Looking to upgrade the JBL "premium" speakers...

"Just replacing the front tweeters" is very easy.

1. Purchase 1" dia tweeters.
2. Remove tweeter assy on the door by grasping it an pulling straight out. (be carefull with the metal clip. mine fell down into the door so I had to get a new one from the dealer $1.59)
3. Remove the old tweeter. (it just snaps in)
4. Fit the new tweeter into the housing. Most people (including me) get the new tweeter to fit securely into the housing by triming a bit of plastic from the housing.
5. Splice in the wires for the new tweeter.
6. Snap the tweeter housing back into your door.

I did one tweeter then listened to the differrence. It was amazing.

It took me about an hour to do both tweeters.

 

<div class='quotetop'>QUOTE(LeVautRien @ Jul 26 2004, 11:12 PM) [snapback]29133[/snapback]</div>

Bose are nice I love Bose Its in my home for the dvd player unit. My Durango has Alpine and they are fabulous! my prius has the regular sound and i was not happy with it either but I am taking my car over to the place my husbands work uses because he does quality work. I am very funny about getting anything done at best buy or circuit city or anythign like that becasue here where i live they hire anybody and being that my husband is a mechanic, he has seen what those places did to very very very high end cars and got the warranty voided by what was done. i was wanting to explore making my stereo sound a bit better too even though its not the premium system.

 

In my 07 Prius, I installed a 4-channel amp between the JBL amp and speakers. (It fits nicely on top of the JBL amp.) This has made a GIGANTIC difference in the sound even with the factory JBL speakers! I had to do a little messing around in handling the front bi-amp output of the JBL by combining the high and low signals through a resistor network. Also had to install a high-pass capacitor in series with the front tweeters to keep the low freqs from busting the domes. It took some time but, all-in-all, well worth it.

I plan to replace the JBL speakers with "more better" ones as my next step but the system really sounds pretty good now.

A "competent" auto stereo shop could do this work for someone not so audio savvy.

Dave

 

<div class='quotetop'>QUOTE(priusenvy @ Jul 5 2005, 03:47 AM) [snapback]104060[/snapback]</div>

Strange.... JBL is part of the Harman Group...
Infinity is also part of the Harman Group,
you may have replaced your speakers with nearly the same... as the different brands use to share parts from one another...

an example... HT component from Lexicon :

http://www.lexicon.com/image_library/MC12BHD_Front_lo.jpg

and professional audio processor from JBL

 

<div class='quotetop'>QUOTE(Tchou @ Sep 10 2007, 10:46 AM) [snapback]510132[/snapback]</div>

You don't know what you're talking about. Anyone who has pulled the stock speakers out of a Prius w/JBL audio system could tell you that they're complete junk and unlike any decent aftermarket speaker. Let's see, the stock mid-woofers have untreated paper cones, while the Infinity component sets have either polypropylene, fiberglass, or aluminum cones. Yeah, that's nearly the same.

 

<div class='quotetop'>QUOTE(banjoman @ Sep 3 2007, 01:27 AM) [snapback]506203[/snapback]</div>

I'm surprised I haven't seen more people doing this. I'm wondering: Does the 4-channel amp fit on top of the amp itself, or the box it's in, or did you remove the box? How did you attach the amp?

 

<div class='quotetop'>QUOTE(banjoman @ Sep 2 2007, 11:27 PM) [snapback]506203[/snapback]</div>

Can you tell me a bit more about the "resistor network". It sound like a nice DIY method without resorting to a JL Cleansweep.

Also, can you tell me which model of amp you purchased?

Thanks

 

<div class='quotetop'>QUOTE(banjoman @ Sep 2 2007, 11:27 PM) [snapback]506203[/snapback]</div>

Can you tell me a bit more about the "resistor network". It sound like a nice DIY method without resorting to a JL Cleansweep.

Also, can you tell me which model of amp you purchased?

Thanks

 

<div class='quotetop'>QUOTE(banjoman @ Sep 3 2007, 01:27 AM) [snapback]506203[/snapback]</div>

Some photos would be much appreciated.

 

<div class='quotetop'>QUOTE(Winston @ Sep 13 2007, 02:28 PM) [snapback]512149[/snapback]</div>

Sorry I've been away from PC for a while. I will update my post this weekend with pictures (maybe.) In short, I'm using a JL Audio 300/4 amp. With the plastic cover removed from the JBL amp, it just fits allowing the seat to move back & forth unobstructed.

I mounted the JL amp on the bracket that held the plastic cover. This required drilling (very carefully) holes in the JL bottom cover and finding just the right nut & bolt to hold it all together. There is probably an easier way to accomplish this--duct tape, wire, strapping tape, etc.--that wouldn't require drilling.

I'm still adjusting the values of the resistor network. Tonight I used a real-time analyzer with pink-noise to see how the frequency response is affected by it. I was surprised at how "un-flat" the JBL electronics are! There's a big (9dB) dip at 125 Hz. and that's without anything I added to the circuit. It's possible that this is to compensate for an acoustic boost added by the JBL speakers and the doors. I don't really know yet.

I have JL ZR speakers coming (hopefully this weekend) to go in the front doors. In the meantime, the JBL speakers are sounding pretty good. I used a 4.7mF capacitor in series with the tweeters since the JL amp is sending "full spectrum" audio to them. It's the same value as on the tweeters in the rear doors (that get full spectrum form the JBL amp.)

The power the JL amp adds is first noticed in increased bass. The JBL system just sounds too thin to be musical. The added amp really fixed this and the JBL speakers seem to handle it OK.

I'll keep you posted.

Dave

 

I will be looking forward to seeing a wiring diagram of your final "resistor network". I have new front component speakers with a nice external crossover so I wont need the capacitor to protect the tweeters. I just need info on your "resistor network" that you made to combine the high and low outputs from the JBL amp.

Also, that amp has an internal crossover, so why do you need the capacitor for the tweeters?

Thanks.

 

<div class='quotetop'>QUOTE(banjoman @ Sep 14 2007, 02:14 AM) [snapback]512399[/snapback]</div>

Thanks for all the good info. I have been wanting to know what the result of an RTA would be, and its not too surprising. the 125 Hz dip jibs with the stats. in this report:

http://www.tom-morrow-land.com/tests/priusaudio/

I just installed some a/d/s 346cs comps, alpine mrp f450 amp and an IDQ10 in my subaru and am getting ready to do our new 07 prius touring (jbl, but non-nav) I was thinking about putting an mrp f450 in-line w/ the stock jbl amp by using the hi-power inputs on the alpine. I've already got some a/d/s 246ix comps ($124 on ebay) to replacce the front tweets and woofers. I'll probably ditch the rear speakers and use that output for a sub.
Like many of us, I would rather avoid the cost/hassle of signal summing/sine sweeping first. So, what I don't get is how is your 300/4 getting a full signal? are you using the rear speaker inputs?

Thanks, Jonas.

 

<div class='quotetop'>QUOTE(JonasB @ Sep 14 2007, 05:32 PM) [snapback]512812[/snapback]</div>

Wow Jonas! You've saved me a lot of work trying to reinvent the wheel. The Tom Morrow link you gave is WAY better research than I'd ever do. My setup is pretty "seat-of-the-pants, trial & error" compared to Tom's. For instance, I didn't think to run curves at different JBL head unit volume levels.

To answer your question, I combined the high & low front outputs from the JBL amp using an "H" pad resistor network. This gave me "full bandwidth"?? into the JL front inputs set to "low" level. I took the JBL rear outputs direct to the JL rear inputs set to "high" level. Then tweaked the JL gains for best front-to-back level when the JBL head unit fader is set to center.

There's a good article at http://www.rane.com/pdf/note109.pdf on combining outputs using resistors. (This is from the Tom Morrow link.) My values were similar, but not exactly what's called out in the article--which are theoretically more accurate. (I tend to use whatever resistor values happen to be handy at the time.)

Sooooo after all that, I was in Wal-mart and found a cleaver box for converting speaker level to line level and it was only $18. What the heck, I got one and am now using it instead of the resistor network to mix the front high/low signals. The box is called a Scosche SLC4. It has transformer isolation AND individual level controls. So, now I go into this box with the front high/low JBL amp outputs and with "Y" connectors combine the outputs of the box into the JL amp front inputs. It seems to be working great and cost a lot less than the Clean Sweep units. Of course, it doesn't do anything about flattening out the system response like the Clean Sweep would do.

That is where I'm at at this moment. Still waiting for the JL speakers to arrive to complete my system.

Thanks again for the Morrow link. Everyone on this thread should read it.

Dave

 

<div class='quotetop'>QUOTE(banjoman @ Sep 14 2007, 11:06 PM) [snapback]512882[/snapback]</div>

What a GREAT find ! That might save me $500 or more. I was thinking of going all the way with the AudioControl DQL-8 and then an amp or two. But really, that was more than I wanted to spend and do.

Question: Might it make sense to run two of these SLC4s, one off the front speaker outputs to add an amp for the front speakers AND one off the rear speaker outputs to add an amp that could drive a subwoofer? I have very limited understanding of car audio so I hope my question makes sense.

By the way, I just took delivery of a brand new set of ZR 650s I got off Craigslist for $235 shipped!! Now I need to install and settle on how to amp them on my wife's 07' Prius with Navigation / JBL. I'm thinking about adding a JL 8" sub to the rear corner storage box on the driver's side (across from the battery).

Thanks for the info.

 

<div class='quotetop'>QUOTE(banjoman @ Sep 14 2007, 11:06 PM) [snapback]512882[/snapback]</div>

Thanks for the info on the LOC, and the article. I'm a little curious: the first thing that article mentions is to NEVER use a Y-adaptor to SUM signals! which sounds like what you are doing after the SLC4, no?

Also, I have looked into LOC's for a while and it seems passive ones like the scoshce and davidnavone LOC's all have a common problem: they kill the bass below 80 Hz. Read here:

http://tom-morrow-land.com/tests/navoneloc/

So, I have resorted to researching a good active LOC, and signal summing devise, such as the JL SSI. Man, it seems like its hard to win with this friggin JBL system in the Prius!

FYI: I get most of my info from caraudioforum.com. Lot so knowledgable people there!

Jonas.

 

<div class='quotetop'>QUOTE(JonasB @ Sep 15 2007, 10:48 AM) [snapback]513061[/snapback]</div>

Y cables should not be used to mix together two channels at speaker level. The passive LOC reduces the speaker level and raises the output impedance. Then, at this lower level, mixing the channels with Ys won't damage the JBL output transistors. The level loss is compensated for by the JL amp using its "low level" inputs for the mixed front channels and its "high level" inputs for the speaker-level rear channels.

The reason I got the LOC was because it was cheap and it has individual level controls on each input. I thought these might be handy as "equalizer" adjustments. The jury is still out on this. I need to spend some more time with the RTA. Interesting about the low end rolloff you mentioned. I'll have to find my old audio oscillator and AC volt meter to check this out. (Way back in the 70s, I was in the recording business and now, 30+ years later, that old test equipment we used for analog tape calibration will come in handy.)

Dave

 

<div class='quotetop'>QUOTE(banjoman @ Sep 15 2007, 09:25 PM) [snapback]513176[/snapback]</div>

Its quite possible the LOC your using does not have this problem. I would be curious to know. What I got from the review was that it seemed to be a common problem amoung passive LOC's.
Man, I wish I had an RTA to use sometimes.... I imagine it would take a lot of the guesswork out of it!

Jonas.

 

<div class='quotetop'>QUOTE(JonasB @ Sep 16 2007, 04:35 PM) [snapback]513425[/snapback]</div>

Take heart! An RTA is only a tool to get you somewhere in the ballpark or maybe just show where the ballpark is. Real pros I've worked with will always defer to their ears for deciding how something sounds no matter what test instruments say. There are so many variations in environments it's impossible to measure and correct them all. In reality a sound field that's plus or minus 10 dB (meaning that some frequencies could be 20 dB higher or lower than the rest) can sound pretty good to some people and even GREAT to others.

 

<div class='quotetop'>QUOTE(JonasB @ Sep 15 2007, 10:48 AM) [snapback]513061[/snapback]</div>

"Well, what did you do today little Davey?"

"Gosh, I hooked up my audio oscillator and AC volt meter to the Scosche SLC-4 LOC--you know, the one I got for $18 at Wal-Mart."

"Then what did you do?"

"Well, I set a reference level of 0 dBu at 1kHz. and then proceeded to plot out its frequency response using discrete audio frequencies."

"And what did you find?"

"Wait a minute! You think I'm just going to tell you the results for free? I suppose you want me to tell you the results of the same test I did on a JL Audio CL-SSI CleanSweep Signal Summing Interface too?

"Of course for free! We are all in this together here on PC, right? Trying to improve things for everyone."

"Well, putting it that way, I guess I could let you know the main points and what I will probably do now with my system. You see, there is a difference in sound between an $18 device and a $150 one. The more expensive one has better frequency response. In fact, I found virtually no roll-off at either the high or low ends--12Hz to 28kHz. It is flat as the world before Columbus--maybe flatter!

"But, the SLC-4 ain't too bad either considering it is a cheap passive device. It is pretty flat from 500Hz. on up to 16kHz. But you remember the test Tom Morrow did with another passive device that was 20dB. down at 20 Hz? The SLC-4 is much better than that. It's only down 6.3dB. at 20Hz! At 30Hz. it's -4.5dB, at 40Hz. -3.4, at 50Hz. -2.7, at 60Hz. -2.2, at 80Hz. -1.8, at 125Hz. -1.3, and at 250Hz. -0.5dB.

"Now, we don't have to worry about this roll-off stuff at all if we just used a few, non-frequency selective, plain old carbon resistors. In fact, I'm about to go back to my original idea of 1K ohm resistors in an "H" pad/mixer with a 20k ohm in the center to combine the front channels. I may adjust these values to "equalize" the high end if needed once my new JL ZR speakers arrive and I get everything in place.

"That's what I did today. Hope you had a good day too."

Dave

 

<div class='quotetop'>QUOTE(banjoman @ Sep 16 2007, 11:58 PM) [snapback]513541[/snapback]</div>

Good news! Thanks for the internal moral battle and the eventual philanthropic outcome. for $18, down 6.3 Hz at 20dB is very livable. I think I'll save the money of an active device.

Jonas.