According to your posted pictures, you're using 12 - 15 cm mid drivers with 25mm VCs running from 200 on up, which will maybe cope with 50-75 watts each for longer periods of time until power compression takes over and the volume goes down. That will happen at about 105 dB and drop within about 30 min or so from that level to about 100 dB. I would at least add a midbass to make this a 4 way system to distribute the power more away from the smaller mids. 200 Hz mid crossover point is reasonable for a small 3 way in an average home audio setting, but not for those volume levels with that small, of a driver, VC and that output level. The tweeter crossover of 2.5k is also too low for that small of a VC at those levels.
The typical 25mm dome can only handle 15 to 20 watts over a longer period of time before burning up. Realistically speaking, it will do roughly 103 dB for a while until it gives up... maybe a little longer if it has ferrofluid, but not by much. You need ro raise the crossover point to about 3.5k and use a steeper HP slope along with a limiter and maybe a poly switch for safe measure.
Those kevlar B&Ws are tough mids. They use good materials in the VC and have very high temp capable windings. They won't defy the laws of physics though if you cross them too low and play them too loud for too long. They can handle about 100 watts each for a while above 400hz, maybe for an hour or two, but again here power compression becomes an issue. The rule here is simple. If you hear any distortion, you're abusing the driver and the rest is obvious.
The VC diameter has alot to do with thermal power handling. Thats why pro drivers have larger diameter coils with better venting. Midbass drivers have a very large concentration of power to deal with and very little VC movement (unlike a sub driver), so the coil relies mainly on convection and heat radiation into the motor and basket to shed heat. A subwoofer has alot of VC excursion at higher power levels which help direct alot of air around the VC and cool it effectively.
The typical 25mm dome can only handle 15 to 20 watts over a longer period of time before burning up. Realistically speaking, it will do roughly 103 dB for a while until it gives up... maybe a little longer if it has ferrofluid, but not by much. You need ro raise the crossover point to about 3.5k and use a steeper HP slope along with a limiter and maybe a poly switch for safe measure.
Those kevlar B&Ws are tough mids. They use good materials in the VC and have very high temp capable windings. They won't defy the laws of physics though if you cross them too low and play them too loud for too long. They can handle about 100 watts each for a while above 400hz, maybe for an hour or two, but again here power compression becomes an issue. The rule here is simple. If you hear any distortion, you're abusing the driver and the rest is obvious.
The VC diameter has alot to do with thermal power handling. Thats why pro drivers have larger diameter coils with better venting. Midbass drivers have a very large concentration of power to deal with and very little VC movement (unlike a sub driver), so the coil relies mainly on convection and heat radiation into the motor and basket to shed heat. A subwoofer has alot of VC excursion at higher power levels which help direct alot of air around the VC and cool it effectively.
I repeat, are you SURE. Take a look at the proper hairy chested B&W speakers say the 804. Completely different midrange and bass units. People spending €11,000 a pair for speakers expect something a bit different and it would be business suicide to offer a driver from the bottom of the range in top of the range.
Please, all of you, have any of you designed / assembled / repaired / otherwise maintained speakers?
JMFahey has, and this OP does not seem to have.
The others, no offense please, but some of you do seem to be better informed than the OP.
The same parts used in a 10x price difference is something I cannot understand, the makers would have gone out of business long back of they pulled a stunt like that.
The OP does not seem to know much about the materials and design of speakers, particularly high output compact speakers, and those are being installed where there is no need to compromise on space.
Roof and wall mounts can be done, for example.
JMFahey has, and this OP does not seem to have.
The others, no offense please, but some of you do seem to be better informed than the OP.
The same parts used in a 10x price difference is something I cannot understand, the makers would have gone out of business long back of they pulled a stunt like that.
The OP does not seem to know much about the materials and design of speakers, particularly high output compact speakers, and those are being installed where there is no need to compromise on space.
Roof and wall mounts can be done, for example.
i suggest you change your max SPL measurement method
from: max SPL = just before the driver blows which, by definition, incudes blowing the driver to
max SPL = when the driver hits a certain THD amount (maybe 10% makes sense)
while also respecting the maximum specifiied thermal load for the drivers...
Hi Norings, you look to have quite a hodge-podge of things going on ! Cool!
If you give the exact driver info, and same for the amps driving them, along with xover topologies, it should be pretty easy to diagnose how well the drivers and amps match up. I've seen scattered info to this effect, but it's a bit hard to dig out....
Before that though (if you're interested in going that route)....i see one of your amps is a CXDQ. Do you have a Core, or did you get someone with a Core to set it up for you? If you do have a Core, it is very easy to place both RMS and peak limiters into the processor flow.
I guess i should ask, What is the processor you're using? I saw you mentioned 96/dB xover slopes. (That sounds like a Core of some other advanced processor. IIR or FIR?).
Beware that such high orders can really jam power into the low knee at xover freq, compared to traditional lower order slopes.
Anyway, good luck !
If you give the exact driver info, and same for the amps driving them, along with xover topologies, it should be pretty easy to diagnose how well the drivers and amps match up. I've seen scattered info to this effect, but it's a bit hard to dig out....
Before that though (if you're interested in going that route)....i see one of your amps is a CXDQ. Do you have a Core, or did you get someone with a Core to set it up for you? If you do have a Core, it is very easy to place both RMS and peak limiters into the processor flow.
I guess i should ask, What is the processor you're using? I saw you mentioned 96/dB xover slopes. (That sounds like a Core of some other advanced processor. IIR or FIR?).
Beware that such high orders can really jam power into the low knee at xover freq, compared to traditional lower order slopes.
Anyway, good luck !
This reminds me of an old friend who had the philosophy that in order to simulate real life sound you needed a ton of amplifier power. I recall back in the 70s he had a system with I believe a pair of 50W amps that he played at very loud volume levels. His speakers were home made using fifteen inch woofers paired with Ionovac midrange/tweeters. The volume was so loud it would at times momentarily extinguish the arc in the Ionovacs'. In later years I suspected he lost some of his hearing thus the need for more power. If you want to keep enjoying audio I would suggest using that power as headroom for audio peaks and keep the volume level down. You might consider getting a sound level db meter to measure the volume level and compare to information on ear damaging volume levels. If you are interested in the Ionovac speakers and how it used a modulated arc search for Ionovac loudspeaker.
Dude... what are you actually trying to accomplish? I feel that you love this stuff and just can't stop yourself. You are so attached to this equipment that are you are blowing drivers faster than they can manufacture them!
Look.... you need to nail down WHAT you want to do first. Do you want a good sounding system? Cool, get amps and speakers that match, OR if you HAVE to have your amps then match the speaker to the amp and please for the love of Pete don't play at actual 125db! That is suicide for your ears.
Also, you say 125db, but no home speaker is designed to play that loud for that long regardless of their "specifications". Some of those specs are just for marketing. Its a bit like the spedometer on your minivan. I'm not taking my Toyota Sienna up to 140mph no matter how cool it would look pegged up there. You are murdering your speakers, actual murder. You need to calm down and forget specifications, forget meters and just hook up some damn wires between normal speakers and normal amps. You don't need an amp per driver. If you feel the NEED to do that you have a problem and need to go talk to someone.
Do you realize that there are literally tens of thousands if not hundreds of thousands of homes in the US that have multi channel house audio that are run off of 35 watts per channel! They sound fine! You don't need 200 watts per driver. I have installed dozens of thousand dollar inwalls running off of 50 watts and the sound absolutely great!
You do realize that about 80% of a systems sound is in the drivers? So your amps aren't doing anything for you really.
Now if you want to put everything in a massive test bench and see what does what, that is fine, go nuts! But if you want to listen to stuff on a daily basis, chill out and get a little more normal, get an 8 channel amp or something. Or even if you want to keep your 200 watts that is fine too, but to the entire channel, woofer and tweeter, not each individual speaker.
ITS JUST TOO MUCH!
Look.... you need to nail down WHAT you want to do first. Do you want a good sounding system? Cool, get amps and speakers that match, OR if you HAVE to have your amps then match the speaker to the amp and please for the love of Pete don't play at actual 125db! That is suicide for your ears.
Also, you say 125db, but no home speaker is designed to play that loud for that long regardless of their "specifications". Some of those specs are just for marketing. Its a bit like the spedometer on your minivan. I'm not taking my Toyota Sienna up to 140mph no matter how cool it would look pegged up there. You are murdering your speakers, actual murder. You need to calm down and forget specifications, forget meters and just hook up some damn wires between normal speakers and normal amps. You don't need an amp per driver. If you feel the NEED to do that you have a problem and need to go talk to someone.
Do you realize that there are literally tens of thousands if not hundreds of thousands of homes in the US that have multi channel house audio that are run off of 35 watts per channel! They sound fine! You don't need 200 watts per driver. I have installed dozens of thousand dollar inwalls running off of 50 watts and the sound absolutely great!
You do realize that about 80% of a systems sound is in the drivers? So your amps aren't doing anything for you really.
Now if you want to put everything in a massive test bench and see what does what, that is fine, go nuts! But if you want to listen to stuff on a daily basis, chill out and get a little more normal, get an 8 channel amp or something. Or even if you want to keep your 200 watts that is fine too, but to the entire channel, woofer and tweeter, not each individual speaker.
ITS JUST TOO MUCH!
Fair dude, thanks for your opinion. Very short reply to questions (only): yes, SPL design requirement was 130 dB not 125,
, yes and yes.From the paragraph that starts with" Also, you say 125db, but no home speaker is designed to play that loud" and all the way to "80% of a systems sound is in the drivers" I think you are spot on, I agree and my experiences in the same matters are very similar.
2 comments: Amp are doing something for me and they do matter when SPL is the topic. I did not bother to do the math, but believe, for any SPL goal, its it is cheaper to buy alot of speaker having large cone area with high sensitive and less amplifier power, compared a few and low sensitive speakers with far less cone area and 10 huge amps. But the last one sounds far superior to the other and takes up less wall area. Also agree that using one amplifier is sufficient to power the entire frequency range but very hard to accomplish without passive crossovers. In my opinion life is to short for them, properly designed they perform fairly well, but require so much more time and are only valid for that setup.
brg Simen
Please let me know where you spotted poorly chosen cables, so I can change. Not my field of expertise.
Did you see the cables used?
Asking for trouble, very irritating when you have a problem.
A central sound system, for the entire house, is it a common thing now, or an oddity?
Sound system with added home control and burglar alarm definitely is an oddity, IMO.
The only thing that matters regarding SPL (or sound power level, for that matter) is Volume displacement (Vd). And when you grasp the limitations of electrodynamic drivers you soon grab big drivers when high SPL is required.
No way small drivers ‘sound’ better than big ones. That is just bad implementation of the latter. As for space required, I agree. Twelve to eighteen inch drivers require more surface. Not so much more volume though. Active EQ deals with that. And since you have ample power available, there really is hardly any excuse.
No way small drivers ‘sound’ better than big ones. That is just bad implementation of the latter. As for space required, I agree. Twelve to eighteen inch drivers require more surface. Not so much more volume though. Active EQ deals with that. And since you have ample power available, there really is hardly any excuse.
Thanks a lot
Also for your offer, but I have now, with support from this forum pinpointed the problem and found a solution. I did a wrap up post where I included some video which showed how huge impact 150W compared to 1500W had on the lifetime of voicecoil of my mid drivers. And I would love to afford some new QSC amps packed with feature like that. My experience and ownership with/of the 2 DCA amps i have has been only one 20 years positive experience. I killed the 1644 bridged it into 4 ohm loads, by mistake, I knew it , Its stated on the box, manual and I also think back of the amp, that NB!!! the 1644 can NOT be bridged into anything lower than 8 ohm. But my speakers had dual 2 ohm coils instead of what i believed which was 4 ohm, stupid mistake. It still lasted more a month in this configuration, and 20 years of 8 ohms load service before that.
The entire system, with such a hodge podge of cables, is going to be a headache when you have a fault.
That is bound to happen sooner or later.
Cable quality is a running joke with the more experienced and hands on members here, ordinary multi strand good quality wire of enough load capacity is enough.
Fancy cables are a way to part fools from their money.
That is bound to happen sooner or later.
Cable quality is a running joke with the more experienced and hands on members here, ordinary multi strand good quality wire of enough load capacity is enough.
Fancy cables are a way to part fools from their money.
Thanks lots of good points and you are probably correct on most of it and I agree with all. I summed it up like this somewhere:
a) I have had too much faith in high-end/good quality hifi drivers ability to dispatch all that heat, created by excessive power.
b) I have not paid attention to excursion limits and sensitivity when choosing drivers vs SPl.
Luckily only a) needs real fixing, I think that I can accept 120 dB as a overall max spl, the last 10 seems to demand too much work in midrange area. The B&W woofer was chosen because of its almost flawless reproduction of 200-2000 hz, good looks and decent power handling. Now I just need to find something similar capable of 6-9 db more power.
brg Simen
There is a very thin and arbitrary line to enjoying very loud music and being physically distressed for some people. Understanding how excessively loud music affects us is important and there's a vast amount of psychology behind it, how its perceived and affects the brain and human nervous system. Obviously our ears aren't linear in response or amplitude scale. Once you get past triple digit dBs, our ears begin to compress and there is a protective mechanism at work with all the myofacial muscles tensing up to reduce ear drum excursion as well as dampen the physical sound waves coming into the ear canal to protect our hearing - the fine hair in the cochlea starts folding over as a result. Our ears will call it quits with dynamic range past 110 dB (A weighted) and thats the point sound becomes painful and physically stressful, as well as the body joining in on the act, picking up physical vibration, adding it to the hearing perception. The tactile vibration is what makes music believable and exciting, but its only perceived in balance when volume levels become unsafe for our ears - you need about 100 dB C weighted SPLs to feel audio as well as hear it. Past 110 dB SPL, it's the adrenalin released by our fight and flight response that makes loud music become exciting - yes, I'm addressing all you metal heads with this one lol. Our brain is no longer effectively processing audio in an intelligently analytical way past the 110 dB point and it starts to trigger the ear's last resort defense mechanisms. Really only the cues which are valuable to life preserving reactions are getting processing priority at this point, so the music can become perceived as physically stressful noise and even as threatening depending on the waveform distortion profile (more noise than music ie. heavy metal sound), an individuals sensitivity threshold and other bodily senses adding to the experience. Loud music can be very addictive for some people as it triggers dopamine release, as do other enjoyable things.
Heavy metal is by far THE MOST ear damaging form of music with its excessively distorted guitars, heavy cymbals and spectral noise density in the mid and high frequencies. I have nothing against really good hard rock or metal if its well produced / recorded. Its just typically the most ear fatiguing music to listen to in its raw form. I remember the guys from the 80s with their Walkmans blasting so loud they leaked "white noise" from their headphones as they listened to Slayer, Anthrax, etc and could still be heard 20+ feet away!
Heavy metal is by far THE MOST ear damaging form of music with its excessively distorted guitars, heavy cymbals and spectral noise density in the mid and high frequencies. I have nothing against really good hard rock or metal if its well produced / recorded. Its just typically the most ear fatiguing music to listen to in its raw form. I remember the guys from the 80s with their Walkmans blasting so loud they leaked "white noise" from their headphones as they listened to Slayer, Anthrax, etc and could still be heard 20+ feet away!
So you want to play 120dB with a hifi mid now? You haven’t really read all the feedback here then. 120dB from 90dB sensitivity is delta +30dB = 1000 watt. Forget it! You need horn-mid/high and PA midbass with 100dB sensitivity. This way 100 watt will be sufficient. Remember the rule of thumb +10dB = 10x power… It’s very simple once you start to think this way. 100 or 200 watt is a small difference, you need to think decade-logarithms. 10^2 or 3 that’s your options. 10 watt for horn mid/high, 100 for mid bass 1000 for sub.
Did you see the easteregg software from Tesla? (scroll 16 second into this:Bloody hell....when I see all these wires everywhere and read bulbes are flashing...
If somebody opens the main door, the hole house goes completely dark & silent for 2 seconds, then this happens:
when these conditions are true: There is light and movement in the livingroom + time/date = midnight at new year (+/-10 min)
(It doesnt really show on the video, and the music is way louder than what is recorded by my phone, but this looks totally ridiculous when a house does it)