New Frontstage-SEAS/Peerless?

solacedagony · Post by **solacedagony** » Tue Aug 01, 2006 6:16 am

I just got an Eclipse 8454 off a guy on DIYMA, so I'm going to be running active. I decided on the SEAS 27AFNC/G tweeters and I'm pretty sure a Peerless Exclusive 7" (was also considering the Seas CA18RNXs). I did, however, notice on the Madisound site that they have recommended enclosure sizes on the bottom of the page. Should these mids be enclosed or is it alright if I just put them in my door? I'm going to be running both off either an Arc 4150 or a JL 450/4.

Another question I had was about the impedance of the drivers. The tweeters are 4 ohm and the mids are 8 ohm. Am I going to run into level problems from the difference in power?

Any suggestions on installation, aiming, and anything else is appreciated. Thanks again for all the help guys!

JeremyC · Post by **JeremyC** » Tue Aug 01, 2006 9:22 am

If you were talking about 2 JL 300/2 to push it I would say no. If you do the JL 450/4 it will set to the 8 ohm load and you will loose output. So the arc might be the better amp for you.

Other than that, 8 ohm drivers "TEND" to be more efficient than 4 ohm (helps make up for the loss of output from the amp)

I don't see a problem with you putting the mids in the door, as long as you seal it off the best you can. If you try to do a sealed box you might run into resonant problems like JoeyC just had.

When you install them start with the mids, and just keep playing with it till you find the sweet spot. Once you get them finished use some double sided tape and start playing with the tweets.

I have word document someone posted about tuning. Remind me when I get home and i will post it. It will help you fine tune once you get it all installed.

solacedagony · Post by **solacedagony** » Tue Aug 01, 2006 9:42 am

Thanks for the reply Jeremy. I wasn't planning on sealing, I was just not sure if Peerless was RECOMMENDING they be sealed, or just giving you some recommendations if you WANTED it sealed. This is my first time getting into going active, so there're some things I'm not quite sure about yet :) Also, the 7"s are a larger driver, so I wasn't sure if the enclosing of a driver is dependant of FR (just low frequencies) or driver size. My brain told me driver size, but I really wouldn't know.

BTW, is there any way to get my mids more on axis, but keeping them in the door? I don't have any room for kick pods in my little truck, but I have some room to play with in the door. I'm not real great at fabricating, but I can easily learn, buy the tools, etc. I just don't know how. So any suggestions there would also be helpful. I think my midbass/midrange right now is suffering from being so off-axis, specifically the driver's side door.

MobileAudio219 · Post by **MobileAudio219** » Tue Aug 01, 2006 10:08 am

solacedagony wrote:Thanks for the reply Jeremy. I wasn't planning on sealing, I was just not sure if Peerless was RECOMMENDING they be sealed, or just giving you some recommendations if you WANTED it sealed. This is my first time getting into going active, so there're some things I'm not quite sure about yet :) Also, the 7"s are a larger driver, so I wasn't sure if the enclosing of a driver is dependant of FR (just low frequencies) or driver size. My brain told me driver size, but I really wouldn't know.

BTW, is there any way to get my mids more on axis, but keeping them in the door? I don't have any room for kick pods in my little truck, but I have some room to play with in the door. I'm not real great at fabricating, but I can easily learn, buy the tools, etc. I just don't know how. So any suggestions there would also be helpful. I think my midbass/midrange right now is suffering from being so off-axis, specifically the driver's side door.

What kind of truck do you have? You could use door pods or just use a mdf ring and shim it (stock location)

solacedagony · Post by **solacedagony** » Tue Aug 01, 2006 10:27 am

2003 Ford Ranger, standard cab. Not much room in there.
By shim, do you mean angle it with the MDF ring? That's what I was thinking but I don't know how to cut wood at angles like that.

Edit: I would like to NOT cut my door if at all possible (I'll see how much a new set of door panels are, I would in a second then). I'll post up a picture of my door panels later to see what you guys think. I'd have to cut out the slotted section of the door where my speakers sit behind to fit in a 7"er.

MobileAudio219 · Post by **MobileAudio219** » Tue Aug 01, 2006 11:18 am

You could just sand the mdf to give it its angle, its a lot of work but might be your best bet...

solacedagony · Post by **solacedagony** » Tue Aug 01, 2006 12:42 pm

Mmm, rough position. I'll have to sit on it and figure out what I'm going to do.

JeremyC · Post by **JeremyC** » Tue Aug 01, 2006 1:39 pm

Take 2 peices of 1/2 mdf, one mounted to the door, and the other out a little. Angle the outer till you get the sound you want, and then fiberglass the rings together.

That will get you pretty close, but if you really want to tweak you need a good EQ.

solacedagony · Post by **solacedagony** » Tue Aug 01, 2006 1:50 pm

JeremyC wrote:Take 2 peices of 1/2 mdf, one mounted to the door, and the other out a little. Angle the outer till you get the sound you want, and then fiberglass the rings together.
That will get you pretty close, but if you really want to tweak you need a good EQ.

That sounds like a plan. There's not much room to work with there, but at least I'll get it all more on axis. Better than nothing.

Edit: How do you go about avoiding phase issues? Can you make the drivers x inches away so that you avoid phasing or is T/A the only option?

JeremyC · Post by **JeremyC** » Tue Aug 01, 2006 4:39 pm

Since the driver seat is off to one side there isn't really any way to totally stop it, but you can play with the polarity of the wires and see what works best.

There are two simple ways to minimize phasing problems. The first is by only using a couple different path lengths. You can do this by installing the speakers close together, and by running a simple 2 way set. The second way is by keeping the speakers as far away from you as you can (making the path lengths more equal) Thats why kick panels are so popular.

But I am in the same situation as you, I can't do kicks without a ton of modifications. So I am putting the mids in the doors with a little angle to both of them, and the tweeters in the A pillar to raise the sound stage. Yes this goes agains the path length rule, but its a price I am willing to pay. AND I have my top secret tuning sheet to help me. (I will post it in a second)

I did some testing a few months ago, and learned a few cool tricks. I ended up firing the right mid forward and up a little (taking it a little of axis) and the left up and back (bringing it more on axis.) That and some tweaking of my time delays sounded really good.

My next step would have been using my EQ to tune everything to center and fine tune the sound.