Add bass to current in-wall setup

[mctimoth]

I have a 5.1 system with Cambridge Soundworks MC300IW for L, C, and R, and Newton Series S300 MultiPole L and R surrounds. I also have a 200W sub in the corner. I think I am missing some upper range lows and lower mid-range coverage. I want to add in-wall woofers in line with the L and R MC300IWs. I do not want them to be separately powered. The head unit is a Denon AVR-X3400H. Can I just install L and R 8", 10", or 12" woofers in line with the MC300IWs, in a boxed in and sealed wall cavity, perhaps with a port? Do I need to check and match the rated ohms? This is all about the WAF and DIY.
TIA.
Tim

 

[WaynePflughaupt]

I can see where the lower mids / upper bass could be missing if your main speakers only have 4-inch woofers. However, it would be best to simply try raising the crossover frequency of the sub.

The reason is, what you’re proposing is going to be a hit-or-miss proposition. Without a crossover between the mains and proposed woofers, the part of the frequency range that they overlap will sound exaggerated. On top of that, if the new woofers are naturally louder, or quieter, than the main speakers (the former is the most likely), there will be no way to adjust their level for a better blend.

Regards,
Wayne A. Pflughaupt

 

[mctimoth]

Thanks Wayne.
The sub is/has been dialed to the widest range from the get go understanding the lack of lows and lower mids from the mains.
Regards,
Tim

 

[everettT]

Thanks Wayne.
The sub is/has been dialed to the widest range from the get go understanding the lack of lows and lower mids from the mains.
Regards,
Tim

Starting with you "think" , have you taken measurements? As Wayne noted your first thought isn't very feasible. I'd look to add additional subs and get measurements first to see what is going on.

 

[William Lemmerhirt]

I think this a case of the juice not being worth the squeeze. In there are just too many variables in just tossing a driver in a box and winging it. You’d need to calculate box volume which won’t be hard but you’ll also need a crossover, and proper connections. The idea itself isn’t horrible, but Frankenstein stuff like that usually just ends up a mess.
I would look at new speakers. What is the subwoofer? Maybe it’s midbass performance isn’t great either?

 

[KEW]

What frequency are you currently crossing the speakers to the sub at?
Do you know what your sub is good for on the high frequency end?
I'd look at crossing at 100 or 120Hz.
This $150 10" sub is rated up to 140Hz, so might be an option to hide behind sofa or under furniture. It is only 6" deep:
https://www.parts-express.com/dayton-audio-sub-1000l-10-100-watt-low-profile-powered-subwoofer--300-639

Here is a comparison review that recommends it:
https://thewirecutter.com/reviews/best-budget-subwoofer/#a-slim-easier-to-hide-alternative

 

[KEW]

Thanks Wayne.
The sub is/has been dialed to the widest range from the get go understanding the lack of lows and lower mids from the mains.
Regards,
Tim

Can you be more specific? What crossover frequency are you using? What subwoofer?

 

[mctimoth]

Thanks Kurt,
It is an RCA 200 watt Sub. The dial range is 50 to 200 and it is set to 200. I ran an initial 20Hz to 20kHz sweep and watched the smart phone SPL using the phyphox app. The whole spectrum seemed to be well represented from about 70Hz to well above 14kHz where I couldn't hear anymore of the sweep. There was a clear spike across the measurement as the frequency grew. I was situated in the sweet spot and had the AVR at normal movie listening volume. The late entry at the beginning was because the app could not register the beginning of the sweep but I was able to hear sound at about 29 Hz and up. This was a very rudimentary and cursory test. Non the less I still feel the space is hollow in the middle; beautiful face and hair, nice butt and legs, but rail thin and flat.

So now I am onto either finding a better set of LCRs or building some in-walls from scratch. Perhaps even taking an old pair of Polk Audio SDA-CRS's and fitting them in the wall including the passive radiator. Or perhaps some other speaker cabinet and taking them apart to fit into the wall. At least that way I know the speakers will have the appropriate crossover.

What I would like is a pair of in-wall mains that I can use for loud music with Denon's Pure Direct which cuts signal to all circuits except the L and R main speakers. Otherwise the system does well enough for general music listening for the kids and for movie purposes. But every once in a while, when the family is away, I pour a beer in the middle of the day and shake the house. The MC300IWs just don't do it justice.

Suggestions?

TIA,
Tim

 

[lovinthehd]

@mctimoth Sounds like all you've done is dialed the low pass filter on the sub up to max value, which is fine when using bass management in the avr....so how is the avr setup, with speakers set to small? What frequency for crossover with your speakers? Didn't even know RCA made a sub....what's the model number?

 

[mctimoth]

@lovinthehd, She's old (maybe 15 years) and dusty but works pretty well. I did the Speaker Calibration when I purchased the AVR and speakers are set to small. I though that included the Audyssey setup but as I go through the app it doesn't appear to be enabled. I'll try to work through that this weekend and see what it puts the crossover to.

Tim

 

[lovinthehd]

@lovinthehd, She's old (maybe 15 years) and dusty but works pretty well. I did the Speaker Calibration when I purchased the AVR and speakers are set to small. I though that included the Audyssey setup but as I go through the app it doesn't appear to be enabled. I'll try to work through that this weekend and see what it puts the crossover to.

Tim

The calibration setup should be intertwined with Audyssey afaik. If speakers are set to small then you should have a crossover already. In setup menu, go to speakers, then manual setup and then to crossovers to see what they're set to.

ps My eyes aren't good enuf to read that model number in your pic, tho.

 

[mctimoth]

@lovinthehd, the Front and Center are set to 80 and the Surrounds are set to 120. The sub did not seem to have a crossover associated with it.

The sub is model number PRO-SW220P.

 

[KEW]

Change the front to 120 as a quick test to see if that gets you closer as far as not leaving a gap between the speakers and the sub.
If it is better, then experiment with 100 and 140 to see if they sound better.

 

[lovinthehd]

@lovinthehd, the Front and Center are set to 80 and the Surrounds are set to 120. The sub did not seem to have a crossover associated with it.

The sub is model number PRO-SW220P.

The crossover is between the speaker and sub (a crossover is a combination of low pass filter for the sub with a high pass filter for the speaker). Some do confuse the LPF of LFE for a separate sub "crossover" which it isn't.

 

[everettT]

Change the front to 120 as a quick test to see if that gets you closer as far as not leaving a gap between the speakers and the sub.
If it is better, then experiment with 100 and 140 to see if they sound better.

I agree that a higher crossover would be better. Adding two good Subs that can play well above 140hz would be optimal. Where are you located?

 

[lovinthehd]

Looked at the manual for the sub, it has a stated frequency range of 36-200hz (but without qualifiers, hard to know what the basis is but you should be good for a higher crossover....