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So having started on these assumptions, has anyone ever tried two bookshelf speakers each paired with its own sub driven from the same signal ?

Yep! Sounded good though two subs are not required.

I've never seen a sub/satellite system that successfully integrated the sub into the system. There's always a hole in frequency response where the subs and the satellites are supposed to meet. I generally prefer the floor standing speakers.

It's like that with anything. You'd be hard pressed to find consensus on anything. Different people have different criteria as to what they consider acceptable, they have different priorities with regard to sound elements that they find important and different points of reference.

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Hi

Just like to get opinions on a concept.

This concept is based on the following assumptions

1 - That bookshelf speakers generally sound a lot more together than a larger floor speaker.

2 - That bookshelf speakers run out of bass extension to early for powerful rock music

3 - That to purchase good floor standers that have great detail and great bass quickly leads to $10,000 + models.

So having started on these assumptions, has anyone ever tried two bookshelf speakers each paired with its own sub driven from the same signal ? im curious as to wether this would just sound disjointed or if it would basically expand the range of the bookshelf to have the musical impact of a large floor stander ?

Alan

If the turnover frequency is a reasonable 80hz (no higher) and the subs are located within 2 foot to 4 foot distances from the sats, as viewed from the DISTANCE of the 'sets' from the listening position (meaning 'sonic arrival' timing)..AND the subs have both a 0/180 degree phase switch AND a 0-180 degree phase DIAL..then you stand a near 100% chance of integrating the two very well with the sat boxes.

The two critical points being the ability to adjust phase agreeance or 'timing' of transient and note delivery with respects to the REST of the 'bass note' timing information that comes from the small boxes.

Always look for these two switches on any subwoofer crossover FIRST, this is the point that separates the great subs from the 'difficult to install' and 'gain satisfaction' from.

Sadly, few subwoofers have these fundamentally necessary switches. It costs, like 2-4 $0.25 opamps and about $2 worth of parts and time to design/install it in even a $200 powered sub. This results in a $20 increase of the retail price. Max. Better parts on the $1000-$3000 sub, raises it's price by $100, maximum.

Yet..it's never there. Sometimes it is on the better subs, but rarely on the average stuff, and suprisingly missing on even some of the most expensive in the world.

But..then again..people cut holes in their speaker boxes!!! Then they expect that this 'out of phase' acoustic distortion at a 50% minimum level, as it comes out of the driver/port system...to sound good? That has always confused me. The broadband acceptance of nasty 'holes in boxes', and calling that acoustic mud...'bass'.

You know what that is? It's 'handed down Dogma', it is literally 'not knowing any better',as the vast majority of audiophiles and even driver companies have given the 'people' what they want, due to the "people's" ignorance driving the market. Thus manufacturers deliver boxes with holes in them and the resultant acoustic mud..and driver manufacturers deliver a near 95% level of woofers that are specifically designed to be used in boxes with holes in them.

That is what the market has developed into.

In essence, 'joe bloe audiophile' and his ignorance of what REAL BASS REPRODUCTION sounds like..and his MONEY..has FORCED the entire industry to twist into a method of 'taking his money'.

But isn't that the case, in just about any given area, where broadband acceptance is required for any kind of market success? I'm saying it -flat out-, just so you are aware that this has happened in the world of loudspeaker design.

The garbage of ported boxes as been around for so long, it has been accepted as the prevailing and nearly 'only known' dogma.

To get back on target, one can get far more tuneful bass and better sub integration if the sat boxes are SEALED. Why? a massive amount of phase distortion and just plain old pure distortion is created in the bass-midbass region (80-150hz) on a small ported box. This is the region you're trying to phase align.

No wonder folks have a difficult time of getting sub-sat integration.

There's nothing to integrate to.

Remember (or know for the first time!), on the big expensive speaker..the midbass section is a SEALED system, specifically due to this phase integration issue.

One trick to try, is to stick a block of foam in the ports of your sat boxes' ports.

You will immediately note the far greater ease and reward of effort - concerning the integration of the subs with the sats.

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One trick to try, is to stick a block of foam in the ports of your sat boxes' ports.

You will immediately note the far greater ease and reward of effort - concerning the integration of the subs with the sats.

Unfortunately, with this "trick" alone, you will also notice the effects of improper alignment of the driver to the enclosure volume. If you successfully seal the port, something not easily done with foam, you will gain a few of the advantages of a sealed system. However, even the smallest air leak will disrupt the performance of any sealed system that relies on the enclosed volume of air acting as a spring for the driver and you will not hear what a sealed system can really do.

What you will easily notice is the low frequency extension of the driver has now been pushed up as much as an octave higher at the beginning of the system roll off. If you've successfully sealed the enclosure, you will have a more gradual roll off than the vented system delivered, but your satellites that could extend down to 45Hz when ported properly might begin their roll out as high as 80-90Hz when operating into a sealed enclosure. (In a semi-sealed enclosure with foam blocking the port you could end up with a higher roll of and more distortion.) That will push your crossover point between sat and sub even higher which, if you don't choose the correct low pass/high pass filter for your subwoofer's amplifier, will make the sub even more difficult to integrate.

I agree that most bass reflex bass response sounds fairly bad in inexpensive speakers, However, since the use of computers and T/S parameters can predict with a high degree of success how to align a bass system, all bass reflex systems are not all bad. If I had my druthers, I'd always take a sealed enclosure or even more preferrably (for me) a transmission line system. Both are out there and available at not too unreasonable prices. But, particularly when you don't really know what you're doing or what the T/S parameters are on the low frequency driver in the speaker you just bought, just stuffing the port isn't the way to go with new speakers you chose - presumably - because you liked the way they sound.

Some drivers used in vented cabinets simply aren't going to sound good when they are placed in a sealed enclosure, the T/S parameters simply aren't correct for swapping betwen enclosure types. You could easily end up with speakers that sound very much like dog doo. This is all very predictable before any drivers ever get placed in a box and you should hope you've purchased from a competent designer/manufacturer who has done their job well. If they've supplied a bung for the ports, then you can experiment with the knowledge you will end up with a higher roll off point in the bass.

Unless you feel unpredictable results are fun, this is a tweak I would pass by. Listen for speakers you like rather than speakers you think you can modify the first day out. My advice would be to buy a system that works well at the dealer's shop before you get it home and try to get it working in your room.

If you can't find a sub/sat system that suits your taste at a dealer, try the Hsu subs on line. Their plate amplifiers have LP/HP filters that can be set as a low as 30Hz and most of their filters are 24dB per octave which will help most systems integrate well. Starting at less than $400 with a 30 day trial period, they are an easy recommendation that should do well with a wide variety of satellite speaker systems.

Put "subwoofer placement" in a search engine and read about how to properly integrate a sub into your system.

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One trick to try, is to stick a block of foam in the ports of your sat boxes' ports.

You will immediately note the far greater ease and reward of effort - concerning the integration of the subs with the sats.

Unfortunately, with this "trick" alone, you will also notice the effects of improper alignment of the driver to the enclosure volume. If you successfully seal the port, something not easily done with foam, you will gain a few of the advantages of a sealed system. However, even the smallest air leak will disrupt the performance of any sealed system that relies on the enclosed volume of air acting as a spring for the driver and you will not hear what a sealed system can really do.

What you will easily notice is the low frequency extension of the driver has now been pushed up as much as an octave higher at the beginning of the system roll off. If you've successfully sealed the enclosure, you will have a more gradual roll off than the vented system delivered, but your satellites that could extend down to 45Hz when ported properly might begin their roll out as high as 80-90Hz when operating into a sealed enclosure. (In a semi-sealed enclosure with foam blocking the port you could end up with a higher roll of and more distortion.) That will push your crossover point between sat and sub even higher which, if you don't choose the correct low pass/high pass filter for your subwoofer's amplifier, will make the sub even more difficult to integrate.

Most boxes are so badly sealed that it won't be a big difference.

The vast majority of ported boxes are ported at a low enough frequency that putting a plug in the port does create a nice roll off and low distortion.

Yes, you do bring up some points, but they can be inconsequential in the vast majority of situations.

I'm well aware of the things you speak of. Due to the majority, the vast majority of the times, stuffing the port can be beneficial to creating a better sub/sat balance.

And yes, the 45hz was crap, anyway. Better of with a clean 80. Especially when attempting to match up with a sub, specifically when searching for the highest fidelity which was the point of the original poster.

Sharp slopes on subs tend to not work all that well.

Middling slopes work best, but the subs must be in acoustic alignment with the sats, with regards to transient arrival times, with respect to the listener's position in the mix.

Once again, we're talking highest fidelity possible, and that's where these rules come in. As the poster asked.

The poster mentioned 'muddy bass with subs'. They specifically spoke of the problems with integration. This means they are sensitive to the bass distortions that that exist when a box has a hole in it. The absolute balls to the wall irrefutable point is that bass porting boxes presumes that we cannot hear phase distortion down there. The distortion is real, it's measurable, it's there.

Obviously, some of us can hear it. I won't own a ported box.

This is the fix.

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The absolute balls to the wall irrefutable point is that bass porting boxes presumes that we cannot hear phase distortion down there.

Other than that one sentence, I disagree with everything in your last post. But if posting it makes you feel better ...

So, what if someone finds he likes stuffing his port?

Is he wrong to like it?

Is port stuffing the Hi Fi act that dare not speak its name?

I say, stuff it and listen. If you like it, it's OK.

If you feel too timid to go whole hog, try a little partial port stuffing. In the privacy of your own room, of course - 'cause every room is different and port stuffing is a matter of personal taste.

Think of it this way, Jan. Almost everything in the world is a compromise. For example, breathing keeps you alive, but oxygen causes/creates/etc oxidation as well. Both good and bad.

Porting boxes is a compromise.

It is one I do not accept.

I've spent about 20 years playing with passive and active and now digital crossover slopes and the energy considerations of each type in each application. I've probably built about 1500 boxes and about 100 variants of ported boxes, types, and tricks not really seen anywhere else, to my recollection. To almost a single case, the variants were good old 'single cause' analysis experiments. I don't think that ported boxes work very well, at all.

Muddy bass, in every single case. Instead of training myself to listen beyond it, I'd done my best to listen -into- it, and hear the flaws for what they are. If not, there is no way I'd be able to hear fixes when they were right in front of me, in one of the experiments. Not psychoacoustically 'cover them up', with my brain's processing and filtering power, like most folks have done. Eyes, brain, and ears open, Jan. According to the threads with Ethan, you seem yourself to be much of the same cloth..this is more of the same, in an area that you might consider looking at - again.

Buddha, I get the feeling you were wearing funny underwear when you posted that.