[Sasha]

Before I ask the question, here are reasons for it.
I cannot part with speakers I presently have as I have not heard anything that betters their midrange.
They are passive 3 way, with cross-over frequencies of 380Hz and 3.8KHz 24db.
What I would like to achieve is get more definition and speed in low end, not more extension, there is a plenty of it.
So, a crazy idea is to add subs and make them sort of passive 4 way speakers, where their LF driver would in fact become a kind of mid bass driver covering range from 380Hz (as per passive cross-over) down to X where sub would take over (as per subs cross-over), and consequently narrow the operating range of LF drivers in speakers, minimizing excursion.
Does this make sense? And if it does, how to execute it?
Speakers have 3 pairs of connectors. If I remove jumpers between MF and LF connectors on speakers and have the present amp drive MF and HF drivers only, how would I go about integrating sub that would work from let’s say 30Hz to X frequency, and have speakers’ LF drivers work from X frequency to 380Hz (assuming 380Hz comes from passive cross-over in speakers).
Kind of by-amping type of thing with introduction of subs.
Am I rambling here or it is feasible and sensible?

[James Tanner]

Hi Sasha,

You really have two options to do it properly IMO. You can use a sub with gain adjustments and some kind of internal electronic crossover/amplifier or a passive sub with external amplifier and electronic crossover.  Intigrating a sub is not an easy task - especially  through the crossover region where the sub overlaps with the woofer in your main speakers. The more flexibility you have through this range the better.

Most powered subs these days come with internal amplifiers and crossovers and gain adjustments built in but you are relying on the quality of the crossover in the sub as all the frequencies above the sub are being sent to the mainspeakers through the subs internal electronic circuit. If you go with a Passive sub then the amplifier chosen and the external crossover chosen is critical to a successful result.

The other way  is to just use the Sub to 'Augment' the mains but that does nothing to reduce the low frequency requirement of you main speakers. The big issue is whether the addition of electronics to your system to add a Sub does more harm than good.

So it can be done but it will take some time and effort to get a seemless integration. If you get it right though it will be worth it.  The main speakers open up even more and the sense of authority and foundation in the very low frequencies improve substantially.

james

[jethro]

Sasha:

Perhaps if you bought an external crossover first you could try the high frequency
outputs of the crossover into your current LF drivers. I think this would cut everything
below your X freqeuency and you could get a sense of the level of improvement.
If you like what you hear (while ignoring the fact that the lowest freqs are missing) then
maybe you could decide on whether to go ahead and buy the subs ?

[Sasha]

jethro,

I assume you are referring to an active external crossover such as Bryston 10B?

James,

I do not understand the differences between 3 models of 10B, which one would be suitable for this kind of application?

Could all this look like the following?
Balanced out of BP26 to Bryston amp, amp output to MF connector on speakers, jumper installed between MF and HF speaker connectors, jumper removed between MF and LF connectors.
Single ended out of BP26 to cross-over (be that an external one or part of an active sub).
Cross-over point set to let’s say 100Hz, so sub works from its low end to 100Hz.
From cross-over output go into second amp and from that amp into LF connector on speakers, so speaker’s LF drivers work from 100Hz to 380Hz.

The reason for making it so complex and not simply going from BP26 into sub and from sub to speaker is to keep MF and LF path intact and as short as it is now, no additional electronics.

[James Tanner]

jethro,

I assume you are referring to an active external crossover such as Bryston 10B?

James,

I do not understand the differences between 3 models of 10B, which one would be suitable for this kind of application?

Could all this look like the following?
Balanced out of BP26 to Bryston amp, amp output to MF connector on speakers, jumper installed between MF and HF speaker connectors, jumper removed between MF and LF connectors.
Single ended out of BP26 to cross-over (be that an external one or part of an active sub).
Cross-over point set to let’s say 100Hz, so sub works from its low end to 100Hz.
From cross-over output go into second amp and from that amp into LF connector on speakers, so speaker’s LF drivers work from 100Hz to 380Hz.

The reason for making it so complex and not simply going from BP26 into sub and from sub to speaker is to keep MF and LF path intact and as short as it is now, no additional electronics.

Hi Sasha,

Complex yes but it looks like it might work.The only issue is the Balanced out on the 26 has 6dB more gain than the unblalnced out.

There are 3 Crossovers:
10B Sub - for integrating subwoofers selectable (6/12/18dB).
10B Standard - for integrating Sub and Mid range/tweeter drivers selectable (6/12/18dB).
10B LR - set 24dB version.

james

[John Casler]

What I would like to achieve is get more definition and speed in low end, not more extension, there is a plenty of it.

Am I rambling here or it is feasible and sensible?

Hi Sasha,

If I might offer comment.

IMHO adding additional Woofer drivers will not:

Increase speed of the drivers

Improve definition

In fact it would complicate the "phase coherancy" issues of having multiple drivers producing the same frequencies from differing locations.

That is, if you don't have the "launch distance" of each of those drivers the exact same distance from your ears, then the result will be signals (of the same frequencies) reaching the ears at differing times.  This will "muddy" the definition and make the woofs sound slower.

If I might suggest that the best way to accomplish what you are seaking is to biamp the drivers you now have and give them more power, and damping.  This will cause them (theoretically) to move faster, and more effectively.

I'd buy a bigger or additional amp. (BRYSTON of course)  Unless your drivers are already "maxed" out perfromance wise, this is a far simpler and likely more to your goals.

Just my 2 cents.

[jethro]

jethro,

I assume you are referring to an active external crossover such as Bryston 10B?

Hi Sasha:

Yes, a 10B for example. Sorry I am so late answering.

[niels]

I agree with John Casler.....but, limiting excursion will not give you much result I believe.
What will give tremendous results is correct placement of the speakers in the room, and the correct placement of you as a listener, see the George Cardas site for suggestions, I guarantee you will get results.
I dont know your speakers, you can tell me what they are, but lifting certain models from the floor will make a big difference in bass response.
If you are not happy with the speakers bass response now, and the amplifier/placement issue is solved I see no reason to not go listen to other speakers.
If you want the ultimate in subwoofer/speaker integration look for a higher end REL subwoofer, or one from the old S-range, Strata III, Storm (bass reflex) or Studio. The REL integration with main speakers is lengendary, but, you must run your main speakers full range, and use the REL only as a supplement, like recommended in the manual!!  I have seen that, especially in the USA there tend to be an opinion that this is how NOT to do it, why I simply dont understand. It seems that over there they want to add as much curcuitry as possible to a signal......