Hi folks
Time for me to have some fun again after a long cold dark depressing Swidish autumn, winter and urly spring.
And have get my hands on a new unused pair of Scan Speak 18M/4631 T00 Relevator for a good price ( from 2017 serienummer 61590-39 and -40)
I want to use them as low as possible and as high as possible, and still be able to play real LOUD! ( 115 dB)
Linear excursion is +-3 mm but MAX mech excursion +-14,5mm, so maby i can go past +-3 mm without to much compromises.
I want to build a slimmed down/slender/thin 3 way, with 15 inch woofer Dayton RSS390ho or JBL 2215h and a Scan speak D2905/93000 or a Viawave SRT 7 ribbon tweeter.
The Viawave don´t take lots of power if i don´t cross it high enough, but think the SS 93000 can go much lower.
Cabinette size can be big in liters but not to wide!
Never used SS midrange before or Dayton RSS series or Viawave SRT 7, so very happy to take advice from those of you who have both experience and competence
Here some data and pic´s ( also xover examples from HifiCompass for the SRT 7)
The JBL 2215h was used in Urei 813c and 815
Best regards John
Time for me to have some fun again after a long cold dark depressing Swidish autumn, winter and urly spring.
And have get my hands on a new unused pair of Scan Speak 18M/4631 T00 Relevator for a good price ( from 2017 serienummer 61590-39 and -40)
I want to use them as low as possible and as high as possible, and still be able to play real LOUD! ( 115 dB)
Linear excursion is +-3 mm but MAX mech excursion +-14,5mm, so maby i can go past +-3 mm without to much compromises.
I want to build a slimmed down/slender/thin 3 way, with 15 inch woofer Dayton RSS390ho or JBL 2215h and a Scan speak D2905/93000 or a Viawave SRT 7 ribbon tweeter.
The Viawave don´t take lots of power if i don´t cross it high enough, but think the SS 93000 can go much lower.
Cabinette size can be big in liters but not to wide!
Never used SS midrange before or Dayton RSS series or Viawave SRT 7, so very happy to take advice from those of you who have both experience and competence
Here some data and pic´s ( also xover examples from HifiCompass for the SRT 7)
The JBL 2215h was used in Urei 813c and 815
Best regards John
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Not much interest in this thread I notice, but can someone say something about S-S 18M/4631 T00 Revelator midrange use for a 3 way?
Can i use it from 150 hz and still play real loud?
And is it good up to 3,5K, or becomes listening from 15-30 degrees "to much" suffering/ to large compromises?
What do you folks think or know?
Oh, forgot to say the woofer will be sidemounted!
Regards John
Can i use it from 150 hz and still play real loud?
And is it good up to 3,5K, or becomes listening from 15-30 degrees "to much" suffering/ to large compromises?
What do you folks think or know?
Oh, forgot to say the woofer will be sidemounted!
Regards John
Midrange appears to be a well behaved unit. On its own high passed at 140 Hz LR4, 4 litres sealed, well damped to Qtc=0.74, without any other consideration, it can be fed with 20Vrms of input and not exceed 2mm of cone travel.
I would have tested it with both HF drivers. Crossing to d2905 conservatively at about 2.3-2.5 kHz.
I would have tested it with both HF drivers. Crossing to d2905 conservatively at about 2.3-2.5 kHz.
Thanks Lojzek
Exactly the information i was after!
Im bad at what things are called ( in the world of the educated), exactly what is a LR4 ?
It would have been interesting to use the Viawave SRT 7, but think i don´t dear to go under 3 k.
Playing a little with SS M18 and the Viawave.
Regards John
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Midrange with 92dB sensitivity at 4R impedance and 38mm coil ... it won't do 115dBSpl, sorry. But louder as most HiFi speakers!
It also has a little resonance at 900Hz (impedance plot), probably a low dampened surround - must not ba a bad thing.
Beams a lot at 3kHz with little dips and peaks, probably no piston movement of the membrane. I would not cross over too high when off axis behaviour is of interest.
Problem is the narrow front baffle! You lose a lot of sensitivity at a few 100Hz already which you can't fill in with your side woofer. You could use a 2nd midrange to fill these ... but already 4R. Not an easy design if you want to keep sensitivity high. And you need when you want to play loud.
It also has a little resonance at 900Hz (impedance plot), probably a low dampened surround - must not ba a bad thing.
Beams a lot at 3kHz with little dips and peaks, probably no piston movement of the membrane. I would not cross over too high when off axis behaviour is of interest.
Problem is the narrow front baffle! You lose a lot of sensitivity at a few 100Hz already which you can't fill in with your side woofer. You could use a 2nd midrange to fill these ... but already 4R. Not an easy design if you want to keep sensitivity high. And you need when you want to play loud.
Thanks for input !
How wide the baffle need to be for not have to large "compromises"?
Is 25-27 cm enough?
What do you meen with "Midrange with 92dB sensitivity at 4R impedance and 38mm coil" explained to one who does not understand all the terms?
Yea,the SS M18 going to beam around 2500 hz and don´t know if i will be a real problem. ( sometimes it works anyway, toe-in, toe-out )
People whrite 4R a lot, what is it ?
Regards John
Linkwitz-Riley 4th order
4 ohms
92 dB/2,83 V at 4 Ohms equals 2 Watts.
you also lose about 4 dB (more or less, depends on speaker placement) of sensitivity at lower end due to baffle step.
that results in effective sensitivity of around 85 dB/W at your desired lower crossover frequency.
To achieve 115 dB you would need 1 kW put into the small 38 mm voice coil. That's too much!
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... at 1 Watt (2 V).
And once you are above baffle step you have the full specified 92 dB @ 2,83 V
That SS mid won't live long feeding it a few hundred watts,,even short term.
For the mid o produce 115dB you'll need 500W input.
A 38mm VC will cope with about 100W long term,. That will get it to just shy of 110dB.
These are reasons why I'd look for a driver with higher sensitivity or with a larger VC.
A 2 inch VC will deal with 150 - 175W long term if it gets fed fresh air, so a smaller sealed box will drop that to around 100W.
For the mid o produce 115dB you'll need 500W input.
A 38mm VC will cope with about 100W long term,. That will get it to just shy of 110dB.
These are reasons why I'd look for a driver with higher sensitivity or with a larger VC.
A 2 inch VC will deal with 150 - 175W long term if it gets fed fresh air, so a smaller sealed box will drop that to around 100W.
Hi,
I don't know of a pro PA Mid that will do your 115dB max, but somebody else might.
Depending on how the 15 inch behaves and sound may this would help with the fun aspect, although would maybe mean your cabinet becomes a bit wider to accommodate an 8 inch. Please see here,
https://www.bluearan.co.uk/index.ph..._8_inch_250W_4_Ohm_Loudspeaker&id=FTP8FE300CF
I don't know of a pro PA Mid that will do your 115dB max, but somebody else might.
Depending on how the 15 inch behaves and sound may this would help with the fun aspect, although would maybe mean your cabinet becomes a bit wider to accommodate an 8 inch. Please see here,
https://www.bluearan.co.uk/index.ph..._8_inch_250W_4_Ohm_Loudspeaker&id=FTP8FE300CF
Depends on the cross over frequency to your bass driver. Ideally the lf driver takes over when sensitivity goes down caused by baffle step.
How loud can your 15" go with your amping, did you simulate?
I have a Cramco Vortex 6 amp ( 2x3kW at 4 ohm) and my Onkyo 747 receiver ( 2x 90 W 8 ohm)
Like to cross the sidemounted woofer, so i don´t suffer from "directsound/pointsource" problem, so my tought was 150 hz.
Here is SPL for the Dayton from loudspeakerdatabase.com and specs for Cramco amp
Simulate some more in Vituixcad alsp with woofer and both with Viawave tweeter and SS 9300, LR2 and LR4
Regards John
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You could run 2 of the SS mids wired in series and shade one of them. It would require a series filter on one driver after the main bandpass filter.
You'd wire a cap and resistor parallel across the shaded mid furthest from the tweeter, then wire this combo in series to the mid closest to the tweeter. This will provide one mid with the full midrange output from the xover and the other mid would only see the lower midrange signal having a cap across it reducing the upper mids. The result is a theoretically flat combined mid response, which also accounts for baffle step loss.
It will also increase power handling and keep the net voltage sensitivity the same, as you're splitting the midrange only in the lower mids and getting back the power loss from wiring it in series with roughly 3 dB more coupling gain. This is due to having double the radiating cone surface area in the lower mids and tapering to only one mid for the upper midrange.
Doing the above practically doubles the midrange power handling. Not cheap, but an effective solution, as you're doubling the mid cone surface area and boosting lower mid output capacity with the required power handling.
You could also use a different driver with more sensitivity, but not many mids will sound as refined as the SS Revelator you have. Its a very good driver and you'd be hard pressed to find a better one. Jantzen makes their 8008 midbass, which is about 94 dB/2.83V and sounds alot like the SS mid.
You'd wire a cap and resistor parallel across the shaded mid furthest from the tweeter, then wire this combo in series to the mid closest to the tweeter. This will provide one mid with the full midrange output from the xover and the other mid would only see the lower midrange signal having a cap across it reducing the upper mids. The result is a theoretically flat combined mid response, which also accounts for baffle step loss.
It will also increase power handling and keep the net voltage sensitivity the same, as you're splitting the midrange only in the lower mids and getting back the power loss from wiring it in series with roughly 3 dB more coupling gain. This is due to having double the radiating cone surface area in the lower mids and tapering to only one mid for the upper midrange.
Doing the above practically doubles the midrange power handling. Not cheap, but an effective solution, as you're doubling the mid cone surface area and boosting lower mid output capacity with the required power handling.
You could also use a different driver with more sensitivity, but not many mids will sound as refined as the SS Revelator you have. Its a very good driver and you'd be hard pressed to find a better one. Jantzen makes their 8008 midbass, which is about 94 dB/2.83V and sounds alot like the SS mid.
It depends on what you're playing back. Drums require those sorts of levels if you want to hear them uncompressed. I sometimes listen at those levels. Very rarely and only if there's something that sticks out at different levels. Its just nice to know you can, but for most people it's not a requirement.
With an electric guitar amp, you're working in the sensitive part of the mids that don't require as much level to be perceived as being loud compared to lower frequencies. IOW, 100 dB @ 3k will melt your face off compared to 110dB @ 500hz thanks to the loudness curve our ears follow. Distortion levels affect perceived volume as well, which is another reason why electric guitars sound louder than undistorted instruments playing at the same level.
With an electric guitar amp, you're working in the sensitive part of the mids that don't require as much level to be perceived as being loud compared to lower frequencies. IOW, 100 dB @ 3k will melt your face off compared to 110dB @ 500hz thanks to the loudness curve our ears follow. Distortion levels affect perceived volume as well, which is another reason why electric guitars sound louder than undistorted instruments playing at the same level.
That's just how it is profiguy.
And I often listen at very high volume, but my speakers have very low distortion so the sound is not perceived as loud. And of course you can't play equally loud on all music, as many recordings are not good enough for that.
Distortion is painful for the ears!
Then I always want some headroom
And I often listen at very high volume, but my speakers have very low distortion so the sound is not perceived as loud. And of course you can't play equally loud on all music, as many recordings are not good enough for that.
Distortion is painful for the ears!
Then I always want some headroom
Many conductors actually lose some their hearing from being in front of a full orchestra. There's alot of acoustical power available from these instruments. Horn sections can top out over 120dB at the conductors location playing full fortissimo.
Big band jazz ensembles are also capable of playing with very high dynamic ranges well in excess of 120dB several feet away. I used to engineer for quite a few larger jazz bands and can attest to how loud and crazy things can get. The dynamics can be insane. Some mics can't handle the levels some horn players can generate, causing transient distortion in preamps and large diaphragm condenser mics. Ribbon mics won't survive these environments in most cases. Van Halen used to record Eddie's guitar parts with ribbon mics and they regularly would fail from this.
Even Tom Jones was known for damaging condenser mics with only his set of pipes. Every time I watch the Italian Job, I can hear how this man can belt out vocals loud enough to blow you out of your seat.
So yes, there are many circumstances where peaks of over 120dB are observed and demand a capable monitoring setup. Most people nowadays don't know how true lifelike dynamics sound from all of the overcompressed junk they are used to hearing through cheap earbuds. Its a shame we have to deal with this. Sometimes a great artist pops up from the big sea of modern music, but they end up sounding like sandpaper on a concrete wall from all the clipping and noise in the recording, thanks to idiot producers who insist this the way it should sound. We can thank the 90s for this when the loudness wars started.... end of rant.
Big band jazz ensembles are also capable of playing with very high dynamic ranges well in excess of 120dB several feet away. I used to engineer for quite a few larger jazz bands and can attest to how loud and crazy things can get. The dynamics can be insane. Some mics can't handle the levels some horn players can generate, causing transient distortion in preamps and large diaphragm condenser mics. Ribbon mics won't survive these environments in most cases. Van Halen used to record Eddie's guitar parts with ribbon mics and they regularly would fail from this.
Even Tom Jones was known for damaging condenser mics with only his set of pipes. Every time I watch the Italian Job, I can hear how this man can belt out vocals loud enough to blow you out of your seat.
So yes, there are many circumstances where peaks of over 120dB are observed and demand a capable monitoring setup. Most people nowadays don't know how true lifelike dynamics sound from all of the overcompressed junk they are used to hearing through cheap earbuds. Its a shame we have to deal with this. Sometimes a great artist pops up from the big sea of modern music, but they end up sounding like sandpaper on a concrete wall from all the clipping and noise in the recording, thanks to idiot producers who insist this the way it should sound. We can thank the 90s for this when the loudness wars started.... end of rant.