I am looking to use two RS150-4's as the .5 driver in a 3way slim tower.
I was wondering about Zobels.
Would it be better to put a Zobel on each woofer or could I calculate the equivalent Zobel for a driver of twice the inductance and resistance since they will be wired in series?
It would definitely be cheaper to have one Zobel on two woofers.
I was wondering about Zobels.
Would it be better to put a Zobel on each woofer or could I calculate the equivalent Zobel for a driver of twice the inductance and resistance since they will be wired in series?
It would definitely be cheaper to have one Zobel on two woofers.
With the drivers in series, your zobel (if you use one) would use twice the resistance and half of the capacitance compared to a single driver. The inductance would double.
For the pair in parallel, the resistance would halve, the capacitance double, and the inductance would halve compared to a single driver.
For the pair in parallel, the resistance would halve, the capacitance double, and the inductance would halve compared to a single driver.
It is common to use a second identical driver that is crossed to cut in as the baffle transitions. It is normally done with a first order filter. This would require impedance compensation or equivalent. You'd normally make sure it is rolled off before the upper crossover.
In your case you'll want to ensure you are getting the correct sound volume out of the other drivers.
In your case you'll want to ensure you are getting the correct sound volume out of the other drivers.
Ok, the eight has a sensitivity of 87dB, that's per Watt. If we make the sweeping assumption that the fours' impedance is half of the eights', two in series will dissipate 1W at the same drive level as the eights will. At this point the eight will be at 87, and the fours, which have a sensitivity of 92 will be at 89 due to them only dissipating half a watt at that point. However, since they're paired up they'll be running together at 92 at low frequencies.
What do you mean when you say that the sealed eight is crossing in at the baffle step frequency?
If I assume you simply have three woofers and one is sealed, it is still not straightforward, but it should be manageable. It looks like you'll have a response rise of about 6dB when all the woofers are working together. I.e. above the cutoff for the sealed and below the baffle step. You'll still be up 5dB until the ported woofers themselves roll off. This could be OK, a raised upper bass region has its followers and can help compensate for various issues. Eventually, unless you like to run a little extra treble, for example, you might find it out of place and running a single four instead, or the pair in parallel, would be even louder. If you're OK with this...
The frequency for crossing in a standard 0.5 way, is the baffle step frequency where the baffle response is down 3dB, and the first order filter on the driver puts it down by 3dB as well. It will be slightly out of phase due to the filter so it will not combine to a full 6dB at this point, but makes a good overall compromise.
Since you have 5dB to kill here, you could simply choose an inductor that is twice as large. These filters aren't doing the full 6dB per octave so close to the turnover frequency. However there are issues with it. The additional phase difference with the filter when used this way, and the sealed roll off added will complicate the issue. What it basically means is that what you hear and what you see may be a little different.
Finally, since having a boost down here is not a 'natural' thing so to speak, it is going to be a matter of taste for you, for your room, the placement, etc. You have a couple of options. Do a thorough power analysis on the set, or get yourself a few inductors and work this one out by trial and error.
If I assume you simply have three woofers and one is sealed, it is still not straightforward, but it should be manageable. It looks like you'll have a response rise of about 6dB when all the woofers are working together. I.e. above the cutoff for the sealed and below the baffle step. You'll still be up 5dB until the ported woofers themselves roll off. This could be OK, a raised upper bass region has its followers and can help compensate for various issues. Eventually, unless you like to run a little extra treble, for example, you might find it out of place and running a single four instead, or the pair in parallel, would be even louder. If you're OK with this...
The frequency for crossing in a standard 0.5 way, is the baffle step frequency where the baffle response is down 3dB, and the first order filter on the driver puts it down by 3dB as well. It will be slightly out of phase due to the filter so it will not combine to a full 6dB at this point, but makes a good overall compromise.
Since you have 5dB to kill here, you could simply choose an inductor that is twice as large. These filters aren't doing the full 6dB per octave so close to the turnover frequency. However there are issues with it. The additional phase difference with the filter when used this way, and the sealed roll off added will complicate the issue. What it basically means is that what you hear and what you see may be a little different.
Finally, since having a boost down here is not a 'natural' thing so to speak, it is going to be a matter of taste for you, for your room, the placement, etc. You have a couple of options. Do a thorough power analysis on the set, or get yourself a few inductors and work this one out by trial and error.
The crossover will be 600/600-5k/5k+
The baffle is 608Hz where the woofer will cross in sealed.
The .5's will cross in to boost the lows since we are talking about 6" drivers here.
I'm really trying to get as much low end as possible and as such the .5's will be in a ported enclosure.
I am trying to get fast bass that has plenty of punch but enough low end to satisfy most music while trying to meet WAF.
The baffle is 608Hz where the woofer will cross in sealed.
The .5's will cross in to boost the lows since we are talking about 6" drivers here.
I'm really trying to get as much low end as possible and as such the .5's will be in a ported enclosure.
I am trying to get fast bass that has plenty of punch but enough low end to satisfy most music while trying to meet WAF.
What you describe has a lot to do with harmonics. The region above 1000Hz has a considerable influence on bass, but this only comes together if the lower harmonics are well balanced. These harmonics (above around 200Hz) are usually affected by reflections, such as floor and ceiling bounce which ought to be minimised in the interest of things sounding balanced. In fact, balance is the key in all this.
You can get away with some boost below around 200Hz but too much will sound muddy. If you over boost the region below around 600Hz everything will sound too rounded and lacking in detail, you'll lose the 'whack' and 'snap'.
You can get away with some boost below around 200Hz but too much will sound muddy. If you over boost the region below around 600Hz everything will sound too rounded and lacking in detail, you'll lose the 'whack' and 'snap'.
Hi,
Now your discussing a 2 way c/o not a 0.5 way.
For a 0.5 way the 8ohm bass/mid has no high pass.
The 4 ohm pair (presumably) in series should be c/o to provide correct BSC.
IMO if you model excursion you'll find with the 3 drivers a 2 way c/o
is best. For a 0.5 way you really should use two 8 ohm drivers.
The sealed/vented split option is unusual but has been done e.g. see :
http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Auriga_copy.pdf
rgds, sreten.
http://sites.google.com/site/undefinition/diy
(see if nothing else, the excellent FAQs)
http://techtalk.parts-express.com/showthread.php?t=219617
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