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Topic: Active setup help and recommendations (Read 17553 times) previous topic - next topic
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Active setup help and recommendations

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

 

Re: Active setup help and recommendations

Reply #1
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.

Re: Active setup help and recommendations

Reply #2
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 or variable in-line attenuators.    (Variable stereo pots/attenuators may not track left & right identically, so that's something to be aware of.)

Quote
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.

Quote
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 (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.


Re: Active setup help and recommendations

Reply #3
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.

Quote
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 (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.



Re: Active setup help and recommendations

Reply #4
You can also buy fixed or variable 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.

Re: Active setup help and recommendations

Reply #5
The room study should be the most interesting part of the project (before choosing anything IMHO)
What about to make a drawing ?

Re: Active setup help and recommendations

Reply #6
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

Re: Active setup help and recommendations

Reply #7
You might want to read this thread thoroughly, as HA has a TOS that applies to all topics
Loudspeaker manufacturer

Re: Active setup help and recommendations

Reply #8
You might want to read this thread 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.

Re: Active setup help and recommendations

Reply #9
I'll add get out if my post please I'm not really interested with your anwsers even if they are goods.

Thanks

Re: Active setup help and recommendations

Reply #10
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.
Loudspeaker manufacturer

Re: Active setup help and recommendations

Reply #11
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  ;)

Re: Active setup help and recommendations

Reply #12
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/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.
Loudspeaker manufacturer

Re: Active setup help and recommendations

Reply #13
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).


Re: Active setup help and recommendations

Reply #14
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

Re: Active setup help and recommendations

Reply #15
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.

Re: Active setup help and recommendations

Reply #16
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.

Re: Active setup help and recommendations

Reply #17
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?

Re: Active setup help and recommendations

Reply #18
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

Re: Active setup help and recommendations

Reply #19
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

Re: Active setup help and recommendations

Reply #20
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)


Re: Active setup help and recommendations

Reply #21
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 ?

Re: Active setup help and recommendations

Reply #22
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.


Re: Active setup help and recommendations

Reply #24
Quote
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.