A disastrous subwoofer journey

[Love4sound]

Oh ok, sorry got mixed up with your current sub model no. I think the 15 inch Rythmik FV15HP will be much more bigger and heavier than a PB 2000(my reference for size) which itself is big and heavy. It may be better to go in person and see if it is there with your dealer to get an idea. Believe me , it's not only the dimensions, but the weight also is a very important factor to consider in our later years as you have to be more bothered about your back or running into hernia issues by lifting heavy stuff. Since the room is small, the choice is there to go for a smaller sub.
It's a good decision you have taken to go with just one good sub considering the room size.

Haha u mixed up ported and sealed now

 

[Nitin K]

Haha u mixed up ported and sealed now

Yes, I sure did, forgot your preference is sealed now.

 

[Love4sound]

Yes, I sure did, forgot your preference is sealed now.

Since it is decided in this room it’s going to be a single sub and in future if I ever get the itch to upgrade I will go for the biggest sub available in my budget so a sealed makes sense. F12 is a good choice but just wondering if E15 will also be suitable in my room.

 

[prateekatasniya]

Hey Prateek do you think a single 15 inch sealed rythmik sub will be good for my use. Already liking the LV12F a lot. Sharing my room size for reference. I went duals after experimenting different dual subs in my place. No intention of upgrading any time soon but in future if I ever feel the need I would like to experiment a good sealed sub.

Sealed 15" and above will perform much better without any doubt.
And even a 21" sealed can be used and will perform even better.. so don't worry of it being overpowering.

A Lamborghini can be driven at 50kmph and also at 300kmph. In the hands of inexperienced driver its overpowering.

I hope this analogy helps clear doubt.

I can put 4 21" subwoofers in your room without them being overpowering.

 

[Love4sound]

Sealed 15" and above will perform much better without any doubt.
And even a 21" sealed can be used and will perform even better.. so don't worry of it being overpowering.

A Lamborghini can be driven at 50kmph and also at 300kmph. In the hands of inexperienced driver its overpowering.

I hope this analogy helps clear doubt.

I can put 4 21" subwoofers in your room without them being overpowering.

Thanks for clarifying.

 

[Love4sound]

Well now that I have shared my journey in words and graphs I think it will be nice to share the journey in pictures. Well to summarise the images it all started with a Yamaha sw50 that came with the yht299. After using it for 3 years went for a Polk psw125. Used the Polk for 7 months and got a Bicpl200-ii. Used it for 2 months and experimented dual pl200-ii. Returned one Bic pl200-ii which was loaned by the dealer and I got the xtz12.17 and the 10.17 edge. Experimented combining all the subs and ended up selling the Bic within 4 months and purchased a xtz10.17.Then after 10 months I was loaned a sealed 12 inch osd sub. Used it for 3 months and also tried mixing sealed and ported. Returned the osd and sold the xtz 10.17 after just 10 months and got a xtz 12.17. After 6 months of using the 12.17 got the xtz 10.17 and went duals. Within a month returned the 10.17 and got rythmik LV12F. Sold the xtz 12.17 after using it for 7 months and went dual LV12F. Sold one rythmik LV12F within a week after going duals and now back to one LV12F phew . Guess I have used most of the common subs and only svs is missing in the list

 

[sandeepmohan]

well it’s very difficult to explain in detail why mini dsp is better in a dual sub calibration over the avr but I’ll try. This image is from YouTube where one aligns 4 subs. If you see in the image there is a huge boost from 30hz and below.Reason to create a house curve like that is to feel low bass much better.

Is that not to be expected with 4 sub's?

The part that I am still struggling to get to grips with are those graphs itself. Its telling you something that its doing but you have no actual way to measure that unless you put a microphone in the room and measure this. Else, its all down to the ear and some perceived, which is fine. Its not like the minidsp is talking to the room nor is it working on current feedback. You feed in some values (I assume via phone or PC) and hope that its doing the right thing. Its not working on actual room feedback is it, like Audyssey does, (albeit to some degree)? Even though it is being set to a curve most suited to you, it assumes its working to some dimensions. It has no knowledge where your subs are in the room (your receiver does). Looking at your room again, anything placed to the left is less than ideal, especially for a sub. The minidsp can't see that so its working to what you set which is a common value for both sub's (I assume you can correct the pre out value for each and thats really winging it). In my view, that won't work or won't be ideal for both the subs. Different scenario had there been a wall right against the sub woofer, like the one on the right. Its in a corner and subs work great when set up like this, especially for HT application.

Don't get me wrong. You have achieved something out of this. My point is, dsp implementation is generally seen in areas where a certain sound cannot be achieved, such as compact enclosure speakers. Here we do have a real challenge and it is because of dsp that a little JBL Charge can pump so much bass out of it. In your application, we most certainly don't have a problem with the size of the speaker or the electronics controlling them.

To your other question about an even bigger sub, I'd say first try and then buy.
You must try and replace those glass supports with 10mm wood or something that won't ring.
Appreciate you trying to explain this.

 

[Love4sound]

Is that not to be expected with 4 sub's?

The part that I am still struggling to get to grips with are those graphs itself. Its telling you something that its doing but you have no actual way to measure that unless you put a microphone in the room and measure this. Else, its all down to the ear and some perceived, which is fine. Its not like the minidsp is talking to the room nor is it working on current feedback. You feed in some values (I assume via phone or PC) and hope that its doing the right thing. Its not working on actual room feedback is it, like Audyssey does, (albeit to some degree)? Even though it is being set to a curve most suited to you, it assumes its working to some dimensions. It has no knowledge where your subs are in the room (your receiver does). Looking at your room again, anything placed to the left is less than ideal, especially for a sub. The minidsp can't see that so its working to what you set which is a common value for both sub's (I assume you can correct the pre out value for each and thats really winging it). In my view, that won't work or won't be ideal for both the subs. Different scenario had there been a wall right against the sub woofer, like the one on the right. Its in a corner and subs work great when set up like this, especially for HT application.

Don't get me wrong. You have achieved something out of this. My point is, dsp implementation is generally seen in areas where a certain sound cannot be achieved, such as compact enclosure speakers. Here we do have a real challenge and it is because of dsp that a little JBL Charge can pump so much bass out of it. In your application, we most certainly don't have a problem with the size of the speaker or the electronics controlling them.

To your other question about an even bigger sub, I'd say first try and then buy.
You must try and replace those glass supports with 10mm wood or something that won't ring.
Appreciate you trying to explain this.

Yeah you need a umik to measure the room response from the MLP. All the graphs I shared are of the sub response for my MLP measured using rew. Yeah thanks for the idea and I will see if I can replace the glass with a wood. For now I have kept isolation pads below the speakers.

 

[lingamkrishnan]

Well now that I have shared my journey in words and graphs I think it will be nice to share the journey in pictures. Well to summarise the images it all started with a Yamaha sw50 that came with the yht299. After using it for 3 years went for a Polk psw125. Used the Polk for 7 months and got a Bicpl200-ii. Used it for 2 months and experimented dual pl200-ii. Returned one Bic pl200-ii which was loaned by the dealer and I got the xtz12.17 and the 10.17 edge. Experimented combining all the subs and ended up selling the Bic within 4 months and purchased a xtz10.17.Then after 10 months I was loaned a sealed 12 inch osd sub. Used it for 3 months and also tried mixing sealed and ported. Returned the osd and sold the xtz 10.17 after just 10 months and got a xtz 12.17. After 6 months of using the 12.17 got the xtz 10.17 and went duals. Within a month returned the 10.17 and got rythmik LV12F. Sold the xtz 12.17 after using it for 7 months and went dual LV12F. Sold one rythmik LV12F within a week after going duals and now back to one LV12F phew . Guess I have used most of the common subs and only svs is missing in the list

going through the 11 pictures show the efforts you put into this HT journey. this needs lots of patience to setup. for beginners like me, your HT setup thread gave lots of information and plan to make a better setup

 

[Love4sound]

So round 2. I thought of giving one option a last chance. Moved the front sub to left and rear sub to right, near to the recliner. I should have done this at the start instead of wasting nearly 2 weeks on the same position which was failing. On the first attempt itself every thing worked and subs aligned beautifully. It just took me 20-25 minutes to align them and eq using mini dsp. Image 1 and 2 are the new position.

3rd Image - pure direct graph of front and rear sub. Red is the response of front sub

4th image-Pure direct graph of both subs with a 17.5ms delay applied to rear sub. To my eyes this response looks as good as post eq. Beautifully both subs have integrated even without any eq. Just look how smooth the response is and I am just drooling looking at it

5th Image- Response of the subs post eq in mini dsp and audysey. Red graph is pure direct response after eq and house curve set by mini dsp and purple is post audysey,dynamic eq enabled

6th-Red graph is mains crossed over at 80. Purple is sub. The subs have integrated with the mains and the response by mains after cross over at 80 is very smooth

Tested few tracks and sounds wonderful. I haven’t even calibrated it accurately. Just tested few tracks post audyssey by changing only the crossovers and distance for sub.Bass is smooth and there is no muddy or boomy notes like the previous position. Also it doesn’t feel like both subs are fighting but working well together. Going to sleep with a huge smile on my face. Thank you all. Both me and the buyer have come to a mutual agreement and I have returned the payment. The sub is staying and pumping at my place. Now I need to re do the wiring work again and make tweaks according to my taste which I won’t doing by testing but will watch movies and correct them on the go if required

 

[pks.k]

So round 2. I thought of giving one option a last chance. Moved the front sub to left and rear sub to right, near to the recliner. I should have done this at the start instead of wasting nearly 2 weeks on the same position which was failing. On the first attempt itself every thing worked and subs aligned beautifully. It just took me 20-25 minutes to align them and eq using mini dsp. Image 1 and 2 are the new position.

3rd Image - pure direct graph of front and rear sub. Red is the response of front sub

4th image-Pure direct graph of both subs with a 17.5ms delay applied to rear sub. To my eyes this response looks as good as post eq. Beautifully both subs have integrated even without any eq. Just look how smooth the response is and I am just drooling looking at it

5th Image- Response of the subs post eq in mini dsp and audysey. Red graph is pure direct response after eq and house curve set by mini dsp and purple is post audysey,dynamic eq enabled

6th-Red graph is mains crossed over at 80. Purple is sub. The subs have integrated with the mains and the response by mains after cross over at 80 is very smooth

Tested few tracks and sounds wonderful. I haven’t even calibrated it accurately. Just tested few tracks post audyssey by changing only the crossovers and distance for sub.Bass is smooth and there is no muddy or boomy notes like the previous position. Also it doesn’t feel like both subs are fighting but working well together. Going to sleep with a huge smile on my face. Thank you all. Both me and the buyer have come to a mutual agreement and I have returned the payment. The sub is staying and pumping at my place. Now I need to re do the wiring work again and make tweaks according to my taste which I won’t doing by testing but will watch movies and correct them on the go if required

Congratulations bro!

At last You got it what you have dreamed..?!

Enjoy good sound ..!!

 

[prateekatasniya]

So round 2. I thought of giving one option a last chance. Moved the front sub to left and rear sub to right, near to the recliner. I should have done this at the start instead of wasting nearly 2 weeks on the same position which was failing. On the first attempt itself every thing worked and subs aligned beautifully. It just took me 20-25 minutes to align them and eq using mini dsp. Image 1 and 2 are the new position.

3rd Image - pure direct graph of front and rear sub. Red is the response of front sub

4th image-Pure direct graph of both subs with a 17.5ms delay applied to rear sub. To my eyes this response looks as good as post eq. Beautifully both subs have integrated even without any eq. Just look how smooth the response is and I am just drooling looking at it

5th Image- Response of the subs post eq in mini dsp and audysey. Red graph is pure direct response after eq and house curve set by mini dsp and purple is post audysey,dynamic eq enabled

6th-Red graph is mains crossed over at 80. Purple is sub. The subs have integrated with the mains and the response by mains after cross over at 80 is very smooth

Tested few tracks and sounds wonderful. I haven’t even calibrated it accurately. Just tested few tracks post audyssey by changing only the crossovers and distance for sub.Bass is smooth and there is no muddy or boomy notes like the previous position. Also it doesn’t feel like both subs are fighting but working well together. Going to sleep with a huge smile on my face. Thank you all. Both me and the buyer have come to a mutual agreement and I have returned the payment. The sub is staying and pumping at my place. Now I need to re do the wiring work again and make tweaks according to my taste which I won’t doing by testing but will watch movies and correct them on the go if required

Do compare the Spectrogram of single vs dual ..

 

[Love4sound]

Do compare the Spectrogram of single vs dual ..

Sure. Do I need to take measurements again or can use the existing measurements?

 

[RajithKumar]

Naveen for ur listening levels ,IMO better stick with a single good sub ( since u r happy with it). Don't do more research and then mainly Y to spend more with hard earned money.

 

[Love4sound]

Naveen for ur listening levels ,IMO better stick with a single good sub ( since u r happy with it). Don't do more research and then mainly Y to spend more with hard earned money.

No more research and testing. All it took was 20-30 minutes of measurements and EQing. Dual subs have integrated well.The sub which I sold will be retained since I haven’t shipped yet. So no extra expense. Placement seemed to be the culprit in my case.

 

[lalit09]

The more I spend and upgrade on subs it just keeps getting worse. I got a single rythmik and it was so good and I was able to enjoy my movie experience. Now that I got a dual rythmik it just killed all the quality bass a single rythmik sub was producing. Lost all the punch and accuracy going duals. Xtz duals was so good and I assumed rythmik would be even better after using one rythmik. 1st image has single and dual response of rythmik. 2nd image is dual xtz. Xtz duals where 10.17, 12.17 and non identical but had no issues integrating. But dual identical LV12F just isn’t integrating. Red graph in 1st image is dual post eq and audysey. Blue graph is single post eq and audysey. Single was much accurate and punchy. With duals all I get is rumble and grunt with no punch at all. For example alita battle bar fight. Lot of punch and kicks and with a single sub it was tight and punchy. With dual there is no tightness and punch. It’s just rumbling when alita attacks or punches others. Thinking of selling both now and just get one fvx12.

Not huge experience in sub but may be after little burnin they improve.

 

[Passive_audio_enthusiast]

The more I spend and upgrade on subs it just keeps getting worse. I got a single rythmik and it was so good and I was able to enjoy my movie experience. Now that I got a dual rythmik it just killed all the quality bass a single rythmik sub was producing. Lost all the punch and accuracy going duals. Xtz duals was so good and I assumed rythmik would be even better after using one rythmik. 1st image has single and dual response of rythmik. 2nd image is dual xtz. Xtz duals where 10.17, 12.17 and non identical but had no issues integrating. But dual identical LV12F just isn’t integrating. Red graph in 1st image is dual post eq and audysey. Blue graph is single post eq and audysey. Single was much accurate and punchy. With duals all I get is rumble and grunt with no punch at all. For example alita battle bar fight. Lot of punch and kicks and with a single sub it was tight and punchy. With dual there is no tightness and punch. It’s just rumbling when alita attacks or punches others. Thinking of selling both now and just get one fvx12.

Could be a phase issue if there is less bass with two subs.

 

[Love4sound]

Not huge experience in sub but may be after little burnin they improve.

Could be a phase issue if there is less bass with two subs.

Placement was the issue. Swapped positions from front right to left and rear left to right. Please find the updated results on post 130

 

[Love4sound]

So the dual subwoofer calibration part is done perfectly and they are well aligned. As you can see from from the 1st image the sub response is smooth in the entire LFE region 19hz-120hz. But stil I have massive bass issues mainly due to the mains. Second image is the L and R speakers measured individually without the sub. But when they are measured together without the sub it’s horrible with massive dips as seen in image 3 which I doubt is the issue for the bass problems in my room at present. Last image has two measurements. One is sub and mains together which is the red graph with the mains crossed over at 80. The blue graph is LR measurement crossed over at 80 but both LR are unplugged from avr. So comparing mains individual measurement in image 3 and with sub combined in image 4 there is a huge dip from 90-135hz. Any suggestions?

 

[liverpool_for_life]

Play around with the distance value for the sub in the AVR and measure for each change a feet at a time, up to 7/8 ft. Pick the distance value with the best looking curve and confirm via listening impressions.