Subwoofer insight.


This is new territory to me. Current speakers are 2 way with frequency response of 60Hz-20KHz with +/- 2dB.  Sensitivity rated as 86dB. Chance to purchase a pair of REL 7 tis. I feel like I am missing something but will have to buy the subs to try out. My basic question is this. Does this purchase sound wise? I know what I am willing to spend but do you think I will notice an appreciable improvement.  I know that no one can listen through my ears but this is my first time doing this. Source is 75 watt integrated tube amp, McIntosh MA-2275. Thoughts appreciated. I am leaning towards going forward with the deal but would appreciate some feedback. Room is large and open, 28X38 feet with 9 foot ceilings. Thanks for any feedback.
ricmci
There are separate right and left 8 ohm taps on the integrated so seems okay for connection purposes.  Main speakers hooked to the 4 ohm taps. Super nice guy I dealt with today.  He gave me a couple of weeks to see if they work for me.  Now I just need to figure out how to get these jokers dialed in properly.  Thank you Eric for the room treatment advice. I recognize that the room size is somewhat of a problem.  I think the best I am going to be able to accomplish is maybe some local treatments around the equipment.  My wife is never going to allow anything hanging on wall.  I don't blame her.  It is as much as her house as mine.  I also appreciate Millercarbon advice on more subs but no way she is going to let cables run across her main living area.  Anyways, I got them hooked up without dialing in or proper positioning.  First impression is good.  Somewhat of guttural feeling or sensation.  Never listened through subs before so it is different indeed.  Need a little more time to get it as right as situation allows, watch some videos, read some discussions, etc on how to do it properly recognizing that there are limitations without professional room treatments and the like.  Any pointers (either personal or recommended videos or articles) from those who have similar experience as I am going though on how to properly dial them in would be appreciated.
Hi @cheeg -
The SB1000s offer good flexibility input wise. See the photo at the link here. They can accommodate speaker or line level input. I’m running 2 sets of speaker cable...one pair to the Forests, a second pair to the subs, both from the outputs of the integrated amp. Don’t know why speaker level input doesn’t overload the subs but it doesn’t.

When running a low power amp (e.g., First Watt F7) I can use output from the pre to line level input on the subs and then line level out from the subs into the power amp; only 1 pair of speaker cables from power amp to the Forests in this case. The fixed 80 Hz high pass filter in the subs will limit the low frequency signal the amp has to handle and lessen the load on it. Not an option with the integrated amp as I don’t have a separate pre-out on it.

I’m thinking because speaker level input impedance of the SB1000s is 2000 ohms the amp isn’t stressed.

https://www.svsound.com/products/sb-1000
Hi @ghosthouse —
thanks for the specifics, and for the link — very informative!  I was wondering how to limit the low-end signal to my main speakers, and SVS has a good solution. Happy listening!
@cheeg 
You are very welcome. 
Apologies to the OP for digressing from his question but depending on how sophisticated you want to get, an external crossover might be something to consider.
In my experience and in my opinion....  

An 8 inch subwoofer in a 28' x 38' x 9' room?   I don't think so.  It's all about moving air. A single 8" driver can't move enough air.   2 x 8" drivers can't move enough air.  8 x 8" drivers can't move enough air.    

I use 2 x 18" subs in a room 14' x 26' x 8 1/2' and have them properly corner-loaded.  And I'm thinking of going to 4 x 18".   They are Eminence Kilomax Pro-18A drivers.  Bullet-proof.  

For your room, I would suggest 4 x 21" drivers and use them below 30hz.  If you want subs to go higher, then consider 8 x 15" (4 per side) using VERY STEEP low-pass filter at 45hz.  32hz / octave is the minimum low-pass slope, the steeper the better.   The object is to keep the anything over 60hz off the sub drivers.  It will cause transient time smear and other problems.