Ohm/watt ratings for stock speakers/head unit

[swarb]

I know ideally that I should match drivers to amps and to a decent headunit. But at this point I am trying to keep a low budget and go for bang for the buck with a small amount of head room later if/when I add amps/headunit/small sub.

So the question is, What is the best bang for the buck upgrade from stock? Or what are weaknesses on the stock setup?

[Chimera]

TBH, it appears as if the absolute best bang for your buck is a OEM+ solution. starts at 1100+ or so but according to reviews what you get you could not replicate on mix match parts at that price. I have never heard one myself, yet.. anyways.. but their reviews are outstanding across the board.

edit: PS if I were in the market again for cheap and simple the OEM+ guys have profiles for a few pioneer HU, i'd prob do a supported pioneer unit and their system.

[babydriver]

Originally Posted by cjd

Not necessarily, though exactly what is the baseline which is expanded might be questioned. You can do some funky things with proper phase mixing, and that can be post-processed. Placement is absolutely a part of the equation though.

I agree, but then we are talking about using out of phase signals to create the illusion of multichannel audio. A lot of fake AV surround sound bars do this and it isn't really multichannel surround sound. You could do the same thing by wiring your stereo loudspeakers out of phase with each other and adding a mono signal center channel. Same thing applies to the speakers at the front of the car; left and right speakers wired out of phase with each other and a center channel mono that sums the output of the two stereo channels. Add two out of phase speakers on the back and VOILA! -- fake quadrophonic surround sound.

The only way to get true multichannel sound is to have discrete channels, separate amps, and dedicated speakers for each channel in the surround matrix. Anything else is pseudo multichannel.

[babydriver]

Is there a factory installed power amplifier, or is it in the head unit? If so, where is it located?

[swarb]

^It is in the spare tire well.

Anyone have any recommendations for bang for the buck upgrade, say 300? I might just get some speakers and plan for an amp/hu later.

[babydriver]

Originally Posted by swarb

Anyone have any recommendations for bang for the buck upgrade, say 300? I might just get some speakers and plan for an amp/hu later.

These people have a lot of choices available at reasonable prices:

http://www.parts-express.com/cat/car-audio/7

Go for a higher power handling capacity and higher efficiency if possible. That way when you upgrade the hu or amp, you'll still be able to use the same speakers.

[cjd]

Originally Posted by swarb

I don't understand what you are trying to explain, can you word it a little more simple? Are you trying to say I am more likely to burn out a driver underpowered than an overpowered driver?

This exactly. You can always stop cranking the volume up if you hear the driver starting to complain (if it's thermal limits this can be really hard to hear over road noise in a car, mind...) I've destroyed drivers at an estimated 20W that had previously taken an estimated 35W on a significantly better amplifier (rated 200W@8ohm) - that 20W was peak output - probably 10% distortion or higher. Completely unlistenable, but also more damaging to the components too.

I have 1kW monoblocks on 90dB/2.83v speakers in one of my rooms - they'r a difficult speaker, so the overkill is partially due to the stability inherent in this particular amp, but... On an average day I don't even run 1/4W of that output.

You have to double power to gain 3dB.

93dB drivers (1W) will be at 96dB for 2W, 99dB for 4W, 102dB for 8W, 105dB for 16W - and we're probably at the RMS limit of the amp we're also well into hearing damage territory for any length of time. This is the reason subs often have huuuuge amps - to get low extension, you ultimately give up something - and the typical compromise nets lower sensitivity. 87dB sensitive speakers require 64W to reach that same 105dB...

On an unrelated note, PE has some great stuff - and some meh stuff. I've done tons of work with their house brand (Dayton) Reference series drivers - superb. I really like the neo magnet ND series as well - haven't worked with the new Esoterics but will. And they have some good non-house brand stuff too, along with some affordable crap. If anyone in Chicago feels inclined to try a 100% custom build, I'm game. I'll be doing my own car soon, and I think I have another custom HT commission coming up soon but... well, it's nice getting to play with others' money here and there.

And on an additional unrelated note, but since we were talking about how phase can do interesting thigns - I get about a 170 degree sound field out of my most recent speaker design with them actually being placed at about 70 degrees and 3M in front of me. It has to be in the mix, of course, but listening to some of the old Living Music stuff in stereo presents just about as precisely on this setup as it does with the 3 discreet channels working.

You guys probably realize by now this is another of my hobbies...

[babydriver]

You can fry the voice coil with too much power or you can drive it out of its gap (again, too much power.) If the amp can't deliver the current to fry the voice coil, the signal may sound like nails on a black board but thermal overload isn't going to happen. Note that I didn't say undistorted signal output; there are plenty of amps out there that will unload a lot of current before the output transistors fry at very high distortion levels. Those amps will cook a voice coil.

If you have a higher powered amp driving a lower powered speaker, then you have to be VERY careful not to play it too loud or either the voice coil will die or mechanical failure will occur. If catastrophic failure can be avoided, it will on average sound cleaner than a low powered amp.

You don't need a lot of power if the speakers are efficient. I have a 15 watt/channel stereo vacuum tube amp driving a pair of Thiel CS 1.2's in a small listening room. Sounds great and fills the room with as much volume as I need. YMMV.

I have never popped a tweeter coil with the tube amp, even driving it hard. It did happen once with a 100 W solid state amp, not pushing it all that hard (this was on a ScanSpeak 9500 tweeter, not on the Thiels). So which is better?

[babydriver]

Originally Posted by cjd

This exactly. You can always stop cranking the volume up if you hear the driver starting to complain (if it's thermal limits this can be really hard to hear over road noise in a car, mind...) I've destroyed drivers at an estimated 20W that had previously taken an estimated 35W on a significantly better amplifier (rated 200W@8ohm) - that 20W was peak output - probably 10% distortion or higher.

In that situation I would guess that the tweeter was the driver that blew. They typically have lower power handling than the mid/woofer and are usually more efficient. If you clip a power amp hard, then I'm sure you know that most of the distortion that is dangerous to the speaker is high frequency. The woofer should have no trouble absorbing the thermal load.

One advantage of a bigger amp (assuming you can keep the volume under control) is that the damping factor is usually higher. The amp keeps a tighter grip on the woofer so you get lower harmonic distortion. I use an old Phase Linear 400 for my subwoofer, running in conjunction with the 15 watt tube amp. This takes most of the load off the mid/woofer in the Thiels. The PL sounds like crap in the higher frequencies, but its sheer power is exactly what the doctor ordered for the low frequencies of the sub.

The exact same principle applies to car speakers. If you have a sub, it can be used to take the worst excursion load off the other, smaller speakers. This results in lower excursion and lower distortion; thus, better sound.

[cjd]

Originally Posted by babydriver

In that situation I would guess that the tweeter was the driver that blew.

Hah. No, it was a 4" (cheap buyout I was sacrificing to demonstrate why cheap amps just don't cut it...)

Funny you mention damping factor - I had the opportunity to play through a series of amps, same tracks, same speakers with a group of locals. Some amps just had no bass extension, but still had issues. Some amps had bass extension and issues. And, of course, the big Class A/B had no issues at all. Lorde "Royals" was the test track, pushed to the point where the woofers were starting to make noise. Aside from things like the cheap T-amps just lacking extension AND authority, damping factor (and power supply stability) were clearly audible as distortion - to the point of causing the woofers to hit their excursion limits at lower output levels on the cheaper amps!

Hobbies can be dangerous.

[Etoine Schrdlu]

I know this is 5 years late, but did anyone answer ANY of your questions? My answers only apply to a 2015 BRZ. I replaced my speakers and had the same questions. I too searched the forums in vain for answers and found no answers (only advice to rip everything out and start all over!)
Q1: the stock door woofers are 2 Ohms. The dash and rear seat panel mid-ranges are 4 Ohm and so is the dash tweeter.
Q2: I found a wiring diagram. Google: BRZ (G4400BE) Pages 316 thru 324 tell you all you need. The rear panel speakers wire directly into the head unit. The front channel wires go into a "junction connector" where they split. One set goes to the dash speakers and the other set heads into the trunk to an amplifier for the door Woofers.
Q3: Channel wattage is a guess. The Subaru brochure says its an 8 channel, 196 Watt system. Certainly a generous 196 Watts peak and who knows how that wattage could be divided between the 8 speakers. The head unit is a Fujitsu Ten and i've found no specs for it. I figure it has typical OEM head unit wattage: 10 to 15 W RMS. Considering the 2 Ohm door Woofers I am guessing the amp is about 25 W RMS. Not big numbers but considering how small the interior is you really don't need much.
Q4: Signal for the door woofer amp is from the "junction connector" on page 322. Stock amp is door woofers only.
Q5: Yes, there are. I found this out by guess / trial and error when installing my replacement speakers. I used 2 pairs of Infinity Reference REF-3032cfx (4 Ohm) to replace the dash and rears and I used the woofers from a set of Polk Audio MM 6502 (also 4 Ohm). Obviously the amp has a low pass filter for the door speakers, so the 6.5" Polk woofers were a direct install. The stock speakers in the dash had high pass caps on the tweeters (that I tossed - Jumper the Siamesed mid/tweeter connector!) but I used the capacitors Infinity supplied with the new "full range" speakers and they sounded great. BTW the stock "mid range" on the dash and the back panel speaker are the exactly the same but screw onto different mounting brackets. (yes, fabricated a few brackets on this install. A 3d printer helps) Because it worked so well on the dash I used the supplied capacitors on the back panel as well, but they were talking to the mosquitoes so I took them off. There must be a high pass built into the harness or head unit somewhere.
The original speakers made me set the equalizer all over the place to get decent tone, but the new speakers only needed a fairly conventional EQ curve to get decent bass, mid-range, and highs. Notice that I selected extremely high efficiency speakers for all placements. Yes, replacing the 2 Ohm door woofers with 4 Ohm models worried me at first, but I have had no problems in the 2 years since installing them.