Hello from Melbourne,
I am planning to build my first 4 way with the following drivers and just had some questions, any help would be appreciated !!
Sub 6.5”
Dayton – Classic series
6.5 inch
4 ohm
100W
MidBass 6.5”
SB accoustics SB17MFC35 – 4 or 8
4 or 8 ohm ?????
51-100w
Mid 4”
Dayton - RS100P-4 or 8???
4 or 8 ohm ??
30W
Tweeter
Sb accoustics ring radiator 4 ohm
100w
I have a Chinese valve amp MC5881 running push pull on 6l6 tubes which might put out 20w at best Id say. It has got taps for 4 ohm and 6 ohm speakers. It currently drives a pair of 4 ohm Dynaudio DM2/7 to pretty loud levels. My rooms about 6x6 meters.
My question is around
1. What ohm drivers should I get for the midbass and midrange?
2. Should I get all 4ohms and then if, after the crossovers have been designed the impedance is too low then add some resistors at the beginning to increase the impedance .
3. Or should I start with 8 ohms for the midbass and midrange?
4.Last but not least will my amp be powerful enough to drive this 4 way speaker when finished?
5. Does any one see any problems with drivers selected?
Dont have a lot of choice for these things in Australia
I am planning to build my first 4 way with the following drivers and just had some questions, any help would be appreciated !!
Sub 6.5”
Dayton – Classic series
6.5 inch
4 ohm
100W
MidBass 6.5”
SB accoustics SB17MFC35 – 4 or 8
4 or 8 ohm ?????
51-100w
Mid 4”
Dayton - RS100P-4 or 8???
4 or 8 ohm ??
30W
Tweeter
Sb accoustics ring radiator 4 ohm
100w
I have a Chinese valve amp MC5881 running push pull on 6l6 tubes which might put out 20w at best Id say. It has got taps for 4 ohm and 6 ohm speakers. It currently drives a pair of 4 ohm Dynaudio DM2/7 to pretty loud levels. My rooms about 6x6 meters.
My question is around
1. What ohm drivers should I get for the midbass and midrange?
2. Should I get all 4ohms and then if, after the crossovers have been designed the impedance is too low then add some resistors at the beginning to increase the impedance .
3. Or should I start with 8 ohms for the midbass and midrange?
4.Last but not least will my amp be powerful enough to drive this 4 way speaker when finished?
5. Does any one see any problems with drivers selected?
Dont have a lot of choice for these things in Australia
hey thanks,
The only major shortcoming is the bass from them. They are not sorely lacking in any way but id like some more. Plus the whole diy speaker thing has me a bit hooked I have to admit.
The other option was just to build two passive sub boxes to sit in parallel under the Dynaudio to enhance the bass. do you think that would be a better option?
No, you want to design a 4 way and then build it. Seeing that way your are planning a big mistake. To put it simple, before running you have to learn to walk.
I'd simply buy/build a sub or a couple of subs. But IMHO the correct integration between the speakers and the subs has to go with powered subs, with integrated and customizable crossover. Without HP filter to the speakers you probably need to put a socket or whatever in the reflex tubes to obtain a 12db/octave rolloff.
Ralf
Apart for smaller box requirement, your chosen sub is not better (deeper/louder/more excursion) than the woofer, making a 4-way not better than the 3-way.
Could build a pair of sub with cabinets just a bit wider than the dynaudio Dm2/7
A bit deeper cabinet with an 8" or 10" driver side mounted
Then place the Dynaudio on top.
Have a read here, Jamesblond has built a pair. (last page has pictures)
I'd like some pointer on an idea for a 12" sub - Morel or ScanSpeak
A bit deeper cabinet with an 8" or 10" driver side mounted
Then place the Dynaudio on top.
Have a read here, Jamesblond has built a pair. (last page has pictures)
I'd like some pointer on an idea for a 12" sub - Morel or ScanSpeak
Thanks all for your suggestions.. although im not sure how my valve amp will be able to send signal to the powerd sub as it doesnt have a sub out. Will need to figure that out. Can i send signal to a sub high level input in parallel to the dynaudio without affecting the impedance?
Looking at the replies the 4 way ive got in mind might not be the best way here. Ill try and think about a 3 or 2.5 way or just a pair of subs underneath the dynaudios.
Looking at the replies the 4 way ive got in mind might not be the best way here. Ill try and think about a 3 or 2.5 way or just a pair of subs underneath the dynaudios.
Serious bass requires 3 things:
1. Low F3
2. Large excursion AND / OR large surface area
3. Consideration of room volume to fill
I wouldn't consider a 6.5" driver for serious bass unless I was in a closet, nearfield or had music without any bass content.
Why not build a sealed Qtc 0.5 12" subwoofer? You'll get lots of lean / tight / low bass with the right driver and will integrate well with your Dynaudio mains with a variable lowpass 12dB filter on an active plate amp.
1. Low F3
2. Large excursion AND / OR large surface area
3. Consideration of room volume to fill
I wouldn't consider a 6.5" driver for serious bass unless I was in a closet, nearfield or had music without any bass content.
Why not build a sealed Qtc 0.5 12" subwoofer? You'll get lots of lean / tight / low bass with the right driver and will integrate well with your Dynaudio mains with a variable lowpass 12dB filter on an active plate amp.
Another vote for a sub to sit below the Dynaudios.
Powered subwoofers usually have speaker-level inputs with a very high impedance - the amp won't notice it's doing any extra work. You run the wires from the main speakers to the sub's speaker-level inputs, and away you go.
That'll get you as much bass extension as you like, although it might be worth finding a way to put a highpass filter on the amp feeding the Dynaudio speakers. That way, the 6" midrange cone isn't flapping around trying to do bass.
Chris
Signal for an active subwoofer usually comes from the preamplifier, not poweramp. Most integrated amps have line-out that follows volume potentiometer. Then you loose the highpass filtering (of main speakers) but all subs and plate amplifiers have adjustable lowpass filter and volume control.
Even better control can be acheved with DSP like Minidsp 2x4HD between pre-and power amplifiers. (but most valve amp users hate everything digital along the line). With dsp you control equalization of each speaker and some room effects, crossovers, delay and spl balance. It is a totally different case and sound quality jumps to another spheres! You can still use our favourite valve poweramp to get those lovely harmonic distortions added!
A 2,5 or 3-way with a decent size bass drivers is wise solution unless one is ready to go big and expensive. If you want tho hear what happens below 40Hz, you need a sub.
2x8" or one 10-12" bass with low Fs and low tuning are minimum requirements for good low-distortion bass in normal living room without a sub, with modest spl. Anything less and you need a subwoofer. This kind of speaker is usually 3-way, or 4-way with active subwoofer.
What comes to power requirement, large multiway speakers typically have much better efficiency than 2-ways, so power requirement gets easier! Don't look at rated power tolerance (100W), look at efficiency (87 dB/1W)! With wise choice of bass drivers a 3-way can have efficiency of 92-95dB/1W when 2-way are 83-86 dB/1W
ps. My No2 stereo system has a tube preamplifier that I use for source selection and volume control. It's line out signal goes to Minidsp 2x4HD, then to solid state class A/AB power am and to subwoofer's classD amp. Dsp equalizes main speaker's and sub's measured room responses, sums L+R to subwoofer, sets crossover between them (I Like LR2 instead of the typical LR4), balances spl and sets some delay to main speakers sot that sub intergates better with the shallow slopes that I use. For quick adjustment the sub's plate amp has it's own volume control too. Sub has two 15" drivers in large closed box (150W amp easily makes them clonk). I get straight response from 15Hz up and low distortion. It is in a small room and low modes are a problem that I can't avoid. In a large room it is wise to use at least two subs near each speaker, or preferably 3-4 subs placed in different locations to control room modes.
Even better control can be acheved with DSP like Minidsp 2x4HD between pre-and power amplifiers. (but most valve amp users hate everything digital along the line). With dsp you control equalization of each speaker and some room effects, crossovers, delay and spl balance. It is a totally different case and sound quality jumps to another spheres! You can still use our favourite valve poweramp to get those lovely harmonic distortions added!
A 2,5 or 3-way with a decent size bass drivers is wise solution unless one is ready to go big and expensive. If you want tho hear what happens below 40Hz, you need a sub.
2x8" or one 10-12" bass with low Fs and low tuning are minimum requirements for good low-distortion bass in normal living room without a sub, with modest spl. Anything less and you need a subwoofer. This kind of speaker is usually 3-way, or 4-way with active subwoofer.
What comes to power requirement, large multiway speakers typically have much better efficiency than 2-ways, so power requirement gets easier! Don't look at rated power tolerance (100W), look at efficiency (87 dB/1W)! With wise choice of bass drivers a 3-way can have efficiency of 92-95dB/1W when 2-way are 83-86 dB/1W
ps. My No2 stereo system has a tube preamplifier that I use for source selection and volume control. It's line out signal goes to Minidsp 2x4HD, then to solid state class A/AB power am and to subwoofer's classD amp. Dsp equalizes main speaker's and sub's measured room responses, sums L+R to subwoofer, sets crossover between them (I Like LR2 instead of the typical LR4), balances spl and sets some delay to main speakers sot that sub intergates better with the shallow slopes that I use. For quick adjustment the sub's plate amp has it's own volume control too. Sub has two 15" drivers in large closed box (150W amp easily makes them clonk). I get straight response from 15Hz up and low distortion. It is in a small room and low modes are a problem that I can't avoid. In a large room it is wise to use at least two subs near each speaker, or preferably 3-4 subs placed in different locations to control room modes.
Last edited:
I'm Having a hard time with this one. Couldn't you use multiple drivers for the base if you chose to limit baffle width. I'm using a single sb acoustics 6 inch driver in a simple two way with a small port and that produces prodigious amount of base in 15x15 foot room. Why not use a quality midbase driver if there are size constraints.
OP`s Tube amp is integrated by the look so even though MiniDSP 2x4 is an excellent choice, it would not be easy to integrate.
A plate Amp with High level inputs (and DSP) would be the way forward.
As juhazi has noted the Dynaudio`s are 86db
A larger sub driver will be a few db higher than this already(or have a bigger xmax)
so you will have gains already.
If you want a totally flat response 86 across the board, Im sure you would be able to go pretty low too
If you are going to make sawdust, Get yourself a Umik-1 for starters!
Acoustic Measurement Tools : UMIK-1
A plate Amp with High level inputs (and DSP) would be the way forward.
As juhazi has noted the Dynaudio`s are 86db
A larger sub driver will be a few db higher than this already(or have a bigger xmax)
so you will have gains already.
If you want a totally flat response 86 across the board, Im sure you would be able to go pretty low too
If you are going to make sawdust, Get yourself a Umik-1 for starters!
Acoustic Measurement Tools : UMIK-1
Definitions of prodigious will vary.
I'd say that starts at 120dB below 50Hz. Others will disagree.
FWIW, a bunch of smaller drivers will have plenty of cone area, but you also need excursion to make bass, and larger drivers tend to have more of that.
Chris
The problem I see is that the first three drivers are too similar. Driver selection in multi-way systems is about going to extremes: each one should specialize in a particular frequency range. Were I to build a four way, it would be something like:
(Sub)Woofer ~12" 20-100hz
Midbass 3-5.25" 100-2500hz
Tweeter 2500hz-10Khz
Supertweeter 10-20Khz
If it were me, I'd keep that Daton and the ring radiator, and pair them with a 12" woofer and make a 3 way or satellite/sub. As mentioned above, there is no substitute for square inches when it comes to bass. And it is a good idea to cover (at least) 200-2000hz with a single driver, this is where our ears are most sensitive to phase/timing, etc.
(Sub)Woofer ~12" 20-100hz
Midbass 3-5.25" 100-2500hz
Tweeter 2500hz-10Khz
Supertweeter 10-20Khz
If it were me, I'd keep that Daton and the ring radiator, and pair them with a 12" woofer and make a 3 way or satellite/sub. As mentioned above, there is no substitute for square inches when it comes to bass. And it is a good idea to cover (at least) 200-2000hz with a single driver, this is where our ears are most sensitive to phase/timing, etc.
While excursion also gives you the displacement, its downside is it is tied with higher distortion and lower efficiency because of the much higher mass, and high losses in the suspension which can't be compensated by the motor, especally at low volumes. So for a tube amp without a subwoofer with its own amp, NO, Surface is the thing you want. Unfortunately more surface also means you need more enclosure volume, VAS is directly tied to the cone surface area. That also applies if you use several smaller drivers. Or in other words: Your speaker gets bigger. You need to set a compromise there
Tube amps greatly benefit in fidelity/sound quality from impedance linearisation. The parts for that can get expensive at low crossover frequencies because of the high value. It might be much cheaper to buy a dedicated subwoofer amp + sub than to build a passive 3- or even 4-way speaker.
Sidenote: Your amp doesn't like low impedances very much, I'd suggest you'd stay at 8 Ohm drivers.
Hi all thanks a lot for the informative advice. I do have a umik and a dats v2 as i have built a few speakers before.
If i connect my tube amp to the subs high level input .. Does running the speakers off the high level outputs from a subwoofer mean that im hearing the subs amp rather than my tube amp?
If i connect my tube amp to the subs high level input .. Does running the speakers off the high level outputs from a subwoofer mean that im hearing the subs amp rather than my tube amp?
No, it does not work that way, you'd use every disadvantage of every involved part of the chain. You need a active crossover or DSP between your preamp and the amplifiers. A pre-out/mains-in wiring can be added to your tube amp and it's not difficult to do it. That way you don't need a different preamp, the signal goes from the source to the usual tube amp inputs, it goes then through the pre-out into the active crossover, the crossover gives the filtered signal back to the main amp stage and to the subwoofer amp aswell.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.