Two LFM-1 EX's to a PB13-Ultra, Stupid to compare? let me know

[ryounglaw]

I am a newb and have a stupid question to ask. I have made several posts to pick a sub and had decided on the PB13-ultra. However I need to ask. . . How would 2 LFM-1 Ex's (about 1K including shipping ) stack up to one PB13-Ultra (1700.00 delivered. I know the price difference. This will be used for 99% HT. I live in a townhouse for now. The room is 13X41X8 = 4,264 cu ft.

Thought? will it be close? This room is pretty big.

A room diagram is here

Saving $700 is an interesting idea but is it worth it and will I be happy?

 

[Chopin_Guy]

I would find it hard to believe that two could come close to the output of the Ultra-13 and I highly doubt they could come near in terms of sound quality (THD) either. But then again, I have not heard one, and am basing this assumption off of specs and what I have read....

 

[gwhiz]

I have the LFM-1 EX and I can tell you it rocks. The only SVS sub I listened to was the PB12-NSD. I like the Outlaw sub better and $519 shipped I don't think there's a better deal around. HSU has the VTF-MK3 on sale for $200 more with shipping. The Outlaw sub is basically a redressed MK3 except it's down firing but that keeps my cats from using it for clawing practise. Two subs would balance out the room and at Outlaws price I'm thinking of a second sub myself.

 

[ryounglaw]

wow, I thought people would come out with a resounding NO.

 

[ParadigmDawg]

Man, I have no idea. Stereo subs with the proper bass management can be awesome but I have no experience with the outlaw subs. I would guess that one awesome sub is better than two fair subs. (I am not saying that the outlaws are only fair as I know nothing about them).

 

[Matt34]

I'm going to be the odd man out and say go for one of the new SVS PB12+. I think it will be more than enough sub for a townhouse and save you some money(compared to the Ultra).

 

[ryounglaw]

thats what they are saying on my post at AVforum

 

[ParadigmDawg]

How about two of Phil's? http://forums.audioholics.com/forums/showthread.php?t=52102

"Folks, I will go ahead and sell both of these for $800 shipped within the USA!!! I will also include a Radio Shack SPL Meter AND a Rives Test CD II calibration disk!!!! Likewise, I will gladly sell a single Plus for $400 shipped within the USA!!!! Have a blessed day."

 

[WmAx]

I am a newb and have a stupid question to ask. I have made several posts to pick a sub and had decided on the PB13-ultra. However I need to ask. . . How would 2 LFM-1 Ex's (about 1K including shipping ) stack up to one PB13-Ultra (1700.00 delivered. I know the price difference. This will be used for 99% HT. I live in a townhouse for now. The room is 13X41X8 = 4,264 cu ft.

Thought? will it be close? This room is pretty big.

A room diagram is here

Saving $700 is an interesting idea but is it worth it and will I be happy?

If you are really interested in using your $$$ to get the most product/performance, for the same cost as a PB13ULTRA, you have two options that have different bentfits.

ALTERNATE OPTION 1 You could buy two of the 3 cubic foot sealed Parts Express pre-built/pre-finished cabinets. Cut a hole in each. Install an Eclipse SW8200 subwoofer in each. Drive the pair with a 700 x 2 watt Yamaha P5000S amplifier. Use a Behringer DCX2496 for the xover and compensation/correction EQ system.

You will have higher overall output with this pair (about 50% - 70% more SPL) as compared to a single PB13ULTRA at 27Hz and over. At 20Hz and under, the SPL will be about the same as a single PB13ULTRA. Being a sealed system with a gradual roll off, you will get in-room -3, -4 dB in the range of 16-18Hz.

For music, stereo subwoofers is going to more easily integrate with your main speakers for a seamless transition. If you use the DCX2496 to it's fullest ability, a seamless transition is guaranteed. You should ideally run your main L, R (or L, R and C if this is a surround set up) through the DCX as well as the subwoofer. It has a far more sophisticated and capable xover as compared to the one built into your reciever which is very limited and can not match the relative acoustic slopes properly, but the DCX can.

ALTERNATE OPTION 2 Buy a single of the Parts Express 3 cubic foot cabinets instead of one. Install an Audio Pulse AXIS 15" and use a bridged Behringer EP2500 amplifier to drive it. Use a DCX2496 as the xover and EQ compensation system. This will outperform the PB13ULTRA in every possible way - not even a fair comparison. However, being a single sub instead of 2, the potential integration with your mains is not as high for music.

Both options above require zero construction, no soldering. Just cut a hole in a pre-painted and pre-finished cabinet. Throw in some acoustic dampening material. Screw in driver. Hook up wires. Both options fit in the budget of a new PB13ULTRA and both both outperform it. One option is for maximum music SQ(the duals) and the other is for maximum SPL and lowest THD.

-Chris

 

[lsiberian]

If you are really interested in using your $$$ to get the most product/performance, for the same cost as a PB13ULTRA, you have two options that have different bentfits.

ALTERNATE OPTION 1 You could buy two of the 3 cubic foot sealed Parts Express pre-built/pre-finished cabinets. Cut a hole in each. Install an Eclipse SW8200 subwoofer in each. Drive the pair with a 700 x 2 watt Yamaha P5000S amplifier. Use a Behringer DCX2496 for the xover and compensation/correction EQ system.

You will have higher overall output with this pair (about 50% - 70% more SPL) as compared to a single PB13ULTRA at 27Hz and over. At 20Hz and under, the SPL will be about the same as a single PB13ULTRA. Being a sealed system with a gradual roll off, you will get in-room -3, -4 dB in the range of 16-18Hz.

For music, stereo subwoofers is going to more easily integrate with your main speakers for a seamless transition. If you use the DCX2496 to it's fullest ability, a seamless transition is guaranteed. You should ideally run your main L, R (or L, R and C if this is a surround set up) through the DCX as well as the subwoofer. It has a far more sophisticated and capable xover as compared to the one built into your reciever which is very limited and can not match the relative acoustic slopes properly, but the DCX can.

ALTERNATE OPTION 2 Buy a single of the Parts Express 3 cubic foot cabinets instead of one. Install an Audio Pulse AXIS 15" and use a bridged Behringer EP2500 amplifier to drive it. Use a DCX2496 as the xover and EQ compensation system. This will outperform the PB13ULTRA in every possible way - not even a fair comparison.

Both options above require zero construction, no soldering. Just cut a hole in a pre-painted and pre-finished cabinet. Throw in some acoustic dampening material. Screw in driver. Hook up wires. Both options fit in the budget of a new PB13ULTRA and both both outperform it. One option is for maximum music SQ(the duals) and one for HT.

-Chris

In the interest of learning. How would that performance compare to a perfect build?

 

[speakerman39]

How about two of Phil's? http://forums.audioholics.com/forums/showthread.php?t=52102

"Folks, I will go ahead and sell both of these for $800 shipped within the USA!!! I will also include a Radio Shack SPL Meter AND a Rives Test CD II calibration disk!!!! Likewise, I will gladly sell a single Plus for $400 shipped within the USA!!!! Have a blessed day."

Thanks Greg for the help. I really do need to move these. Most of my set-up has now been sold. It is most appreciated my friend. Have a blessed day.

Cheers,

Phil

 

[Matt34]

In the interest of learning. How would that performance compare to a perfect build?

If I understood Andrew correctly, one ported Kappa perfect would roughly equal one sealed Axis 15". I'm not sure where the Eclipse pair would fit in.

 

[WmAx]

If I understood Andrew correctly, one ported Kappa perfect would roughly equal one sealed Axis 15". I'm not sure where the Eclipse pair would fit in.

Not quite true. The Kappa would have about 3 dB less at 20Hz as compared to the AXIS; the AXIS has 50 percent more output(3dB) at 20hz. By 25Hz, the AXIS has 2x(6dB) more output, and by 35Hz, the output is 2.5 x the Kappa Perfect ported unit. Under 20Hz, the AXIS has far more output as compared to the Kappa Perfect ported unit. There is a narrow range where the two have a 3dB difference, where they are sort of close(but 3dB is actually a substantial difference) output since the sealed alignment loses LF output compared to a ported system. Also, if you use a 4000-5000 watt amplifier, the AXIS will also produce 2x more output at 20Hz than the Kappa Perfect ported system. The above differences are stated assuming use of 2000-2500 watts. But the AXIS can easily use a 4000-5000 watt amplifier.

-Chris

 

[WmAx]

In the interest of learning. How would that performance compare to a perfect build?

The Kappa Perfect and the Eclipse sealed design would have the same output at 30Hz and above. Under 30Hz, the ported Kappa Perfect system will produce more output. At 20Hz, the Kappa will produce about 75-80% more output. For music, the Kappa Perfect's additional output would be of no help under 30hz. But for HT, the Kappa Perfects additional output would be valuable, since lots of movie sound F/X reside around 20Hz-25Hz. The statements here presume you use 800-1000 watts per Eclipse SW8200 along with a suitable digital EQ system.

-Chris

 

[lsiberian]

Not quite true. The Kappa would have about 3 dB less at 20Hz as compared to the AXIS; the AXIS has 50 percent more output(3dB) at 20hz. By 25Hz, the AXIS has 2x(6dB) more output, and by 35Hz, the output is 2.5 x the Kappa Perfect ported unit. Under 20Hz, the AXIS has far more output as compared to the Kappa Perfect ported unit. There is a narrow range where the two have a 3dB difference, where they are sort of close(but 3dB is actually a substantial difference) output since the sealed alignment loses LF output compared to a ported system. Also, if you use a 4000-5000 watt amplifier, the AXIS will also produce 2x more output at 20Hz than the Kappa Perfect ported system. The above differences are stated assuming use of 2000-2500 watts. But the AXIS can easily use a 4000-5000 watt amplifier.

-Chris

But I think the AXIS driver does run in the 800 dollar range. So in essence you could build 2 Kappas for the less than the cost of that driver. Which I'm thinking would out perform the Axis working together. Is this true? Obviously at this level of SQ you can't really go wrong with either option. Especially compared to the commercial offerings. Which is why I'm glad people point this out. I can't wait until my subs are done. It may take time, but I know i will save money and end up with a better product.

 

[WmAx]

But I think the AXIS driver does run in the 800 dollar range. So in essence you could build 2 Kappas for the less than the cost of that driver. Which I'm thinking would out perform the Axis working together. Is this true? Obviously at this level of SQ you can't really go wrong with either option. Especially compared to the commercial offerings. Which is why I'm glad people point this out. I can't wait until my subs are done. It may take time, but I know i will save money and end up with a better product.

It depends. If you used the AXIS in a ported cabinet, it would still produce more output than two Kappa Perfects, and in addition, you can use the AXIS to a much lower frequency range. You do need to use a sufficient amplifier on the AXIS to extract it's full performance. This does mean an amplifier in the range of 4000-5000 watts should be used. While a static model program like WinIsd might lead one to believe the single AXIS is just slightly more output than a pair of Kappa Perfects, you need to consider that in reality the AXIS has incredible thermal dissipation abilities and extraordinary BL strength through a huge excursion range. I would expect the AXIS to have around 40-60% more output minimum compared to a pair of the Kappa Perfect units. The AXIS was specifically developed to be the highest output SPL driver with superb sound quality according to TC Sounds. Is this just a marketing claim? I don't know, but TC Sounds has quite a bit of credibility and their rather big claims have been backed up by 3rd party measured data in the past. TC Sounds is known as the most capable high quality subwoofer driver manufactuer that has existed, based on measured data. Their ultimate SQ driver, the LMS 5400(a.k.a. Ultra LMS) has been confirmed as such by objective measure by credible 3rd parties. Now, the LMS 5400 will produce less THD than the AXIS, but these are two different purpose drivers. The LMS5400 was designed to be the highest SQ subwoofer driver with high output. The AXIS was designed to be a SPL driver with high SQ, and they did make some compromises to increase SPL ability, but the LMS5400 still has more output capability. In reality, this is academic. You are not going to hear the THD from the AXIS; it's far under human audibility thresholds, and it's going to be superior to just about any other 15" driver in this regard except when compared to something of the caliber of the LMS5400, which is simply the best measuring driver known to exist so far.

-Chris

 

[croseiv]

Their ultimate SQ driver, the LMS 5400(a.k.a. Ultra LMS) has been confirmed as such by objective measure by credible 3rd parties. Now, the LMS 5400 will produce less THD than the AXIS, but these are two different purpose drivers. The LMS5400 was designed to be the highest SQ subwoofer driver with high output... of the LMS5400, which is simply the best measuring driver known to exist so far.

The LMS5400 is a beautiful beast for sure... Any idea what it weighs?

 

[WmAx]

The LMS5400 is a beautiful beast for sure... Any idea what it weighs?

The Audio Pluse LMS Ultra (modern version of LMS5400) in 15" diameter is specified as weighing 75lbs. But as I understand it(and I could be wrong), this weight is a side effect of an action taken to compensate for the poor flux strength present in the LMS motor due to the unusual coil winding that permits the incredible wide and flat BL for this driver. As a result, a much more powerful/larger motor is required to get the same BL density as a much smaller motor that uses a more traditional type of coil winding.

-Chris