Questions about subwoofer in 2 channel system

[STROP]

1 hour ago, Snoopy8 said:

I assume you are trying to add the left and right signals to mono?

My family member thought that was the best method, but after reading your supplied link he has finally seen the light ...thanks for your help

[davewantsmoore]

5 hours ago, andyr said:

why, IMO, "augmentation" is not the best ...

 

These generalisations about non-linear distortion aren't always true.

 

Sure... if the mains have distortion which is too high.... then high passing them can be a good idea.

 

Although with appropriate EQ.... "augmented" mains will be ~ -3dB anyways  ... and this is significant in the peak power and excursion department.  (as they'll have EQ to reduce the response where they're combined with the sub.... so the total frequency response would be the same as without the sub)

 

[davewantsmoore]

1 hour ago, STROP said:

As bass is a mono signal wouldn't you need only one RCA cable from the Pre out to your sub?

 

This assumes that all stereo recordings, have mono bass..... often this is true.... but not always.    Especially at the higher end of a subwoofers range.

[andyr]

2 hours ago, Snoopy8 said:

The preouts will output the left and right signals, not mono.  The sub should add the signals and convert to mono.

 

Absolutely - for a setup with just 1 sub!  

 

But if you have 2 subs - in a music system (ie. not HT) - then I suggest R pre out --> R sub and L pre out --> L sub. 

 

Andy

 

 

[Snoopy8]

1 hour ago, andyr said:

 

Absolutely - for a setup with just 1 sub!  

 

But if you have 2 subs - in a music system (ie. not HT) - then I suggest R pre out --> R sub and L pre out --> L sub. 

For 2 subs, I prefer feeding to a DSP to sum (less 6dB) and provide mono to the subs.

[Rocketfrogs]

3 hours ago, STROP said:

One last question, would adding a Y splitter after the Pre outs be a better solution?

 

 

I'm quoting Zaphod and he said...

 

"DO NOT EVER use a Y cable. Never ever for such a purpose. You are unlikely to blow anything up (though there is a remote possibility of damage to the preamp), but the sound quality will suffer.

 

You MUST use a cable equipped with resistors, as per Andy's cite. 

 

Do not use a Y cable. "

[Rocketfrogs]

Not trying to hijack the thread but opinions on 'ported' or 'sealed' subs?

[andyr]

2 hours ago, Rocketfrogs said:

Not trying to hijack the thread but opinions on 'ported' or 'sealed' subs?

 

Whoooaaa - you seem to like causing trouble, R!  

 

My view is that ported subs - or ported spkrs for that matter - are an attempt to "squeeze a quart out of a pint pot"!   iow, get more bass out of the box than the size of the cabinet would suggest.

 

The result, unfortunately ... is a compromise.  

 

Andy

 

Edited April 17, 2021 by andyr

[Guest crankit]

FWIW, I have tried both line level and high level with time spent on each, the latter IMO is tighter, quicker and utilises the amps sound signature. Then enters Spatial M3 triode speakers 4 x 15" woofers and the rest is history!

[Rocketfrogs]

17 hours ago, andyr said:

My view is that ported subs - or ported spkrs for that matter - are an attempt to "squeeze a quart out of a pint pot"!   iow, get more bass out of the box than the size of the cabinet would suggest.

 

The result, unfortunately ... is a compromise.  

 

I've taken Andy's advice about porting and added a SVS SB 1000 Pro which is a sealed enclosure with a 12" woofer and bluetooth connectivity.  First impressions are very favourable!  So go for it DT999!

 

[andyr]

2 hours ago, Rocketfrogs said:

I've taken Andy's advice about porting and added a SVS SB 1000 Pro which is a sealed enclosure with a 12" woofer and bluetooth connectivity.  First impressions are very favourable!  So go for it DT999!

 

 

    

 

Can I suggest a minor change to the situation you show in your pic?  The sub seems to be located outside of the L spkr ... therefore it is a bit further away from your ears than the L spkr is.

 

The ideal situation is for the sub to be time-aligned with the L spkr - can you move it forwards a bit ... so that the front of the cone-cover on the SB-1000 is the same distance away from your L ear as the top of the silver cone-cover on your L spkr?

 

Andy

 

Edited April 18, 2021 by andyr

[DT999]

1 hour ago, Rocketfrogs said:

I've taken Andy's advice about porting and added a SVS SB 1000 Pro which is a sealed enclosure with a 12" woofer and bluetooth connectivity.  First impressions are very favourable!  So go for it DT999!

 

Thanks, my new SB 1000 will hopefully arrive tomorrow but I have to wait for cables to be made before I can try it out.

[Rocketfrogs]

15 minutes ago, andyr said:

The ideal situation is for the sub to be time-aligned with the L spkr - can you move it forwards a bit

Will do.  Thanks!

[lemarquis]

1 hour ago, DT999 said:

Thanks, my new SB 1000 will hopefully arrive tomorrow but I have to wait for cables to be made before I can try it out.

I'm sure you'll love it. Do you have any spare speaker cables?

[DT999]

1 hour ago, lemarquis said:

I'm sure you'll love it. Do you have any spare speaker cables?

No I don’t  have speaker cables, and I need 3m RCA cables to reach from my amp to where sub will be located.  I'll just have to wait a bit, hopefully not too long though before I can try it out. Have been listening today and can't help wonder what the sub will add.

[Lam Pham]

On 13/04/2021 at 3:54 PM, andyr said:

Absolutely it will.  Only after I got my subs did I fully realise just what I'd been missing out on for 20 years, with my big Maggie bass panels!

What brand of subs did you go for? Thanks

[andyr]

31 minutes ago, Lam Pham said:

What brand of subs did you go for? Thanks

 

I had them made by Paul Spencer of Red Spade Audio, here on SNA, Lam.

 

They are sealed, external cabinet dimensions about 900H x 400W x 600D and use a 15" Dayton 'Ultimax' driver, driven by a Hypex 800w plate amp.  They were designed to fit into the front corners of my listening room.

 

Andy

 

[GregWormald]

On 18/04/2021 at 7:20 PM, DT999 said:

No I don’t  have speaker cables, and I need 3m RCA cables to reach from my amp to where sub will be located.  I'll just have to wait a bit, hopefully not too long though before I can try it out. Have been listening today and can't help wonder what the sub will add.

There's a tendency to overdo it at first but it's not fatal.

The real way of telling is to listen so you can barely hear it. Enjoy some music—then turn it off!

[Guest crankit]

11 hours ago, GregWormald said:

There's a tendency to overdo it at first but it's not fatal.

The real way of telling is to listen so you can barely hear it. Enjoy some music—then turn it off!

 

Oh yeah agree. On my previous 2.2 ProAc stand mount setup had both subs set at 60hZ with a tiny bit of volume just enough to appreciate sub bass roll off

[almikel]

On 19/04/2021 at 11:08 PM, GregWormald said:

There's a tendency to overdo it at first but it's not fatal.

The real way of telling is to listen so you can barely hear it. Enjoy some music—then turn it off!

agreed

subs should be subtle...and if you can locate them by ear, they're either too loud or poorly integrated.

 

With well integrated subs, all the sound "appears" to come from your mains, just extended lower.

 

You experience depth and weight to the music but you should never be able to identify/localise the sub source as different from your main speakers.

It's only when you turn your subs off that you notice the gap in the bottom octave.

 

Mike

[andyr]

6 minutes ago, almikel said:

agreed

subs should be subtle...and if you can locate them by ear, they're either too loud or poorly integrated.

 

With well integrated subs, all the sound "appears" to come from your mains, just extended lower.

 

You experience depth and weight to the music but you should never be able to identify/localise the sub source as different from your main speakers.

It's only when you turn your subs off that you notice the gap in the bottom octave.

 

Mike

 

Absoloootely!  

 

However, I would say that "well integrated subs" require:

• R & L subs (at the minimum)
• careful positioning to time-align the subs with the woofers on the mains (or use delay with a DSP unit)
• rolling off the mains to match the roll on of the subs.

 

Andy

 

 

[Batty]

Just upgraded the plate amp in my DIY Sw19 from 50 watts to 250.

Main power amp is only 8 watts per channel so the volume on the sub is right down, but yes, the difference is good.

[almikel]

On 13/04/2021 at 6:54 PM, andyr said:

Only after I got my subs did I fully realise just what I'd been missing out on for 20 years, with my big Maggie bass panels!

I had a similar experience - I thought my TD18s had good bass, until some friends listened to my system playing the Boston Philharmonic Orchestra's  version of "Fanfare for the Common Man", and they commented the lower octave was missing...and around the same time I listened to Jiri's system, and the low bass made the hairs on the back of my neck stand up...

...I built my T20 tapped horn sub after that... 

 

...subtle but loads of weight to below 20Hz.

 

Mike

[davewantsmoore]

On 17/04/2021 at 6:50 PM, Snoopy8 said:

For 2 subs, I prefer feeding to a DSP to sum (less 6dB) and provide mono to the subs.

 

It's a really tough one between what you've said and AndyR.....  as if the artist really did make stereo bass, then I'd like to respect that (sometimes).

 

 

Ultimately I almost always do what you do.... as in theory, doing what AndyR suggested is very likely to lead to worse results (if anything).

 

.... but it depends on some ifs and buts.

[davewantsmoore]

21 hours ago, almikel said:

agreed

subs should be subtle...and if you can locate them by ear, they're either too loud or poorly integrated.

 

I don't usually do this.

 

Bass content in recordings vary wildly.... so it's hard to know what to expect by ear.

 

All systems should be setup from a calibration system (even if you like to have an adjustable sub level, you want to know where it's calibrated/flat) .... and so just rely on that.