VMPS Larger Subs - Upgrade or Replace?

Conradicles · « **Reply #20 on:** 4 Jun 2011, 03:23 am »

Quote from: DFaulds on 3 Jun 2011, 01:43 pm

I have a line on a larger sub with mega woofers and the 1,000 watt amp. What would it cost to get the ultra-megs and the better passive?

Don't sleep.

JP78 · « **Reply #21 on:** 4 Jun 2011, 04:34 pm »

Quote from: Linkwitz Riley on 21 Feb 2011, 01:45 pm

Yeah ctviggen, mine will bottom out badly on movie soundtracks and come close on music played at a higher level. I think part of it may also have to do with the fact that these 2 are trying to fill a large room and when I use the RTA on my AudioControl Richter Scale III and the 1/2 octave EQ, I end up boosting some of the lower frequencies by as much as 6db in order to achieve a smooth response. It does sound very good at low to medium levels, but when I am doing my critical listening to music I like it a little louder. I can get through a movie without bottoming by engaging the subsonic filter & rumble reducer switches on the AudioControl, but it really kills a lot of bass. Disengaging the EQ on the unit makes the bottom end sound bloated and very unnatural. I need drivers that can handle this scenario.

From somebody that's owned a pair of Largers (megawoofers, older PR), I'm confident in recommending you revise the front end of your subs. I strongly doubt your amplifier can handle the 6db increase in lower end eq and this may well be contributing to your problem; otherwise you must have peaks well over 110dB. A 6dB boost requires 4x as much power, so with headroom you need 16x the power rating of the amplifier to achieve the same results as the rest of the frequency range not eq'ed.

When I ran my Largers I had a NAD 218THX running bridged for each subwoofer, and even before the subs bottomed out I could occasionally engage the clipping light. This was in a a 40' x 20' x 12' room.

I did experience much better bass quality by moving the subs out of a corner and towards the middle of the back walls. This only needed me to reduce some of the bass around 80Hz for smooth, even response.

Also, a big part of that visceral feeling may be from not having enough current. A good friend of mine has RM2s; when he ran them full range the bass simply wasn't there when listening to Dark Side of the Moon. Biamping solved this problem handily, and brought the speakers much closer to the impact levels I've heard from (what I consider the reference for visceral) MBL 101e speakers.

Best of luck,

John Casler · « **Reply #22 on:** 5 Jun 2011, 02:21 pm »

Quote from: DFaulds on 3 Jun 2011, 01:43 pm

I have a line on a larger sub with mega woofers and the 1,000 watt amp. What would it cost to get the ultra-megs and the better passive?

Still at the show, but PM'd you pricing

Linkwitz Riley · « **Reply #23 on:** 28 Jun 2011, 04:58 pm »

Yeah JP78, I fully agree with you. About a month ago I removed the AudioControl from the system and installed an Antimode 8033. As we all know, that device cures many room effects but does not boost any frequencies. Immediate improvement. Never bottomed a driver since. Before doing that I had started looking around and was considering a pair of JTR Captivators (new version, passive, in black oak finish), but now I'm kind of happy...still wondering if I should go ahead with the driver & PR upgrade though. Anyone know what the impedance of the UltraMega woofers are?_{EDIT: I now remember John Casler telling me that they are 4 ohms each (the 12" & 15" Ultras)}

John Casler · « **Reply #24 on:** 28 Jun 2011, 05:43 pm »

Quote from: Linkwitz Riley on 28 Jun 2011, 04:58 pm

Anyone know what the impedance of the UltraMega woofers are?_{EDIT: I now remember John Casler telling me that they are 4 ohms each (the 12" & 15" Ultras)}

We'll need to have B, pipe in on that one as I think they are now 8ohms per driver, but can be wired together for 4 ohms if you like in the sub.

Brian Cheney · « **Reply #25 on:** 28 Jun 2011, 06:45 pm »

Ultras are 4 Ohm drivers, both 12" and 15", and can be run individually or in series for an 8 Ohm load. They are quite an improvement, as others here have noted.

JP78 · « **Reply #26 on:** 29 Jun 2011, 10:49 pm »

Quote from: Linkwitz Riley on 28 Jun 2011, 04:58 pm

Yeah JP78, I fully agree with you. About a month ago I removed the AudioControl from the system and installed an Antimode 8033. As we all know, that device cures many room effects but does not boost any frequencies. Immediate improvement. Never bottomed a driver since. [/sub]

Glad you've found the issue! Now the fun begins in tuning in truly subterranean bass. I think you'll be amazingly surprised at how low a pair of Largers can go when you have no boost in EQ. Please report results as you've had more time to experiment.

Linkwitz Riley · « **Reply #27 on:** 6 Jul 2011, 01:38 am »

There is a guy on the other forum who is ordering the Ultramegas for his larger and a TC sounds PR? He claims he has another Larger sub already with the TC PR. He says it is factory "set" for 11 Hz. What's up with that? I thought that the Big Bump PR was the only one that would fit the older lowboy cabinets. Is there an option for, and an advantage to, having a TC PR along with my Ultramega upgrade instead of the BB PR?

bsoko2 · « **Reply #28 on:** 6 Jul 2011, 02:40 am »

I'm only doing that due to having one already with the TC Sounds PR installed. In fact, I am replacing the Mega's in the current VMPS Large with the Ultras so they will both match for the room.

Bill

Linkwitz Riley · « **Reply #29 on:** 6 Jul 2011, 02:47 pm »

Bill,
Do you have to re-cut the opening for your TC passive or is it a drop-in? Any other mods required to do this? I have a pair of largers myself and have been considering the same mods that you are doing. I like the idea of 11 Hz extension with the TC PR for home theater useage.

bsoko2 · « **Reply #30 on:** 7 Jul 2011, 04:30 pm »

The TC PR was already installed when I bought it.

John Casler · « **Reply #31 on:** 7 Jul 2011, 06:54 pm »

Quote from: Linkwitz Riley on 6 Jul 2011, 02:47 pm

Bill,
Do you have to re-cut the opening for your TC passive or is it a drop-in? Any other mods required to do this? I have a pair of largers myself and have been considering the same mods that you are doing. I like the idea of 11 Hz extension with the TC PR for home theater useage.

According to Brian, the TC Passive "is not" a drop in/bolt in and does require cabinet surgery.

However, you should be just as happy (if not more so) with the Big Bump PR which is tuned to 10Hz and of a compliance to match both the MegaWoofers and ULTRAMegaWoofers.

As well it is $66 compared to over $200 for the TC PR.

Brian Cheney · « **Reply #32 on:** 7 Jul 2011, 08:01 pm »

The TC Sounds PR's have some great advantages, primarily the one piece, rigid alloy cone. Their compliance is low and moving mass very high. Mms is given as over 550g for the 15" (likely with all weight added) vs about 90g for the "Big Bump" PR. There is a substantial cost difference as well.

Bill S. has the TC PR with the stock Megas in a Larger and is getting good results. He has ordered a matching Larger with Ultramegawoofs and the TC 15" PR, and I'll be interested to see how things work out, sonically. He is also upgrading his old Larger to Ultramegas with the TC PR, so he'll be in a unique position to report how various combinations pan out.

vin69 · « **Reply #33 on:** 9 Jul 2011, 11:54 pm »

How much does the upgrade of Larger sub to Ultramegawoofers & BBPR cost? Is it easy to replace the drivers on sub?

John Casler · « **Reply #34 on:** 12 Jul 2011, 11:01 pm »

Quote from: vin69 on 9 Jul 2011, 11:54 pm

How much does the upgrade of Larger sub to Ultramegawoofers & BBPR cost? Is it easy to replace the drivers on sub?

Hi Vin,

Have e-mailed you the pricing info and it is also on the "stickie" here on AC.

Swapping the Woofers in the VMPS Subs is one of the simplest things you can do as a DIY in the field change.

Except for the OMG swap which is one of the more complex due to woodworking requirments.

If you can use a screw driver, to unscrew and screw the fastening screws, and you can remember or mark the wiring to the drivers, you should be good to go.

I understand your old woofs are proving hard to remove, and you may want to let gravity have the first crack at getting them out.

First disconnect the wiring and mark it so you know how to reconnect the new woofers.

Then unscrew all the fastening screws and lie the sub "face down" on the carpet (woofers firing into the carpet) Raise one end a couple inches so each woofer can gently fall into the carpet without damage, and leave them overnight to see if they will come loose with just gravity over time.

If this does not work, then you may need to apply manual force from inside the cabinet by reaching through the opening after you remove the Passive Radiator.

Good Luck!!

vin69 · « **Reply #35 on:** 16 Jul 2011, 06:45 am »

How do I disable to EQ on Dayton SA1000 sub amp? Currently I have frequency & bandwidth knobs at lowest setting & the EQ level knob at 0. Would this take the EQ on the sub amp out of equation? I am planning to use the sub with Antimode 8033.

vin69 · « **Reply #36 on:** 18 Jul 2011, 01:52 pm »

I calibrated the sub with current drivers & am using Dayton SA1000 amp to drive it. Everything is calibrated properly. The amp keeps shutting down. I am wondering if the older drivers are presenting a difficult load. Are the new Megawoofers rated at 8ohms rather than 4 ohms? I am waiting for my new Megawoofers.

John Casler · « **Reply #37 on:** 18 Jul 2011, 02:23 pm »

Quote from: vin69 on 16 Jul 2011, 06:45 am

How do I disable to EQ on Dayton SA1000 sub amp? Currently I have frequency & bandwidth knobs at lowest setting & the EQ level knob at 0. Would this take the EQ on the sub amp out of equation? I am planning to use the sub with Antimode 8033.

I think setting the EQ dial to 0 will do it. You may want to check with Dayton/Parts Express if that is where you got it. They have a support team for that model.

John Casler · « **Reply #38 on:** 18 Jul 2011, 02:26 pm »

Quote from: vin69 on 18 Jul 2011, 01:52 pm

I calibrated the sub with current drivers & am using Dayton SA1000 amp to drive it. Everything is calibrated properly. The amp keeps shutting down. I am wondering if the older drivers are presenting a difficult load. Are the new Megawoofers rated at 8ohms rather than 4 ohms? I am waiting for my new Megawoofers.

Sounds like a short somewhere, or the amp is faulty. You sub is a 4 ohm load and the Dayton should handle that without a problem. Again if you got it from Dayton just call them.

vin69 · « **Reply #39 on:** 18 Jul 2011, 04:03 pm »

Thanks John. I think the amp is defective. I am sending it back for exchange. Can't wait for my new Megawoofers to get installed & get the place rocking again.