Question about speakers with built in subs. [Archive] - Audio & Video Forums

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GMichael
07-20-2007, 08:06 AM
If you have speakers with built in subs (and amp), I would think that you'd want to send them a full range signal. But will doing that tax your external amp more? I know that your external wouldn't actually be driving the sub, but does the amp know that? It's still sending that signal right? So isn't it doing more work than if it was crossed at a higher frequency? Do these type of speakers normally have much higher resistance at the low frequencies to keep the external amp from being over worked?

kexodusc
07-20-2007, 09:07 AM
If you have speakers with built in subs (and amp), I would think that you'd want to send them a full range signal. But will doing that tax your external amp more? I know that your external wouldn't actually be driving the sub, but does the amp know that? It's still sending that signal right? So isn't it doing more work than if it was crossed at a higher frequency? Do these type of speakers normally have much higher resistance at the low frequencies to keep the external amp from being over worked?
If you use a receiver, and set the speaker to "small" it acts no differently than a sub/satellite style system.
Actually, it won't act any differently than the sub/sat system anyway.
GM, the built in subs have plate amps typically that receive the LFE input from receiver/amp, and some have high level inputs. They operate no differently than if you were to put your speaker on top of your subwoofer now. They aren't actually wired to the speaker. At least not any models I'm aware of.

If you sent the sub the full-range signal at high level, I supose there's some added effort but yeah, the resistance is such that you won't fry your amp or anything.

GMichael
07-20-2007, 09:26 AM
If you use a receiver, and set the speaker to "small" it acts no differently than a sub/satellite style system.
Actually, it won't act any differently than the sub/sat system anyway.
GM, the built in subs have plate amps typically that receive the LFE input from receiver/amp, and some have line level inputs. They operate no differently than if you were to put your speaker on top of your subwoofer now. They aren't actually wired to the speaker. At least not any models I'm aware of.

If you sent the sub the full-range signal at line level, I supose there's some added effort but yeah, the resistance is such that you won't fry your amp or anything.

Thanks.

What I am hoping to do is to use the pure direct mode on my receiver for 2 channel music. That will cut off the LFE so my MKIII will go off and a full range will go to the speakers. Then when I watch movies I can switch to DD or DTS and then send the speakers 40htz and above while the MKIII gets below that.
Does that seem reasonable?

kexodusc
07-20-2007, 09:31 AM
Thanks.

What I am hoping to do is to use the pure direct mode on my receiver for 2 channel music. That will cut off the LFE so my MKIII will go off and a full range will go to the speakers. Then when I watch movies I can switch to DD or DTS and then send the speakers 40htz and above while the MKIII gets below that.
Does that seem reasonable?

Yeah, sounds reasonable...and is exactly what I do in my HT system when I can't be bothered to go downstairs to my stereo system

Except...with your receiver...why you crossing over so low?
:)

GMichael
07-20-2007, 09:38 AM
Yeah, sounds reasonable...and is exactly what I do in my HT system when I can't be bothered to go downstairs to my stereo system

Except...with your receiver...why you crossing over so low?
:)

Right now, it's crossed over at 80. But if I get the Mini Stradas (and this is close to happening) then they will have subs built in. They go down into the high 20's. Why not let them go down to 40 and that way the MONSTER can focus on the low lows.
I'm just hoping that it's not too much strain on my receiver. I'll get an amp later but still want it to sound good "now".
The mini's Impedance curve looks like it should be OK.

basite
07-20-2007, 09:44 AM
so you're getting yer mini's eh?

congrats (and be sure to post pics & stuff like that)

it should work that way :)
however, when you plan to get an amp later, you could add a crossover between the receiver and the amp so it will be less stressed...

GMichael
07-20-2007, 09:51 AM
so you're getting yer mini's eh?

congrats (and be sure to post pics & stuff like that)

it should work that way :)
however, when you plan to get an amp later, you could add a crossover between the receiver and the amp so it will be less stressed...

Got a decent bonus last spring, so the cash is ready. Wifey asked me what I wanted for my birthday (late August). I told her that she doesn't need to get me anything. I'll buy them myself. Just say it's OK. TA DA.........

kexodusc
07-20-2007, 09:56 AM
Right now, it's crossed over at 80. But if I get the Mini Stradas (and this is close to happening) then they will have subs built in. They go down into the high 20's. Why not let them go down to 40 and that way the MONSTER can focus on the low lows.
I'm just hoping that it's not too much strain on my receiver. I'll get an amp later but still want it to sound good "now".
The mini's Impedance curve looks like it should be OK.
How are you connecting the plate amp to the receiver? low-level (LFE cable) or high-level (speaker cables from receiver speaker terminal)?
If it's just the low-level RCA cable (preferred) there's no extra strain.

GMichael
07-20-2007, 10:12 AM
How are you connecting the plate amp to the receiver? low-level (LFE cable) or high-level (speaker cables from receiver speaker terminal)?
If it's just the low-level RCA cable (preferred) there's no extra strain.

High-level. In pure direct mode the LFE is cut off by my receiver.
The LFE is connected to the MKIII.

I like the sound of pure direct more that the straight mode, but my Infinities can't go low enough for me.

kexodusc
07-20-2007, 10:50 AM
You can run the high-level no problem. The high-level has sufficient impedance to protect your speaker in the parallel configuration, and uses the plate-amp's crossover rather than the receiver's. What order is the filter in your sub amp?

GMichael
07-20-2007, 10:55 AM
You can run the high-level no problem. The high-level has sufficient impedance to protect your speaker in the parallel configuration, and uses the plate-amp's crossover rather than the receiver's. What order is the filter in your sub amp?

Amplifier: Built-in 350 watt class A/B for the powered woofer. Includes LINK cable so no additional speaker wire is required for connection. Features crossover, gain, variable phase and high level/low level inputs and outputs.
Crossover Network: Includes air core inductors, polypropylene capacitors and non-inductive wire wound resistors. 4th order acoustic slopes on the upper end and 2nd order slopes on the bottom end.
Crossover Points:
8" woofer : 27 Hz - (user definable)
5.25" has a 1st order high pass at 80Hz
5.25" mid-bass coupler to 8" midrange : 650Hz
8" midrange to tweeter : 4100Hz
Frequency Response: 27 Hz to 35 KHz (± 3 dB)
Impedance: 8 Ohms nominal
Efficiency: 86 dB (@ 1 watt / 1 meter)


http://www.av123.com/products_product.php?section=speakers&product=78.1

kexodusc
07-20-2007, 12:13 PM
The 5.25 rolls off at 6 dB/octave...the woofer must roll off above 80 Hz at 12 dB/octave...that's most common for sub amps.

GMichael
07-20-2007, 12:32 PM
The 5.25 rolls off at 6 dB/octave...the woofer must roll off above 80 Hz at 12 dB/octave...that's most common for sub amps.

The upper end for the woofer is "user definable". Adjustable. I was thinking that 80 is a good number though. I could set it higher but not sure what that would net me. It might take a little strain off the 5.25" mid base, but I don't think that adjustement effects the mid base at all.

kexodusc
07-20-2007, 12:47 PM
The upper end for the woofer is "user definable". Adjustable. I was thinking that 80 is a good number though. I could set it higher but not sure what that would net me. It might take a little strain off the 5.25" mid base, but I don't think that adjustement effects the mid base at all.
Ugh, bad case of fingers typing without consulting the brain.
Yeah, your sub's crossover is variable (user defined) and not fixed at 80, my bad. The slope is what I was curious about. Can you find any more info on the sub amp's crossover slope?
I haven't heard these at all, but they certainly look like a well thought out speaker, and I trust av123.

GMichael
07-20-2007, 12:56 PM
Ugh, bad case of fingers typing without consulting the brain.

Oh no! You pulled a Pixle! Does it hurt?


The slope is what I was curious about. Can you find any more info on the sub amp's crossover slope?

I'll try to find out more. All I saw was, "4th order acoustic slopes on the upper end and 2nd order slopes on the bottom end."


I haven't heard these at all, but they certainly look like a well thought out speaker, and I trust av123.

They have received many great reviews. The one bad review they got was from a guy who doesn't like any planner or electrostatic speakers. I've heard the 3.6 Maggies as well as a few different ML's. I know that I do like that sound.

GMichael
07-20-2007, 01:31 PM
so you're getting yer mini's eh?

congrats (and be sure to post pics & stuff like that)

it should work that way :)
however, when you plan to get an amp later, you could add a crossover between the receiver and the amp so it will be less stressed...

When the time comes, you'll have to show me what you mean.

Luvin Da Blues
07-20-2007, 04:58 PM
Amplifier: Built-in 350 watt class A/B for the powered woofer. Includes LINK cable so no additional speaker wire is required for connection. Features crossover, gain, variable phase and high level/low level inputs and outputs.
Crossover Network: Includes air core inductors, polypropylene capacitors and non-inductive wire wound resistors. 4th order acoustic slopes on the upper end and 2nd order slopes on the bottom end.
Crossover Points:
8" woofer : 27 Hz - (user definable)
5.25" has a 1st order high pass at 80Hz
5.25" mid-bass coupler to 8" midrange : 650Hz
8" midrange to tweeter : 4100Hz
Frequency Response: 27 Hz to 35 KHz (± 3 dB)
Impedance: 8 Ohms nominal
Efficiency: 86 dB (@ 1 watt / 1 meter)


http://www.av123.com/products_product.php?section=speakers&product=78.1


Nice GM, if they sound half as good as they look..............

Congrats :16:

Hope they don't get wrecked at the party. :sad:

Rich-n-Texas
07-20-2007, 05:12 PM
Nice GM, if they sound half as good as they look..............

Congrats :16:

Hope they don't get wrecked at the party. :sad:
My car has a pretty big trunk...
:ihih:

Luvin Da Blues
07-20-2007, 06:12 PM
My car has a pretty big trunk...
:ihih:

OK I'll distract him.........Hey GM look at the bird.....




Rich....don't scratch them..bring some moving blankets.:cornut:

basite
07-21-2007, 02:03 AM
keep looking at the bird Mike, Rich has some troubles lifting your speakers :)

GMichael
07-21-2007, 04:25 AM
OK I'll distract him.........Hey GM look at the bird.....




Rich....don't scratch them..bring some moving blankets.:cornut:

OOOOOO Pretty bird.........
Oh look! Two of them. :dita:

GMichael
07-21-2007, 04:31 AM
Nice GM, if they sound half as good as they look..............

Congrats :16:

Hope they don't get wrecked at the party. :sad:

TANX. I'll put the covers on them.

Luvin Da Blues
07-21-2007, 05:19 AM
OOOOOO Pretty bird.........
Oh look! Two of them. :dita:


I knew you would be up to having a good come back. :thumbsup: good one