Sub Config Advice for 2.1 (Newbie Alert)

[woodbutcher68]

Hello, all. I’m very new to the area of your expertise. I'm a lifelong guitar player and music enthusiast, but somehow I have never had more than a “decent” quality boombox/component system. The most recent one died and I decided to do something a little better for myself. Emphasis on “little” – I live in an apartment and I’m trying to put my kid through college, so money is tight.

(Apologies for the longish post, but I'm trying to anticipate your questions...)

(Also - I posted this in the "neophyte" area, too. If this is a non-no, the faux pas is unintentional...)

Here’s my projected 2.1 setup:

Philips CDR795 2-Disc CD Recorder (already had this…)
Harman Kardon HK-3390 receiver (just arrived, haven’t unpacked it)
Klipsch B-2 speakers (got these a week ago)
The Speaker Company ASW-8 sub (enroute to me)

I’m puzzled about setting up the sub. The HK receiver has two dedicated sub outs, and also info about “trigger outputs” and “link switches”.

Related text from HK manual:

Subwoofer Outputs: If you have a powered subwoofer, connect these jacks to the line-level inputs on the subwoofer. The same fullrange signal is output through both jacks. Thus, you have the option of connecting each jack to the line-level input on a separate subwoofer, or to use these full-range outputs to feed a remote room in a distributed audio application. If you have only one subwoofer with a single line-level input, connect it to the right Subwoofer Output on the HK 3390.

Subwoofer Trigger Outputs: Connect these outputs to a compatible trigger input on the subwoofer connected to the Subwoofer Output immediately to the right of the Trigger Output. Consult the owner’s manual for the subwoofer to set its trigger input correctly, and the subwoofer will automatically turn on or off when the HK 3390 is turned on or off. In addition, the Trigger Outputs are used with the Subwoofer Link Switches to conserve energy by powering off the subwoofer’s amplifier when it is not needed. The Subwoofer Trigger Outputs send a signal of 15 volts DC.

Subwoofer Link Switches: Each switch affects the subwoofer connected to the jack immediately to the left of the switch. To use the switch , first connect the corresponding Subwoofer Trigger Output to a compatible trigger input on the subwoofer, and make sure the subwoofer’s instructions are followed to activate its trigger input. When the Link Switch is on, the HK 3390 will remove the trigger signal whenever the corresponding pair of main speakers are not in use, thereby conserving energy that would otherwise be used to maintain the subwoofer’s amplifier in standby mode. This feature is activated any time no signal is present at the main speaker outputs, including when the Speaker 1/2 Switch turns off both speaker pairs, when the HK 3390’s output is muted, or when the headphones are plugged in. See Table A2 in the appendix for details.

The ASW-8 sub manual tells me this info about interfacing with the receiver:

Option #1
Connect the receiver’s Front LEFT and RIGHT channel preamp outputs to the LEFT and
RIGHT “LINE IN” RCA jacks on the subwoofer’s amplifier panel.

Option #2
Connect the receiver’s SUB or “LFE” preamp output to the LEFT “LINE IN” RCA jack on the subwoofer’s amplifier panel. The inputs are summed together internally. Note: In this configuration, leave the crossover setting at the highest frequency.

Option #3
Connect the receiver’s Front LEFT and RIGHT speaker outputs to the LEFT and RIGHT “HI LEVEL
IN” connectors on the subwoofer’s amplifier panel. Then, connect the front speakers as well, either to the
subwoofer connector (as shown) or at the receiver. Note: Observe correct polarity, + to + and - to -.

Before you begin, ensure your subwoofer is hooked up properly and the controls are set at these initial settings.
• On/Auto/Standby: On or Auto • Phase: 0°
• Subwoofer Volume: 12 o’clock or slightly higher •Crossover Frequency: 160Hz (ASW-8)

Once you’ve found the subwoofer’s “sweet spot”, you can tweak performance even more!
• Switch the Phase control to the 180° position and listen. Does the bass sound more solid and substantial? If so, leave the phase control there. Or did bass lose impact and sound more “hollow” and “thin”? If so, switch the control back to its original position.
• Use the Subwoofer Volume control to reduce subwoofer volume if the whole bass spectrum sounds overpowering compared to the sound from the other speakers. Or turn it up a bit if those explosions or bass notes feel a bit anemic. • Experiment with the Crossover Frequency control to fine tune the upper bass response so you’re your subwoofer and your wide range
speakers are working optimally. Read the owner’s manual for those speakers for guidance on what setting will work best. Note - if you connected the sub using Option #2 (SUB or LFE channel output on a 5.1/7/1 receiver, leave the crossover in the highest setting.)
What you will find that in going through the setup process is that all of these adjustments interact. In other words, changing the Phase setting may mean you’ll have to increase or reduce the Volume setting a bit, etc. Again, experimentation is the key.

Perhaps one of you might be kind enough to clear this up for me? Not quite the “plug and play” I had hoped for.

These are the specs on the B2’s:
Specifications (b2)
FREQUENCY RESPONSE 62Hz - 23kHz +/-3dB
POWER HANDLING 75 w (300 w peak)
SENSITIVITY 92dB @ 2.83 volts/1 meter
NOMINAL IMPEDANCE 8 ohms
CROSSOVER FREQUENCY 2300Hz
TWEETER 0.75” (1.9cm) aluminum dome tweeter
HIGH FREQUENCY HORN 4” (10.2cm) 90 x 60 Tractrix Horn
WOOFER 5.25” (13.3cm), magnetically shielded woofer
ENCLOSURE TYPE Bass reflex via rear-firing port
DIMENSIONS 12.5” (31.8cm) x 7” (17.8cm) x 8” (20.3cm)
MOUNTING None
WEIGHT 11lbs. (5kg)
BUILT FROM 2004

What should the sub’s crossover be set to given my speaker specs?

What’s the optimal way to hook up this sub given it’s controls/inputs and those of the receiver? Just out the R output of the HK into the L input of the ASW-8 (?) Both HK outputs into both ASW inputs (?)

What’s this Trigger/Link stuff? Does it apply to me?

Also, the sub is not shielded. How far do I need to keep it from my laptop?

Thanks in advance for your help!
Tom

 

[GAiDENgt]

I'm just starting with the home theatre knowledge so I can't help you there, but I've been in IT forever so I can help with your laptop question.

You have a few concerns when you're placing computers next to magnetic fields, such as those generated by speakers.

The first and most important issue is your hard drive. Never set your computer directly in contact with the sub or any other speaker. If it's at least 5-6 feet away then I would say you're totally safe from the field and having any of your data wiped out.

However, even at that distance the subwoofer is going to produce powerful vibrations which can disrupt the normal functioning of the drive and cause a crash (total failure) by shaking the drive head out of place and breaking it or scratching the platters in your drive. Since laptops are light and thin this is especially worrysome -- there's less to absorb the shock. Normally they have countermeasures to lock the hard drive spindle when the laptop encounters a shock (dropped from a distance, for example) but that's not going to save you from the constant pulsing of a decent sub --it's being shocked over and over and over.

Get it cushioned by something and as far away from the sub and the floor as possible. I think that's a bigger worry than the magnetic field.

 

[woodbutcher68]

There seems to be some disparity in the amt of concern shown re: computer proximity to the sub. I won't be listening to this thing at crushing volumes, but I think I'll play it safe per your advice here. Thanks much!

 

[TLS Guy]

Hello, all. I’m very new to the area of your expertise. I'm a lifelong guitar player and music enthusiast, but somehow I have never had more than a “decent” quality boombox/component system. The most recent one died and I decided to do something a little better for myself. Emphasis on “little” – I live in an apartment and I’m trying to put my kid through college, so money is tight.

(Apologies for the longish post, but I'm trying to anticipate your questions...)

(Also - I posted this in the "neophyte" area, too. If this is a non-no, the faux pas is unintentional...)

Here’s my projected 2.1 setup:

Philips CDR795 2-Disc CD Recorder (already had this…)
Harman Kardon HK-3390 receiver (just arrived, haven’t unpacked it)
Klipsch B-2 speakers (got these a week ago)
The Speaker Company ASW-8 sub (enroute to me)

I’m puzzled about setting up the sub. The HK receiver has two dedicated sub outs, and also info about “trigger outputs” and “link switches”.

Related text from HK manual:

Subwoofer Outputs: If you have a powered subwoofer, connect these jacks to the line-level inputs on the subwoofer. The same fullrange signal is output through both jacks. Thus, you have the option of connecting each jack to the line-level input on a separate subwoofer, or to use these full-range outputs to feed a remote room in a distributed audio application. If you have only one subwoofer with a single line-level input, connect it to the right Subwoofer Output on the HK 3390.

Subwoofer Trigger Outputs: Connect these outputs to a compatible trigger input on the subwoofer connected to the Subwoofer Output immediately to the right of the Trigger Output. Consult the owner’s manual for the subwoofer to set its trigger input correctly, and the subwoofer will automatically turn on or off when the HK 3390 is turned on or off. In addition, the Trigger Outputs are used with the Subwoofer Link Switches to conserve energy by powering off the subwoofer’s amplifier when it is not needed. The Subwoofer Trigger Outputs send a signal of 15 volts DC.

Subwoofer Link Switches: Each switch affects the subwoofer connected to the jack immediately to the left of the switch. To use the switch , first connect the corresponding Subwoofer Trigger Output to a compatible trigger input on the subwoofer, and make sure the subwoofer’s instructions are followed to activate its trigger input. When the Link Switch is on, the HK 3390 will remove the trigger signal whenever the corresponding pair of main speakers are not in use, thereby conserving energy that would otherwise be used to maintain the subwoofer’s amplifier in standby mode. This feature is activated any time no signal is present at the main speaker outputs, including when the Speaker 1/2 Switch turns off both speaker pairs, when the HK 3390’s output is muted, or when the headphones are plugged in. See Table A2 in the appendix for details.

The ASW-8 sub manual tells me this info about interfacing with the receiver:

Option #1
Connect the receiver’s Front LEFT and RIGHT channel preamp outputs to the LEFT and
RIGHT “LINE IN” RCA jacks on the subwoofer’s amplifier panel.

Option #2
Connect the receiver’s SUB or “LFE” preamp output to the LEFT “LINE IN” RCA jack on the subwoofer’s amplifier panel. The inputs are summed together internally. Note: In this configuration, leave the crossover setting at the highest frequency.

Option #3
Connect the receiver’s Front LEFT and RIGHT speaker outputs to the LEFT and RIGHT “HI LEVEL
IN” connectors on the subwoofer’s amplifier panel. Then, connect the front speakers as well, either to the
subwoofer connector (as shown) or at the receiver. Note: Observe correct polarity, + to + and - to -.

Before you begin, ensure your subwoofer is hooked up properly and the controls are set at these initial settings.
• On/Auto/Standby: On or Auto • Phase: 0°
• Subwoofer Volume: 12 o’clock or slightly higher •Crossover Frequency: 160Hz (ASW-8)

Once you’ve found the subwoofer’s “sweet spot”, you can tweak performance even more!
• Switch the Phase control to the 180° position and listen. Does the bass sound more solid and substantial? If so, leave the phase control there. Or did bass lose impact and sound more “hollow” and “thin”? If so, switch the control back to its original position.
• Use the Subwoofer Volume control to reduce subwoofer volume if the whole bass spectrum sounds overpowering compared to the sound from the other speakers. Or turn it up a bit if those explosions or bass notes feel a bit anemic. • Experiment with the Crossover Frequency control to fine tune the upper bass response so you’re your subwoofer and your wide range
speakers are working optimally. Read the owner’s manual for those speakers for guidance on what setting will work best. Note - if you connected the sub using Option #2 (SUB or LFE channel output on a 5.1/7/1 receiver, leave the crossover in the highest setting.)
What you will find that in going through the setup process is that all of these adjustments interact. In other words, changing the Phase setting may mean you’ll have to increase or reduce the Volume setting a bit, etc. Again, experimentation is the key.

Perhaps one of you might be kind enough to clear this up for me? Not quite the “plug and play” I had hoped for.

These are the specs on the B2’s:
Specifications (b2)
FREQUENCY RESPONSE 62Hz - 23kHz +/-3dB
POWER HANDLING 75 w (300 w peak)
SENSITIVITY 92dB @ 2.83 volts/1 meter
NOMINAL IMPEDANCE 8 ohms
CROSSOVER FREQUENCY 2300Hz
TWEETER 0.75” (1.9cm) aluminum dome tweeter
HIGH FREQUENCY HORN 4” (10.2cm) 90 x 60 Tractrix Horn
WOOFER 5.25” (13.3cm), magnetically shielded woofer
ENCLOSURE TYPE Bass reflex via rear-firing port
DIMENSIONS 12.5” (31.8cm) x 7” (17.8cm) x 8” (20.3cm)
MOUNTING None
WEIGHT 11lbs. (5kg)
BUILT FROM 2004

What should the sub’s crossover be set to given my speaker specs?

What’s the optimal way to hook up this sub given it’s controls/inputs and those of the receiver? Just out the R output of the HK into the L input of the ASW-8 (?) Both HK outputs into both ASW inputs (?)

What’s this Trigger/Link stuff? Does it apply to me?

Also, the sub is not shielded. How far do I need to keep it from my laptop?

Thanks in advance for your help!
Tom

I took a look at all your manuals.

This is how you need to set this up. Your Bookshelf speakers will have to go full range. You don't have any other option. The F3 point is 62 Hz.

There is no crossover in your receiver, the left and right preamp outputs are full range. Connect the left and right pre amp outs of the receiver to Left and right inputs on the sub with RCA cables. The sub will sum the bass from the left and right inputs.

You need to set the sub crossover to twice the F3 of your speakers, which will be 125 Hz.

There will be localization issues at this frequency, so place the sub as close to one of the main speakers as possible.

Set the sub volume level to where you think the sound is balanced. Play something with deep bass and see whether 0 or 180 degree position gives the best bass output.

Set the sub standby switch to on.

You should then be set up.

Your sub has an F3 of 35 Hz, and is only 50 watt. It will only supplement your speakers gently. You are not going to get deep thunderous bass. It will extend the reach of your speakers by one octave, but you will still be missing most of the last octave.

 

[j_garcia]

Already have a thread going:

http://forums.audioholics.com/forums/showthread.php?t=57580

 

[woodbutcher68]

Hi, TLS guy.

Apologies for the double thread - didn't know that was a no-no, but I suspected it might be. I meant no offense. Thanks for responding.

Your advice says: There is no crossover in your receiver, the left and right preamp outputs are full range. Connect the left and right pre amp outs of the receiver to Left and right inputs on the sub with RCA cables. The sub will sum the bass from the left and right inputs.

The preamp outs and not the sub outs? Why?

 

[TLS Guy]

Hi, TLS guy.

Apologies for the double thread - didn't know that was a no-no, but I suspected it might be. I meant no offense. Thanks for responding.

Your advice says: There is no crossover in your receiver, the left and right preamp outputs are full range. Connect the left and right pre amp outs of the receiver to Left and right inputs on the sub with RCA cables. The sub will sum the bass from the left and right inputs.

The preamp outs and not the sub outs? Why?

According to your manual, that receiver has no internal crossover and the sub outs and pre outs are the same thing. They are both full range and have the same signal. It will be easier if you use the outputs labeled subwoofer as you won't need a Y to feed the signal back to the amp.

 

[woodbutcher68]

I think I understand some of the terminology here but want to be certain.

Some receivers are capable of sending only certain/higher frequencies to the L/R speakers and only the lower ones to the sub - but this particular one does not have that capability (?)

So the crossover knob on the sub allows me to set a "cutoff" in a way that there is minimal overlap between the two (?)

The HK receiver was $217. For a music-only application like this - and given those price constraints - have I chosen unwisely? I started with an Onkyo rated at 50W/channel that sounded nice to my ears with the Klipsch L/R's, but took it back due to lack of a sub out (wanted just a touch more low end, no need for fratboy fartage...) and since rating was lower than speakers (dangers of "clipping" if pushed, from what I understand).

(See, I learned that much, anyway. That, and also that the words "Bose" and "Monster Cable" tend to get people riled up around here...)

 

[TLS Guy]

I think I understand some of the terminology here but want to be certain.

Some receivers are capable of sending only certain/higher frequencies to the L/R speakers and only the lower ones to the sub - but this particular one does not have that capability (?)

So the crossover knob on the sub allows me to set a "cutoff" in a way that there is minimal overlap between the two (?)

The HK receiver was $217. For a music-only application like this - and given those price constraints - have I chosen unwisely? I started with an Onkyo rated at 50W/channel that sounded nice to my ears with the Klipsch L/R's, but took it back due to lack of a sub out (wanted just a touch more low end, no need for fratboy fartage...) and since rating was lower than speakers (dangers of "clipping" if pushed, from what I understand).

(See, I learned that much, anyway. That, and also that the words "Bose" and "Monster Cable" tend to get people riled up around here...)

I think you will be fine unless you play your rig very loud. Yes you HK will send a full range signal to your main speakers and sub. The crossover on you sub will not change the signal going to your main speakers.

Usually setting the sub crossover at X2 the F3 point of you main speakers, (the point were in your case the sound pressure level is 3 db down and in your speakers will fall at 24 db per octave), is a good place to start, as it usually produces the smoothest integration.

If you plan on playing music with a lot of bass at high volume, then you may have made a poor choice. Your options then are to by a crossover to go between you receiver and sub, using the pre outs and amp ins on your receiver.

Getting a receiver with built in crossover, or getting a larger more robust pair of main speakers.

 

[woodbutcher68]

Thanks Again, TLS Guy...

It was kind of you to look at my various manuals and provide exact setup advice - much more than I expected.

My sub arrived (TSC 8") and it seems to be just as reviewed - punchy, not boomy.

Your setup advice worked perfectly.

For apartment living, I think these gear choices turned out to be just fine and I'm pleased with the results of my research - max "bang for the buck."

If anything, these Klipsch B2 speakers are freaking me out a little. Every now and then I think something must be wrong with a piece of equipment, wiring, etc... so I'll listen to a "troubling" passage a few times to try and see if I'm hearing what I'm hearing and what might be wrong... and instead it's something flawed in the source material!

Interesting how much "new" I'm hearing in very familiar recordings just since it's all so much more defined and not "sonically smeared".

Thanks again!

 

[TLS Guy]

It was kind of you to look at my various manuals and provide exact setup advice - much more than I expected.

My sub arrived (TSC 8") and it seems to be just as reviewed - punchy, not boomy.

Your setup advice worked perfectly.

For apartment living, I think these gear choices turned out to be just fine and I'm pleased with the results of my research - max "bang for the buck."

If anything, these Klipsch B2 speakers are freaking me out a little. Every now and then I think something must be wrong with a piece of equipment, wiring, etc... so I'll listen to a "troubling" passage a few times to try and see if I'm hearing what I'm hearing and what might be wrong... and instead it's something flawed in the source material!

Interesting how much "new" I'm hearing in very familiar recordings just since it's all so much more defined and not "sonically smeared".

Thanks again!

Thanks for the follow up. Glad to know everything worked out and that I could be of help.