Castles_Saloon

This forum has been great for getting tips about amp installation. Thanks!
Check out some pics of my install...
https://picasaweb.google.com/1159328...eat=directlink

Sounds pretty good so far, but have more tweaking to do and the new speakers aren't broken in yet.

I hope to do some frequency sweeps of the system and note the results.

Castles_Saloon

Some pics


Power Cable and fuse


Custom passive xover (12dB/oct @ 10kHz, Linkwitz riley filter). Splits custom mid/tweet speakers


Custom Auxillary input board (feeds MS-8). Choice of Ipod or 3.5mm input. Choice of charging Ipod. No added noise when charging (I didn't know that before the install, hence the switch)!!


Custom mid/tweet speakers for dash. Helps with vocals sound stage I think instead of door midwoofer trying to play vocals off axis.


MS-8 installed on trunk ceiling. Needed ~1.5 to 2" spacers to avoid bars. Added steel shield to protect the ms-8. Didn't want my 5 gallon water jugs falling into the processor.


Easy to hide glove box mounted display

fourthmeal

Try getting a center in there.

dykyy

Hey, install looks great, should sound amazing!

And can you tell me what your aux/ipod board is all about...

Castles_Saloon

I'll skip on the center. The soundstage impressively centers using the MS-8's calibration. But I can't move my head too much

MS-8 has 2 inputs, Head unit and AUX. The AUX board gives me multiple inputs to the MS-8's single AUX input. I wanted to be able to attach generic inputs using 3.5mm or 1/8" stereo plug or connect the line out of my Ipod. So there is a switch that routes the MS-8's AUX input to either the 3.5mm stereo jack or custom 5 pin DIN jack for the IPOD. I was concerned about potential noise if the IPOD was charging and playing so I added another switch to connect/disconnect USB +5V to 2 of the 5 pins of the DIN connector. After trying trying to play and charge, no noise, but I have the switch anyway. For the Ipod, I made a 5 pin cable with a 5 pin DIN plug on one end and a Ipod connector on the other end. Online provided the pinouts for Ipod connector and voila!

I figure with the 3.5mm input now I can do things like connect a laptop and play tunes or watch a movie. And soon I'll be using my laptop to do some frequency responses of the cabin, maybe before and after the MS-8's calibration

fourthmeal

exactly, the "center" of the illusory stage is limited without a true physical center channel, you are discovering the limitation and described it well.

Castles_Saloon

I must say adding the MIDs and Tweets above the dash I think helped quite a bit for staging, but figuring the xover point between the mid and woof I'm still tweaking. Right now I'm at 800Hz 12 dB/oct slope.

If others have experience with mid/woofer xover points and slopes, I'm curious what you have used?

BTW,
Tweets are Dayton ND16FA
http://www.parts-express.com/pe/show...number=275-025
Mids are Tang Band W2-748SG
http://www.parts-express.com/pe/show...number=264-861
Woofs are Dayton RS150-4
http://www.parts-express.com/pe/show...72&FTR=rs150-4

eggyhustles

You def need a center

fourthmeal

A few links to help, keep them around:

http://www.kodachrome.org/salt/sunderst.htm

http://www.independentrecording.net/...in_display.htm

So what you want to do is keep the vocals primarily in a single point-source, in this case the midrange drivers. Of course, you want to do this ONLY if the harmonic distortion and power handling limitations of the driver allow you to. This is why a 3-way speaker configuration is often chosen as the best compromise in car systems. This, and the nature of directivity in speakers for their size.

I'm looking at the plot of the midrange on the PDF of its specs, and I see that there is a droop in response after 900hz or so. Now nobody to my knowledge has done a distortion plot or anything, so we're going free form. Given the mere .75mm xmax throw I would start at 900hz and test from there. I would probably not go much lower than 600hz on a steep slope, at least at first.

The closest match to this driver I think I would own would be the Aura drivers on sale at Madisound.

Castles_Saloon

Thanks for links Fourthmeal... I like the interactive frequency chart!

My xover started at 600Hz, 12dB/oct, but it sounded like most of the volume was in upper end. Now its 800Hz, 12dB. I realize a 2" driver won't produce much acoustic power in the lower registers, but I wanted to lift the vocals up some more and figured more frequencies on the dash the better.

I used my "Loundspeaker cookbook" book to look up directivity of the driver vs frequency. A 6" is -3dB by 1.5-2kHz when off axis ~45 degrees which is close to angle of door speakers to my head. So I tried to limit its frequencies, but I suppose a 900Hz or 1kHz xover should be fine too.

I'll tweak a bit more and generate a frequency response. Then, of course, tweak some more. The results will of course be posted.

Why do you recommend the Aura drivers?

fourthmeal

the Aura drivers are on a huge sale at Madisound, only $12.50 ea for the 3" models. These have HUGE x-max and with a small tweeter and plenty of power, are great mids. Zaph at www.zaphaudio.com reviewed them and the plots look great, in fact he made a few projects with them successfully.

The main reason I suggest them more than what you used is the dollar to performance ratio. They ARE less efficient however, that's the trade-off for being such large excursion drivers.

I would also vote in the FR88 or FR89EX as a possible contender, OR since you're on axis you could even use the TB Bamboo 3" drivers, which while limited on xmax they are known to sound incredible.

Nothing wrong with your choice though, I'm just going through my "woulda" list.

Castles_Saloon

Thanks for the info! Yeah, I didn't research much info before selecting these drivers. I think there was 1 review at PartsExpress.com. I went for 2" drivers for space reasons, but have very little experience with mids. The gap between the dash and windshield doesn't allow for much. An my front baffle has less than 1" left. Perhaps next time or next car.

I don't use separate amps (ms-8's internal amps only) so losing efficiency could matter.

BTW, I have some Dayton RS52 mids for a home project whenever I decide to build some towers. Those should sound sweet...