Tall boy setting for the Largers -- How do they work?

woodsyi · « **on:** 23 Aug 2005, 01:43 pm »

My bass with the Largers have improved vastly. I have seen and heard them the tall way in John Casler's apartment. I have arranged mine the same way within my room limitations.

I saw that John also had them up like this at the recent demo in LA. This orientation for me is clearly better then before when I had them right side up and off line from the RM40 woofers. Why does it work? What does Big B. think of it? Are we onto something?

KJ · « **Reply #1 on:** 23 Aug 2005, 02:34 pm »

Woodsyi or John,

Given how close the Largers are to the RM40s, do you have any concerns regarding the magnetism? One would think the Largers are emanating a significant amount towards the RM40's drivers.

Nice setup by the way!

-KJ

John Casler · « **Reply #2 on:** 23 Aug 2005, 03:38 pm »

Quote from: KJ

Woodsyi or John,

Given how close the Largers are to the RM40s, do you have any concerns regarding the magnetism? One would think the Largers are emanating a significant amount towards the RM40's drivers.

Nice setup by the way!

-KJ

I actually have my LARGERs well over a foot from the my RM30s (which sems to yeild a HUGE soundstage, and I haven't noticed any difference in the RM30 woofs at all.

I noticed that Woodsyi has removed the slot (which I have not done) and I think I'll try that too.

I think the "magic" is trying all possible positions. I mean I even tried lying the subs on their back, with the active woofers firing to the ceiling, and the passive firing back towards the "front" wall. (this might have the greatest WAF if you use the grills) to a great result.

ctviggen · « **Reply #3 on:** 24 Aug 2005, 12:36 pm »

I'm going to also be putting my Largers on their sides, as I've purchased some bass traps/stands to put the Largers on. I may also take off the slot, as the sub stands I'm going to get (I have one and am in the process of purcasing the second) are 22 inches wide.

A review of ths substand:

http://www.stereophile.com/musicintheround/904music/index1.html

woodsyi · « **Reply #4 on:** 24 Aug 2005, 01:09 pm »

Bob

How high is your ceiling? I am very interested in hearing your result with this basstrap/stand. The stand would place all four (2 on sub 2 on RM40) woofers at different height. A line array?

ctviggen · « **Reply #5 on:** 24 Aug 2005, 01:43 pm »

My ceiling is 7'8" tall (about). I was planning on generating some room acoustics curves (using ETF) with the following: no trapping (I would remove my 6 realtraps); with trapping but not substands (add back in my 6 realtraps); with trapping and substands. I guess to be more scientific, I should put the two largers on their sides prior to performing the initial measurements (and readjust phase when the subs are placed on the stands).

I'll post the results and my impressions, although this might not be for a month, as I have to get the second stand and have a helper (my girlfriend).

woodsyi · « **Reply #6 on:** 25 Aug 2005, 03:33 pm »

Quote from: ctviggen

I'll post the results and my impressions, although this might not be for a month, as I have to get the second stand and have a helper (my girlfriend).

Well,

I am all ears whenever you can get your girlfrind to help to get the job done.

John Casler · « **Reply #7 on:** 25 Aug 2005, 05:59 pm »

Quote from: ctviggen

I'm going to also be putting my Largers on their sides, as I've purchased some bass traps/stands to put the Largers on. I may also take off the slot, as the sub stands I'm going to get (I have one and am in the process of purcasing the second) are 22 inches wide.

A review of ths substand:

http://www.stereophile.com/musicintheround/904music/index1.html

OK Bob, because of you, I placed my front LARGERs on very sturdy Parsons Tables and added a "beard" and damn if the bass didn't gain even another layer of texture and detail, as well as envelopment.

And guess what I used for a "beard"? I used the black "plate" that you'll be removing from yours.

I can see that the device you're refering to is "more" than just an elevation for the sub, but elevating mine, did move my bass to another level. (literally

)

woodsyi · « **Reply #8 on:** 25 Aug 2005, 06:41 pm »

John,

You beat me to it. I am elevating mine tonight! You don't have side wall being much of a factor but I do. I have modes at 38 and 70. I will see what elevation of subs do with my Real Traps. I think I would still want a subwoofer base that is a tuned 40 Hz trap.

ctviggen · « **Reply #9 on:** 26 Aug 2005, 12:37 pm »

I do think that raising the sub (without the bass trapping in the stands I'm buying) will help, as the sub will interact less with floor-to-ceiling room modes. Similarly, the ASC guys recommend putting subs 29% into the room both front-to-back and side-to-side for the same reason (different modes, of course). That's one reason why the tall boy technique works. In my case, I have my subs along the front wall and my RM40s are about 29% into the room (both ways -- which I did by hearing, although I backed up the positioning with tests on my ETF program). I am going to try to put the subs a bit further into the room, but I'm not sure how far I'll be able to put them due to space constraints.

As for the sub stands, I think they're a great idea, but I question the expense. Luckily, I'm buying two used stands, which will cost a little more than one new stand. But two new stands would be over $1000. When you consider how many Realtraps you could buy for that, the sub stands are down on my totem pole of room treatments. However, I already have 6 Realtraps (two Mondos, two HF minis and two Mircos) and feel that I could splurge on the stands, especially since I could get them used.

My next acoustics treatments are ceiling treatments, diffusion, and also more bass trapping.

woodsyi · « **Reply #10 on:** 26 Aug 2005, 01:38 pm »

Quote

As for the sub stands, I think they're a great idea, but I question the expense. Luckily, I'm buying two used stands, which will cost a little more than one new stand. But two new stands would be over $1000. When you consider how many Realtraps you could buy for that, the sub stands are down on my totem pole of room treatments. However, I already have 6 Realtraps (two Mondos, two HF minis and two Mircos) and feel that I could splurge on the stands, especially since I could get them used.

Bob,

You make a good point about the cost. I am going to have to look around for a used pair but I don't recall seeing any. In the mean time I will look into custom building a pair of sub stands that will act as Helmholtz trap for 38 Hz. I hope the necessary size work out for me! There is just never an end in this hobby. Is there?

John Casler · « **Reply #11 on:** 26 Aug 2005, 01:43 pm »

If you guys really want the best stands, simply "stack" the sub on another Sub.

I think most of the improvement is from the elevation and the "absorbing" duties are a little bit overstated. Maybe Ethan could offer an opinion.

If these things are really $1K, then you can certainly find 2 stock LARGERs, or 215's for around that.

I used a couple really sturdy tables ($19) from Ikea.

ctviggen · « **Reply #12 on:** 27 Aug 2005, 01:28 pm »

The substands are traps designed to absorb some low frequency energy. So, theoretically, they'll work better than another sub. Nonetheless, if you have the time to build a Helmholtz trap, then I think a Helmholtz trap will be as good or better. However, I will be testing my system with ETF, which will show me how well (or how poorly) the substands work. I can also test this out -- I have some ottomans (sp?) that I can use instead of the subtraps. They're about the same height though not as large. I can test with the ottomans then with the substands to see which is better.

As for the Helmholtz trap, what type are you building? Are you building one in a tube-within-a-tube configuration? ETF allows you to design that type of trap (and also one other, I believe). The problem is getting a high Q (ratio of center frequency to "spread" of frequencies at some point, I think -3dB is chosen). Some people also see these types of traps. I would probably buy two (or several):

http://www.tubetrap.com

I think the interesting thing about the latter tube traps is the diffusion part. I'm planning on purchasing some diffusive elements and putting them (actually, having a helper put them) in various locations to see what, if any, difference there is.

My big thing is time. I still have yet to actually adjust my RM40s after performing the mid-bass upgrade! Luckily, my girlfriend is going away for a weekend, the weekend of my 100 mile bike ride. So, I will have a Friday night and Saturday all day to mess around with the system. The bad thing is that adjusting bass levels and particularly phase are hard to do without a helper. If I adjust phase myself, I cannot tell a difference. The last time she helped me by turning the phase adjustment whilst I sat in the sweetspot, I was instantly able to discern a difference. Anyway, more in a few weeks, when I have my 1.1 days of fooling around with the stereo!

woodsyi · « **Reply #13 on:** 27 Aug 2005, 03:12 pm »

Quote

As for the Helmholtz trap, what type are you building? Are you building one in a tube-within-a-tube configuration? ETF allows you to design that type of trap (and also one other, I believe). The problem is getting a high Q (ratio of center frequency to "spread" of frequencies at some point, I think -3dB is chosen). Some people also see these types of traps. I would probably buy two (or several):

Bob,

I been reading about perforated hole type and slat type of DIY resonators. I have to think obout structural integrity to be able to suport a Larger sub. I haven't figured out if a retangular box with multiple damped membranes can be built for 40 Hz. When you get your base can you tell me weather it's slats, perforated holes or damped membrane inside?

ctviggen · « **Reply #14 on:** 27 Aug 2005, 03:28 pm »

I have a base, and I'm not sure what's inside. Here's the best representation I can find:

http://www.acousticsciences.com/subtrap.pdf

(Note -- I have the old style, which has a post at each corner; I think the post is used along with thick top/bottoms to support the weight of a sub.) It appears that they are using a tuned system. They have a core surrounded by a tubular portion with holes, surrounded by air, then insulation and covering. Without taking the stand apart, I can't really see what they're doing.

I purchased one on Audiogon. The second one, a guy (Jim) from ASC found an older model in the factory, and the old model is similar to the one I currently have. I was able to get this model for half off. So, I ordered two stands for about 60% of the total cost of two new stands. I just ordered longer interconnects and speaker wire for my sub so that I can play around with moving the sibs out. I can bring them out somewhat, but I have space considerations that are hard to overcome. (And, when critically listening, I put my HF traps between my RM40s. I might be putting the subs where the HT traps go, which I'm not sure I want to do -- the HF traps really help with imaging; sometimes I have to get up and see if my center channel is on, as the image is so far back, but without the HT traps, the imaging is not as good.)