Subwoofer for Magnepans Purchase Suggestion

[nightflier]

I've been struggling to integrate a pair of Magnepan MC1s with an SVS PB12+ sub. The problem is that the cut-off on the MC1s is 80 Hz, and rather immediate, too. Unless my aging ears are lying to me, pretty much everything from 50ish Hz to 80 Hz seems directional and with the SVS to the side, this gets distracting very quickly. So I've been toying with the thought of adding a second sub in the front of the room to handle the upper bass frequencies and provide "some illusion" that this is coming from the Maggies. So my first question is whether this will work.

My second question is what are my options? I need a narrow sub so that it doesn't stick out of the front of the room too much, something not much deeper than 6-8 inches. I don't mind it being large or wide, but the depth is an issue. The other issue is that it will be connected with speaker-level inputs and will need cross-over adjustment, so that eliminates a lot of smaller "cute" subs. Finally, it needs to have some power behind it. The SVS will handle the deep bass, but I still think that 200W is the mid-bass is as low as I'd be willing to go. My budget is about $1000.

Any thoughts, suggestions?

[luvtolisten]

I've been struggling to integrate a pair of Magnepan MC1s with an SVS PB12+ sub. The problem is that the cut-off on the MC1s is 80 Hz, and rather immediate, too. Unless my aging ears are lying to me, pretty much everything from 50ish Hz to 80 Hz seems directional and with the SVS to the side, this gets distracting very quickly. So I've been toying with the thought of adding a second sub in the front of the room to handle the upper bass frequencies and provide "some illusion" that this is coming from the Maggies. So my first question is whether this will work.


My second question is what are my options? I need a narrow sub so that it doesn't stick out of the front of the room too much, something not much deeper than 6-8 inches. I don't mind it being large or wide, but the depth is an issue. The other issue is that it will be connected with speaker-level inputs and will need cross-over adjustment, so that eliminates a lot of smaller "cute" subs. Finally, it needs to have some power behind it. The SVS will handle the deep bass, but I still think that 200W is the mid-bass is as low as I'd be willing to go. My budget is about $1000.

Any thoughts, suggestions?

No, you're ears are fine. Yes it will work, HSU sells a sub, a "Mid Bass Module" just for that purpose.
http://www.hsuresearch.com/products/mbm-12.html

But what's killing you is your depth restraint, 6-8 ''. I don't know of any off hand that satisfies that requirement. Here is one from Sunfire, a little larger than your looking for, (9X9X9)', 1500W, $1000 :
http://www.sunfire.com/productdetail.asp?id=10

I have read on the HSU forum where a person used a HSU sub (not the Mid Bass Module) with a SVS sub. The HSU for the mid bass, the SVS for the lower bass. The HSU from what I've heard (I have never made a direct comparison myself) is said to be more musical in the mid bass, whereas the SVS handles the lower frequencies better.
.

[nightflier]

Yes, I had considered the Sunfire, but it does not have speaker-level outputs. I also thought the NHT:

http://www.audioadvisor.com/images/NHTVWOOFER_LIFE.jpg

would be the right size (it even has two drivers), but same problem. The Hsu is too big. The Velodyne MicroVee is one option, but I'd really like to get something a little thinner and less boxy. Is there a panel-based sub that would work?

[blackraven]

Get a sub that is non ported sub if you can like the Martin Logan Dynamo, Velodyne Microvee.

This Definitive Technology Sub is only 10" deep-

http://www.definitivetech.com/products/products.aspx?path=Subwoofers&productid=SuperCube%20III#More

If you can swing the space and extra cash, I would get this REL sub-
http://www.sumikoaudio.net/rel/prod_r205.htm

http://www.sumikoaudio.net/rel/manuals/R-SeriesManual_UK.pdf

[blackraven]

Here's a Mirage sub at 7.9" http://shopper.cnet.com/subwoofers/mirage-mm-6-subwoofer/4014-11312_9-33669554.html#info-5


Here's the 9" sunfire for $779 http://www.independentaudiovideo.com/store/item_view.asp?estore_itemid=1000551

[Mr Peabody]

Size could be a problem but i second the REL, maybe the T series. They are actually designed for speaker level hook up.

How old is your PB+? I didn't think there would be that much difference between the SVS models but my 13U integrates very well with my system. I would have thought SVS would design there subs to go up to at least 100 Hz as they would be most likely used for home audio. Have you emailed SVS about this? They are pretty good on responses. Are you bypassing the SVS internal crossover? Could be the Maggies aren't flat to 80 as well.

[nightflier]

My setup is per Magnepan's suggestions: the front L& R pre outs are connected straight into the sub and then out to the amp that drives the speakers. The source is set for no sub and front L&R large, because I need all the low frequencies to go through the sub's cross-over to be filtered out.

With the second sub, I was going to use the speaker level inputs and outputs and filter the mid-bass out before it got to the speakers. The whole chain would look like this:

player > pre > large sub > amp >> small sub >> front speakers

where:

> = RCA
>> = Speaker Cables

Because the large sub is near the pre & amp, I can use RCA connections, but because the smaller sub will be in the front of the room with the speakers, it will need to use speaker level inputs, instead. The reason for placing the sub near the speakers is because the mid-bass being much more directional, I thought that putting this up front would give the "illusion" that it was coming from the speakers.

With a single large sub, the problem is that I can clearly hear where the mid bass sounds are coming from (the rear-right of the room where the sub is located).

[Sir Terrence the Terrible]

If you can "hear" a subwoofer, then it is too loud. Bass below 80hz is non-directional(and that includes 50-80hz). That is unless there is a considerable amount of above 80hz information coming through the sub. This is a crossover issue, and no reason to add a mid-bass woofer to a system. You need to check the slopes of the crossovers that you currently have. The best slopes are 18 and 24db slopes. A 12db slope is not good enough, as it allow too much mid bass to come from the sub.

You need to calibrate both the speakers and the sub first. You start by getting the peaks and valleys out of the sub's frequency response as best you can, or else you will just be calibrating to the loudest peak in your room. The next step is to make sure the SPL of the main speakers and the subwoofer splice together seemlessly. This REQUIRES an SPL meter, as our ears are poor measuring devices when it comes to bass and deep bass frequencies. You start with the subwoofer in the FRONT corner by the mains, and if that position is not good, move the subwoofer closer to the main speakers by sliding it up the front wall towards the center of the room. I have found that setting the sub exactly between the front mains is a very workable solution, but you will have to create a house curve to counter the deep bass fall off.


So I've been toying with the thought of adding a second sub in the front of the room to handle the upper bass frequencies and provide "some illusion" that this is coming from the Maggies. So my first question is whether this will work.

The answer, probably not. By adding a second sub in a room (unless it is an identical sub placed in the opposite corner) is likely to create more acoustical problems than it solves. It adds unnecessary complexity to your installation as well. If you want the illusion that bass is coming from your maggies, then you will have to located the sub near the maggies, especially of there is considerable mid-bass leakage emanating from the sub. If you add another sub without dealing with the crossover and balancing issues, then it is likely the room will have too much mid bass from the overlap of frequencies the two subs will share which will obscure the detail of all frequencies above it.

My question to you is why you are not using the bass management of your reciever or pre-amp? What you are proposing is overly complex, pricey, and completely unnecessary.

[nightflier]

Thank you. I will take another look at the cross-overs.

I'm now using the McCormack which does not include any processing. The sound is a vast improvement, but the setup is much harder. It certainly was a lot easier with a pre/pro and more full-range speakers. Maggies are a whole other beast. 'Still new to the panel experience.

[E-Stat]

Unless my aging ears are lying to me, pretty much everything from 50ish Hz to 80 Hz seems directional and with the SVS to the side, this gets distracting very quickly. So I've been toying with the thought of adding a second sub in the front of the room to handle the upper bass frequencies and provide "some illusion" that this is coming from the Maggies.
As TtT pointed out, you are getting audible output at least one octave above the nominal xover point. Which is why I'm not a fan of single sub solutions. You'll also note that there are a sum total of zero world class speaker systems that are configured that way.

My objectives for adding subs to the modest HT system are threefold:

1. Extend low end response
2. Improve headroom of satellites
3. Allow subs to participate in room correction via EQ

Such requires two subwoofers and a higher than usual xover point. I run mine at 200 hz which allows the subs to equalized to fix errors above 80 hz and avoid the audible sins of running it full range. It is a win-win-win situation.

rw

[Sir Terrence the Terrible]

Thank you. I will take another look at the cross-overs.

I'm now using the McCormack which does not include any processing. The sound is a vast improvement, but the setup is much harder. It certainly was a lot easier with a pre/pro and more full-range speakers. Maggies are a whole other beast. 'Still new to the panel experience.

Gotcha! So this is for a two channel system I take it. If you go with the single sub suggestion, then front mid wall placement will work well. As E-stat states, another option would be to go the two identical sub option, and place them right next to the main speakers. Whatever you choose, parametric EQ has to be in the equation, or the system will not sound right.

[nightflier]

Actually, no, it's a 5.1 HT with the MAP-1 as the pre.

[Sir Terrence the Terrible]

Actually, no, it's a 5.1 HT with the MAP-1 as the pre.

It really doesn't matter if it is for two channel or 5.1, the advice is still the same since this is an acoustical and crossover issue. The SVS sub has an adjustable crossover section, and while lowering it would have helped your problem easily, you just cannot afford to introduce any more bass to your mains. This does leave you in quite a quandary. Now you really do have to do what E-stat says, and raise the crossover to 100hz and above, and you really HAVE to locate your one sub in between the mains, or purchase two subs and place them directly next to the mains, or you will always be able to tell where the sub is. You will also have to have all of your speakers physically equi-distant from the sweet spot(the preamp has no delay).

[nightflier]

I hadn't considered moving the SVS. It is where the old put-sub-in-seating-position-and-crawl-around-the-room technique dictated where it should go. I'll need to do some more crawling around this weekend.

[Mr Peabody]

Sir T, NF will be getting the Oppo BR player, how much speaker set up is included in that unit? Anything that will help his situation?