Stacking speakers

GaryM44

Member
2013-01-25 5:10 am
This probably a newbie question, but I'm a newbie, so I hope you all are forgiving.

I'm considering building a pair of 2-way kits (SEAS Idunn kits) and combining them with a pair of SB or Scanspeak 12" subwoofers (also kits).

Would there be any prob using the subs as stands for the Idunns (with an additional supporting post, about 6" high, to bring the Idunns to ear level)?

I'm worrying about transmitting vibration form the subs to the Idunns. But most 3-way systems use drivers which are all bolted to the same baffle, so I wondering whether this worry is idle.

Any advice?
 
The question is whether or not the two systems can be practically integrated, in terms of frequency range and sensitivity. Most likely the low-frequency cut-off the two-way or f3 is compatible with the upper frequency limit of the sub-woofer, but that might be a problem. Is the sub-woofer a passive speaker system only, or is a dedicated amplifier included?

If you are willing to work with separate power amplifiers for the two-way and sub-woofer, that would make integrating them easier. On the downside, then, however, you are dealing with more equipment than if the same amplifier drives the two-way and sub-woofer.

If you use the same (power) amplifier to drive both sub-woofer and two-way (per stereo channel), then relative sensitivity is a big question. Usually a sub- woofer will have much less sensitivity than a two-way. As the idea is to have flat frequency response, that presents a problem.

I don't think that vibration from the sub-woofer to the two-way would present a problem, but I could be wrong, not having much experience in that area. If that is a problem, I'm sure that there is some way that you could isolate the vibration while still using the sub-woofer as a stand.

-My two cents. I'm sure that many others with more experience will chime in about your query.

Regards,
Pete
 
Pole mounting

This probably a newbie question, but I'm a newbie, so I hope you all are forgiving. I'm considering building a pair of 2-way kits (SEAS Idunn kits) and combining them with a pair of SB or Scanspeak 12" subwoofers (also kits).Would there be any prob using the subs as stands for the Idunns (with an additional supporting post, about 6" high, to bring the Idunns to ear level)?

I'm worrying about transmitting vibration form the subs to the Idunns. But most 3-way systems use drivers which are all bolted to the same baffle, so I wondering whether this worry is idle.Any advice?

Hi there: G: Go to search and look-up "The Blackmores", post #26, to see multiple drivers (including a 12") on a frame. I've run a bare TB Full Range, pole attached to an OB bass section with out problems. Try out your concept, should work. ...regards, Michael.
 
further on sub-woofer to 2-way vibration transmission

Does anyone understand the mechanics of spikes or spiked feet on floor-standing speakers? The spikes are meant to prevent the vibrating speaker system from vibrating the floor, is that correct? I wonder if spikes on the 2-way supported on the sub-woofer (ouch!) would in a like manner block vibration from the sub-woofer to the 2-way? -Just a thought.
 
There is no better place for subs than as stands for the mains. Some may say you don't get enough "air" around the mains, but I will give that up for the ease of integration and freedom to pick a crossover point much higher.

All the transmission issues are only an issue if you don't know how to build cabinets. You can always put the mains on their own stand, not touching the subs.

Works for Wilson.
 
I don't think that vibration from the sub-woofer to the two-way would present a problem, but I could be wrong, not having much experience in that area.


Mmmmmmmmmmmm

My sister's system - the sub, that is, WILL shake the floor - yes, the floor!


My sub will shake things off my desk!!

So the sub may not affect the other speakers directly but you may have artifacts introduced from the cabinet being banged about.
 

GaryM44

Member
2013-01-25 5:10 am
Why 2 subs?!

Actually, there will be 3.:)

The 2 new ones will simply serve as woofers for a pair of SEAS Idunns I plan to build. I'll roll them off below 30Hz and try to blend them into the bottom end of the Idunns. They will be used for music.

I already have another sub, which will continue to handle the cannon fire and explosions (LFE stuff) in movies.
 
In one of my books on audio I found one paragraph on spikes. Apparently the idea behind spikes is not isolation, but rather to prevent movement of the speaker.

Given what Kmossman has to say about the vibrations that a sub can produce, putting a two-way system with spiked feet on top of a sub-woofer would be a tremendously bad idea!

Rather instead, perhaps a better idea would be to bolt the two-way and sub-woofer together, such as T-nuts in the top panel of the sub-woofer and bolts thru the floor of the two-way system. That way, with some difficulty, the two-way system could still be separated from the sub-woofer.

-Pete