i'm looking for something to give my new 8" mids the band of sound i want them to play.
right now they are being severely underpowered at 1/2rms and i dont plan on giving them a more efficient larger enclosure anytime soon considering i just finished these!!
ok- as of now i'm running a 400wmax Crunch amp on the mids with the built in 250hz LPF with decent results. my problem ends up being that i cant get them louder than the point where the sub range dominates the higher range (lil bit'o boost! GRIN) the drum set and bass guitar come out great i'm just tired of the lows creeping in!
so my question is this, i want to HP @70-90 and need a suggested LP for these mids! then where can i look to purchase these kinds of xovers?
-Drew
Replies (6)
swez on 07/31/2008 04:41:59
Sure, consider F-Mods from Parts Express if these are amped speakers. These are 2nd order filters that offer -12dB slopes. They come in fixed value HP or LP versions, depending on your application.
Since the amp mentioned has LPF that tops out at 250 Hz., you'll need to figure out the lowest HPF to block subwoofer signals to the MB drivers. I would suggest the HPF version at 100 Hz. This will be -12dB down at 50 Hz., and more like -6dB down at 75 Hz., -3dB down at ~87 Hz.
This is a pretty narrow BP region to play with, but that's what MB drivers are for. If we consider the F3 points, (-3dB down) for each filter, the F3 LP is more like 300 Hz. The F3 HP is more like 87 Hz. So, with this in mind, the usable BP range will be more like 87-300 Hz. Not bad at all. The only thing remaining is amping power to get the sound you are looking for. (Balancing the system to your liking)
Got all that?
Swez
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=266-274
Ash on 07/31/2008 08:48:21
What are the specs on those mids?
Going bigger in enclosure size will decrease efficiency for a tradeoff of lower bass output. Going smaller will give them more snap with a robust midbass as well as increasing efficiency.
It could be possible that they are a simple mismatch for the rest of the system. Like me, building your own comps or just adding drivers for each range. there is a lot of experimentation before you find the right mix. Can't tell you how many different mids, tweets, and crossover combinations I've tried.
Plus their placement could be causing some cancellation as well. Have you tried different phasing techniques? Sometimes that can help. Something else to try is to turn your sub off and tune the rest of the system individually. Once you have the sound right on or close to where you want, then try blending the subs back in. Could have the sub turned up too loud for the midwoofers. If that doesn't work then you may have to opt for some different drivers and/or amps.
swez on 07/31/2008 14:20:22
Thanks for adding those well-timed comments Ash. Was hoping you would latch on to this one and add a few of your own experiences to the
mix.
As we look at the MB pods in relationship to the rear wall of a sub and the mid/highs, I see some slight/possible phase alignment issues here. The MB pods are closer to the front stage than the speakers on the rear wall. (What.. maybe 24" from the Mid/Tweets) This may not matter much if the M/T's are HPF'd above 300 Hz.
The sub will not matter too much and if slightly out of phase, many good amps have 0-180 degree phase adjustments to bring them into proper alignment too.
The only other issue to look carefully at would be the punch and power to the front stage part of this system. Ideally, this is well amped and enough EQ power to bring up the Mids and Highs to balance out this system.
Some tweaking tips:
1. Set up the front stage first (Strong, clean and robust)
2. Blend in the rear stage M/T's (Just enough to suit your taste)
3. Blend in the MB next (Fill in as needed with power/gain control)
4. Bring up the sub last (Fills in the low end smaller speakers cannot manage)
Do you agree with that strategy Ash?
Swez
newB on 07/31/2008 17:40:12
points well taken and appreciated.
I've gained a bunch from the sub since installing for some reason. ? phase?
When i ran them on the kicker 400.1 the response was amazing in the region mentioned (87-300ish) and they actually moved!!
hoping there are no phasing issues when i'll have more power and the HPF ( 25$?? really??)
-Drew
swez on 07/31/2008 22:58:00
Yep, $12.50 x 2 = $25.00 a pair for such a compact passive crossover is not a bad deal. These are shielded coil and capacitor, (passive) HP filters from Harrison Labs. The price has actually dropped over the past few years. They used to sell for $30.00 a pair.
Quote: "When i ran them on the kicker 400.1 the response was amazing in the region mentioned (87-300ish) and they actually moved!!"
Sure... there will be a good deal of cone movement in the MB region mentioned. Most of that is the kick drum, floor toms and mid-upper bass regions on the bass guitar or synth.
As for "more bass" in the overall system, expect that as you now have more cone area and amping power to move low frequency sound waves around. If they couple well, (Sub and MB) better bass extension in the upper bands of MB will add more punch to the entire bass region.
If the MB/Sub power/SPL is additive, you have good phase alignment. If they deminish, reverse polarity on the sub and see how that changes the overall impact.
Swez
Ash on 08/1/2008 08:36:34
Agree with that process Swez....
Blending a simple system with no more than 1- 2 crossover points is fairly simple. You choose frequencies within the driver's limits and blend them in with the gain.
When we start to add more drivers for narrow bandpasses (4-way (T-MR-MW-SW) problems can really develop. Not only does how each is blended drastically change the overall sound, but crossover points, differing sensitivity levels, placement, driver behavior, etc becomes even more of a factor.
Expect to do numerous lengthy auditions after making fine adjustments. Here a RTA would be useful as well so that you don't get way off the mark.
If you really want to get control of things, I would suggest an Audio Control digital crossover/ equalizer combo or something similar. Expensive somewhat, but almost impossible to do without when using drivers for each individual range. Can really cut down on tuning time also.
right now they are being severely underpowered at 1/2rms and i dont plan on giving them a more efficient larger enclosure anytime soon considering i just finished these!!
ok- as of now i'm running a 400wmax Crunch amp on the mids with the built in 250hz LPF with decent results. my problem ends up being that i cant get them louder than the point where the sub range dominates the higher range (lil bit'o boost! GRIN) the drum set and bass guitar come out great i'm just tired of the lows creeping in!
so my question is this, i want to HP @70-90 and need a suggested LP for these mids! then where can i look to purchase these kinds of xovers?
-Drew
Replies (6)
swez on 07/31/2008 04:41:59
Sure, consider F-Mods from Parts Express if these are amped speakers. These are 2nd order filters that offer -12dB slopes. They come in fixed value HP or LP versions, depending on your application.
Since the amp mentioned has LPF that tops out at 250 Hz., you'll need to figure out the lowest HPF to block subwoofer signals to the MB drivers. I would suggest the HPF version at 100 Hz. This will be -12dB down at 50 Hz., and more like -6dB down at 75 Hz., -3dB down at ~87 Hz.
This is a pretty narrow BP region to play with, but that's what MB drivers are for. If we consider the F3 points, (-3dB down) for each filter, the F3 LP is more like 300 Hz. The F3 HP is more like 87 Hz. So, with this in mind, the usable BP range will be more like 87-300 Hz. Not bad at all. The only thing remaining is amping power to get the sound you are looking for. (Balancing the system to your liking)
Got all that?
Swez
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=266-274
Ash on 07/31/2008 08:48:21
What are the specs on those mids?
Going bigger in enclosure size will decrease efficiency for a tradeoff of lower bass output. Going smaller will give them more snap with a robust midbass as well as increasing efficiency.
It could be possible that they are a simple mismatch for the rest of the system. Like me, building your own comps or just adding drivers for each range. there is a lot of experimentation before you find the right mix. Can't tell you how many different mids, tweets, and crossover combinations I've tried.
Plus their placement could be causing some cancellation as well. Have you tried different phasing techniques? Sometimes that can help. Something else to try is to turn your sub off and tune the rest of the system individually. Once you have the sound right on or close to where you want, then try blending the subs back in. Could have the sub turned up too loud for the midwoofers. If that doesn't work then you may have to opt for some different drivers and/or amps.
swez on 07/31/2008 14:20:22
Thanks for adding those well-timed comments Ash. Was hoping you would latch on to this one and add a few of your own experiences to the
mix.
As we look at the MB pods in relationship to the rear wall of a sub and the mid/highs, I see some slight/possible phase alignment issues here. The MB pods are closer to the front stage than the speakers on the rear wall. (What.. maybe 24" from the Mid/Tweets) This may not matter much if the M/T's are HPF'd above 300 Hz.
The sub will not matter too much and if slightly out of phase, many good amps have 0-180 degree phase adjustments to bring them into proper alignment too.
The only other issue to look carefully at would be the punch and power to the front stage part of this system. Ideally, this is well amped and enough EQ power to bring up the Mids and Highs to balance out this system.
Some tweaking tips:
1. Set up the front stage first (Strong, clean and robust)
2. Blend in the rear stage M/T's (Just enough to suit your taste)
3. Blend in the MB next (Fill in as needed with power/gain control)
4. Bring up the sub last (Fills in the low end smaller speakers cannot manage)
Do you agree with that strategy Ash?
Swez
newB on 07/31/2008 17:40:12
points well taken and appreciated.
I've gained a bunch from the sub since installing for some reason. ? phase?
When i ran them on the kicker 400.1 the response was amazing in the region mentioned (87-300ish) and they actually moved!!
hoping there are no phasing issues when i'll have more power and the HPF ( 25$?? really??)
-Drew
swez on 07/31/2008 22:58:00
Yep, $12.50 x 2 = $25.00 a pair for such a compact passive crossover is not a bad deal. These are shielded coil and capacitor, (passive) HP filters from Harrison Labs. The price has actually dropped over the past few years. They used to sell for $30.00 a pair.
Quote: "When i ran them on the kicker 400.1 the response was amazing in the region mentioned (87-300ish) and they actually moved!!"
Sure... there will be a good deal of cone movement in the MB region mentioned. Most of that is the kick drum, floor toms and mid-upper bass regions on the bass guitar or synth.
As for "more bass" in the overall system, expect that as you now have more cone area and amping power to move low frequency sound waves around. If they couple well, (Sub and MB) better bass extension in the upper bands of MB will add more punch to the entire bass region.
If the MB/Sub power/SPL is additive, you have good phase alignment. If they deminish, reverse polarity on the sub and see how that changes the overall impact.
Swez
Ash on 08/1/2008 08:36:34
Agree with that process Swez....
Blending a simple system with no more than 1- 2 crossover points is fairly simple. You choose frequencies within the driver's limits and blend them in with the gain.
When we start to add more drivers for narrow bandpasses (4-way (T-MR-MW-SW) problems can really develop. Not only does how each is blended drastically change the overall sound, but crossover points, differing sensitivity levels, placement, driver behavior, etc becomes even more of a factor.
Expect to do numerous lengthy auditions after making fine adjustments. Here a RTA would be useful as well so that you don't get way off the mark.
If you really want to get control of things, I would suggest an Audio Control digital crossover/ equalizer combo or something similar. Expensive somewhat, but almost impossible to do without when using drivers for each individual range. Can really cut down on tuning time also.
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