bi-amping and xover?

Do some searches in this forum for the key words you mentioned.  Start reading and you'll gain a lot of information.  Then you'll probably arrive at an idea for a solution for whatever problem (you didn't say, specifically) you are having.  At that point you'll be a lot more informed for a Q & A session about your setup. 

But it makes me wonder why you would arrive at the decision and then install two sets of components up front...which is a considerable amount of work and expense...without knowing something about those basics.

stevdart,

thanks for the reply.  i guess when i started this project, i wanted a system that is very "powerful" upfront.  I wanted a loud and high impact system.  I already owned the JL XR's from a previous installation, and got a good deal on the diamonds.  In my thinking, two sets of comps are better than one for the loudness factor.

basically i'm looking for ways to improve the sound quality of my system. seeing if there are things i've done wrong, or things that i could do over that will be better.

OK, so after spending an hour or so reading the forums here and else where, i'm stil not sure i grasp the concept of bi-amping?  It seems all of the posts are discussing the topic in great detail, but even the links within the posts that go to bi-amping tutorials i'm having trouble understanding. 

tell me if i'm wrong, but is the basic concept to use one amp for the highs, one amp for the mids, and one amp for the lows?  then trash the passive xovers that came with the comp's and use a active eq such as the Alpine HXAP701?

FYI, my current system:

Boss 200amp alternator

"BIG 3" wiring

Alpine IVA-D310 DVD/MP3/CD/XM Head unit

Alpine TUE-T151 TV tuner

JL Audio XR650CSi components w/ xovers in front doors

Diamond Audio D661s components w/ xovers in kick panels

Kicker 05DS46 4X6 speakers in rear doors

JL Audio 300/4 amp running all mids and highs

(2) JL Audio 10W7's

JL Audio 1000/1 amp running subs

Stinger and Tsunami wiring

Viper 791XV alarm/remote start

You got the main point.  To biamp, you use the active crossovers on the amp rather than the passive network that came with the set.  So, you use 4 channels of amplification to drive the front speakers.  The tweeters are connected to a pair of outputs (set to HP) and mids are connected to a set of outputs (set to LP).  A subsonic filter would come in handy to limit the bass that reaches the mids as well.

The most likely problem with your sound is that you are driving 2 sets of components with the same frequencies in the same general location of the car.  You said these things all sort of fell in your lap and that you were trying to gain a big impactful sound.  But your question deals with other issues  and that is clouding the problem.

Bi-amping has nothing to do with fixing the problem (and there IS a problem when you tell us you are looking for ways to improve the sound quality).  The problem is too many speakers.  Big, impactful sound is accomplished with an upfront set of quality components that are in the right place, the support of sound damping, and plenty of high quality amplification.  Putting in the extra set was the mistake and that should be dealt with first instead of trying to find a way to put a bandaid on it.

Choose the best set up front you have or do away with both of them and select something else.  Give them plenty of clean power.  Damp the doors (if that is the location) on both skins.  Use the supplied passive crossovers that came with the set.  Take your time in experimenting with tweeter location.  Cleaning up and tweaking will become a lot easier, if it is needed, when you have simplified the install back to the basics. 

You're not to the point of going the more esoteric route of using additional amplifiers, taking out the passives and replacing with active crossovers by bi-amping the speakers you now have in place.  It's the basics that you first need to perfect.  You would have had to tell a completely different story of how those front components were selected for me to agree that tweaking them with bi-amping and actives is the right approach now.

I agree completely, Steve.  I didn't read the long list of gear installed.

stevdart,

thank you VERY much for your in-depth reply.  I now see your point and want to take action.  I guess the next step is to figure out the components i want to use, and the ones i want to remove.  If i'm going to keep a set, i would deffananelty keep the JL's.  The tweeters are much crisper and have a much better "impact", which is what i love about them.  That probably has alot to due with them being aluminum tweets and the diamonds being silk.  Comparing the mids, i think they are both very close, and both not very good.  On a scale of 1-10, i would put the JL's at a 7 and the diamonds at a 6.  That is just my opinion, i'm sure others would think differently.

Steve, have you personally heard the JL XR line of speakers?  My first guess is to replace both the diamonds and the JL's with a high end comp set that will give me both, the "bright, impactful" highs that i crave, and the "full, punchy" mids that i love.  Since I like the sound of JL tweets, and them being aluminum, i should probably look for a new comp set with aluminum tweets right?

Another limiting issue is that the twees are flush mounted in my doors.  I don't know why i did this,....probably because i thought it looked cool, but now this forces me to one single tweeter mounting location, as i now have big holes in my door panels.  On the bright side of this, they are only about 6-8 inches away from where the mids are mounted, so that should be about right i think?

Next, i have already ordered 42 square feet of dynamat extreme.  It should be in this week. I plan to do the whole truck, excluding the floors.

After doing some reading, some more reading, then some more reading yesterday, i found a set of comps that looked ok, but need opinions on them.  what does everyone think of the Dynaudio System 240 GT comps?  here are the specs:

System 240 GT

These are the 6.5" woofers, they should fit in my doors just fine, but it would be sweet IF i could fit a 7" mid in there. Dynaudio has a comp set that has a 7 instead of the 6.5.

You like the sound of the JL comps so I think you should work with that pair before looking into another set just yet.  With the door damped and a good crossover transition from these comps to the sub, you should be able to achieve a good midbass punch that may not be bettered with a 7" driver in its place.  And I'm not aware of how those tweets came packaged, but you may be able to trade out the flush retaining ring for the swivel ring and experiment with the angle that way.  Other than that, the distance from the mids seems like it would be acceptable.

BTW, you said you were dynamatting the trunk, so does that mean the doors are done as well as they can be?  If they're not, be sure to make that a priority.  Also, mounting the mids on a MDF baffle will bring out a more substantial punch, too.  It makes the mounting location more rigid which results in a more powerful impact.

stevdart, thanks again for your excellent and timely response, you ARE being quite helpful.

just to clear things up, nothing is damped yet.  i have not recieved the dynamat yet.  will probably be done this weekend if it comes in.  also, i have a truck, so there is no trunk. i'm only dynamating the cab/extended cab area and the doors.  not the floor, except where the kicks are, i will dampen behind them. (if i don't remove them completely like you suggested).

the tweeters are flush mounted, BUT do have a swivel so i can position them if need be.

how do i achieve a "good" xover transaction from the sub to the mids as you stated above?  what xover settings are you recommending?  my head unit does have a fairly good amount of adjustment and slopes to play with.  if you can give me a "base" to work with, i can tweak from there?

what do you mean by "mdf baffle"?  are you referring to a piece of wood mounted to the door, thenn mount the mids to the wood?  if so, i don't know if my mounting area will allow for this, but i will check this weekend when the dynamatting commenses