JL 450/4 for Diamond Hex 6.5 front stage only?

[pudgewack 10+ year member]

Would the JL 450/4 be overkill for my Hex 6.5 comps? I would use the active x-over. Each woofer would run off their own channel at 150 w each. Each tweeter would run off their own channel at 75 w each. I am consider this option mainly for midbass. According to the email that I received from Diamond, they would not recommend doing this b/ they said that all the speakers would "easliy" be able to handle that amount of "clean" power (they only recommend using the included x-over).

I got the idea from a salesman that works at a local audio shop. Generally I take caution in listening to salesmen because they are just looking for a profit. The thing is the shop that the salesmen works at doesnt even sell JL, so he would not profit from this idea.

Before I was told about that, I was thinking about getting a 75w x 4 amp and giving the tweets and woofers the same amount of power b/ still going with an amp that has a active crossover.

Assumsing money was not a factor, is the 450/4 a good idea? Or should I just stick with amp that has the same power on all channels (possibly the JL 300/4)?

Thanks,

Matt

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[slick316 10+ year member]

i dunno, i would think its best to just use the supplied crossover, i mean, why would they include it if they didnt think it was needed, right?

i once ran 300 wrms per side to my HEX's and they handled them fine, and i'm currently running 150+ wrms to them. they handle power just fine, but its not necessary to put a lot of power on them

if it were me, i'd just go with an amp like the JL 300/2, 150watts x 2 is plenty for those speakers.

 

[cjj2d 10+ year member]

I have a set of Hex's as well and I almost think they couldn't handle 150rms. I may have my amp set wrong though. I am running 100x2. When I crank it up they start getting rough sounding. I am going to tune the tweets down 2db so the mids can keep up.

 

[slick316 10+ year member]

they should handle 100watts with ease, unless you are pushing your headunit into clipping, then it doesnt matter how much power you have, its gonna sound like a$$ and ruin the speakers.

 

[cjj2d 10+ year member]

what do you mean by pushing the head unit into clipping??

 

[pudgewack 10+ year member]

I was wanting to use an active x-over instead of the passive that was included w/ the speakers. I am under the impression that an active x-over has the abilty to fine tune the sound more so than the with the passive x-over. Not only would all of the speakers be balanced, I would be able to have more options in chosing the x-over points for both the tweeters and woofers as well as be able to create a steeper slope. It would take a lot more tunning, but I think the end result would be better with an active vs passive xover.

The only thing that I am worried about is the effect the sound stage would have with the woofers each having 75w more than the tweeters. I definatly want well- defined midbass, but I dont want the midbass to over power the highs from the tweets.

Thanks for the responces,

Matt

 

[brandont 10+ year member]

Usually tweeter's are more sensitive anyways. Many people who bi-amp, tri-amp, ore more have more power going to the midbass speakers.

Slick316 is correct though, the supplied crossover is good, that's why it comes with the speakers. Sometimes it's recommended not to bi-amp the components (Infinity Perfects, JBL GTI's, etc), but read the article from the link below. You might end up more confused, but if you read it carefully, you can learn alot.

http://www.audiocontrol.com/techpapers/techpaper104.pdf

 

[slick316 10+ year member]

what do you mean by pushing the head unit into clipping??

where you turn the volume past the point of clipping, for instance, my old clarion dxz835mp sent a clean signal to the amps until you hit 30 on the volume, after that, the signal was clipped, and was distorted.

also, you could be over equalizing the speakers, on the deck or whatever. turning up the bass too much will result in the speakers popping and crackling at higher volumes, try running EQ settings on flat.

i can make my HEX's sound like 8" subs almost, they have incredible midbass, try messing with your settings on your HU a little more and make sure you have your amps properly gained.

 

[slick316 10+ year member]

hmm, i just noticed that you have 5.25" HEX's, mine are 6.5" and that could be the reason for midbass to sound rough, 5.25" wont handle bass as well as the 6.5", hell, i'm running my HEX's full range right now, so they are playing those really low bass notes, and its not hurting them.

high pass your HEX's at 80hz or so, and turn down the bass on the HU, should work fine.

 

[MrBill2U 10+ year member]

I love my Hex's. They handle 150 RMS per side with ease. I had some clipping problems, but it was because my amps were tuned wrong. After tuning them myself according to JL's reccomendation I am blown away by these speakers.

 

[cjj2d 10+ year member]

I am off tomorrow and am going to be tweaking out my system all day.

MrBill- I have the same headunit, what do you have your HU crossover tuned too? and what about the timecorrection and eq? any help would be great. Do you use the MX feature? I haven't had this HU long and am still trying to set it the most accurate.

 

[cjj2d 10+ year member]

would a line driver help with preventing the HU front clipping/sending a bad signal?

 

[MrBill2U 10+ year member]

I am off tomorrow and am going to be tweaking out my system all day.
MrBill- I have the same headunit, what do you have your HU crossover tuned too? and what about the timecorrection and eq? any help would be great. Do you use the MX feature? I haven't had this HU long and am still trying to set it the most accurate.

They did the time correction for me at the boom shop, so I haven't had to mess with that. I only have the 5.25 hexes running now untill I find time to mount up the midbasses, so I am running my x-over at 100hz with the slope set to 4. I NEVER use the mx function because it EQs the hell out of the sound. I have my eq set to +3 at 250 hz with a Q of 1. That helps bring up the midbass some. I set my high eq to 10khz and am running that -3 with a Q of one to ease the tweeters off a little bit. My car tends to resonate around 100hz, so my sub slope is really steep from 100 down. I took care of that by setting my bass eq on the amp to +12db at 38 hz with a Q of 1.1 and my infrasonic filter at 20 hz. I know most people do not use the infrasonic filter with a sealed box, but with my boost set so high I didn't want to waste power on subsonic ques.

I am really happy with how it is set now. I use the sub controll on this HU all the time. I like to set sub levels so they blend well in classical music at +6. This gives me 9db of headroom to pump it up when I want to turn heads with some ghetto and the option of dropping the sub -6db so I can hear how my comps are doing with the bass.

Also, this HU starts clipping around 29 on the vloume knob. I tuned my amps to max unclipped signal with a 0db sine wave with the volume at 27 and the sub set to +12 according to JLs amp specs. I have yet to turn it up past 24 because it is quite loud at that level and very clean (and I am still breaking in my new tweeters). I also found that when I used those specs I ended up with my gain up about half way with the gain switch set to low voltage. Your amps will be different, but don't treat the 4volt output rating as scripture....

If you are running this HU at volumes past 29 the signal from your HU is clipping. All a line driver will do is amplify an already clipped signal.

If you really want to tune properly, use ohm's law. From an amplifiers rms power rating and the load you are going to drive off of it, you can tell how many volts you should be driving to achieve the max unclipped power. This page makes it easy, just type in your amp's RMS rating in the watts field and your speaker impedance in the ohms field and click ohms law.

Use NCH tone generator to make a wav file of 1khz for 2 minutes at 0db attenuation. Play this track with out your speakers hooked up and a digital AC voltmeter hooked up where the speakers would be. Do this without any equalization and your HU at 27. Adjust the gain on your amplifier untill you hit the target voltage. (ie, for 100 watts onto a 4 ohm speaker adjust to 20 volts, for 150 watts at 4 ohms use 24.4 volts). After you do this you will know what unity gain is for your HU and amplifier. NEVER take your gain past this point as you will be clipping the amplifier. I would also never run my volume past 27 after this. This should tune your comps and amp so they are at max volume cleanly at 27.

You can do the same thing for your subs, only you want to use a 50 hz 0db sine wave and your sub controll at +12. Again, make sure all EQ on the HU and amp are turned off prior to setting the gain. After you tune both amps this way turn your bass eq on the amp back on and listen to see how the balance is. If your subs are way too loud, turn the gain down on the subs. If your comps are way too loud, turn the gain down on your comps. Just remember, NEVER adjust your gain higher than what this tuning method gives you.... consider that a hard cap.

Hope this helps //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[cjj2d 10+ year member]

thanks for taking the time to type all that out. It is going to take me some time now to get this done as I am not familiar with all that. But oh well. I will learn. Thanks again.

 

[cjj2d 10+ year member]

what is the Q level you speak of?