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cfox10
12-05-2012, 03:28 AM
A single set of midbass drivers around 60hz and up on 100w rms, or two on 50w rms each with my crossover a little lower around 45hz. Which will give more output?

I'm asking because if I give rated power to my current polks, I have to up the crossover a lot. If I have them running on a lower rated amp, I can up the xover but output is weak.

I want as much midbass as I can without compromising on SQ

cfox10
12-05-2012, 04:23 AM
Hmmmm.... anybody?

More mids lower power

less mids higher power?

mlstrass
12-05-2012, 04:29 AM
single better midbass per side gets my vote...

Imtjnotu
12-05-2012, 04:30 AM
Keep hope alive will answer this give him tine and he shall come

cfox10
12-05-2012, 12:58 PM
Keep hope alive will answer this give him tine and he shall come

Sounds good.

cfox10
12-05-2012, 12:59 PM
single better midbass per side gets my vote...

Can I ask why? Just curious. Which midbass drivers get low with some power without distorting? I'm tired of having to crossover so high. I heard CDT get pretty low with power.

Sonic.
12-05-2012, 01:02 PM
Cross your subs higher and use a single mid bass driver per side.

cfox10
12-05-2012, 01:05 PM
Cross your subs higher and use a single mid bass driver per side.

My subs are tuned around 32hz, and they hate playing higher notes. I'm looking at either new subs or new midbass drivers, and at this point new midbass drivers would be cheaper unless I want to make a new box and see if my subs do well on the higher notes... then I'd be dropping off a lot on my lowend notes. It's in a truck so no room for 4th order or anything tricky.

mlstrass
12-06-2012, 04:55 AM
Can I ask why? Just curious. Which midbass drivers get low with some power without distorting? I'm tired of having to crossover so high. I heard CDT get pretty low with power.

AA carbon fiber mids were some of my favs, not sure if you can still get them new though. I've run those in a few vehicles.

This would be another good option: DIYCable.com : Intro Home Exodus Anarchy (http://www.diycable.com/main/product_info.php?cPath=24&products_id=538)

TheUnderFighter
12-06-2012, 05:28 AM
Can I ask why? Just curious. Which midbass drivers get low with some power without distorting? I'm tired of having to crossover so high. I heard CDT get pretty low with power.

Well my only complaint with my CDT's was that I had to cross them so high. I had to cross them around 100hz or so, granted I was running about 100w per side. Now I'm running Crescendo mids crossed at 70hz w/ ~120w per side.

gckless
12-06-2012, 05:58 AM
Experimentation is key here. No one knows what that sound is in your head that you are looking for. The more you play around with things, the more you will find what you like. Go with one setup, and then in 6 months or so go with the other one. See which you like better, and run with it.

And definitely cross your mids higher than 45Hz. 80Hz is a decent starting point. Some people prefer 100Hz, some people like 70Hz. When it comes to that, it's a lot about your install and how well your sub will blend with your mids at a certain frequency. Again, play around with it, the outcome will be better to your ears than something someone here will suggest, more than likely.

gckless
12-06-2012, 06:00 AM
keep_hope_alive ;

mlstrass
12-06-2012, 06:25 AM
OP go over to diyma and do some reading. There's a ton of info/reviews on every popular mid out there...

keep_hope_alive
12-06-2012, 10:23 AM
in order to get good response down to 40Hz, I had to fully seal my door and also fill it with PVC encased fiberglass batt. midbass response requires good isolation of the rear wave. i wouldn't hassle with two - you'll have comb filtering issues as frequency increases and it's much more complex to build well. the time and effort is better spent on one set of nice midbass woofers, and the install required.

wickedwitt
12-06-2012, 10:26 AM
Cross your subs higher and use a single mid bass driver per side.
This is the proper answer.

My subs are tuned around 32hz, and they hate playing higher notes. I'm looking at either new subs or new midbass drivers, and at this point new midbass drivers would be cheaper unless I want to make a new box and see if my subs do well on the higher notes... then I'd be dropping off a lot on my lowend notes. It's in a truck so no room for 4th order or anything tricky.

Then you have designed an enclosure that falsely eliminates frequency response by losing output before your mids can take charge. You should not be using midbass drivers to produce the sound between 45-60hz. That is a "sub" range.

whitedragon551
12-06-2012, 10:46 AM
How about properly deadening and sealing your door before you run and buy more drivers? You can have the best equipment and have it sound like garbage if you dont install it properly. Treat the doors and see where your current midbass stand. If they still arent what your after upgrade to a single better driver or to a larger driver.

Also as your setup currently sits you should be crossing mids at or above 80Hz. Subs anything under 80Hz.

cfox10
12-07-2012, 03:51 AM
Okay, I completely sound deadened my door with hushmat (our local shop had it) and also used a spray for all the edges and corners and sealed off all the holes. The mids sound a ton better. I crossed them over at 80hz like everyone suggested and I can actually hear them now. I think I'm going to upgrade to some cdt mids and keep the tweeters and crossovers from the polk's.

Thanks for the help

zako
12-07-2012, 04:19 AM
A single set of midbass drivers around 60hz and up on 100w rms, or two on 50w rms each with my crossover a little lower around 45hz. Which will give more output?

Two woofers will sound better in general, but I think it's pointless to move the crossover so low. You should almost certainly use a subwoofer to fill frequencies below 80Hz, and most certainly below 60Hz.


First, I think the rule of thumb is that doubling the cone area on the same power gives you +3dB, so the later will be louder. However, doubling the speaker's cone area will not change the fact that they are rolling off in the midbass region. Take a look at this picture (http://www.avtozvuk.com/az/2009/06/Comp%20gr/Comp_gr_polk.jpg). This is measured frequency response for Polk MM woofer. It's rolling off sharply below 100Hz. This is typical of most 6.5 inch speakers. Granted, at the limit, the two speakers will be less likely to bottom out, unless you take their crossover frequency to like 45Hz.

IMHO, one rule of thumb for midbass is the following. Set your high pass filter no lower than the resonance frequency of the woofer. The resonance frequency of Polk MM speakers is at about 80Hz, so I suggest to set your high pass at that frequency with whichever slope works best for you.






I'm asking because if I give rated power to my current polks, I have to up the crossover a lot. If I have them running on a lower rated amp, I can up the xover but output is weak.


This is why speaker's RMS power ratings are often useless. The rating is usually done for thermal power handling, but most 6.5 inch speakers will run out of usable excursion if their crossover is set low enough. A typical "100watt RMS" speaker will bottom out on 50watts of power with a high pass crossover low enough. 80Hz is enough for a lot of speakers if you send something like resembling rated RMS wattage to them.


So my point is, two woofers will sound better, but there is still no need to take their high pass frequency so low. If you have a subwoofer, the midbass woofer's overall contribution at 45-50Hz is pretty much in-audible. You have a problem if your subwoofer does not play loud in that region IMHO.

If you want the front speakers to play more bass and handle more power, take a look at Massive Audio CK6. Everyone says they can handle bass pretty well.

cfox10
12-07-2012, 04:45 AM
Very informative, thank you. So should I set my sub xover 100? to account for the rolloff? or should I just play with it and see what sounds better?