I would like to swtich to an active setup. After reading It looks like that I don't have ideal speakers to do it.
My speakers are :
Horn loaded compression driver : TAD TD-4002, 110db/w
Woofer : TAD TL-1603, 97db/W
I would like to use a MiniDSP 2x4 HD as a crossover and small room corrections. Note that I'm working a lot on my room treatment so, EQ will be minimal.
The gain structure seems to cause problem with high sensitivity components. If I understand correctly a preamp would be a good thing to level match drivers and woofers.
Source -> miniDSP -> preamp -> power amps ->speakers.
As always budget is thight. And I have on hand and planned to use :
Pioneer SA-9900 with pre-out 2V/main-in
Luxman r-114 also with pre-out ?V/main-in
*Pioneer A-09 integrated class A amp that I really like but no pre-out/main-in.....
My idea was :
SA-9900 preamp -> miniDSP -> sa-9900 amp --> woofers/luxman amp -> drivers.
Again if I understand correctly does this setup will cause level/gain mismatch issue?
New plan :
SA-9900 preamp or usb dac, optical CD player -> miniDSP --> Unknown preamp* -> sa-9900 amp --> woofers/luxman amp -> drivers.
* This where I need recommendations. Can I use the luxman active preamp? Do I need a passive preamp? What would be the best solution to keep noise, distorsion as low as possible with a low cost.
At this point I'm wondering if an integrated amp would get the job done.
Source -> miniDSP -> S-9900 power amp -> woofers
A-09 integrated -> drivers
Links
SA-900
http://audio-database.com/PIONEER-EXCLUSIVE/amp/sa-9900-e.html
Luxman
http://www.hifi-classic.net/review/luxman-r-114-5.html
A-09
http://www.thevintageknob.org/pioneer-A-09.html
I would like to swtich to an active setup. After reading It looks like that I don't have ideal speakers to do it.
My speakers are :
Horn loaded compression driver : TAD TD-4002, 110db/w
Woofer : TAD TL-1603, 97db/W
I would like to use a MiniDSP 2x4 HD as a crossover and small room corrections. Note that I'm working a lot on my room treatment so, EQ will be minimal.
The gain structure seems to cause problem with high sensitivity components. If I understand correctly a preamp would be a good thing to level match drivers and woofers.
Source -> miniDSP -> preamp -> power amps ->speakers.
As always budget is thight. And I have on hand and planned to use :
Pioneer SA-9900 with pre-out 2V/main-in
Luxman r-114 also with pre-out ?V/main-in
*Pioneer A-09 integrated class A amp that I really like but no pre-out/main-in.....
My idea was :
SA-9900 preamp -> miniDSP -> sa-9900 amp --> woofers/luxman amp -> drivers.
Again if I understand correctly does this setup will cause level/gain mismatch issue?
New plan :
SA-9900 preamp or usb dac, optical CD player -> miniDSP --> Unknown preamp* -> sa-9900 amp --> woofers/luxman amp -> drivers.
* This where I need recommendations. Can I use the luxman active preamp? Do I need a passive preamp? What would be the best solution to keep noise, distorsion as low as possible with a low cost.
At this point I'm wondering if an integrated amp would get the job done.
Source -> miniDSP -> S-9900 power amp -> woofers
A-09 integrated -> drivers
Links
SA-900
http://audio-database.com/PIONEER-EXCLUSIVE/amp/sa-9900-e.html
Luxman
http://www.hifi-classic.net/review/luxman-r-114-5.html
A-09
http://www.thevintageknob.org/pioneer-A-09.html
hello,
You should ask diyaudio.
I've never used the miniDSP but can't you adjust/balance the levels with it??? Volume adjustment is about the "easiest" digital signal processing you can do!
Typically the preamp/line output goes to the crossover. The (line-level) crossover outputs go to the power amplifiers. The crossover should have separate level controls for each band and most power amplifiers have level controls too.
You can buy active crossovers starting at around $100 USD and they always have separate level controls for each output. (That won't help with any other room/speaker EQ.)
You can also buy
fixed (https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244) or
variable (https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244) in-line attenuators. (Variable stereo pots/attenuators may not track left & right identically, so that's something to be aware of.)
Note that I'm working a lot on my room treatment so, EQ will be minimal.
I hope you're measuring your room? ….Diagnosis before treatment! But, you need to measure your room & speakers together so you can't finish the room treatment before the speakers are done.
Horn loaded compression driver : TAD TD-4002, 110db/w
Woofer : TAD TL-1603, 97db/W
I assume you'll be making some measurements (with a horn attached and the woofer in a cabinet)?
The Internet says the compression driver is 16 Ohms,. If that's true that means half the power compared to 8 Ohms (-3dB). (With the same amplifier & settings). Do you have the gain (or sensitivity) specs for both amps?
If the woofer amp has enough gain everything may be OK.
P.S.If your speakers have an existing passive crossover, maybe you can figure-out the (existing) high-frequency attenuation. There should be a
voltage divider (https://en.wikipedia.org/wiki/Voltage_divider) (AKA a "pad"), or a potentiometer or a series resistor.
If there's a potentiometer it's probably audio-taper (non-liner) and you'd need a multimeter to measure the resistance ratio where you like it.
I've never used the miniDSP but can't you adjust/balance the levels with it??? Volume adjustment is about the "easiest" digital signal processing you can do!
Yes it's possible to adjust digitaly for every output. I'm confused on how digital volume works. I've read that lowering volume would lower the number of bits. Also that there's a possibility to raise SNR.
I hope you're measuring your room? ….Diagnosis before treatment! But, you need to measure your room & speakers together so you can't finish the room treatment before the speakers are done.
Yep I bought a umik-1 and did a lot of measurements. I'm still waiting for some comfortboard to arrive.
Horn loaded compression driver : TAD TD-4002, 110db/w
Woofer : TAD TL-1603, 97db/W
I assume you'll be making some measurements (with a horn attached and the woofer in a cabinet)?
I already measured the horn while investigating a ~ 1 khz to 2 khz dip (that the reason I want to test an active setup and to change crossover 800hz to 600hz or 650hz). As well as speakers, mostly in room due to size. It won't be a problem to level match woofer/driver with the DSP as well as Time align them.
The Internet says the compression driver is 16 Ohms,. If that's true that means half the power compared to 8 Ohms (-3dB). (With the same amplifier & settings). Do you have the gain (or sensitivity) specs for both amps?
I have on hand for experimentation a :
Pioneer SA-9900 for woofers
http://audio-database.com/PIONEER-EXCLUSIVE/amp/sa-9900-e.html
Luxman R-114 for drivers
There's not a lot of informations about this one on Internet.
https://www.hifiengine.com/manual_library/luxman/r-114.shtml
P.S.
If your speakers have an existing passive crossover, maybe you can figure-out the (existing) high-frequency attenuation. There should be a voltage divider (https://en.wikipedia.org/wiki/Voltage_divider) (AKA a "pad"), or a potentiometer or a series resistor.
If there's a potentiometer it's probably audio-taper (non-liner) and you'd need a multimeter to measure the resistance ratio where you like it.
Crossover is tad TN-4 woofer 36db/oct, Driver 12db/oct. No pot (I had one but I removed it since it is not needed. Parts for the crossover are covered, so I didn't break anything in case I would sell them.
You can also buy fixed (https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244) or variable (https://www.parts-express.com/harrison-labs-12-db-rca-line-level-audio-attenuator-pair--266-244) in-line attenuators. (Variable stereo pots/attenuators may not track left & right identically, so that's something to be aware of.)
It looks interresting. The whole idea behind the use of a preamp after the DSP is to have manual volume control on amps.
The room study should be the most interesting part of the project (before choosing anything IMHO)
What about to make a drawing ?
The room study should be the most interesting part of the project (before choosing anything IMHO)
What about to make a drawing ?
You'll find my room layout here, as well as measurements from last years. I did somes changes today but measurements were more complicated with kids on the house (waterfall graph is horrible when kids bounce on the floor during a sweep ;) ), I'll post new measurements soon, still not get my pack of comfortboard. But anyway Impulse response looks very good, as well as RT60, reflexions are tame.
http://the-audio-expert.freeforums.net/thread/458/thicker-more-panels?page=1
You might want to read this thread (https://hydrogenaud.io/index.php/topic,110549.0.html) thoroughly, as HA has a TOS that applies to all topics
You might want to read this thread (https://hydrogenaud.io/index.php/topic,110549.0.html) thoroughly, as HA has a TOS that applies to all topics
I'm asking for recommandations and suggestions. If It's not allowed a mod will delete my post.
Then I clearly need help to understand some basic technical points, and that's the reason I'm posting here. (I think HA is a good place to get rationnal and helpful informations).
Then I've read a couple of your posts including the one you refered me, and you are a troll looking for trouble. So I'll remain polite : give me your suggestions and/or help me with the technical side of where I'm wrong OR get out if my post please.
I'll add get out if my post please I'm not really interested with your anwsers even if they are goods.
Thanks
I'm asking for recommandations and suggestions.
give me your suggestions and/or help me with the technical side
That's why I recommended you read that relevant to what you are doing thread.
But anyway Impulse response looks very good, as well as RT60, reflexions are tame.
http://the-audio-expert.freeforums.net/thread/458/thicker-more-panels?page=1
Hello, sorry, i can't upload the images but anyway it is very easy to have good measurements and bad ones by just moving the microphone a few ;)
There are 2 very good articles on room acoustics chronologically.
The latter one is actually in response to the nonsense article posted on the Winer site, which itself seemed a response to the 1st.
https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation (https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation)
https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation/what-do-listeners-prefer (https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation/what-do-listeners-prefer)
Huge caveat, the intellectual capacity to comprehend Toole et al work might be insurmountable. If this is the case, default to EW forum instead.
IMHO before anything else, it is better at first to elude all the useless parts of the problem by knowing the radiation patterns and the loudspeakers drivers loadings (horns and boxes).
But anyway Impulse response looks very good, as well as RT60, reflexions are tame.
http://the-audio-expert.freeforums.net/thread/458/thicker-more-panels?page=1
Hello, sorry, i can't upload the images but anyway it is very easy to have good measurements and bad ones by just moving the microphone a few ;)
I know, I took a lot of measurements (2 or 3 weeks of moving evrything) and I experienced a lot with speakers placement, reflections, comb filtering, etc. I learned a lot.
Note that the first goal of going active is to get rid of the passive crossover that I have. I'll try a little bit of EQ but I doubt it will work
My concern with not ideal speakers (and miniDSP) is the fact that they are sensitive and that there's 13db difference with woofer and driver, so I'm concerned about gain and noise.
Note that the first goal of going active is to get rid of the passive crossover that I have. I'll try a little bit of EQ but I doubt it will work
EQ will kill your direct sound field.
My concern with not ideal speakers (and miniDSP) is the fact that they are sensitive and that there's 13db difference with woofer and driver, so I'm concerned about gain and noise.
It is not a really a problem, i use a 28dB Lpad on my 2"horn setup (112Db) and there is no hiss at all even with the head into the horn in the night.
Note that the first goal of going active is to get rid of the passive crossover that I have. I'll try a little bit of EQ but I doubt it will work
EQ will kill your direct sound field.
My concern with not ideal speakers (and miniDSP) is the fact that they are sensitive and that there's 13db difference with woofer and driver, so I'm concerned about gain and noise.
It is not a really problem, i use a 28Db Lpad on my 2"horn setup (112Db) and there is no hiss at all even with your head into the horn in the night.
Thanks! So a basic L-PAD would get the job done?
I'll have to check for a 16ohm L-PAD that gives me at least 12db right?
I'll have to check for a 16ohm L-PAD that gives me at least 12db right?
http://www.mh-audio.nl/att.asp
10W ceramic resistors cost around 0.12€
https://www.digikey.fr/products/fr/resistors/through-hole-resistors/53?k=ceramic+resistor&k=&pkeyword=ceramic+resistor&pv2=10&FV=ffe00035&quantity=0&ColumnSort=0&page=1&pageSize=25
I'll have to check for a 16ohm L-PAD that gives me at least 12db right?
http://www.mh-audio.nl/att.asp
10W ceramic resistors cost around 0.12€
https://www.digikey.fr/products/fr/resistors/through-hole-resistors/53?k=ceramic+resistor&k=&pkeyword=ceramic+resistor&pv2=10&FV=ffe00035&quantity=0&ColumnSort=0&page=1&pageSize=25
Is ok to try to nail it to get -13db 12.42ohm and 4.62 ohm = R1+R2 12 ohm+0.5ohm 10w / R3+R4 4ohm + 0.6ohm 10w or at this point it doesn't matter. Resistor are dirt cheap so I'll try to be precise
To make sure that I understand :
Woofers and drivers will be level match, since my amplifiers don't have volume pot I'll no longer have to worry about them.
So the L-PAD allow me to not affect the gain structure on the miniDSP and master volume control will be done with preamp before miniDSP or with miniDSP's master volume control (remote needed with 2x4hd, no more pot is possible)
To make sure that I understand :
Woofers and drivers will be level match, since my amplifiers don't have volume pot I'll no longer have to worry about them.
So the L-PAD allow me to not affect the gain structure on the miniDSP and master volume control will be done with preamp before miniDSP or with miniDSP's master volume control (remote needed with 2x4hd, no more pot is possible)
not sure... could you say where your doubt is coming from ?
I re-checked the miniDSP manual and there's -72db of gain attenuation, even with -12db I still have plenty of room, I think there's no reason for worrying. With the l-pad I'll have the same gain on all 4 outputs channels. I want to be able to crank the speakers from time to time.
https://www.minidsp.com/applications/dsp-basics/gain-structure-101
My concern with not ideal speakers (and miniDSP) is the fact that they are sensitive and that there's 13db difference with woofer and driver, so I'm concerned about gain and noise.
You may need to make it adjustable, or select the resistors after measurement...
- You never said how much attenuation there is in the current passive design.
- You can't go by the raw driver specs. The output from the compression driver will vary depending on the horn and the output from the woofer will depend on the cabinet design.
- From what you've said, you are using two different amplifiers and the gains may be different.
BTW - The woofer is also a "driver". i.e. A 3-way speaker system has 3 (or more) drivers.
- You never said how much attenuation there is in the current passive design.
Because I don't know, but this an original crossover from TAD made to use the woofer and compression driver that I use. Without a rotary l-pad it's ok so I guess there's a 13 db attenuation. First post I gave sensivity specs of woofer and compression drivers.
- You can't go by the raw driver specs. The output from the compression driver will vary depending on the horn and the output from the woofer will depend on the cabinet design.
This a clone of a pioneer/TAD design. If you need more details, but I don't see what the horn has to do with gain?
http://www.geocities.jp/arai401204/Horn/A290/A290.html
- From what you've said, you are using two different amplifiers and the gains may be different.
True that's what I specified in first post. Both amp are integrated amplifiers (I gave link to specs) and I'll bypass the preamp section, so I guess no more volume pot.
Current crossover is 800hz.
Compression driver + horn are designed to go to 600hz.
Pioneer/TAD did 650hz for two models and one at 800hz but allow double woofers (using the same slopes W -36db/oct Comp D -12db/oct).
I want an active system to test at 600hz or 650hz. I don't want to spend more money than the miniDSP, that's why I listed the amplifiers I own right now.
Speakers are up ans running for 3 years now. They measure well, so as my room with treatment.
Now I just want to know what could be the issues with my plan. If it's clear that it won't work O won't buy the miniDSP. I don't need help for room treatment and measurements, no help for crossover setup.
This a clone of a pioneer/TAD design. If you need more details, but I don't see what the horn has to do with gain?
The cabinet & horn change the dB output. So I don't trust that 13dB number.
Plus, at 16 Ohms you have half the power at the same voltage (I assume the woofer is 8 Ohms?). Half the power is -3dB so you'd be down to a 10dB difference (with matched amplifiers).
More gain = more output. Less gain + less output. For example, If there is really a 13dB difference and the woofer amplifier has 13dB more gain (unlikely) every everything is OK. But, if the high-frequency amplifier has more gain than the woofer amp, that makes things worse.
This a clone of a pioneer/TAD design. If you need more details, but I don't see what the horn has to do with gain?
The cabinet & horn change the dB output. So I don't trust that 13dB number.
Plus, at 16 Ohms you have half the power at the same voltage (I assume the woofer is 8 Ohms?). Half the power is -3dB so you'd be down to a 10dB difference (with matched amplifiers).
More gain = more output. Less gain + less output. For example, If there is really a 13dB difference and the woofer amplifier has 13dB more gain (unlikely) every everything is OK. But, if the high-frequency amplifier has more gain than the woofer amp, that makes things worse.
Yep woofers are 8 ohm.
Cabinet
http://www.geocities.jp/arai401204/Enclosure/E170/E170.html
No amps are not matched : Pioneer 110w (8ohm) on woofer
Luxman 50w (8ohm) on comp drivers.
So I guess luxman has less gain than pioneer.
Specs are available with links from the first post.
For me going active allow me to use two different amplifiers : one more powerfull for the 16" woofer and a less powerfull amplifier with a high sensitivity comp driver. And I think that's something comon to Do? I don't see the point of using the more powerfull amp on horn.
For amplifier gain
110w @8hom with a 97db woofer = 20.4 db of gain
25w @16ohm (I halved the 50w @8ohm published by manufacturer) with a 110db CD = 14 db of gain.
But anyway why on the hell I'll use all this amount of gain? I use fractions of a watt at normal listening level
So basically I'll have to attenuate ~7 db (if the horn or cabinet don't change the sensitivity of the drivers. I'll try to measure it for fun)?
I can do this with the miniDSP output gain or with a L-PAD right?
For amplifier gain
110w @8hom with a 97db woofer = 20.4 db of gain
25w @16ohm (I halved the 50w @8ohm published by manufacturer) with a 110db CD = 14 db of gain.
Gain is independent of power. A lower power amplifier can have more gain.
i.e. Amplifier A is a 100W amp and Amplifier B is a 50W.
Amplifier A might put-out 10 Watts with 1 Volt in. Amplifier B might put-out 20W with 1V in.
Typically, you don't see a "gain" spec. You might find a "sensitivity" spec that says "full power at 1V in", or "full-lower at -10dBV in".
Gain (in dB) is actually
voltage gain. i.e. 20dB gain is 10V out with 1V in. They don't give you voltage-out but you could calculate it (if you have the sensitivity spec.).
Amplifiers are (approximately) "constant voltage" devices. Of course the voltage isn't really constant because it depends on the program material and the volume control setting. It means voltage is independent of the impedance load.
10W into 8-Ohms is 12.5V. If the amplifier is putting-out a 12.5V test tone and we disconnect the speaker it still puts-out (approximately) 12.5V, but zero Watts. If you connect a 16-Ohm speaker you'll get 12.5V and 5W.
However, if the amplifier is putting-out full power and you connect a lower impedance speaker the voltage may drop, and if it does the amplifier will clip. Most solid state amplifiers are rated for twice the power at 4-Ohms but sometimes you'll seem the same power rating at 4 and 8 Ohms. But, the voltage gain is the same (up to the point of clipping).
If you connect too-low of an impedance the amplifier might overheat and shut-down or burn-up.
The power-outlet in your house is also constant voltage... The same voltage is present when nothing is plugged-in or if a 100W lamp or a 1200W toaster is plugged-in. The power & current depend on the resistance of the load. If you draw too much current the circuit breaker blows and voltage drops to zero.
--------------------------------------------------------------------------------
But anyway why on the hell I'll use all this amount of gain? I use fractions of a watt at normal listening level
In that case, you can potentially use the lower-power amplifier for the woofer if it has more gain.
Have you checked to see which amp is "louder"? You could connect one amp to the left speaker and the other to the right to see which is louder (if there's a difference). Typically, the higher-power amp would have more gain but you can't be sure of that.
...Since your power amps don't have volume controls
you can't change the gain of the power amps. You can only adjust the gain (or attenuation) of the preamp
What about those calcultors?
http://www.sengpielaudio.com/calculator-amplification.htm
I re-checked the miniDSP manual and there's -72db of gain attenuation, even with -12db I still have plenty of room, I think there's no reason for worrying. With the l-pad I'll have the same gain on all 4 outputs channels. I want to be able to crank the speakers from time to time.
Ok 8)
The NF of you active system will be very bad, the Lpads are here to improve that parameter only , without them you will hear a huge noisefloor (and all its audible artifacts)
I have 28dB on my compressions and 6dB and my woofers, the MP3 sound perfect with no artifacts at all :D
The levels shoud be adjusted later IMHO, measurements will give you the way to do it especially if there are a lot of reflexions, you are using wide dispertion biradial horns of the reference desing close to the walls... the soup of reverberations will affect the levels.
The levels shoud be adjusted later IMHO, measurements will give you the way to do it especially if there are a lot of reflexions, you are using wide dispertion biradial horns of the reference desing close to the walls... the soup of reverberations will affect the levels.
I'm working on this. There's less reflexions already with the panels that I have. I'll receive 6 - 2"x36x48 comfortboard this week (I hope).
I'm working on this. There's less reflexions already with the panels that I have. I'll receive 6 - 2"x36x48 comfortboard this week (I hope).
What kind of absorption do you expect from these panels ?
Have you a rough idea ?
I'm working on this. There's less reflexions already with the panels that I have. I'll receive 6 - 2"x36x48 comfortboard this week (I hope).
What kind of absorption do you expect from these panels ?
Have you a rough idea ?
2" will turn down the treble non-linearly, so that the reflections are even more unlike the onset wavefront. Blind tests show this to be worse perceptually for a variety of reasons, but belief in nonsense and the visual/expectation aspect will trump that and it will in extreme likelihood, "sound" better. The studios use stuff that look similar, so you should too.
It's all explained in Toole's IQ test, excuse me, writings.
(https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation/copy_of_Figure7.6RIvsangularabsorption.jpg/image_preview2)
I'm working on this. There's less reflexions already with the panels that I have. I'll receive 6 - 2"x36x48 comfortboard this week (I hope).
What kind of absorption do you expect from these panels ?
Have you a rough idea ?
First I want to lower reflexions. Still don't know if I'll do 6 x 2'' panels or 3 x 4'' panels. The 4 panels that I built last year are 4'' installed at first reflexion points. Absorption will be welcome, but for now I have +/- 5db to almost 20hz to 20khz and a big part at +/- 3db. Since I take the frequency response with a grain of salt I guess it's pretty good. I don't know yet if I'll hear a difference once I'll get the new panels on walls. I guess I'll have to sacrifice myself and listen to a lot of music for the coming days :p
I'll try both configuration (2'' or 4'') before final installation And I'll measure (almost) all the possible combinations.
If you can go to this forum you'll find a part measurements I took today.
http://the-audio-expert.freeforums.net/thread/458/thicker-more-panels?page=3&scrollTo=4037
or check the REW file I attached
Oups notes are in french.
First measurements siting square, ears at same level has the center of the horn.
Second 4'' lower (siting late at night lol)
I took a lot of measuements today 40 to 50, several for each change to see if results are consistent.
2" will turn down the treble non-linearly, so that the reflections are even more unlike the onset wavefront. Blind tests show this to be worse perceptually for a variety of reasons, but belief in nonsense and the visual/expectation aspect will trump that and it will in extreme likelihood, "sound" better. The studios use stuff that look similar, so you should too.
It is an empirical aproach, some people are adjusting their "soup" of reverberations to their taste and perform inaccurate measurements in order to interpret them as a confirmation bias.
IMHO, it seems to be more a guru job than a real technical work.
It is an empirical aproach
Round these parts it's called sighted, belief approach.
Btw, needless to say, didn't register at other site to see expanded full size graphs, but the speaker FR snapshot appear to be 10db (!!) scaling, which would make the native onset response rather poor (assuming competence in the measurement/system). If that is
with DSP, it's frankly horrific.
Under those pathological circumstances, by all means pad the room with gauze/bandaids, aka the "less worse" option.
REW's mdat file is attached, so no need to go to forum to see graph.
83% of frequency response is +/- 3b, and 92% +/-5 db, it's not that hard to see that with a 10 db scale. Note that scale can be adjusted freely with REW.
As for freq response I always take those graphs with a grain of salt since it change with a couple of inches mic placement. However acoustic panels allowed me to get a fixed image (a larger window). Before singer's position slip from center to left or right with small head mouvements. Blinded listening revealed the same thing.
Now I can move freely at my siting position without loosing singer and instrument "placement". Measurements at different position confirmed it since frequency response shape is quite "stable" but with db change. It can be easily seen with the spl graph.
Now at this point I'll keep my subjective point of view for me. But I have a stable image and it is something that I really appreciate. Other panels will help me with the other reflexions, absorption coeficient at this point doesn't matter to me. Comfortboard are easy to work with and can look good, it can even help to hold my beer while playing rock band with my friend.
I won't do ABX with room acoustic in my house. No one told me or suggested me to do acoustic treatment. I experienced adding stuff 2 years ago it gives me benefits that I appreciate.
Again ajinfla you're trying to troll, and you're thread crapping my post. I've read your points about this in the other post you link, it's time to move on.
Before singer's position slip from center to left or right with small head mouvements. Blinded listening revealed the same thing.
¯\_(ツ)_/¯
REW's mdat file is attached, so no need to go to forum to see graph.
83% of frequency response is +/- 3b, and 92% +/-5 db, it's not that hard to see that with a 10 db scale. Note that scale can be adjusted freely with REW.
Your NF is high, do you hear it ?
Have you applied some EQ ?
PS : imaging should be a space oddity because of your horns firing on the walls.
Don't know where the mic is, but if the measurement setup isn't broken, the loudspeaker is.
(https://www.amazon.com/drive/v1/nodes/6HCguLzgQZmKWxyRogX-Ug/contentRedirection?querySuffix=%3FviewBox%3D1023%2C529&ownerId=A2OBO7C8S5RCX7&cb=1532638305889)
Unsurprising no one said a word on the iso-ward forum. Casting pearls before the swine.
I hope the polars aren't worse. This thing needs some "treatment" alright.
REW's mdat file is attached, so no need to go to forum to see graph.
83% of frequency response is +/- 3b, and 92% +/-5 db, it's not that hard to see that with a 10 db scale. Note that scale can be adjusted freely with REW.
Your NF is high, do you hear it ?
Have you applied some EQ ?
PS : imaging should be a space oddity because of your horns firing on the walls.
Noise floor? +/- of being flat response.
Dead silent setup, no EQ.
I'll call major Tom to see if it's the case
I'll call major Tom to see if it's the case
On your measurements, the NF is high...
So, you are trying to find a tonal equilibrium on a very, very difracted soundfield, why not, but it is a llittle naive to expect anyting good concerning the imaging.
I'll call major Tom to see if it's the case
On your measurements, the NF is high...
So, you are trying to find a tonal equilibrium on a very, very difracted soundfield, why not, but it is a llittle naive to expect anyting good concerning the imaging.
Where do you see the noise floor?
For amplifier gain
110w @8hom with a 97db woofer = 20.4 db of gain
25w @16ohm (I halved the 50w @8ohm published by manufacturer) with a 110db CD = 14 db of gain.
Gain is independent of power. A lower power amplifier can have more gain.
i.e. Amplifier A is a 100W amp and Amplifier B is a 50W.
Amplifier A might put-out 10 Watts with 1 Volt in. Amplifier B might put-out 20W with 1V in.
Typically, you don't see a "gain" spec. You might find a "sensitivity" spec that says "full power at 1V in", or "full-lower at -10dBV in".
Gain (in dB) is actually voltage gain. i.e. 20dB gain is 10V out with 1V in. They don't give you voltage-out but you could calculate it (if you have the sensitivity spec.).
Amplifiers are (approximately) "constant voltage" devices. Of course the voltage isn't really constant because it depends on the program material and the volume control setting. It means voltage is independent of the impedance load.
10W into 8-Ohms is 12.5V. If the amplifier is putting-out a 12.5V test tone and we disconnect the speaker it still puts-out (approximately) 12.5V, but zero Watts. If you connect a 16-Ohm speaker you'll get 12.5V and 5W.
However, if the amplifier is putting-out full power and you connect a lower impedance speaker the voltage may drop, and if it does the amplifier will clip. Most solid state amplifiers are rated for twice the power at 4-Ohms but sometimes you'll seem the same power rating at 4 and 8 Ohms. But, the voltage gain is the same (up to the point of clipping).
If you connect too-low of an impedance the amplifier might overheat and shut-down or burn-up.
The power-outlet in your house is also constant voltage... The same voltage is present when nothing is plugged-in or if a 100W lamp or a 1200W toaster is plugged-in. The power & current depend on the resistance of the load. If you draw too much current the circuit breaker blows and voltage drops to zero.
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But anyway why on the hell I'll use all this amount of gain? I use fractions of a watt at normal listening level
In that case, you can potentially use the lower-power amplifier for the woofer if it has more gain.
Have you checked to see which amp is "louder"? You could connect one amp to the left speaker and the other to the right to see which is louder (if there's a difference). Typically, the higher-power amp would have more gain but you can't be sure of that.
...Since your power amps don't have volume controls you can't change the gain of the power amps. You can only adjust the gain (or attenuation) of the preamp
I was looking at emotiva amp as a final setup (amp listed in first post are for testing)
MiniDSP 2x4 HD : input 2v or 4v @ 10k ohm
output 2v @ 560 ohm
PT-100 preamp : Max output 4v ?ohm
Amp : A-100 input 600mV ?ohm with 8 ohm load
50 w - 8 ohm
Amp - A-300 input 1.2 v 27k ohm with 8 ohm load
Gain 29 db
150w 8 ohm
Driver 1 - sensitivity 110db - 16 ohm
Driver 2 - sensitivity 97db - 9 ohm
What would be the gain structure ( I sent an email to emotiva to get missing information
Where do you see the noise floor?
The distortion tab (red)
The NF (green)
(https://nsa39.casimages.com/img/2018/07/28/mini_180728081035811575.png) (https://www.casimages.com/i/180728081035811575.png.html)
Where do you see the noise floor?
The distortion tab (red)
The NF (green)
(https://nsa39.casimages.com/img/2018/07/28/mini_180728081035811575.png) (https://www.casimages.com/i/180728081035811575.png.html)
Both sweep shows a different noise floor level : one with the highest peak at 3,87% and the other 6.79% at a different frequency.
Sweep test are done at ~ 75dp spl in my basement at listening position. But there's no noise that I can hear (except the room noise), even If I place my ear in the horn. Also there's no audible distortion. I don't know what kind of noise floor is expected but looking at REW's help exemple and other users measurement there's no issue here. Maybe there's something I'm missing, can you point me out where the issue is, and what should I hear?
I browse the REW help file and it seems that a stepped sine measurement (from the RTA window), would give a better result for distortion measurements.
Both sweep shows a different noise floor level : one with the highest peak at 3,87% and the other 6.79% at a different frequency.
Sweep test are done at ~ 75dp spl in my basement at listening position. But there's no noise that I can hear (except the room noise), even If I place my ear in the horn. Also there's no audible distortion. I don't know what kind of noise floor is expected but looking at REW's help exemple and other users measurement there's no issue here. Maybe there's something I'm missing, can you point me out where the issue is, and what should I hear?
Have you calibrated your mic ?
Have you enter the calibration profile in REW ?
My test setup is 0.035% and the NF is around 45dB in the journey, it is not really a stellar performance.
Concerning the THD you have a serious issue around 70 Hz (over 6%... -23dB should be audible) and 1313Hz (over 4% -27dB should be audible because composed of H3 harmonics)
Both sweep shows a different noise floor level : one with the highest peak at 3,87% and the other 6.79% at a different frequency.
Sweep test are done at ~ 75dp spl in my basement at listening position. But there's no noise that I can hear (except the room noise), even If I place my ear in the horn. Also there's no audible distortion. I don't know what kind of noise floor is expected but looking at REW's help exemple and other users measurement there's no issue here. Maybe there's something I'm missing, can you point me out where the issue is, and what should I hear?
Have you calibrated your mic ?
Have you enter the calibration profile in REW ?
My test setup is 0.035% and the NF is around 45dB in the journey, it is not really a stellar performance.
Concerning the THD you have a serious issue around 70 Hz (over 6%... -23dB should be audible) and 1313Hz (over 4% -27dB should be audible because composed of H3 harmonics)
Yep I use the umik-1 calibration file.
Around 70hz there's a room mode (height) as you can see on frequency graph, same thing goes for 1300hz region. (300hz too) So, no nothing can be really heard at those frequencies at listening position
Look at group delay graph with minimum phase you'll see that there's no hope to totally correct at those frequency.
I could check with a proper setup to measure distorsions, but again there's nothing I can hear.
By the way I'm using the last beta 5.19 I think.
Yep I use the umik-1 calibration file.
Around 70hz there's a room mode (height) as you can see on frequency graph, same thing goes for 1300hz region. (300hz too) So, no nothing can be really heard at those frequencies at listening position
Look at group delay graph with minimum phase you'll see that there's no hope to totally correct at those frequency.
I could check with a proper setup to measure distorsions, but again there's nothing I can hear.
Do you calibrate the SPL of your mic... with an external device (calibrator) ?
I believe you, the numbers that you are pointing on are as you expect them.
Do you calibrate the SPL of your mic... with an external device (calibrator) ?
No
I'll check again but in room noise floor was below 45db for sure.
Do you calibrate the SPL of your mic... with an external device (calibrator) ?
No
I'll check again but in room noise floor was below 45db for sure.
Your SPL measurement will be wrong with an uncalibrated microphone.
Your SPL measurement will be wrong with an uncalibrated microphone.
MiniDSP umik-1 only has a calibration file. Since it's usb there's not a lot things I can do to calibrate it.
Here'S an RTA window, with kids in the house.
Sorry took the measurment with wrong mic above I changed it
RTA with pink noise
I did a couple of tests with the RTA and sine wave generator. The noise floor remained low, too low to have an effect.
Again using the tone generator, sine wave that I raise manually from 1200 to 2000 hz, 300hz and 68hz and nothing sound strange (no noise or distortion). There's a db drop but room related, moving in the room change the db level.
Your SPL measurement will be wrong with an uncalibrated microphone.
MiniDSP umik-1 only has a calibration file. Since it's usb there's not a lot things I can do to calibrate it.
IMHO Rew need to be exteraly calibrated with a mic calibrator in order to have an accurate SPL measurement.
... the whole point of getting a UMIK-1 (or similar) is that it's already calibrated at the factory and applying the calibration file will produce accurate SPL values in the application program. Unless you feel you need to re-calibrate the mic because you don't trust their lab, in which case you're going to need ANOTHER calibrated mic, which if you don't trust...
... the whole point of getting a UMIK-1 (or similar) is that it's already calibrated at the factory and applying the calibration file will produce accurate SPL values in the application program. Unless you feel you need to re-calibrate the mic because you don't trust their lab, in which case you're going to need ANOTHER calibrated mic, which if you don't trust...
You are confusing two different types of calibrations... it is perhaps time for a good reading :
https://www.amazon.fr/gp/search/ref=a9_asi_1?rh=i%3Aaps%2Ck%3Asound+engineer+handbook&keywords=sound+engineer+handbook&ie=UTF8&qid=1532967654
Since you're not hearing noise it's a non-issue.
And, you're not driving your amps into clipping (at least not under normal listening conditions) so amplifier-distortion is not an issue either.
It's also highly-unlikely that you are driving your speakers in to "breakup". There is always some speaker-distortion but it's generally unnoticeable (or at least tolerable) as long as the speakers are not over-driven, and there's not much you can do about it anyway without completely re-designing the speaker.
Amp : A-100 input 600mV ?ohm with 8 ohm load
50 w - 8 ohm
Amp - A-300 input 1.2 v 27k ohm with 8 ohm load
Gain 29 db
150w 8 ohm
Now that I've had a chance to get back to the spreadsheet...
Those two amplifiers are closely matched in gain. (Possibly exactly-matched with some rounding in the published specs so they can publish "even numbers".)
50W @ 8 Ohms = 20V RMS
150W@ @ 8 Ohms = 34.64V RMS
Voltage gain = 20/0.6 = 33.3 =
30.5dB Voltage gain = 1.2/34.64 = 28.9 =
29.2dB...Feel free to double-check my numbers because I'm violating the rule,
"Never do math in public." ;)
Since you're not hearing noise it's a non-issue.
IMHO you should be more careful with this argument the noise get is sometimes higher with large amplitude modulations.
Now that I've had a chance to get back to the spreadsheet...
Those two amplifiers are closely matched in gain. (Possibly exactly-matched with some rounding in the published specs so they can publish "even numbers".)
50W @ 8 Ohms = 20V RMS
150W@ @ 8 Ohms = 34.64V RMS
Voltage gain = 20/0.6 = 33.3 = 30.5dB
Voltage gain = 1.2/34.64 = 28.9 = 29.2dB
...Feel free to double-check my numbers because I'm violating the rule, "Never do math in public." ;)
:)) :)) Thanks for your help, except the typo for second amplifier's voltage gain it looks good.
For mic calibration I won't invest money to calibrate it. There's no audible noise or distortion so I'm not worry about that.
I was doing the math for my current amplifiers and the Pioneer has 29,44 db of gain.
Now looking at the luxman R114 spec I found
50w @ 8ohm = 20Vrms
Main : 150mV @ 43khom (looks like the same thing as a line in).
20/0.15 = 133.33 db
That's huge, is it something possible? Do you think there's an error in the service manual? I understand that my amplifiers are not matching and that it'll cause issues.
I was doing the math for my current amplifiers and the Pioneer has 29,44 db of gain.
Now looking at the luxman R114 spec I found
50w @ 8ohm = 20Vrms
Main : 150mV @ 43khom (looks like the same thing as a line in).
20/0.15 = 133.33 db
That's huge, is it something possible? Do you think there's an error in the service manual? I understand that my amplifiers are not matching and that it'll cause issues.
You forgot something: 20*log(20/0.15)=42.5dB, not 133dB
You forgot something: 20*log(20/0.15)=42.5dB, not 133dB
Yep thanks, it makes more sense.
There's still a big difference though.
At this point since de luxman main in, is just a line in, I should use my integrated amplifer, wich is 35w @ 8ohm. Input 150mV which gives me 40.95 db if gain, which is more closed. I'll gain a volume pot to match drivers sensitivity.
On your measurements, the NF is high...
So, you are trying to find a tonal equilibrium on a very, very difracted soundfield, why not, but it is a llittle naive to expect anyting good concerning the imaging.
I was thinking about noise floor. Is it possible that it comes from the cd player/DAC output (this is what I use wirh REW)?
CDP : 2,3Vrms
Amp input : 150mV
I never have to get the dial up to have it loud, maybe the voltage is just too high for my vintage amplifier?
I was thinking about noise floor. Is it possible that it comes from the cd player/DAC output
Probably not. There is
some noise from the analog-side of the DAC but it's usually very-low level. And, any noise before the (analog) volume control gets attenuated along with the signal so the signal-to-noise ratio is not affected. If you are attenuating digitally you're making the signal-to-noise ratio worse.
There could be noise coming from the preamp (if you're using one), otherwise most of the noise is probably coming from the power amp. There's always
some noise generated in the active-analog electronics. But, you said you're not hearing noise.
But, you said you're not hearing noise.
Yes and it's still the case.
I'm just looking at at input/output voltage ans it comes to my mind. I'll test to see if I get the same results if I measure with 512k instead if 1 m