Anyone know car speakers?

Shaun @ Tru6 · 02-29-2016, 06:13 PM

I recently put in an old Eclipse head unit and JL 400/4 amp in my car, a 94 E320. Then put in an old pair Eclipse 8251 speakers, nice little 4.5 inch speakers that were a little too big for the dash corners. The good news is the front speakers drive the active bass speakers in the doors and those ended up working very well actually. With some Boston Acoustic 5.25s in the back, it was an excellent system sounding better than the stereo in a 2015 Volvo S60 T5 I recently rented.

Anyway, needing smaller speakers for the dash, I got a pair of NOS Eclipse SP8944s. These have a built in crossover and are supposed to be the balls. Installed, they are very clear and clean, but are not as loud as either the original factory speakers or the 8251s. This lack of volume is enough that I'm not happy with them.

I put a voltmeter on the incoming + — terminals and got micro fluctuations as you would expect. Putting the leads on the crossover terminals flatlines the meter at 0.

Is that normal or should it also have microfluctuations per the music?

Not sure if the eBay seller will refund me, or give me another set, but he has been very nice and communicative so far and has 100% positive feedback with 1700 sales, so he seems like a good guy. Here's the original ad

New Eclipse SP8944 4" 2 Way Coaxial Speakers RARE NOS Vintage Point Source | eBay

Any thoughts on this?

Cajundaddy · Cajundaddy's Garage

Speakers have different efficiencies (loudness) and the smoothest response is often not as loud/watt as more average sounding speakers. If you can simply adjust the amp fader to balance your speakers front to back you may be very pleased with them. If not, get the rated efficiency of your current speakers and find some dash speakers that both fit and match the rest of your system.

I personally like Polk, Boston Acoustic, Focal, and Alpine brands but finding a good match for your system is often more important than buying the "bees knees". Crutchfield is a good resource.
Car speakers: what to look for

Shaun @ Tru6 · 02-29-2016, 06:52 PM

Doing some research, I think this will help in setting up the JL properly.

https://jlaudio.zendesk.com/hc/en-us/articles/204374120-Amplifier-Level-Setting-Guide

Gogar · 02-29-2016, 07:49 PM

My first thought was that maybe the 8251s have a lower impedance than the 8944s and so when you substituted the 8944s they don't seem as loud.

I had a hard time finding a spec sheet for either one that included impedance though.

maybe ask Brian (bell) he forgot more about that crap than the rest of pelican ever knew.

Shaun @ Tru6 · 03-01-2016, 03:15 AM

Thanks Jeremy, I was hoping that but all are 4 ohm.

scottmandue · 03-01-2016, 08:31 AM

Quote:

Originally Posted by Gogar

My first thought was that maybe the 8251s have a lower impedance than the 8944s and so when you substituted the 8944s they don't seem as loud.

I had a hard time finding a spec sheet for either one that included impedance though.

maybe ask Brian (bell) he forgot more about that crap than the rest of pelican ever knew.

Impedance IS important but there is also sensitivity (SPL?)

Shaun @ Tru6 · 03-01-2016, 10:24 AM

I turned up the sensitivity on the front speakers, plain Eclipses in there now, and it changed the system substantially. Clearly I have to follow the link above and the manual in setting the input sensitivity and gain on the amp. It's very possible the crossovered Eclipses need a lot more juice to come alive. Not sure.

What bothers me is on a gut level I think I should see micro voltage fluctuations on the crossover spades. That's now my #1 question.

aschen · 03-01-2016, 11:08 AM

Im not 1005 sure what you are asking. IT sounds like you are pushing on the cone and looking for some mv signal on the crossover inputs?

It dosnt sound weird to me to see 0 mv in this case. The crossover is filter network and its response will depend on how it is implemented and constructed. For example the inductor looks like a short at low frequencies and will have no voltage across it for low freq disturbances. Or that cap may act as a simple in series "bass blocker" and will not let any Voltage through until the frequency is near its cut of fpoint.

Gogar · 11:41 AM

My second thought was "put away the multimeter and turn up the volume knob."

If the speakers you bought had a lower sensitivity (dB @ 1W @ 1meter is usually how it's listed) than the older ones,

Then it would make sense that they would be a little quieter than the old ones.

This is the kind of "sensitivity" that scottmandue is talking about. How loud a noise a certain speaker makes given the same amount of power put into it.

"Sensitivity" on your JL setup is not the same thing, but if you set it up like in the instructions it'll be great. Set up the trim on the amp and then turn things DOWN to get the balance you want. If you turn UP the trim on the amp you might clip the input stage of the amp at higher volumes and it won't sound as good as it could.
have fun!

Shaun @ Tru6 · 03-01-2016, 02:24 PM

Quote:

Originally Posted by aschen

Im not 1005 sure what you are asking. IT sounds like you are pushing on the cone and looking for some mv signal on the crossover inputs?

It dosnt sound weird to me to see 0 mv in this case. The crossover is filter network and its response will depend on how it is implemented and constructed. For example the inductor looks like a short at low frequencies and will have no voltage across it for low freq disturbances. Or that cap may act as a simple in series "bass blocker" and will not let any Voltage through until the frequency is near its cut of fpoint.

This is good to know, thank you.

Shaun @ Tru6 · 03-01-2016, 02:30 PM

Quote:

Originally Posted by Gogar

My second thought was "put away the multimeter and turn up the volume knob."

If the speakers you bought had a lower sensitivity (dB @ 1W @ 1meter is usually how it's listed) than the older ones,

Then it would make sense that they would be a little quieter than the old ones.

This is the kind of "sensitivity" that scottmandue is talking about. How loud a noise a certain speaker makes given the same amount of power put into it.

"Sensitivity" on your JL setup is not the same thing, but if you set it up like in the instructions it'll be great. Set up the trim on the amp and then turn things DOWN to get the balance you want. If you turn UP the trim on the amp you might clip the input stage of the amp at higher volumes and it won't sound as good as it could.
have fun!

More excellent information, thanks. I'm pretty sure I can download a midrange 1K tone and play with it this weekend. I love learning about this stuff.

One note is by turning up the sensitivity on the amp, the active bass speakers in the doors were clipping while the dash speakers were clear and bright. It could just be the speakers in the doors are 22 years old and should be replaced with small subwoofers. I'd rather replace those than put in a 6 channel amp though some 6.5 midrange speakers in the bottom front of the doors or footwells would really help fill the cabin. I could then turn the dash and active bass speakers down and the midranges up/normal.

Gogar · 03-01-2016, 03:05 PM

Quote:

Originally Posted by Shaun @ Tru6

One note is by turning up the sensitivity on the amp, the active bass speakers in the doors were clipping while the dash speakers were clear and bright. It could just be the speakers in the doors are 22 years old and should be replaced with small subwoofers. I'd rather replace those than put in a 6 channel amp though some 6.5 midrange speakers in the bottom front of the doors or footwells would really help fill the cabin. I could then turn the dash and active bass speakers down and the midranges up/normal.

1. So when you say "Active Bass Speakers" do you mean that the bass speakers in the doors are self powered?

2. And it seems like earlier you said they get their signal from the dash speakers? Like . . . they accept the (speaker level) signal from the dash speakers and use it for their input?

3. If so, it makes sense that they are much louder now that you've turned up the dash speakers, right?

4. The factory dash speakers were probably matched to sound right with the door speakers so when you changed the dash speakers the balance was a little off.

5. Maybe those "active bass speakers" have a trim pot as well! Turn em down a tiny bit. If they don't you could put a resistor or potentiometer in-line at the bass-speaker input to turn it down.

scottmandue · 03-01-2016, 03:10 PM

Quote:

Originally Posted by Gogar

My second thought was "put away the multimeter and turn up the volume knob."

If the speakers you bought had a lower sensitivity (dB @ 1W @ 1meter is usually how it's listed) than the older ones,

Then it would make sense that they would be a little quieter than the old ones.

This is the kind of "sensitivity" that scottmandue is talking about. How loud a noise a certain speaker makes given the same amount of power put into it.

"Sensitivity" on your JL setup is not the same thing, but if you set it up like in the instructions it'll be great. Set up the trim on the amp and then turn things DOWN to get the balance you want. If you turn UP the trim on the amp you might clip the input stage of the amp at higher volumes and it won't sound as good as it could.
have fun!

Thanks for clearing that up for me. I am at work and my boss expects me to be productive and not answering questions on the internet.

well excuse me!

scottmandue · 03-01-2016, 03:14 PM

Quote:

Originally Posted by Shaun @ Tru6

What bothers me is on a gut level I think I should see micro voltage fluctuations on the crossover spades. That's now my #1 question.

You will need an O-scope if you want to see anything, Do you have any techy friends that might have one?

Shaun @ Tru6 · 03:24 PM

I honestly didn't research the active bass speaker system as much as I should have mostly because the door speakers worked, and worked well, after wiring in the amp. The bits and pieces I found on benzworld.org is that they driven off the front dash speakers but have a "black box" somewhere in the system. Here's the only wiring diagram I could find.

I didn't do any fancy wiring, just carefully clipped and connected the 4 channel amp like I only had front and rear speakers.

If I could easily find the bass speaker wiring, I would probably do what you said, but I don't think I'll be able to quickly/easily find them. I could post on benzworld about that and see what others have done.

Here's the only schematic I could find. If you can't read it, the bass door speakers are at the very bottom corners with the "black box" center bottom.

With the amp sensitivity turned down, the active bass added a lot. But with it turned up, it got ugly at high volume...think Evanescence Bring Me to Life...beautiful, clean, clear and bright voice but shuddering bass that wasn't right. Have to find a balance.

Shaun @ Tru6 · 03-01-2016, 03:22 PM

Quote:

Originally Posted by scottmandue

You will need an O-scope if you want to see anything, Do you have any techy friends that might have one?

I do, yes.

Shaun @ Tru6 · 03-01-2016, 03:29 PM

I will say this is great practice for putting a top of the line 2003 Eclipse head unit (no amp in it) with two A/D/S PH15s in the 928 with some old MB Quart system speakers I had in my old 84 Targa. The 928 has a 10 speaker system in it that I want to be crushing when it's done.

Gogar · 05:36 PM

From that diagram it looks to me like the Bass amp is driven from the speaker outputs right before the Front/Rear Fader, so that the bass stays on even though you fade from front to back.

If you can find that Bass amp maybe it has a trim pot on it.

Or just turn up the trim on your JL and see if you can get your ideal balance where the bass speaks and the dash ones start to sound like crap at the same time.

Is it this?

biosurfer1 · 03-01-2016, 07:27 PM

Seems like you are figuring it out, but man does this thread bring back memories of highschool. My friends and I were car stereo's 24/7.

What was really funny is how all those terms came back in my Circuits classes at college and how easy it was to pass once I linked the two...speakers (resistors), amps (amps/op amps), caps (capacitors), etc.

And my parents said all that stereo crap was a waste of time and money..sure showed them!

Shaun @ Tru6 · 03-02-2016, 03:58 AM

Just read through that thread, yes it is, thanks. Thread doesn't say where it's located but I can find it I'm sure, looks like the trunk. Something to add to the list this weekend, like finishing the powder coating oven. I wish I had time to pull the door panels off and put in new subwoofers, I think it would make a real difference.

I feel like I have the Turbo boost bug.

Quote:

Originally Posted by Gogar

From that diagram it looks to me like the Bass amp is driven from the speaker outputs right before the Front/Rear Fader, so that the bass stays on even though you fade from front to back.

If you can find that Bass amp maybe it has a trim pot on it.

Or just turn up the trim on your JL and see if you can get your ideal balance where the bass speaks and the dash ones start to sound like crap at the same time.

Is it this?