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Need help with a quad subwoofer setup - Page 3

post #61 of 152
Quote:
Originally Posted by Alan P View Post

I just gotta say Mr. Basshead - you sure have become a wealth of information, and a huge asset to our little community here at AVS. I remember just a short 8 months ago you knew next to nothing about subwoofers - now you seem to know just about everything!

Keep up the good work my friend! biggrin.gif

Thanks! To be honest I have been around subwoofers(car and home audio) for 20yrs. Being new to the forum I did not want to come off as a know it all and by all means still have a long way to go. Imo thats not the proper way to build friendships. However I have learned ALOT since joining and strive to learn more everyday. I am like a sponge when something interests me. I really try and pay attention to guys like Bill F, Archea, Dominguez, Luke Camp, Bossobass, MKtheatre..etc to name a few. Tom and Jim @ PSA have been a wealth of information too. I thank you all! You and Beeman helped me alot when I first joined with Rew and getting familiar with ID sub companies. Did I mention I love this site? lol
post #62 of 152
Thread Starter 
I am not doubting you but from what is listed on Rythmik's website, the FV15HP has a 5db advantage at 20hz over the F15HP. With the steeper roll off for the FV15HP in either mode, how does the advantage go up to be 6-8db at lower frequencies. It should go down if I understand correctly. Am I missing something?
Quote:
Originally Posted by basshead81 View Post

I beg to differ....read the ULF thread and gain some knowledge. The FV15HP is tuned very low(14hz) and will have a 6-8db advantage of its sealed sibling the F15HP around its tune.

Edited by ahmedreda - 11/8/13 at 4:21pm
post #63 of 152
Quote:
Originally Posted by basshead81 View Post

Oh no your good Bee, I think dual FV15HP's is what you will want.
+1. I know that Beeman has been setting his mind on seal subs from PSA and Rythmik for a long while. Not sure of the real reason going seal. Don't know about PSA but I don't think one can really tell the different between seal and port Rythmik in a blind test due to its damping control setting. For me, I prefer ported sub for more output at port tune which dual FV15hps can produce in most room and it takes more than 4 seal subs to achieve that level unless you have 2 Triaxes or JTR S2, etc...
post #64 of 152
Quote:
Originally Posted by ahmedreda View Post

I am not doubting you but from what is listed on Rythmik's website, the FV15HP has a 5db advantage at 20hz over the F15HP. With the steeper roll off for the FV15HP in either mode, how does the advantage go up to be 6-8db at lower frequencies. It should go down if I understand correctly. Am I missing something?

because more then like that is only comparing the FV15HP IN 2 PORT MODE. IN 1 PORT MODE IT MAINTAINS THAT ADVANTAGE DOWN TO AROUND 12HZ. Dont take the all caps as yelling, more or less trying to make that point clear. take the time to look at data-bass.com then you will understand what I am saying.

FV15HP 2 port mode 12.5 hz = 89db, 16hz= 102db, 20hz 108db

FV15HP 1 port mode 12.5hz = 98db, 16hz= 104db, 20hz 108db

see the difference?

The F15HP is down 5db @ 20hz and depending on room gain will roll off at the same rate or steeper then the FV15HP in 1 port mode.


Take some time and look at this thread:

http://www.avsforum.com/t/1488059/your-home-theater-ulf-score
post #65 of 152
Quote:
Originally Posted by basshead81 View Post

No they dont. You automatically assume a sealed sub has more output in the infrasonic range(which seems to be a popular trend here) but that is false. The FV15HP will have a 6-8db advantage over its brothern around its tune. With the FV15HP in 2 port mode, they would be close @ 12hz. In 1 port mode or 14hz tune again your looking at a 6-8db difference. go to www.data-bass.com/systems and compare the PB13U 15hz tune compared to its sealed mode. The 15hz tune has a 5db advantage at 12.5hz. The FV15HP vs F15HP would be even more because its tuned lower then the PB13U.
This was based on my side-by-side comparison between the F25 and FV15HP in 1 port mode, and getting stronger subsonic from the F25.
I did just assume that the F15HP would be similar - perhaps not?
I see your point about the 12hz tune. I didn't measure, but I thought I saw some measurements in one of those subwoofer comparison tables. I'll have to dig that up...

Edit:
After some Google'ing, I couldn't find the table I was thinking of, but I pulled up the 1-port FV15HP graph from the Rythmik site and overlaid it over the F15 graph. Offsetting it by Rythmik's numbers with FV15HP at +1db over the F25 and +5db over the F15HP...

Relative to the FV15HP:
At 12hz, F15HP is +2db and F25 is +6db.
At 10hz, F15HP is +12db and F25 is +16db.

Based on this, I'd conclude that there is more at work here than the port tuning frequency and power efficiency. It must be limited by the high-pass filter.
Edited by rcohen - 11/8/13 at 6:18pm
post #66 of 152
Quote:
Originally Posted by basshead81 View Post

You and Beeman helped me alot when I first joined with Rew and getting familiar with ID sub companies.

...biggrin.gif
post #67 of 152
Quote:
Originally Posted by rcohen View Post

This was based on my side-by-side comparison between the F25 and FV15HP in 1 port mode, and getting stronger subsonic from the F25.
I did just assume that the F15HP would be similar - perhaps not?
I see your point about the 12hz tune. I didn't measure, but I thought I saw some measurements in one of those subwoofer comparison tables. I'll have to dig that up...

Edit:
After some Google'ing, I couldn't find the table I was thinking of, but I pulled up the 1-port FV15HP graph from the Rythmik site and overlaid it over the F15 graph. Offsetting it by Rythmik's numbers with FV15HP at +1db over the F25 and +5db over the F15HP...

Relative to the FV15HP:
At 12hz, F15HP is +2db and F25 is +6db.
At 10hz, F15HP is +12db and F25 is +16db.

Based on this, I'd conclude that there is more at work here than the port tuning frequency and power efficiency. It must be limited by the high-pass filter.
It goes against the laws of physics, sorry I aint buyin it. The FV15HP is tuned to 12hz in 1 port mode, there is no way the F15HP is going to have +2db more output @ 12.5hz. Look at data-bass.com and compare the PB13U in Sealed mode vs 15hz tune.


http://www.avsforum.com/t/1488059/your-home-theater-ulf-score
post #68 of 152
Quote:
Originally Posted by basshead81 View Post

It goes against the laws of physics, sorry I aint buyin it. The FV15HP is tuned to 12hz in 1 port mode, there is no way the F15HP is going to have +2db more output @ 12.5hz. Look at data-bass.com and compare the PB13U in Sealed mode vs 15hz tune.


http://www.avsforum.com/t/1488059/your-home-theater-ulf-score

I think you are confusing usable extension modes with tuning frequency. From my understanding, 12hz is not the tuning frequency, but the in useful room extension you can expect. The actual tuning frequency is higher on the FV15HP. rcohen breakdown is pretty spot on regarding what you can expect from the sealed vs. ported. Sealed gains low end extention, ported gives higher output over 18hz.
post #69 of 152
Quote:
Originally Posted by basshead81 View Post

It goes against the laws of physics, sorry I aint buyin it. The FV15HP is tuned to 12hz in 1 port mode, there is no way the F15HP is going to have +2db more output @ 12.5hz. Look at data-bass.com and compare the PB13U in Sealed mode vs 15hz tune.


http://www.avsforum.com/t/1488059/your-home-theater-ulf-score

Hmm...I heard it myself, and showed you the data from the Rythmik graphs...what's will it take? I suppose I'll keep trying...

Not all sub designs are the same. Low-end extension of a ported sub is based on a combination of the physical properties and the electronics. There are lots of tradeoffs and multiple parameters in the equation - not just the tuning frequency.
post #70 of 152
Quote:
Originally Posted by rcohen View Post

Hmm...I heard it myself, and showed you the data from the Rythmik graphs...what's will it take? I suppose I'll keep trying...

Not all sub designs are the same. Low-end extension of a ported sub is based on a combination of the physical properties and the electronics. There are lots of tradeoffs and multiple parameters in the equation - not just the tuning frequency.

did you take the time to read the link I posted? The FV15HP knocked down 98db @ 12.5hz 2m rms. There is no way in hell a F15HP will do 100db @ 12.5hz 2m rms. The sealed Stereo Integrity 18" diy sub only put down 92db @ 12. 5hz with a ton more power then what the F15HP has. Sealed subs are normally down 10-12 db @ 12hz from 20hz. The FV15HP put down 108db @ 20hz, the F15HP is down 5db, so your looking at 103db. Subtract 10-12db and your at 91-93db @ 12.5hz, which is still 5-7db down from the FV15HP.
Edited by basshead81 - 11/8/13 at 10:35pm
post #71 of 152
Are those in-room or ground plane measurements?
post #72 of 152
Quote:
Originally Posted by rcohen View Post

Are those in-room or ground plane measurements?

ground plane...i provided links. The Rythmik graphs are not to determine max output, they are for showing frequency response. You can not lay them over the top of each other and determine what has more output. Yes sealed will extend lower but you can not use them to determine how much more output. Bottom line there is no way the F15HP will have the same output of the FV15HP around its tune, its the laws of physics. Not sure how many times I have to repeat that. Rythmiks site even proves it by showing the FV15HP +5db @ 20hz, put it into 1 port 12hz tune and the difference will be the same down @ 12hz because thats its tuning point... The data-bass measurements back this theory up since output increases 9db going from 2 port 18hz tune to 1 port tune 12hz.

Now if you have a Small 1000-1500^3 room, sure the F15HP might get enough room gain to match the FV15HP, but in rooms over 3000^3 its highly unlikely...this was my point from the get go when conversating with Beeman.
post #73 of 152
Quote:
Originally Posted by basshead81 View Post

Now if you have a Small 1000-1500^3 room, sure the F15HP might get enough room gain to match the FV15HP, but in rooms over 3000^3 its highly unlikely...this was my point from the get go when conversating with Beeman.

The living room is 3,300^3 and via two six foot by eight foot openings (one at each end) as through these openings the living room opens up to a large kitchen/hall and medium size dining room. Adding all the room measures together and subtracting for walls/furniture/cabinets, I'm working with some 7,300^3. I can work with two subs and keep the wife happy as the budget won't allow for the really expensive (good) stuff as I have to lock the budget down at three grand.

(intrinsic details are such a buzz kill)

Is there anything that has more output in the lower octaves? It seems the FV15HP is the Top Dog in this department and then one has to step up to Seaton/Funk/JTR subwoofers as a solution and working with a $3k budget I'm beating on the budget as much as I can and not get myself into the dog house. In this case, if I pushed harder, it would cause some hurt for the wife which isn't a good thing. She's very fiscally conservative and I will feel her pain. eek.gif

-
Edited by BeeMan458 - 11/9/13 at 10:58am
post #74 of 152
Quote:
Originally Posted by basshead81 View Post

ground plane...i provided links. The Rythmik graphs are not to determine max output, they are for showing frequency response. You can not lay them over the top of each other and determine what has more output. Yes sealed will extend lower but you can not use them to determine how much more output. Bottom line there is no way the F15HP will have the same output of the FV15HP around its tune, its the laws of physics. Not sure how many times I have to repeat that. Rythmiks site even proves it by showing the FV15HP +5db @ 20hz, put it into 1 port 12hz tune and the difference will be the same down @ 12hz because thats its tuning point... The data-bass measurements back this theory up since output increases 9db going from 2 port 18hz tune to 1 port tune 12hz.

Now if you have a Small 1000-1500^3 room, sure the F15HP might get enough room gain to match the FV15HP, but in rooms over 3000^3 its highly unlikely...this was my point from the get go when conversating with Beeman.
Thanks...I didn't see the part that said they were ground plane.

I agree with your point that all else being equal, a vented sub should be much more power efficient than a sealed sub at the tuning frequency. So, either it's actually tuned higher, and the usable extension is what's quoted, or else the high-pass filter is limiting the output at normal listening levels.

Regardless of all this, I can tell you that in my room, level matched, listening to real movie material at normal listening levels (not sine waves at max spl), the bottom line was that although the FV15HP in 1 port mode was good, the F25 had significantly more quantity and more detailed subsonic than the FV15HP. I didn't do the synthetic 12hz max spl sine wave test.

I believe you're right, though, that the FV15HP has more headroom, even compared to the F25. Different people have different priorities and preferences.
post #75 of 152
^^ you have/had both the F25 and FV15hp in your room?
post #76 of 152
Quote:
Originally Posted by Cowboys View Post

^^ you have/had both the F25 and FV15hp in your room?
Yep. I'd recommend either of them, depending on your taste or needs. My only regret about the F25 is that it isn't available in the piano finish. The FV15HP in piano is gorgeous.
post #77 of 152
^^ so they do sound differently between ported and sealed Rythmik. Good to know. It is going to be harder now for Beeman to decide, lol.
post #78 of 152
Quote:
Originally Posted by BeeMan458 View Post

The living room is 3,300^3 and via two six foot by eight foot openings (one at each end) as through these openings the living room opens up to a large kitchen/hall and medium size dining room. Adding all the room measures together and subtracting for walls/furniture/cabinets and I'm working with some 7,300^3. I can work with two subs and keep the wife happy as the budget won't allow for the really expensive (good) stuff as I have to lock the budget down at three grand.

(intrinsic details are such a buzz kill)

Is there anything that has more output in the lower octaves? It seems the FV15HP is the Top Dog in this department and then one has to step up to Seaton/Funk/JTR subwoofers as a solution and working with a $3k budget I'm beating on the budget and much as I can and not get myself into the dog house. In this case, if I pushed harder, it would cause some hurt for the wife which isn't a good thing. She's very fiscally conservative and I will feel her pain. eek.gif

-

With your room dual FV15HP's are the top dog based on your budget. The only way you will get more is stepping up to some JTR Cap 2400's.
post #79 of 152
Quote:
Originally Posted by Cowboys View Post

^^ so they do sound differently between ported and sealed Rythmik. Good to know. It is going to be harder now for Beeman to decide, lol.

Bran Ding noted there is a slight difference...but if one wants strong ULF in a large room the FV15HP wont be beat.
post #80 of 152
^^ But RCohen stated 'F25 had significantly more quantity and more detailed subsonic than the FV15hp''. Must be 35hz and above region but still 'significantly more quantity'?
post #81 of 152
Quote:
Originally Posted by Cowboys View Post

^^ But RCohen stated 'F25 had significantly more quantity and more detailed subsonic than the FV15hp''. Must be 35hz and above region but still 'significantly more quantity'?

Yea I would believe the F25 has a significant advantage over the FV15HP above 30hz. Beemans concerns were about sub 20hz output, which is where the FV15HP shines. However the FV15HP uses the better driver over the F25.

RCohen could so be getting some substantial room gain. Thats what makes or breaks a sealed sub on the Low end. I dont believe he mentioned the side of his room or has provided any data?

I am not trying to take anything away from the sealed F25, its a beast. I was simply making a suggestion to Beeman for his room constraints. A 3300^3 with double openings into other areas of the house will be better served by the FV15HP. Same goes for the OP in his room. I think some of my post was being taken out of context.

Ill break this down into layhmans terms. Smallish sealed room = F25, larger open room = FV15HP
Edited by basshead81 - 11/9/13 at 11:00am
post #82 of 152
Quote:
Originally Posted by basshead81 View Post

Bran Ding noted there is a slight difference...but if one wants strong ULF in a large room the FV15HP wont be beat.
The difference is only in the bottom-end frequencies, and is honestly pretty small in 1-port mode.

FV15HP has more power, and a slightly thicker sound.
F25 (and presumably F15HP) has more bottom-end extension and bottom-end detail, and a leaner sound.
Another option is to get multiple sealed subs, for the sealed sound at greater volumes (along with other benefits.)

If you want the ground to shake and feel loud explosions like you are at the movies, the FV15HP delivers.
If you want realism and detail like you can feel a boulder rolling over each little bump and musical instruments that sound like a live, unamplified performance, the sealed ones do that better.

A great example is the scene in Incredibles when Mr. Incredbile goes to the island and fights the first big robot. It chases him, rolling through the forest and rocks.
With the FV15HP, it was like a good movie theater. BOOM, boom, Thunder! Loud and thick impacts and after-shocks.
With the F25, it was like being there, beyond what you get at the theater. You could sense each tiny tremor and impact, and really feel the robot crushing individual obstacles small and large, as if you were standing there.

When I describe them that way, it sounds more different than they really were. They were actually quite similar. Still, I think this accurately describes the nature of the small differences.
I'm not talking about mid-bass. The mid-bass sounds the same. I'm talking about detail in the lowest bass.
I think this is what Rythmik means by articulate.
The ported ones are especially articulate for ported subs.
The sealed ones are even more articulate.

So, you could just as easily use the F25 description to describe how the FV15HP differs from typical ported subs.
Edited by rcohen - 11/9/13 at 10:57am
post #83 of 152
Quote:
Originally Posted by basshead81 View Post

With your room dual FV15HP's are the top dog based on your budget. The only way you will get more is stepping up to some JTR Cap 2400's.

Then it looks like I'm at the end of the trail as a pair of JTR Cap 2400s would be in the $5k range and fiscally I don't want to go there.

-
Edited by BeeMan458 - 11/9/13 at 11:24am
post #84 of 152
Some more details, in case it's helpful.

My room is a large sealed rectangle, at 6120 ft^3, with the listening position at around 3/5 back.

I started with 1 Velodyne DD15, which worked well at the old house.
1 DD15 sub at any location in the new room was awful, which got me looking to add more subs, and looking for a better value than Velodyne. So, I sold the DD15 and tried Rythmik.
Placing two subs in the front two corners was still awful, with terrible nulls at the MLP.
One in the front & back center finally got me balanced frequency response, but the sound was still anemic in my large room, even with 2x F25s.
Subs in opposing corners finally got me the sound that I'm describing here that I'm very happy with, particularly after I got my (sealed) mains on stands at the proper height.
Still, it left me wondering if more would be better, so I tried 2x F15HPs and arranged them in the other two opposing corners, and did a lot of listening.
It turns out I prefer Rythmik's sealed sound, and next I'll see how 4x sealed compares to 2x sealed. Seat-to-seat consistency was better with the center placement, so I'm optimistic that 4 in each corner will combine that consistency with power.
Edited by rcohen - 11/9/13 at 11:31am
post #85 of 152
Quote:
Originally Posted by BeeMan458 View Post

Then it looks like I'm at the end of the trail as a pair of JTR Cap 2400s would be in the $5k range and fiscally I don't want to go there.

-
You can get a pair of the passive version for about $3k or so and add a Behringer INuke amp ($300-500)to drive them both.
post #86 of 152
Thread Starter 
My room is only 2000^3. The F25 is not an option due to its size. How much advantage would you say the FV15HP would have? I tried that ULF score spreadsheet and I got 1000@12.5, 909@16, 1111@20 assuming 5 db under the FV15HP across the board and no room gain. The FV15HP gave 556@12.5 , 500@16 and 667HZ. If the metric is any good. that puts the F15 at 4 stars (around reference) and the FV15 at 4.5 stars (above reference). Would that advantage be significant in my space?
Quote:
Originally Posted by basshead81 View Post

Yea I would believe the F25 has a significant advantage over the FV15HP above 30hz. Beemans concerns were about sub 20hz output, which is where the FV15HP shines. However the FV15HP uses the better driver over the F25.

RCohen could so be getting some substantial room gain. Thats what makes or breaks a sealed sub on the Low end. I dont believe he mentioned the side of his room or has provided any data?

I am not trying to take anything away from the sealed F25, its a beast. I was simply making a suggestion to Beeman for his room constraints. A 3300^3 with double openings into other areas of the house will be better served by the FV15HP. Same goes for the OP in his room. I think some of my post was being taken out of context.

Ill break this down into layhmans terms. Smallish sealed room = F25, larger open room = FV15HP
post #87 of 152
Quote:
Originally Posted by Cowboys View Post

You can get a pair of the passive version for about $3k or so and add a Behringer INuke amp ($300-500)to drive them both.

Not trying to be difficult as your above is an excellent recommendation, I saw what you suggest on JTR's website. I don't want to have to deal with a pair of amplifiers out in the open as we don't have room to place and hide two more amplifiers. I would have to go with dual Amps as the subs are going be on opposite wall in the living room and as it is, I'll have to run one of the subwoofer cables under the house. All surround speakers have had their cables run in wall and under the house so my wife couldn't see the speaker cables. I'm trying.

The whole placement issue revolves around WAF and not turning "HER" living room into a repurposed Home Theater Palace. If the budget was there, which it isn't, I could find the room to upgrade to a pair of JTR 2400s but the amplifiers would cause tears to flow. She's old school. Her thinking, a living room is a living room and our place doesn't have a family room I can take over and repurpose into a Home Theater Palace. She's quite on edge regarding this matter and with her, less is more. But, your suggestion is still an excellent idea. biggrin.gif
post #88 of 152
post #89 of 152
Quote:
Originally Posted by rcohen View Post

Well, if you're looking for a project, ...

...eek.gif

Thank-you for an excellent suggestion but in retirement, I don't want to do anything more constructive then repairs around the home.

(above post has been edited so the below comment won't make any sense because this post didn't make any sense)

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Edited by BeeMan458 - 11/9/13 at 4:58pm
post #90 of 152
Sorry...trying to extract the important details from your post...

Are you saying your wife was a Dallas Cowboy cheerleader?
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