Subwoofer purchase question

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precisi0n12

Audiophyte
I told myself I would not post a "help me decide on a subwoofer" thread, as there are plenty, however I am about brain-dead with all of the information out there. Hopefully, I can get some solid recommendations for what to do.

I have living room space that is 22x16x13 that is open to the kitchen and dining room through archways. I am mostly flexible on placement, which is why I am partially considering duals. The space is used for 60% movies and 40% music.

My decision has come down to a single FV15HP or dual PSA XV15s. Any input would be appreciated.
 
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shadyJ

Speaker of the House
Staff member
Give this Parts Express kit a look. A couple of those would be a bit more expensive than your other choices (after shipping) but they would have great sound quality. The driver used in that kit is very high quality. It is a very easy kit to assemble too, all you need is a screwdriver, some glue, and an hour of assembly time. I think that solution would give you both the high sound quality and big output of the Rythmik and the benefits of a multisub setup. Outside of that I would go with the Rythmik, because it will have better sound quality and a lot more features than the XV15, and you could always add another one later for a really killer setup. Next to that I would get a Hsu VTF3 dual drive.
 
theJman

theJman

Audioholic Chief
My decision has come down to a single FV15HP or dual PSA XV15s. Any input would be appreciated.
A pair of either will not have a problem in a room that size, so there's no bad choice in this case. The XV15's would probably have a little output advantage, while the FV15HP's would probably have slightly better overall sound quality.
 
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shadyJ

Speaker of the House
Staff member
a single FV15HP will have more output power, but a single XV15 has better lower extension.
Um the Rythmik has more extension even in its higher tuning mode. According to data-bass, you would have to have two XV15s co-located to have more deep bass output than a FV15HP, and even then they would only do it at 16 Hz, and by 2 only dB, and with considerably more distortion.

The Dayton kit would be killer though. But remember those scores were achieved with a 12 kW amp. You would have to shave off some of that higher frequency output for a more realistic amplifier. However, down low, you would only need a few hundred watts to max it out.
 
ImcLoud

ImcLoud

Audioholic Ninja
what about HSU? VTF15 vtf3 ULS15 cant forget them guys... and very cost effective..
 
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precisi0n12

Audiophyte
I haven'y totally forgotten about HSU... I have been looking into the VTF-15 as a possible candidate. I suppose my main question would be, would I actually get better output from oneFV15HP compared to 2 XV15s? Based on numbers alone, I think the FV15 may have the edge, although having two subwoofers may give me better overall coverage in the space?
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
The Dayton kit would be killer though. But remember those scores were achieved with a 12 kW amp. You would have to shave off some of that higher frequency output for a more realistic amplifier. However, down low, you would only need a few hundred watts to max it out.
The driver is rated at max continuous power of 900w. Crown XLS1500 bridged at 4ohm delivers 1550w. No need for 12kW amp to get same results.
Besides then I will build this kit, It will pretty limited anyways, since below 20hz the distortion at and above 110db is just too high, but then again even a "humble" 105db at 20hz is nothing to sleaze at

and re: FV15HP - I was looking at 2port. Yes, at 1port open vs XV15 - FV15HP has better extension
 
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shadyJ

Speaker of the House
Staff member
Take a look at the voltages applied at 40 Hz and above. No ordinary Crown amp that I know of can generate the power needed for that kind of output:
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
From Josh Ricci:
This system does not require huge power to get the most from the driver and amplifiers with a rating from 500-1500w into a 4 ohm load would be the best match in a sealed enclosure of this size. With 1500w being the upper ceiling past which the driver may become in danger of being able to be bottomed out with too much gain. The voice coil appears to be able to cope with this amount of power as long as the duty cycle isn't too high. The driver is rated as a 900w rms driver.
 
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shadyJ

Speaker of the House
Staff member
Not to be argumentative, but I think Josh was talking more about the low frequencies there. Drivers can reach their xmax with a lot less power at low frequencies than they do at higher frequencies. If my understanding of electrical power is correct, no ordinary 20 amp circuit is going to give you enough juice to hit the output levels that Josh achieved at 40 Hz and above on that driver.
 
Ricci

Ricci

Bassaholic
If you look at the CEA-2010 output for any of the DIY systems you cannot use enough amplifier to produce the upper bass output levels without also having a system that could be catastrophically damaged at any second by too much signal wither for too much duration or too much power in the deep bass.

The RS18HO for example can work safely with an amplifier of 1500w rating or less in a sealed enclosure of that size or smaller. If you look at the voltages used during the long term output sweeps and during CEA-2010, the potential maximum voltage output of the amplifier should realistically be kept under 85 volts to prevent the driver from being potentially bottomed out in the low bass. Looking at the impedance measurement of the system shows it to be a 4ohm minimum load which along with an 85 volt maximum input indicates a power input of about 1800w. Any more voltage potential than this can cause mechanical damage to the driver potentially.

This does not address thermal limits or long term safety of the driver vc from burning when using an amp with this much potential as that will be determined entirely by the signal content, duration and the users aggresiveness with the volume knob. The driver could probably be torched with that much amplifier but it would be unlikely if the user had any sort of common sense, however that is far from guaranteed.

Anyway both Shady and Bored are correct. You only need in an amplifier in the 750-1500w range to get maximum "safe" potential out of the RS18, but you will not be able produce the CEA-2010 peak output levels recorded at 40Hz and above and will likely run into amp clipping 4-6dB earlier.
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
If you look at the CEA-2010 output for any of the DIY systems you cannot use enough amplifier to produce the upper bass output levels without also having a system that could be catastrophically damaged at any second by too much signal wither for too much duration or too much power in the deep bass.

The RS18HO for example can work safely with an amplifier of 1500w rating or less in a sealed enclosure of that size or smaller. If you look at the voltages used during the long term output sweeps and during CEA-2010, the potential maximum voltage output of the amplifier should realistically be kept under 85 volts to prevent the driver from being potentially bottomed out in the low bass. Looking at the impedance measurement of the system shows it to be a 4ohm minimum load which along with an 85 volt maximum input indicates a power input of about 1800w. Any more voltage potential than this can cause mechanical damage to the driver potentially.

This does not address thermal limits or long term safety of the driver vc from burning when using an amp with this much potential as that will be determined entirely by the signal content, duration and the users aggresiveness with the volume knob. The driver could probably be torched with that much amplifier but it would be unlikely if the user had any sort of common sense, however that is far from guaranteed.

Anyway both Shady and Bored are correct. You only need in an amplifier in the 750-1500w range to get maximum "safe" potential out of the RS18, but you will not be able produce the CEA-2010 peak output levels recorded at 40Hz and above and will likely run into amp clipping 4-6dB earlier.
Thank you very much Josh !
 
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Tom V.

Audioholic
a single FV15HP will have more output power, but a single XV15 has better lower extension.
Go to Data-bass.com to compare the measurements....
Now pick ether system and compare it to this one: Data-Bass
I have few notes about it here: http://forums.audioholics.com/forums/diy-corner-tips-techniques/86486-sealed-18-dayton-rss460ho-4-4-cu-ft-kit-best-thing-since-sliced-bread.html#post983759

Depends what extension mode is used on the 15hp. If in max output mode, the XV15 has a bit of an extension edge. If in max extension mode, the edge goes to the 15hp. In max extension mode the 15hp has a 2.5(ish)dB advantage in output per the 20-63hz 2010-cea scorecard. A second XV15 will generally add 3.5 to 5dB to a single unit in most room environments. All the 2010-CEA data is accumulated using strict distortion limits. Don't get overly hung up on a dB or two difference either way though. I always recommend looking at the entire picture---customer service, warranty, size, not to mention the real benefits dual subwoofers can offer with regards to smoothing bass response in the room.

Tom V.
Power Sound Audio
 

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