Dash and rear speaker recommendations

[B-R-Z]

How do these JBL GTO328's sound. I searched a little and few said they were not quite worth upgrading over stock. I'd like to spend approx $50 per set of 3.5"s if possible.

[toast]

Originally Posted by B-R-Z

Using a Soundstream RUB4.500 4 channel amp (125x4 @ 2 ohm), I am considering JBL GTO328 in dash and rear, and maybe Infinity Reference 6032cf in doors. Can I run the door and dash speakers both off of the same channel? I will probably cross the front channel where it eliminates door vibrations. I have a sub in the trunk for bass.

Do I really even need the door speakers when I have a powerful sub in the trunk? My system/highs sound plenty loud with door speakers disconnected, even when my stock radio was being used. What do you guys think?

Most 10" subs start to sound like crap above 100 Hz and there is no way you are going to get any level of sound out of 4" speakers down to 100 Hz. The door speakers allow you to run the sub up to ~70 Hz, doors 70-600 Hz and the dash speakers the rest of the way up. Properly crossed over most speakers can handle a LOT more power than they are rated at.

I went with 7" drivers in the door and 2.5" full range in the dash crossed over at 800 Hz with only 6 dB crossovers to get a nice transition without phasing isssues. My 12" sub is in the trunk and takes over from 70 Hz.

[Chimera]

Originally Posted by toast

Most 10" subs start to sound like crap above 100 Hz and there is no way you are going to get any level of sound out of 4" speakers down to 100 Hz. The door speakers allow you to run the sub up to ~70 Hz, doors 70-600 Hz and the dash speakers the rest of the way up. Properly crossed over most speakers can handle a LOT more power than they are rated at.

I went with 7" drivers in the door and 2.5" full range in the dash crossed over at 800 Hz with only 6 dB crossovers to get a nice transition without phasing isssues. My 12" sub is in the trunk and takes over from 70 Hz.

did you make your own crossover?

[B-R-Z]

@toast, how much work is it to get 7" speakers to fit in doors? And am I able to pull off 4" speakers in the front dash and rear (if I choose to do rear)? Are you running rear speakers as well?

Since my amp is 4 channel, I am leaning towards powering the door and dash off of the amp, and maybe rears directly from HU. I just need to do serious sound deadening in doors. I already pulled out the window switches and put some electric tape between the switch box and bracket to prevent some rattling, I hope thats enough for that part of the rattling.

[toast]

You have to make adapters to run the 7" drivers. I simply traced the door speaker pattern on a sheet of 3/4" MDF then measured the opening needed for the new driver and cut that out of the sheet. Plasti-Dip the whole thing so that moisture doesn't eventually make it fall apart.

I'm not running rear speakers. Rather than writing out everything again, I put a post about my setup here: http://www.ft86club.com/forums/showthread.php?t=79172

Making a 6 dB crossover is trivial, it is just a capacitor inline with the small driver and an inductor inline with the large one. For convenience I grabbed a big sheet of breadboard from RadioShack and cut it to just barely fit the components. Soldered everything up and then dipped the whole thing in epoxy. Crossovers are mounted in the dash. I don't remember the values I used, but you can google '6db crossover' and get all you need there.

Honestly if your amp has a high-pass crossover like most do, just turn that on for your front channels. The doors really only make a racket when the drivers try and go lower than they should. If you cross them over above 70 Hz that will really minimize rattles. Not that I'm against sound deadening, I spent a weekend with the entire interior removed. Car is much quieter now.

[kberkel]

Originally Posted by B-R-Z

Do I really even need the door speakers when I have a powerful sub in the trunk? My system/highs sound plenty loud with door speakers disconnected, even when my stock radio was being used. What do you guys think?

Personally I'd neglect the rears. Powerful front stage with rear fill.

I wouldn't want only highs in front of me with the mid range behind me.

But if you like it, do it

[Chimera]

you don't really want to mix amped and non amped speakers. I did for a bit, the non amped ones will clip WAY before the amped ones and mess up your setup.

[B-R-Z]

Thanks @toast. Do you think using 7" woofers is worth the effort instead of just using 6.5" which requires no special adapter?

Dayton audio DCS165-4 6.5" looks nice if it'll fit, and can handle my amps output without breaking a sweat. I sadly don't see anything made by them in the 3.5"-4" size, 4 ohm, that can take 75 watts RMS for the dash. How much wiggle room do I have with sizing in the dash?

My amp has only one HPF which is used for all 4 channels. Will I be ok with it set to something like 70 for both the dash and door speakers, or do I need one with a higher cutoff frequency for dash speakers?

[Chimera]

Crossover matters for power handling, my infinity 3.5s are rated 25rms, 50 max. I'm powering at 45, and crossed over between 375hz and 2625hz

Originally Posted by B-R-Z

Thanks toast. Do you see using 7" woofers being worth the effort instead of just using 6.5" which requires no special adapter? Dayton audio DCS165-4 6.5" looks nice if it'll fit, and can handle my amps output. I just don't see anything in the 3.5" size, 4 ohm, that can take 75 watts rms.

My amp has only one hpf used for all 4 channels so I would need a separate crossover for fronts or doors.

[toast]

You are going to need an adapter no matter what, the stock speaker itself has a built in frame that spaces the driver out away from the door sheet metal.

I don't have any experience with anything other than the reference series. The 3" full range driver can easily handle your amplifier output provided you cross it over high enough. The setup I linked above is running 130 watts/channel. High pass from the amp at 12 dB/octave set to 70 Hz, then the 6 dB caps/coils to separate the door and dash speakers at 800 Hz.

If you have the extra two channels you can drive a pair of reference 4's for the rear provided you put a capacitor inline that will block the bass. I would put in the appropriate cap for a 200 Hz high pass.

[B-R-Z]

Originally Posted by toast

You are going to need an adapter no matter what, the stock speaker itself has a built in frame that spaces the driver out away from the door sheet metal.

I don't have any experience with anything other than the reference series. The 3" full range driver can easily handle your amplifier output provided you cross it over high enough. The setup I linked above is running 130 watts/channel. High pass from the amp at 12 dB/octave set to 70 Hz, then the 6 dB caps/coils to separate the door and dash speakers at 800 Hz.

If you have the extra two channels you can drive a pair of reference 4's for the rear provided you put a capacitor inline that will block the bass. I would put in the appropriate cap for a 200 Hz high pass.

Its a 4 channel amp, so would I run dash and doors from the same 2 channels? Or would I be better off running each speaker (total of 4) off of a separate channel? If I ran each on their own channel I would leave rears not used, or run directly from radio.

In either scenario, I would put the 6db cap/coils on the dash speakers since I do not want them running at the same freq/level as doors. If they can really handle that much power when crossed correctly, I prefer to go the 2-ohm/125 watt route. Does Dayton make a 3.5" and 6.5"/7" 2-ohm that you feel could handle 125 watts?

Thanks a lot for your response

[Chimera]

If you are crossing over use 2ch, if you are running full range, use 4. If you are thinking about crossing over there are several generic 2 way crossover options that give a 12 db rolloff.

[B-R-Z]

Originally Posted by Chimera

If you are crossing over use 2ch, if you are running full range, use 4. If you are thinking about crossing over there are several generic 2 way crossover options that give a 12 db rolloff.

Amp output options:
RMS Power 4Ω 75 x 4
RMS Power 2Ω 125 x 4
RMS Power 4Ω Bridged 250 x 2

So if I send 250 watts to each channel, will I be ok? Why not use all 4 channels to utilize the juice better? Sorry, I'm new to the dynamics of this stuff.

Here's the controls on the amp itself that I am working with:

[Chimera]

250 to speakers is a lot of juice. I think that's into the 'extreme performance' realm on Crutchfield for speakers. If I were you I would do front and rear channels, but then that's what I did, so I familiar with it. Still 250 is a lot to put to regular speakers.