Hi guys!
After long research,discusion and space menangment,plan is finished!
I'm gona build a sealed subwoofer,in box of 120l. In that 120l is everything calculated,driver,bracing,damping.
Woofer is Eminence Kappa pro 18lf-8.
Yamaha P3200 in bridge mode will be power monobloc for woofer.
I'm also gona make linkwitz transform in try to get as flat as posible down to 20Hz.
Woofer is big,amp is big so i have place for at least 20dB gain if needed.
I will use woofer in home setup for music,maybe some time for movies,but music is first plan.
Woofer will play L i R chanel in mono mode,it have only 1 coil.
And that will be help to my Dallas II with Fostex FE206EN and Monacor super tweeter driven by KT88 SE amp.
They play almost flat from 55Hz to 15000Hz,+/-3dB.
I'm happy with that but i want low end.
For now i put woofer in H frame,and its driven with subwoofer modul 150W 8Ohm,with activ crossover. Its ok,but is not linear and i think that can be much cleaner without thos subwoofer module.
So,the only thing wich is left undefined is crossover,low pass filter.
What to use for that purpose,what will you use in this situation and why.
Passive or active? I know there are nice analog active crossover,but 3k€ is waaaay to much for me in this situation.
I will take signal from KT88 SE speaker out,paralel with Dallas.
So im not sure what to use. Some old speaker builder,from MIR AUDIO told me to use passive and nothing else,that everything else will color signal.
And if this is the best way to go,what to do with phase if in the end i need to switch it?
After long research,discusion and space menangment,plan is finished!
I'm gona build a sealed subwoofer,in box of 120l. In that 120l is everything calculated,driver,bracing,damping.
Woofer is Eminence Kappa pro 18lf-8.
Yamaha P3200 in bridge mode will be power monobloc for woofer.
I'm also gona make linkwitz transform in try to get as flat as posible down to 20Hz.
Woofer is big,amp is big so i have place for at least 20dB gain if needed.
I will use woofer in home setup for music,maybe some time for movies,but music is first plan.
Woofer will play L i R chanel in mono mode,it have only 1 coil.
And that will be help to my Dallas II with Fostex FE206EN and Monacor super tweeter driven by KT88 SE amp.
They play almost flat from 55Hz to 15000Hz,+/-3dB.
I'm happy with that but i want low end.
For now i put woofer in H frame,and its driven with subwoofer modul 150W 8Ohm,with activ crossover. Its ok,but is not linear and i think that can be much cleaner without thos subwoofer module.
So,the only thing wich is left undefined is crossover,low pass filter.
What to use for that purpose,what will you use in this situation and why.
Passive or active? I know there are nice analog active crossover,but 3k€ is waaaay to much for me in this situation.
I will take signal from KT88 SE speaker out,paralel with Dallas.
So im not sure what to use. Some old speaker builder,from MIR AUDIO told me to use passive and nothing else,that everything else will color signal.
And if this is the best way to go,what to do with phase if in the end i need to switch it?
https://sound-au.com/project123.htm A simple but good X- over for your set up, combine both low outputs for your mono sub.
Don't take the signal from the output of your KT, feed the KT with the high output of the X over.
Don't take the signal from the output of your KT, feed the KT with the high output of the X over.
I would strongly advise against trying to "go flat to 20Hz". You are overlooking an important design variable: the room. Unless the room and any connected air space is rather large, the subwoofer will combine with the low frequency room gain. If you don't want the low bass to sound bloated, it would be a better approach to try and figure out what the room gain might be for your listening space and then set the LT parameters so that the combination is reasonably flat. THis will take some study and modeling, or you can do it by ear if you have none of those skills. A starting point might be Q=0.6 and Fc=35Hz. Smaller rooms require Fc to be higher than this, and very large rooms will require Fc to be lower.
Although you have an 18 inch driver its not really a subwoofer - it's a pro audio woofer. Xmax (8mm) is not all that high, but if your space is modest in size that will probably be enough. The sensitivity below Fs (32 Hz or so) is not high, so you will need all the power of that amp.
I did a similar thing back in the late 1990s. I bought two EMinence 18" pro audio woofers and used a Carver M1.0t amp to drive them, with an active, adjustable LT circuit from Marchand Audio. Both woofers were in about 7 cubic feet. It didn't sound very good and was not the strong low bass I had hoped for despite twin 18s. But that was before I knew any better...
At least that will be better than your small H-frame for the low bass you seek!
I almost forgot. Just get a cheap (used is fine) dBx 223 or 223xl analog crossover. It will sum to mono for the sub and has easy to use controls. That should be perfect for your needs and it is built well.
Although you have an 18 inch driver its not really a subwoofer - it's a pro audio woofer. Xmax (8mm) is not all that high, but if your space is modest in size that will probably be enough. The sensitivity below Fs (32 Hz or so) is not high, so you will need all the power of that amp.
I did a similar thing back in the late 1990s. I bought two EMinence 18" pro audio woofers and used a Carver M1.0t amp to drive them, with an active, adjustable LT circuit from Marchand Audio. Both woofers were in about 7 cubic feet. It didn't sound very good and was not the strong low bass I had hoped for despite twin 18s. But that was before I knew any better...
At least that will be better than your small H-frame for the low bass you seek!
I almost forgot. Just get a cheap (used is fine) dBx 223 or 223xl analog crossover. It will sum to mono for the sub and has easy to use controls. That should be perfect for your needs and it is built well.
Thanks! Sound's like a good solution.
Signal i will take from KT88 from speaker out becuose i hear diference on otber systems when we try sub out on amp and speaker out. Every amp give some coulor to final output so there is no better matching then to take speaker signal.
What if i build just low pass filter,so just half of xover,eill that work? Becuose for my situation i need it just for woofer.
Thnks! I dont know how to calculate room gain,but idea is to make LT on breadboard and then listen,messure response onistening position i see where am i and from there start with fine tuning.
My idea was to start with Fc=20 or even 18Hz,but i will try your advice to see what is hapening.
So you think dBx 223 is clean enough for woofer? How much did you pay for used one?
I look for dBx 223 and found one on used market. Im waiting for replay becuose guy sell it with bass bins and amp. I hope he will sell it alone.
It realy have everithing i need. And if sound is good...than this is good way to start.
I hope guy will sell it snd give good price🤞🤞
I don't think you understand how this works, the X over works on line level signals, not speaker output signals from an amp..........
Source.....X -over high ........KT 88
X -over low ........P 3200
Just my 2 cents.
Yes,i understand,but you use simple resistor circuit and then you get again "line" signal,but with coloration wich your amp make.
Here you can see some info on this topic. This is how i use it for last 2 years and stil workin perfectly!
https://www.diyaudio.com/community/...nvert-a-speaker-out-to-line-level-out.166500/
OK got it, make sure you use metal film resistors in that circuit.
Sorry guy, you are on a very strange path.
Even if it works to drive a sub amp from the speaker out of another amp, this is a very crude way to do it.
As you even have main speakers, with caps and coils as x-over, connected to the amp out, these will have an unpredictable effect on the once clean output signal. This makes it a no go from a serious view.
Tube amps have even less potential to keep the voltage at the speaker output identical to the input signal. So you do not have a linear voltage input for a sub from such a construction. Which can be described as "garbage in = garbage out" situation for an low frequency signal. So your whole project failed even before starting.
I know, you are one of the "tube amps sound so bla, bla" guys, but all you get is an unpredictable diffused and distorted signal for your sub amp. You tell your self you like the "sound" from this output, just because you never had a well build, room matched sub.
You seem to have no idea what raw response an 18" PA speaker will give you from closed 120 liter. You will hardly hear any bass at all and a Linkwitz transform will not work in your small room. "Not work" because it does not correct for the room influence.
You need a good measuring microphone and an DSP to maybe get some descend sound.
With a DSP and measuring you might even get your H-baffel work in this room, but only if you take the clean input signal from the pre amp.
Then, if anything starts to make sense, you may try to distort the low frequency input signal to the DSP with your "special valve sparkle unicorn" bass.
You are a typical example of what one get's in a critical situation if he does not measure and mixes in all kind of different information from the net. Sorry again.
Even if it works to drive a sub amp from the speaker out of another amp, this is a very crude way to do it.
As you even have main speakers, with caps and coils as x-over, connected to the amp out, these will have an unpredictable effect on the once clean output signal. This makes it a no go from a serious view.
Tube amps have even less potential to keep the voltage at the speaker output identical to the input signal. So you do not have a linear voltage input for a sub from such a construction. Which can be described as "garbage in = garbage out" situation for an low frequency signal. So your whole project failed even before starting.
I know, you are one of the "tube amps sound so bla, bla" guys, but all you get is an unpredictable diffused and distorted signal for your sub amp. You tell your self you like the "sound" from this output, just because you never had a well build, room matched sub.
You seem to have no idea what raw response an 18" PA speaker will give you from closed 120 liter. You will hardly hear any bass at all and a Linkwitz transform will not work in your small room. "Not work" because it does not correct for the room influence.
You need a good measuring microphone and an DSP to maybe get some descend sound.
With a DSP and measuring you might even get your H-baffel work in this room, but only if you take the clean input signal from the pre amp.
Then, if anything starts to make sense, you may try to distort the low frequency input signal to the DSP with your "special valve sparkle unicorn" bass.
You are a typical example of what one get's in a critical situation if he does not measure and mixes in all kind of different information from the net. Sorry again.
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No problem,thanks for your opinion!
One info about my speakers,inside are fostex FE206EN driven as full range,and super tweeter with one cap in circuit. So no coils and no xover.
And second thing,this is like a women. If i like big chubby women and you like thin bone women,that dosent mean that one of us is wrong,its just difrent aproch and diferent details wich gives you plesure.
So thx for your opinion but i stick whit my way and posebilitis that i have now.
Cheers!
The DBX223 has everything you need other than the low frequency EQ and a high pass below the EQ.
I bought one back when DSP tended to sound worse than analog, later I bought DBX DriveRackPA, got rid of my analog EQs and kept the DBX223 for a back-up crossover.
The DBX223 only has one HP choice, 40Hz.
Odd thing about the DBX223, 40Hz HP cuts at 24dB per octave to only -22dB, then rises back up below 8Hz to only -12dB.
At any rate, a DSP like the
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4-hd
is inexpensive considering it can do any transform EQ and HP you would like, and also has 4 presets, useful for different types and volume levels for music and movies.
Art
That sounds very very good. It offers all solution to all my problems. Only thing what i can not find for now in manual is if it can make mono sub out from stereo input?
But if can make all this things,i supose it can do such simple thing also?
Yes, on the Inputs and Routing tab, set the sub output to both Input 1 (L) and Input 2 (R) (page 25 of the manual).
If you decide to add additional subs, you can choose whether to go stereo or mono, and can also use completely different parameters for each sub.
High passing the Dallas II around 55Hz will clean up their response when the program material has a lot of low end.
Thank you Art very much!🙏
So your advice is also to cut signal before SE KT88 and Dallas,not to go with full signal in SE KT88 and then take signat to DSP only for sub?
The Fostex FE206EN has only 0.8mm linear excursion (Xmax), below the horn cutoff very little power will push the coil out of the magnetic gap.
High passing the Dallas will keep low frequency content from modulating the upper frequencies.
High passing the Dallas will keep low frequency content from modulating the upper frequencies.
How good is dac inside? Its hard to belive it will make good job for so small money,and probably with switching power supply.
Can you get so much with high passing that is worth to give exelent analog signal to be convertet to digital,cut,and then back converted to analog?
I dont have experience with dsp,but i never heard dac for 200,300€ to sound better then my setup now,so its hard to believe this can make better sounfing Dallas than its now.
For sub sure ok.
Can you get so much with high passing that is worth to give exelent analog signal to be convertet to digital,cut,and then back converted to analog?
I dont have experience with dsp,but i never heard dac for 200,300€ to sound better then my setup now,so its hard to believe this can make better sounfing Dallas than its now.
For sub sure ok.
Depending on where you live, this one may be a better option for 120€ and your PA amp will be more happy with it.
https://www.diyaudio.com/community/threads/t-racks-4x4-mini-dsp-undressed.394296/#post-7232962
The simple cause for the low price- high performance in PA electronics is the huge number produced in robust cases.
If you spend 500€ for a housing, 200€ for fancy connectors, 50€ for a heavy toroid transformer, wire it with Teflon silver and write some Voodoo story around it, you may sell this 120€ DSP as a 2000€ Hifi product. That is how a lot of high end works. Same chips inside, more Voodoo around.
https://www.diyaudio.com/community/threads/t-racks-4x4-mini-dsp-undressed.394296/#post-7232962
The simple cause for the low price- high performance in PA electronics is the huge number produced in robust cases.
If you spend 500€ for a housing, 200€ for fancy connectors, 50€ for a heavy toroid transformer, wire it with Teflon silver and write some Voodoo story around it, you may sell this 120€ DSP as a 2000€ Hifi product. That is how a lot of high end works. Same chips inside, more Voodoo around.
Both the technology and my ears have advanced far beyond noticing A/D conversions 😉
You can also get the Dallas II +/-3dB response down to +/- 1dB, time align the phase between the mains and subs, and if you find the improvements are not worth the A/D conversions, you can skip it.
Lucky you,my ears are still developing😁
Thanks for advice,i think i will go with minidsp 2x4 hd,have all in one place so its a good starting point if not finishing one.
Do you maybe know where is the best price for europe?