Sda's For Home Theater?

racer4551

Ihave a sherbourne 3 channel amp that i am using to power the sda's and the center speaker, it is rated at 200w at 8ohms,300 at 4 ohms,1.25db dynamic headroom, 5hz to 75khz power bandwidth,gain 30db,signal to noise ratio 10db/wide band, 110db/a weighted,1.10 volts high level sensitivity.Idont expect svs sub quality bass but really have to force the tone controls to get decent bass.

racer4551

Here are pics......................(yeah i like showin them off)

racer4551

Another...........................

racer4551

Last one.......................

racer4551

Do you think it matters that these speakers are 28 in away from back wall and the same from the side wall.

racer4551

I would think my amp is healthy enough but wonder what a different amp would do............., looking at a amp on audiogon, a carver m 4.0t silver 7, anyone know anything about this amp, good or bad?

F1nut

I would try placing the speakers next to the TV if at all possible. 28 inches is too far away from the back wall, you can also improve the bass by installing spikes. I also think you would benefit from a high current amp.

racer4551

I am going to try a set spikes and see what that does since the floor has a extra thick carpet pad, could be absorbing too much bass?IT would be hard to put the speakers beside the tv, audio cables are just long enough now............would hate to buy longer cables.What would moving them beside the tv do for their performance?

F1nut

Ok, extra thick padding will definitely kill the bass. I don't know exactly what would happen by placing the SDA's next to the TV, but room acoustics play a large part and thought it might be worth trying. IMO, the speakers are to far out from the wall and too close on the sides, but Russman has his in the corners and gets tons of bass. You just have to play around with them and get a high current amp.

disneyjoe7

Racer,

Don't forget you have replaced 2 6.5" speakers per side for a total of 4 6.5" with double that. So yes your amp may not have the balls to move all those drivers on the low end, killing bass response at the speakers.

Also I do think carpet spikes could help also with the bass issue, but you may find the above to be true.


BTW, like your picture with ESPN / Drag racing in it

00p225

Ok, I decided to rearrange my living room. I originally had the sda-1c's 2.5 feet from the left and right wall and 5.5" from the rear wall. I now moved them to the long wall to get the distance between the speakers and my listening position close to the same distance apart. The sda's are now 6 feet from the left side wall and 8 feet from the right side wall. They are also 3" from the rear wall. I have electrical outlets behind each speaker so I couldn't get any closer. Bass was much improved closer to the wall. Soundstage opened up big time! Since I don't like moving heavy speakers with spikes, I cut two pieces of 3/4" mdf the same size as the speaker bottoms and screwed them down through the subfloor using a bubble level. I also put 4 rubber stick on furniture pads on each panel and set the sda's on these. Bass is way better now, it can be felt as well as heard. I lucked out on this as there's no noticable subfloor resonance. The best thing is the midrange detail improved greatly. Just keeping the speakers from rocking slightly on the thick padding and carpet really helps here. I also have a powered 12" sub and find it is not needed anymore with this layout for music. I guess if I worried about wowing visitors while watching movies the sub would be usefull, but I really can't see myself using it unless someone comments to "turn up the bass".

Racer, you really need to get those sda's closer to your rear wall. 28" is killing any bass you would have. If they are close to the side walls, you will lose some of the soundstage beyond the speakers. Keep experimenting and see if you can borrow someone elses amp if moving the speakers closer to the rear wall doesn't help. The toughest adjusment for me was going to the sealed boxes with passive radiators that polk uses. Iv'e always used ported boxes, and while they may give more bass for the same driver size, it may not be better, just boxier in some types. Regards.

racer4551

Thanks oop25,i really cant move them around too much, if i move them back closer to the wall i cant get behind the entertainment center to do anything,i am going to try some spikes and maybe another amp,looking at a carver amp, but am unsure of there performance,have never heard any of their amps,just hard to beleive that they make any power being small and lightweight?

Tour2ma

The M-4.0t is a very nice amp, maybe the best of the 2 ch Carvers and should mate nicely with your 1C's.

Carpet spikes are a good next move.

While your 1C's could benefit from being nearer the back wall, I think they would benefit more from moving closer together as F1 suggested a few posts above...

dorokusai

Racer - Spikes galore from www.oregondv.com , very well made, and he is a Polk Forum supporter.

SDA spikes are 1/4 20

racer4551

Thanks doro for the info, paul hooked me up with a piece of granite with spikes for my svs that worked out super.Thanks tour for the info on the carver,looks like a done deal so will see.Do you know if that amp is common ground?

Tour2ma

Yes, the 4.0 is common ground.

kelley

I just looked at this thread after it had been going quite a bit. I was rather worried as I read on and saw that we were going to test the common/non-common ground theory at low levels. Let me tell you from experience that if you have a non-common ground amp and hook it to the SDA's without using the interface cable or, as some models of amps including mine respond to just connecting a jumper to the negative terminals between the different channels on the amp. Low volume or high will result in the same violent reaction in your system. You must figure the grounding type of your amp some other way than just giving it a try. My Denon mono amps, and 3.1tl's survived 2 instances of of non-common ground hookup. Someone else on this board had their amp burn up fairly quickly. You roll the dice if you want to try it the "connect it and see what happens way". I am glad it worked out for you since your amp must've been common ground.

racer4551

I am kinda dissapointed with my new to me sda1c's.There is very little bass output,i even went as far as taking the passive radiator out and checking for loose wires or anything .I am glad i did that though, i found the crossover assembly had come loose and was hanging by one plastic clip that holds them to the winding assembly and in the same speaker, the passive radiator had come apart where it is glued together in the back of the speaker(super glued it back together,looks like new,cant even tell)Tightened all the screws on all the speakers while i was at it,even installed some speaker spikes.They did sound a little better.I am just confused ,i know these speakers have to sound better than they do now.Iam going to try another amp, a carver m4.0t silver seven(375 watts per channel).I have been listening to these in two channel by themselves,with some good sacd stuff that should have some good bass, but hardly any bass output until i turn on the sub.The only thing i havent tried is moving them up against the back wall,which is kinda hard the way everything is put together in my entertainment center,but if this would make them sound better i will try to move them.I just dont understand how this helps bass output,someone please educate me...........Maybe i am expecting too much with these speakers,i am only used to the way a traditional 3 way speaker sounds with that good low bass before subs became popular.Can or should the passive radiator put out this kind of bass?Maybe i am just confused on how the passive radiator works,does the bass output come from the mids only?