speaker size / impedance question - BMW Forum

mikester328 · 10-20-2006, 12:20 AM

Well, i have a couple of blown speakers and I'm going crazy. I have a HK package w/ a Pioneer AVH-P5700 DVD head unit, that coupled with my HK stuff the sound is great, cept for the speakers that are blown. One speaker is in the front, and I have searched and searched for the size of it and I don't want to guess wrong, I'm guessing it's 3 1/2" correct? (the larger speaker of the two, the small tweeter is fine). Also in the back, I took out the HK 6x9 speakers and saw on a sticker "3 ohm 20 watts, 2 ohm 30 watts" I believe, I have to double check but I'm 99% sure. What will happen if I purchase a 4 ohm 6x9 speaker? Please let me know, I'm a musician and I have to have crystal clean bass/sound.

Mike

mikester328 · 10-20-2006, 12:24 AM

this speaker:

da_bull · 10-20-2006, 05:35 AM

They are about a 3.5" speaker, but unless you go back with factory, it really wont sound right because any 3.5" aftermarket speaker will be four ohms, and the stock ones being 3 ohms or 2 ohms they will be louder on the 2/3 ohm side. In the rear, if you are replacing both speakers it wont be much of an issue, because they are further away from your ears, they'll just be a touch softer than the factories are. You can always go up in impedance (from 2/3 ohms to 4) it'll just be a tad more quiet than stock, but you cant go the other way(3 ohms to 2 or 1), as you may damage amplifiers if they arent designed for it. Hope that helps...

mikester328 · 10-20-2006, 10:59 AM

would the 3.5" be the same impedance as the rear speakers - all speakers in the car are the same impedance? If I buy 4 ohm rear 6x9's, does that mean the volume will just be lower but still powerful, or will they not have any power if I shift the fader to the back?

da_bull · 10-20-2006, 06:10 PM

you can shift the fader a little to the rear, you may not notice much (if any) difference between the two. The thing you will most notice is that you will have additional tweeters which will bring more high frequencies to the playing field. You'll have to see what the speakers actual measure (or see if they are marked) for the proper ohm reading.

mikester328 · 10-22-2006, 11:49 PM

oh, in the rear the 6x9 speakers currently have tweeters also on them, I guess that's a 2 way speaker? anyways, currently the back mids/tweeters whatever they're called are blown and rattle, so I actually cut the wire to them (tweeters) and now I have bass from the back, but I'd like them back so I need to get 2 way speakers in the rear, hopefully I can install them in the current HK speaker holders. here goes, I'll show pics of them installed once i get 'em, thanks bull.

Mike

da_bull · 10-23-2006, 04:56 AM

If I recall right, the ones in the door are the ones that are going to be the pain. I dont believe the grills remove from the speakers, so when you go to remove the speakers , the grill comes with it. It seems the last one I did, we had to carefully pry the grill from the original speaker and mount the aftermarket speaker to the door, and mount the original grill back on the panel. Almost any 6x9" will fit in the rear without much modification at all. Hope that helps...

mikester328 · 10-27-2006, 01:37 PM

well, just an update,

I got the 6x9's, and when i hooked the speakers up, when the volume goes up, buzzing and crackling happens, but they aren't blown or anything, it's like there's not enough power going to the speakers, maybe the impedance issue is the cause? Iguess I have no other choice but to either redo my entire system or buy the HK speakers that I need... any other suggestions/ comments...?

da_bull · 10-27-2006, 06:35 PM

What flavor 6x9's did you get? Some speakers are less sensitive than others. Which may be the case. Which means your aftermarket speakers may require more power than what the stock ones do. The impedance difference will make your amp put out less power than it was. The combination between a less efficient speaker and the amp putting out less power may be your issue. If you have access to a small amplifier to just power those speakers may be another answer.