Hi, I am attempting to build some rear speakers for the rear. I don't listen very loud anymore, I just want as clean as possible. I plan on using a Kicker 47KEY2004 in biamp mode, one amp driving a Morel Virtus nano MM2 midrange and a Memphis Audio PRX10 tweeter. The other amp with a Dayton Audio CF120-4 mid bass.
First question is what is the best way to protect the Morel mid? At such low power, would the 120hz hi pass filter on the amp be ok? Or just use a 200hz bass blocker?
2nd question. For the Dayton mid bass, should I just seal it in the enclosure, or try a passive radiator or tuned port?
Thanks in advance.
First question is what is the best way to protect the Morel mid? At such low power, would the 120hz hi pass filter on the amp be ok? Or just use a 200hz bass blocker?
2nd question. For the Dayton mid bass, should I just seal it in the enclosure, or try a passive radiator or tuned port?
Thanks in advance.
Others may disagree but, in my opinion, having the rear speakers will not make the audio as clean as possible if you have front speakers playing the same content. There is going to be a phase difference between the two speakers playing the same content and moving your head just slightly will make the phases of that same content go in and out of phase. It's hard to detect with music, especially in a car where there are so many other issues but it's there.
Protect from what? If it's power that you're concerned about, it's not a simple thing because you don't know how the power handling is rated. Then you have the content of the music and the crossover points and even equalization that you need to use to get the sound where it's acceptable to you. To know what you're driving to the speaker, you need a scope. A garbage $25 scope will do the job but without that, everything is a guess.
Protect from what? If it's power that you're concerned about, it's not a simple thing because you don't know how the power handling is rated. Then you have the content of the music and the crossover points and even equalization that you need to use to get the sound where it's acceptable to you. To know what you're driving to the speaker, you need a scope. A garbage $25 scope will do the job but without that, everything is a guess.
Hi, to clarify, all three drivers are rated to handle the 50w/ch of the Kicker amp. The lower frequency response of the Morel mids is 200hz, I was wondering if it would be a problem to use the hi pass filter of 120hz from the amp, or just use a 200hz bass blocker?
Also, this amp has a microphone that automatically sets the EQ and delay needed to tune it to the driver's seat. I hope that will help, if not, it will be an expensive experiment.
Also, this amp has a microphone that automatically sets the EQ and delay needed to tune it to the driver's seat. I hope that will help, if not, it will be an expensive experiment.
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How do you define 'bass blocker'?
The DSP can cause far more power than expected to be driven to a speaker.
You cannot hear the onset of clipping with music. If you ever get to listening at a higher than expected volume, the speakers could be damaged unless they are rated (honestly) well above the rating of the amp. People want absolutes when trying to protect speakers and there are simply far too many variables to do this unless the speakers are well known to handle FAR more power than the amplifier can drive into them.
Are you using an electronic crossover for the 120Hz (no inline passive)?
The DSP can cause far more power than expected to be driven to a speaker.
You cannot hear the onset of clipping with music. If you ever get to listening at a higher than expected volume, the speakers could be damaged unless they are rated (honestly) well above the rating of the amp. People want absolutes when trying to protect speakers and there are simply far too many variables to do this unless the speakers are well known to handle FAR more power than the amplifier can drive into them.
Are you using an electronic crossover for the 120Hz (no inline passive)?
Bass blocker online 199uf filter, for instance. Blocks everything below 200hz.
The Morels handles up to 60 watts RMS (100 watts peak power).
My question, which I appreciate you working with me to answer is would the 120hz hipass from the amp be ok, or should I use an inline filter to block everything below 200hz, 300hz,etc?
The Morels handles up to 60 watts RMS (100 watts peak power).
My question, which I appreciate you working with me to answer is would the 120hz hipass from the amp be ok, or should I use an inline filter to block everything below 200hz, 300hz,etc?
Technically, a 'Bass Blocker' is/was a capacitor that had a parallel resistor. There are devices that use the name/designation but aren't the same (no parallel resistor)... and some are identical. The name Bass Blocker may have belonged to a particular company (Stinger?) but I can't remember which.
An inline capacitor can serve as a 6dB/octave passive filter but the value determines the crossover point. The 199uf cap crossover point will vary depending on the speaker's impedance. 200uF is 200Hz for 4 ohms.
Crossovers don't block everything and a simple 6dB/octave has a slow roll-off.
Maybe someone who knows Morel speakers can tell how reliable their power ratings are.
Did you already buy the morels? They have low efficiency which means that you'll have to drive them with more power.
Why down to 120Hz? The midbass will go well above 120Hz.
An inline capacitor can serve as a 6dB/octave passive filter but the value determines the crossover point. The 199uf cap crossover point will vary depending on the speaker's impedance. 200uF is 200Hz for 4 ohms.
Crossovers don't block everything and a simple 6dB/octave has a slow roll-off.
Maybe someone who knows Morel speakers can tell how reliable their power ratings are.
Did you already buy the morels? They have low efficiency which means that you'll have to drive them with more power.
Why down to 120Hz? The midbass will go well above 120Hz.
I started as a loudspeaker design engineer and morphed into many years in autosound and even-the horror! the horror!-working in the Marketing department. From all that here are some thoughts:
- A capacitor in series with a resistor will cut the power -6 dB per octave below the filter frequency. A capacitor in series with a woofer, ugh. God only knows, to quote The Beach Boys. The impedance of a speaker is complex and changes with level and a simple series capacitor does not work very well (I had to redesign a product like that and barf).
- Speaker power ratings are totally useless crap. Sorry, apologies on behalf of the entire speaker industry. Power handling is just way too complex to distill down to a number or two. Amp power ratings are not too much better since they are measured into resistors which speakers do not resemble. The reality is if you TURN THE VOLUME DOWN as soon as the sound is bad all should be fine; if you "crank to 11" into amp clipping none of the power numbers will matter, stuff will break. Hence you hear it is better to have more power, for headroom.
- The 120 Hz highpass will be fine as long as you follow that rule. While the Morel will be subject to more power from 120-200 Hz again the passive won't really cut the power it should, plus on the amp it is at least a -12 dB slope, cutting out way more low bass power and excursion compared to passive.
- Rear speakers are stupid. They are literally a historical relic from the days when there was one speaker in the front powered by a 3.2 watt tube, and people in the back could not hear it. Nobody sane runs duplicate rear stereo at home. The only use of rear speakers is sometimes to cover up the awful sound of the fronts! (2009 Jetta, looking at YOU).
In my opinion the 120Hz high pass for the midrange is too low.
With its structure and low sensitivity i would cut above 500Hz.
The Dayton mid-bass rises a lot so the crossover is not a problem.
The best thing is always to try.
I don't know the answer to the second question, it needs a good installation with soundproofing.
Greets!
Conventional wisdom says at least -24 dB @ Fs, so lowest is 2x Fs = 290 Hz @ 4th order XO regardless of power to protect it from any amp clipping if nothing else, but I'm decades out of date WRT HIFI/competition mobile audio and never heard of a 'bass blocker' per se, just so called infinite slope XOs that I never messed with.
If you use a 4th order XO = 126.4 Hz, you're 'close enough' to use the 120 Hz XO.
HR calcs a 1.5" i.d. x 7.875" vent yields 6+ dB @ 120 Hz, but due to the necessarily tiny box required it will ideally need to be critically damped (attached) for high SQ, so a bit less.
Re PR, no clue what's available, just that it needs to have at least an Sd = 1.75x driver Sd.
