Hello all,
I'm normally to find in the Solid State forum, however now I'm need some serious advise for my new active speaker systems.
At the moment, I have a pair of home made speakers with following drivers and passive filter:
Top: one 1" VIFA D26TG-05 and one Audax TW025a10
Mid: one 6.5" VIFA PL18WO09
Bas: one 15" No name crap bass
I've just got my hands on some high quality 15" bass drivers (99% equal to the bass drivers used in the new B&O BeoLab 5 1000W active speaker), and will use the oppertunity to make my self some state of the art active speakers.
As I see it now, for a 3-way system, the active crossover will be set to 200 Hz and 2 kHz. The amplifiers will be suitable 200-800 Watts each
However I have a few concerns regarding the 200 Hz crossover frq between the bass and the mid.
1. I'm afraid that the PL18 mid will sound pressed and distorted when handling high power down to 200 Hz
2. I'm not sure that I will get the right punch in the lower mid/upper bass
3. Could one or two extra 6.5" or 8" lower mid/upper bass from 150 to 500 Hz be a solution, without causing to many sound problems around the crossover frq's ???
What are your experiences????
I'm normally to find in the Solid State forum, however now I'm need some serious advise for my new active speaker systems.
At the moment, I have a pair of home made speakers with following drivers and passive filter:
Top: one 1" VIFA D26TG-05 and one Audax TW025a10
Mid: one 6.5" VIFA PL18WO09
Bas: one 15" No name crap bass
I've just got my hands on some high quality 15" bass drivers (99% equal to the bass drivers used in the new B&O BeoLab 5 1000W active speaker), and will use the oppertunity to make my self some state of the art active speakers.
As I see it now, for a 3-way system, the active crossover will be set to 200 Hz and 2 kHz. The amplifiers will be suitable 200-800 Watts each
However I have a few concerns regarding the 200 Hz crossover frq between the bass and the mid.
1. I'm afraid that the PL18 mid will sound pressed and distorted when handling high power down to 200 Hz
2. I'm not sure that I will get the right punch in the lower mid/upper bass
3. Could one or two extra 6.5" or 8" lower mid/upper bass from 150 to 500 Hz be a solution, without causing to many sound problems around the crossover frq's ???
What are your experiences????
The Vifa is a very good driver with a lot of output capability in the midbass region, I dont think you will have a problem at all. If you are really worried, try a Scanspeak driver for truely great midbass and a huge x-max of +-6mm linear and 11mm max!
Maybe I forgot to tell, that total system power will be app. 1200 Watts pr. channel 😉 (just to have reserve for dynamic peaks)
The datasheet for the VIFA PL18WO09 shows Sd=132cm^2 and Xmax=4mm and Pmax=100 watts. If you put it in a sealed box, as is often done to simplify the crossover and achieve the best transient response, the 4mm Xmax will allow SPL=109db/1m at 200Hz with about 20 watts of power.
LineSource
Thanks for your help.
I understand your calc as an upper bas would be needed to ensure high output handling capacity.....
Thanks for your help.
I understand your calc as an upper bas would be needed to ensure high output handling capacity.....
Well JMO but you seem to have no idea of actual power amplifier
output requirements for active speakers to cover each frequency
range and 200/800 watts per amplifier is so way off its not funny.
I don't see anything that would qualify the speaker as "high end".
If your into designing amplifiers, fine, stick to what you know.
🙂 sreten.
output requirements for active speakers to cover each frequency
range and 200/800 watts per amplifier is so way off its not funny.
I don't see anything that would qualify the speaker as "high end".
If your into designing amplifiers, fine, stick to what you know.
🙂 sreten.
But as an example 4 800w amplifiers used in an active 4 way
theorectically can produce peaks equivalent to the same 4
way with a passive crossover driven by a 12.8kW amplifier.
Active speakers are superb at handling wideband transient peaks.
(work out voltage swing per driver, and assume the "peak"
causes full voltage swing across each driver, not very real )
🙂 sreten.
theorectically can produce peaks equivalent to the same 4
way with a passive crossover driven by a 12.8kW amplifier.
Active speakers are superb at handling wideband transient peaks.
(work out voltage swing per driver, and assume the "peak"
causes full voltage swing across each driver, not very real )
🙂 sreten.
454Casull said:
You're right, I should have been more polite, it reads worse
than what I was thinking, just trying to get someone to stop
and think, but as he's a veteran of the solid state forum I
wasn't thinking "kid gloves" are required.
🙂 srteten.
Srteten,
I too am new to this forum.
As a veteran in the speaker forum, I’d expect you to know that a 1 kW amp in an active sub and upper bass is not too far of target. I plan a sub (with Jan) at the moment, which combined with a top system, made as either a thee or four way system, will be my new system. The question ad had was whether or not the midrange/upper bass drivers Jan has at the moment will be able to match the new 15” driver.
I plan to use a 1 kW amp for the sub, because it is a relatively small box, and therefore needs some EQ in the bottom end to perform well down to about 20 Hz. This however leaves me with the question of choice upper base driver. It must match the sub in turns of SPL and will need to be used as a “stand alone” system should I choose not to use the sub with the top system.
Ohh yes, while I remember - Active speakers often have need for amps with the same voltage swing for all channels – including the tweeter, simply to avoid clipping – as any veteran would know 🙂
What do you think about that?
\Jens
I too am new to this forum.
As a veteran in the speaker forum, I’d expect you to know that a 1 kW amp in an active sub and upper bass is not too far of target. I plan a sub (with Jan) at the moment, which combined with a top system, made as either a thee or four way system, will be my new system. The question ad had was whether or not the midrange/upper bass drivers Jan has at the moment will be able to match the new 15” driver.
I plan to use a 1 kW amp for the sub, because it is a relatively small box, and therefore needs some EQ in the bottom end to perform well down to about 20 Hz. This however leaves me with the question of choice upper base driver. It must match the sub in turns of SPL and will need to be used as a “stand alone” system should I choose not to use the sub with the top system.
Ohh yes, while I remember - Active speakers often have need for amps with the same voltage swing for all channels – including the tweeter, simply to avoid clipping – as any veteran would know 🙂
What do you think about that?
\Jens
JensRasmussen said:
I'm simply not prepared to go into this as its very complicated.
Even the basics of active speakers are not mentioned.
I'd say as any veteran is used to being misinformed.
IMO its simply impossible for an amplifier designer to
make a good active "high end" loudspeaker, TBH you
really don't have a clue whats going on.
🙂 sreten.
When in doubt, ask for help.
Please enlighten us, you seem to have the edge. What sort of amps is needed for a project like this?
\Jens
Please enlighten us, you seem to have the edge. What sort of amps is needed for a project like this?
\Jens
I assume you're thinking speaker design problems and not amplifier design problems.sreten said:
If so then I agree, I'm fairly certain I could take a typical 3-way passive, gut out the xover, substitute equivalent active line level filters and some DIY amps and get it sounding better than the original passive.
Starting from scratch I'd be paying a lot more attention to the polar response of the drivers, the baffle dimensions etc. the same as with a passive speaker. Amplification would be last on my list.
As far as I'm concerned you normally need about 100W for the tweeter, 200W for the mid and >400W for the woofer. That's assuming the same impedance and approximate passband sensitivity.
Obviously if you have a much more efficient mid, you probably need less power for the mid than the tweeter, although the baffle step might make the difference in required power an irrelevance.
The voltage swing and the gain are irrelevant, the total summed response (both axial and polar) is of prime importance.
Obviously if you have a much more efficient mid, you probably need less power for the mid than the tweeter, although the baffle step might make the difference in required power an irrelevance.
The voltage swing and the gain are irrelevant, the total summed response (both axial and polar) is of prime importance.
JensRasmussen said:
subwo1 said:
I'm probably not to comment on this as I use sleezy 9W monoblocks at the moment, and are upgrading my mid and HF bands with a 1W El-Spuddo amplifier, but; isn't a kilowatt overkill for pretty much everything exept pro audio bass? no?
Can one really get decent sounding results from kilowatts of power? I can hardly imagine anything resembling "high-end" coming from such a vast ammount of watts and speaker inefficiency..
Sreten:
No comments!
454Casull:
Thanks for sticking to the diy-spirit 😉
Jens:
Thanks for joining my thread 😉
Mudge:
Thanks for your input.
As I recall, the "normal" power distribution betwen speakers
are 75% for the bass, 20% for the mid and 5% for the tweeter.
But as Jens also pointed out (which I sadly didn't in the beginning of the thread), is that we (both Jens and I) would use a sofisticated active filter with Eq's to make the woofer go down to 20 Hz (by the way... The original Beolab has a 1000W IcePower amp to drive the active speaker) 😉
Bill Fitzpatrick:
You are right... It all depence on sensitivity of the speaker driver 😉
Rocky:
It's not all about the Wattage, but mostly current and the amplifiers ability to control the driver (especially the woofer) = damping factor..... Live concert levels (my favorite 😀 ) demands a lot of power (current) to keep the woofer from sounding whooly... My experience says that 4 times the normal listening level... 😉
Please keep posting, as this seems to be quite controversial 😉
No comments!
454Casull:
Thanks for sticking to the diy-spirit 😉
Jens:
Thanks for joining my thread 😉
Mudge:
Thanks for your input.
As I recall, the "normal" power distribution betwen speakers
are 75% for the bass, 20% for the mid and 5% for the tweeter.
But as Jens also pointed out (which I sadly didn't in the beginning of the thread), is that we (both Jens and I) would use a sofisticated active filter with Eq's to make the woofer go down to 20 Hz (by the way... The original Beolab has a 1000W IcePower amp to drive the active speaker) 😉
Bill Fitzpatrick:
You are right... It all depence on sensitivity of the speaker driver 😉
Rocky:
It's not all about the Wattage, but mostly current and the amplifiers ability to control the driver (especially the woofer) = damping factor..... Live concert levels (my favorite 😀 ) demands a lot of power (current) to keep the woofer from sounding whooly... My experience says that 4 times the normal listening level... 😉
Please keep posting, as this seems to be quite controversial 😉
ACD
From the literature, there seems to be two main philosophies for Reference 3-way designs.
1) crossover 300-400Hz and 3,000-4,000 Hz. The 3,000 is safe for most tweeters and puts 1,000 - 3,000 that is considered sensitive to phase and dispersion on one small diameter speaker, usually 5". A wide bandwidth woofer is required, usually two 10" or a light Mms 12" - 15", often in ported boxes to increase efficiency and get an additional octave. Modest slope crossovers are usable, and helpful for the bass-mid which is crossed in the main vocal range. Check reference speakers like the B&W Nautilus 804.
2) crossover 80-100Hz and 1,200-1,500Hz. This puts human voice on one driver, usually new wide BW 8" like Seas Excel, and uses new low Fs tweeter like Millennium or 27TDFC. Bass can be large Xmax 15" and reach down to 20Hz. LR4 crossovers are needed to remove strain from mid and tweet. The 8" should have curvilinear cone shape to improve high freq dispersion. Some Pro audio use 10" JBL midranges to cover this band with authority, sacrificing some sound stage dispersion for SPL. Adire Audio is coming out with wide BW and high Xmax 6.5" and 8" for both this 3-way philosophy, and also for MTMs that can go low enough to work with subwoofers crossed at 40-60Hz for HT.
From the literature, there seems to be two main philosophies for Reference 3-way designs.
1) crossover 300-400Hz and 3,000-4,000 Hz. The 3,000 is safe for most tweeters and puts 1,000 - 3,000 that is considered sensitive to phase and dispersion on one small diameter speaker, usually 5". A wide bandwidth woofer is required, usually two 10" or a light Mms 12" - 15", often in ported boxes to increase efficiency and get an additional octave. Modest slope crossovers are usable, and helpful for the bass-mid which is crossed in the main vocal range. Check reference speakers like the B&W Nautilus 804.
2) crossover 80-100Hz and 1,200-1,500Hz. This puts human voice on one driver, usually new wide BW 8" like Seas Excel, and uses new low Fs tweeter like Millennium or 27TDFC. Bass can be large Xmax 15" and reach down to 20Hz. LR4 crossovers are needed to remove strain from mid and tweet. The 8" should have curvilinear cone shape to improve high freq dispersion. Some Pro audio use 10" JBL midranges to cover this band with authority, sacrificing some sound stage dispersion for SPL. Adire Audio is coming out with wide BW and high Xmax 6.5" and 8" for both this 3-way philosophy, and also for MTMs that can go low enough to work with subwoofers crossed at 40-60Hz for HT.
Mudge:
If you assume that the band pass sensitivity is the same for all drivers (Mounted in their respective boxes) in a system, does this not mean that they would need amps with similar voltage swing capabilities in order to ensure that nothing clips when you play the system at the maximum power level?
LineSource:
Also, and I’m probably wrong as I’m a speaker building newbee, does the power needed to get a driver to it’s maximum excursion not depend heavily on the volume of the enclosure the driver sits in? I ask this because I don’t fully understand the calculation in POST#5. What enclosure is this done with?
I know that the perception of sound means that the ear is less sensitive to clipping distortion at 20 kHz compared to low freq clipping but an active system gives you a great opportunity to avoid clipping of any kind.
\Jens
If you assume that the band pass sensitivity is the same for all drivers (Mounted in their respective boxes) in a system, does this not mean that they would need amps with similar voltage swing capabilities in order to ensure that nothing clips when you play the system at the maximum power level?
LineSource:
Also, and I’m probably wrong as I’m a speaker building newbee, does the power needed to get a driver to it’s maximum excursion not depend heavily on the volume of the enclosure the driver sits in? I ask this because I don’t fully understand the calculation in POST#5. What enclosure is this done with?
I know that the perception of sound means that the ear is less sensitive to clipping distortion at 20 kHz compared to low freq clipping but an active system gives you a great opportunity to avoid clipping of any kind.
\Jens
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