Running two 8" subs in stereo or mono?

[drone007]

Hey everyone,

I am putting together a setup; I picked 4 6.5" speakers for front L/R and rear L/R channels that are considered to have enough high frequency and lack low frequency. I have 2 12" subs for the low end that will of course be receiving the sub signal from my kenwood excelon dvd player. now, i also have two 8" subs that I want to take care of the higher lows and mids that are excluded from the other drivers. do people normally run two 8" subs on a two channel L/R amp? or does the ear have trouble telling the difference like it would with those big 12" subs?

Thanks

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[SSS 18734 5,000+ posts]

The 8's are unnecessary. Make sure the doors your 6.5's are in are well deadened and you should see reasonable response down to 60-80hz. Cross your 12's over to play below that.

 

[slam 5,000+ posts]

search thru my threads... i have a build log for something similar to what ur doing

 

[drone007]

thanks for the replies.

well the 8" subs are already purchased with a 2-channel amp, so even if it's unnecessary i'm probably going through with it. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

slam -- great install idea on that center console 8" sub! I guess my question pertains more to the routing of the signal path...

If I have a headunit that has FR(L/R), BK(L/R), CTR, SUB preamp signals. How would you all suggest routing the RCA cabling to the 8" subs? That SUB preout on the headunit is probably a mono line isn't it? Should I run the 8" subs on the same mono line as the two 12" subs I have or would I benefit from running them off of the BK(L/R) output along with my smaller 6.5" speakers?

 

[James Bang 5,000+ posts]

you might want to search "dedicated midbass"

 

[PaulD 10+ year member]

^^^^ What you are describing is a midbass, and yes they will need to be stereo to sound good. You will also need a way to go 4 way active or use pasives on the mid/tweets and you can do active 3 way.

 

[drone007]

just read through 3 pages of threads on "dedicated midbass". THREADS, not posts haha. so I think I understand the underlying applications.

I have an in-dash dvd player that has stereo front, stereo rear, center, and sub 7V preamp outs.

here is the equipment i already have:

4X 6.5" speakers that are reviewed by customers as "lacking in mid range but better in high range"

1X 4 channel amp for those speakers

2X 8" subs rated for 80-250Hz response

1X 2 channel amp for those subs

2X 12" subs rated at typical sub range

1X Mono channel amp for those subs

Here's another crucial (i would guess) piece of info... I am putting all of this into a honda odyssey minivan. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif not the most stylish, but that's what I'm doing. There is much talk about front staging and the use of rear placed midbass which could potentially pull the stage to the back of the car. what if I have a potentially very deep soundstage like in the van? Stock this thing came with a set of front door speakers and two wall mounted speakers next to the third row seating... If I mounted the 8" subs somewhere in the middle of the car, would that suffice?

Also, the talk of being 4 way or 3 way active, how close am i to that? I thought I was good with my 4 channel and 2 channel amps for the speakers and 8" subs

 

[PaulD 10+ year member]

As long as you cross over the midbass around 250 Hz or so, you should be fine mounting them in the rear doors or where the 3rd seat is. At freq's that low the ear is better at discerning distance (intensity) direction.

Depending on the crossover capabilities built into your amps and headunit, you may already have all the equipment you need. Are the 6.5" speakers just midranges, mads and tweets with crossover box or coaxials ?

 

[NightDrifter05 10+ year member]

I wouldn't bother with it. Chances are the people who said they were lacking in mid range didn't bother to deaden the door's, didn't have enough power, didn't spend the time tuning, or just didn't know what they were doing. You should just put the 6.5's in and spend a little money on sound deadening and see how they perform. Then if they don't give you the sound you want you can come back and put the 8's in.

 

[drone007]

I wouldn't bother with it. Chances are the people who said they were lacking in mid range didn't bother to deaden the door's, didn't have enough power, didn't spend the time tuning, or just didn't know what they were doing. You should just put the 6.5's in and spend a little money on sound deadening and see how they perform. Then if they don't give you the sound you want you can come back and put the 8's in.

that's def. a valid point and something i considered while i was reading the reviews. the comments came mostly from people who replaced stock door speakers with these speakers and realized a big loss in lower frequency response.