I am in the middle of building Zaph's Project #14
These are fairly small speakers (4" woofer), with power handling issues if driven in the lower frequency's... thus a sub is rather encouraged.
Also encouraged is a wife that doesn't crush me dead spending money ;-)
To that end, I have a theory 🙂
I am driving these speakers from a fairly cheap Sony receiver -- STR-DE598. 70w per channel (in theory 🙂). It has a separate set of outputs "A" vs "B" (A does 6.1, B is just stereo).
So, I simply build a box out of the Dayton 8" sub, and add a passive cross over to it. I am not super sure what "dual voice coil" means, but I assume it means I hook up both "left" and "right" outputs to the same speaker? Does that mean its getting double the power?
I think I can lie to my receiver, and tell it I have a sub on the "A" set, and it will let me set the crossover value from 40-160hz, 160hz being best for power handling on the 4" woofers. Otherwise I can just add a pass xover to those as well, and maybe do it at 200hz to further help power handling.
One problem will be balancing the volumes of the sub vs mains, I guess I can just add a potentiometer to the sub (assuming its louder than the mains... which seems likely if its getting double power, and has a higher SPL @ 89db vs 85db on the 4" woofers).
Anyway... thanks for any input you guys have. Trying to avoid having to buy/build an amp for the sub... and thus save some duckets and some wife aggro 🙂
These are fairly small speakers (4" woofer), with power handling issues if driven in the lower frequency's... thus a sub is rather encouraged.
Also encouraged is a wife that doesn't crush me dead spending money ;-)
To that end, I have a theory 🙂
I am driving these speakers from a fairly cheap Sony receiver -- STR-DE598. 70w per channel (in theory 🙂). It has a separate set of outputs "A" vs "B" (A does 6.1, B is just stereo).
So, I simply build a box out of the Dayton 8" sub, and add a passive cross over to it. I am not super sure what "dual voice coil" means, but I assume it means I hook up both "left" and "right" outputs to the same speaker? Does that mean its getting double the power?
I think I can lie to my receiver, and tell it I have a sub on the "A" set, and it will let me set the crossover value from 40-160hz, 160hz being best for power handling on the 4" woofers. Otherwise I can just add a pass xover to those as well, and maybe do it at 200hz to further help power handling.
One problem will be balancing the volumes of the sub vs mains, I guess I can just add a potentiometer to the sub (assuming its louder than the mains... which seems likely if its getting double power, and has a higher SPL @ 89db vs 85db on the 4" woofers).
Anyway... thanks for any input you guys have. Trying to avoid having to buy/build an amp for the sub... and thus save some duckets and some wife aggro 🙂
If the A and B outputs are driven by the same channels on the receiver, then having both on is like wiring them in parallel. In that case you will present too low of an impedance to the receiver.
It is a surround receiver, why not just use the rear channels.
Dan
It is a surround receiver, why not just use the rear channels.
Dan
So... basically, you are saying "your receiver is happy w/ an 8 ohm speaker, if you do that madness... it will look like 4 ohm's, and mr. receiver may get quite cranky".
Sadness.
re: using rear channel... not sure how that would work. I don't think there is a mode where it is sending the same signal to the rear speakers as the fronts.
Still, even if the dual coil madness doesn't work, couldn't I sent just the left (or right) to my passive sub?
Sadness.
re: using rear channel... not sure how that would work. I don't think there is a mode where it is sending the same signal to the rear speakers as the fronts.
Still, even if the dual coil madness doesn't work, couldn't I sent just the left (or right) to my passive sub?
I think in A+B mode, these will be in series, since I doubt if the amp maufacturer will allow for the amp to be overdriven.
All my amps have the series set up, I can notice the volume levels on A to reduce when the set B is also switched on.
Also, I doubt if there are so kind manufacturers who provide an extra set of amplifiers to power another set of speakers.
Now for setting the crossover frequency on your receiver, you cannot do it only for one set(A or B).
In case you really want to use a passive sub through set B, a low pass filter is all you need. But it needs careful tailoring to match up with the mains. In other words, it would be similar to using 3-way loudspeaker if your present mains is 2-way.
Lots of effort required.🙂. May not be worth the effort afterall.
BTW, dual voice coils can be connected as you say, but take care of polarity.
"Does that mean its getting double the power?" - Yes
Regards,
Francis
P.S: I hate to call your by name, you are not😉 😀
All my amps have the series set up, I can notice the volume levels on A to reduce when the set B is also switched on.
Also, I doubt if there are so kind manufacturers who provide an extra set of amplifiers to power another set of speakers.
Now for setting the crossover frequency on your receiver, you cannot do it only for one set(A or B).
In case you really want to use a passive sub through set B, a low pass filter is all you need. But it needs careful tailoring to match up with the mains. In other words, it would be similar to using 3-way loudspeaker if your present mains is 2-way.
Lots of effort required.🙂. May not be worth the effort afterall.
BTW, dual voice coils can be connected as you say, but take care of polarity.
"Does that mean its getting double the power?" - Yes
Regards,
Francis
P.S: I hate to call your by name, you are not😉 😀
francis varkey said:
LOL. I am so dumb 🙂
Okay, so xover from the receiver is totally out (else I am only gonna send high freq's to not only the mains... but my sub... not savory).
So, I am thinking passive 4th order xover (at say... 175hz) for both my two way Zaph 14's, and my hypothetical sub (which will be that dual voice coil Dayton, hooked up to the "B" mode)
Hi,
There is no way round doing this properly.
A passive sub will cause you untold grief, unless you get the right
specification driver you will never get it right, even if you do I doubt
you'll ever get the crossover to work properly. The crossover parts
wil likely cost you more than the plate amplifier below.
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=300-784
Is the sort of thing you need. Note that you should use something
like WinISDPro to match the limited maximum levels of your speakers
to the subwoofer level. There is no point building a sub far too loud
for the main speakers, a less loud sub gives deeper bass. That is
choose a bass driver of the correct sensitivity for the application.
🙂/sreten.
There is no way round doing this properly.
A passive sub will cause you untold grief, unless you get the right
specification driver you will never get it right, even if you do I doubt
you'll ever get the crossover to work properly. The crossover parts
wil likely cost you more than the plate amplifier below.
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=300-784
Is the sort of thing you need. Note that you should use something
like WinISDPro to match the limited maximum levels of your speakers
to the subwoofer level. There is no point building a sub far too loud
for the main speakers, a less loud sub gives deeper bass. That is
choose a bass driver of the correct sensitivity for the application.
🙂/sreten.
You are a party pooper, and you get to tell my wife 🙂
Probably go with this one I guess:
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=50-6266A
My receiver can cross over between 40 and 160hz... obviously higher the better in my scenrio. I suspect 160hz will allow me to get loud enough for my tastes, else I am still gonna need to add a passive xover to my main speakers.
btw, how do I know if I have gone "too loud"? (ie, exceeded Xmax...)
Probably go with this one I guess:
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=50-6266A
My receiver can cross over between 40 and 160hz... obviously higher the better in my scenrio. I suspect 160hz will allow me to get loud enough for my tastes, else I am still gonna need to add a passive xover to my main speakers.
btw, how do I know if I have gone "too loud"? (ie, exceeded Xmax...)
Can't make out if this one has a built in power supply, whereas the one suggested by sreten does indeed have one.
If you're going to feed the sub amp from the speaker outputs, you shouldn't set the crossover in your receiver.
Since you'll then deprive the sub's amp of a significant amount of bass info.
If you use the receivers sub-out, then you can.
My advice is to set the gain(of plate amp) starting off from its minimum upto the point where you can clearly hear the low bass.
Note that the mains should be playing as well. Try not to go much beyond that.
Hope this helps,
Francis
Hi,
I really don't understand what you think is going on.
AFAIK (i don't have HT stuff, just pure Stereo) an AV amplifier that
allows you to set the main speakers high pass c/o frequency will
route bass below that frequency to the 0.1 channel.
For the subwoofer you only set its level, you use a bypass input
so the AV amplifier can implement the subwoofer low pass.
Adding a further passive high pass to the speakers will upset this.
(And require expensive components to do properly. If 160Hz ends
up being too low, basically you should have used the 5" driver)
For max levels etc model speakers and sub in WinISD Pro.
🙂/sreten.
I really don't understand what you think is going on.
AFAIK (i don't have HT stuff, just pure Stereo) an AV amplifier that
allows you to set the main speakers high pass c/o frequency will
route bass below that frequency to the 0.1 channel.
For the subwoofer you only set its level, you use a bypass input
so the AV amplifier can implement the subwoofer low pass.
Adding a further passive high pass to the speakers will upset this.
(And require expensive components to do properly. If 160Hz ends
up being too low, basically you should have used the 5" driver)
For max levels etc model speakers and sub in WinISD Pro.
🙂/sreten.
My n00b'ness is probably confusing you, I will restate how things are layed out in my head 🙂
Say I set the active xover on my receiver to 160hz, and all is pretty well... until I turn the volume up too loud (and excede the Xmax of the woofer on my main).
Two questions:
a) How do I know that happened?
b) What are my options at that point?
I actually have no idea if this is a reasonable concern, since I don't have any concept of how many decibels it takes to get on the loud side, nor whether my HT receiver can reach those levels.
But if it does happen (all hell breaks loose at a volume I want to listen at)... I am just wondering what I can do about it 🙂
So, say I want it louder... seems to me the only option would be to xover a bit higher to keep the lows out of the mains... say, xover at 200hz.
For the sub, the dayton plate amp can xover as high at 200hz (the other plate amp I listed only goes to 160). I suppose I won't be able to use the "sub out" out my receiver at that point (since I am sure its always crossover, and won't go higher than 160)... so I would have to use speaker input's to the plate amp for the sub, and set it for 200hz. Fine.
For the mains... I would need to add a high pass filter at 200hz.
Okay, all that was to answer "I really don't understand what you think is going on." 🙂
btw, you can see http://www.zaphaudio.com/audio-speaker14.html for Zaph's page on these speakers, and you can look at the power handling chart "Power vs excursion 1-128 watts" to get a feel for the xover values I am talking about.
Hopefully this is is all strictly acedemic, I don't suspect I will want to play these loud, ... I am just concerned since I have no idea what "loud" is 🙂
Say I set the active xover on my receiver to 160hz, and all is pretty well... until I turn the volume up too loud (and excede the Xmax of the woofer on my main).
Two questions:
a) How do I know that happened?
b) What are my options at that point?
I actually have no idea if this is a reasonable concern, since I don't have any concept of how many decibels it takes to get on the loud side, nor whether my HT receiver can reach those levels.
But if it does happen (all hell breaks loose at a volume I want to listen at)... I am just wondering what I can do about it 🙂
So, say I want it louder... seems to me the only option would be to xover a bit higher to keep the lows out of the mains... say, xover at 200hz.
For the sub, the dayton plate amp can xover as high at 200hz (the other plate amp I listed only goes to 160). I suppose I won't be able to use the "sub out" out my receiver at that point (since I am sure its always crossover, and won't go higher than 160)... so I would have to use speaker input's to the plate amp for the sub, and set it for 200hz. Fine.
For the mains... I would need to add a high pass filter at 200hz.
Okay, all that was to answer "I really don't understand what you think is going on." 🙂
btw, you can see http://www.zaphaudio.com/audio-speaker14.html for Zaph's page on these speakers, and you can look at the power handling chart "Power vs excursion 1-128 watts" to get a feel for the xover values I am talking about.
Hopefully this is is all strictly acedemic, I don't suspect I will want to play these loud, ... I am just concerned since I have no idea what "loud" is 🙂
Hi,
what is the power output of your AV amplifier ?
Its likely on good quality programme, voltage clipping will indicate
max volume, not over excursion of the satellites bass drivers.
But heavily compressed music the story may be different.
~ 150Hz should be fine for say ~ 70w a channel AV amplifier.
🙂/sreten.
what is the power output of your AV amplifier ?
Its likely on good quality programme, voltage clipping will indicate
max volume, not over excursion of the satellites bass drivers.
But heavily compressed music the story may be different.
~ 150Hz should be fine for say ~ 70w a channel AV amplifier.
🙂/sreten.
amp: http://www.amazon.com/gp/product/B0007Y6AN0/002-2661611-3760802?v=glance&n=172282
In theory, 90w per channel I guess.
From Zaph's Page:
I am not qualified to read his graph and say how many watts I can put through if I xover at 160hz, nor how many db it will be putting out at any given wattage. But, 10w max does seem very low if I don't xover 🙂
In theory, 90w per channel I guess.
From Zaph's Page:
I am not qualified to read his graph and say how many watts I can put through if I xover at 160hz, nor how many db it will be putting out at any given wattage. But, 10w max does seem very low if I don't xover 🙂
Okay, after looking at Zaphs chart over and over, I now understand what it is saying 🙂
So, lets take 64w (reasonably high level for my amp, and 2nd from the top on Zaph's chart). That blue line... looks like it peaks at about 101db. According to http://home.new.rr.com/trumpetb/audio/dBexamp.html, that is "very loud classical" (and also the noise level a NY subway 🙂).
Looking at the correspoding ugly green/brown line 2nd from the top.... if ran full range, we expect to hit almost 10mm of excursion... not good w/ an Xmax of 2.7mm 🙂
However down there at 200hz, its only at about 2.5mm... no prob there. 160hz looks more like 3.5, and I suppose seriously hurting my speaker. 🙂
So, I would estimate that if I xover at 160hz, I can go up to more like 30w safely, which gives something like 98db (makes sense, half the watts, 3db drop)... still somewhere between "loud" and "very loud". Sounds fine to me...
Wow -- so much to learn, and that Zaph sure puts a crazy amount of info on his project pages. 🙂
So, lets take 64w (reasonably high level for my amp, and 2nd from the top on Zaph's chart). That blue line... looks like it peaks at about 101db. According to http://home.new.rr.com/trumpetb/audio/dBexamp.html, that is "very loud classical" (and also the noise level a NY subway 🙂).
Looking at the correspoding ugly green/brown line 2nd from the top.... if ran full range, we expect to hit almost 10mm of excursion... not good w/ an Xmax of 2.7mm 🙂
However down there at 200hz, its only at about 2.5mm... no prob there. 160hz looks more like 3.5, and I suppose seriously hurting my speaker. 🙂
So, I would estimate that if I xover at 160hz, I can go up to more like 30w safely, which gives something like 98db (makes sense, half the watts, 3db drop)... still somewhere between "loud" and "very loud". Sounds fine to me...
Wow -- so much to learn, and that Zaph sure puts a crazy amount of info on his project pages. 🙂
Sillyboy said:
Hi,
160Hz is already too high for your xo point unless you have stereo subs, one under each mains.
You'll know if you exceed the xmax of the speakers - you'll hear it.
If you want to increase the power handling, I'd suggest adding a woofer per side that rolls of naturally at 80Hz Q=0.71, and cross it to your mains around 200 - 300hz. - I'd go 4th order LR
Still use a sub with the mains set to small, xo 80Hz btw.
The eminence delta 12LF has been mentioned a few times on various forums - models well for a sealed box @ 80Hz
fwiw My old 5.5" mids used to struggle crossed at 250Hz. I changed to a 10" pro mid, and have since moved / am moving on to horns.
You should be able to get close to home theater levels with the added 12" drivers..if they're clean try them up to 500Hz... ?
Cheers,
Rob
EDIT:
btw home theater at reference level expects 105dB out of each speaker, with 115dB from the sub.... If you want to direct all the bass from the other speakers, expect 121dB from the sub..
Sillyboy said:
Hi,
also note that for a 2nd order Linkwitz Riley high pass the response
is 6dB down at the crossover point - equals two steps of the line.
At 160Hz c/o point I estimate to keep xmax < 2mm = ~ 70W.
For 90W per channel it should stay below ~ 3mm.
That is with a ~ 150Hz point your amp will not seriously
overdrive your bass/mid drivers into their endstops.
🙂/sreten.
Okay, so as long as I stop wimping out, and just build a powered sub, xover at about 150hz, then all is right w/ the world 🙂
Simple question: The AV receiver is going to xover at (150hz is what we chose) ... is the xover on the plate amp set at 150hz as well? What weird affect does that have? Can the xover on the plate amp be turned off usually?
Simple question: The AV receiver is going to xover at (150hz is what we chose) ... is the xover on the plate amp set at 150hz as well? What weird affect does that have? Can the xover on the plate amp be turned off usually?
Hi,
The c/o in a plate amp can usually be bypassed.
Depending on the type of filters the AV amplifier and the Sub
implement (usually 4th or 2nd order Linkwitz/Riley or Butterworth)
the AV amp and sub slopes can sometimes be combined.
Also discussed somewhere on Zaph's site, W3-781 archive I think.
You really need the bass management specs of your AV amplifier.
🙂/sreten.
The c/o in a plate amp can usually be bypassed.
Depending on the type of filters the AV amplifier and the Sub
implement (usually 4th or 2nd order Linkwitz/Riley or Butterworth)
the AV amp and sub slopes can sometimes be combined.
Also discussed somewhere on Zaph's site, W3-781 archive I think.
You really need the bass management specs of your AV amplifier.
🙂/sreten.
Sounds like Zaph is happy w/ using both xovers... good enough for me.
Okay people, lets get serious! Time to build a sub! 🙂
Goals:
#1: Cheap Cheap!
#2: Smaller the better... as long as...
#3: Reasonable match for my Zaph 14's project
a) What driver? Current thinking: This 8" dayton It says 8ohm "per coil" which still confuses me. Does that mean I can run it at 4ohm somehow? Do I want to? Some other inexpensive sub I should look at instead?
b) What amp? Parts Express 70w @ 4ohm or MCM 150w @ 4 ohm
The latter seems worth it for an extra 10 bucks. more attractive and more watts 🙂
Thanks again folks 🙂
Okay people, lets get serious! Time to build a sub! 🙂
Goals:
#1: Cheap Cheap!
#2: Smaller the better... as long as...
#3: Reasonable match for my Zaph 14's project
a) What driver? Current thinking: This 8" dayton It says 8ohm "per coil" which still confuses me. Does that mean I can run it at 4ohm somehow? Do I want to? Some other inexpensive sub I should look at instead?
b) What amp? Parts Express 70w @ 4ohm or MCM 150w @ 4 ohm
The latter seems worth it for an extra 10 bucks. more attractive and more watts 🙂
Thanks again folks 🙂
Hi,
IMO you are not spending enough on the driver.
10$ for double the power ? nobrainer, get the 150W amplifier.
You should be considering the 8" tangband drivers with 12mm of excursion.
or this :
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=55-2421
with this :
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=55-2425
All the above will make excellent compact subwoofers.
🙂/sreten.
IMO you are not spending enough on the driver.
10$ for double the power ? nobrainer, get the 150W amplifier.
You should be considering the 8" tangband drivers with 12mm of excursion.
or this :
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=55-2421
with this :
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=55-2425
All the above will make excellent compact subwoofers.
🙂/sreten.
Apparently, somebody forgot goal #1 🙂
I should probably have clarified that its not important to me to get home theater low's w/ this sub... I actually have a completely separate room for watching movies 🙂 This is just for light tv watching and music.
Can you be a bit more specific on how I will find the cheaper dayton sub lacking? (cuz there is no way I convince the wife w/ the powerful arguement of "it doesn't cost enough" 🙂)
I should probably have clarified that its not important to me to get home theater low's w/ this sub... I actually have a completely separate room for watching movies 🙂 This is just for light tv watching and music.
Can you be a bit more specific on how I will find the cheaper dayton sub lacking? (cuz there is no way I convince the wife w/ the powerful arguement of "it doesn't cost enough" 🙂)
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