sound. I will probably add one in the fall/winter, but we'll see. My original goal was just to hear music on the freeway, not build a great stereo, and I hate the idea of adding any significant weight to the car. The weight of the amplifier still kind of bothers me, but it sounds so good I'm willing to deal with it. I just kept letting myself improve it more and more... and I really like it.

The ground issue is still not solved, and I'll post when I get it worked correctly. My amplifier issue--nintendo sound--is due to low voltage somewhere. It happens consistently when the car is not running but never when the alternator is going. I'm not sure if I'll fix the spring on the center console cupholder. I tried, but it's a PITA and wasn't intuitive to me. If I find a DIY and it's not a long repair I'll do it, but until then...

On sound:
I love the HU and amp. I would recommend them to anyone. I have extremely low noise, and the reproduction per dollar spent is really excellent.

I really enjoy the speaker set. Here are the cons and pros:
The speaker set has a nonlinear peak around the 2-5kHz zone and requires additional attenuation when played at high volumes. I have it equalized correctly for moderate volumes but I have to superimpose 1-3dB of attenuation on the frequencies in that region when I turn it up. That is also my crossover point, and swapping tweeters for a better set might be all it takes to fix this. People give mixed reviews on rock music on this set of speakers; IMO that is a large part of why--you must attenuate the guitars a little when you turn it up, but it sounds better without the attenuation when the volume is low.
The bass response of these 6.5s is the best I've ever heard--though I haven't heard higher end speakers--and they really sound great on vocals. I love listenting to stringed and brass instruments, drums, and anything else with a lot of natural frequencies that can be illuminated. It's wonderful having a good set of quality speakers. Most everything I listen to in everyday life sounds vastly inferior to my car. So while I'm sure there are contenders for a better set, this one is very good, and it's also quite inexpensive. I will probably try the scanspeak revealators or the SEAS speakers at the ~$200/speaker price point if I decide to upgrade, but the full set would cost a little over double what I spent.

Again, to help the sound of these speakers I have an auto-EQ flattening the frequency response (and time alignment). The frequency response is good uncorrected, but it sounds noticeably better after equalization. Some of that is due to compensation for the terrible acoustics of our cars.

 

did you wire the amp to the headrest tweeters as well or is the hu powering those?