DIY Adire subs and DIY speaker stands versus SVS (1 Viewer)

[Rob Formica]

Ok, I've been reading around the forums planning ahead for possible music room / HT upgrades... I had a couple of questions and ideas for DIY subs and speaker stands I'd like to throw around. I have yet to build the dedicated room so this is really just in the planning stage. I'm in Canada and my budget is limited... so no Krell amps and TUMULT drivers...

I'd like to upgrade my sub (65% music + 35% movies) and I've considered dual shiva subs or a single tempest driven by either a plate amp (tempest) or a used pro amp (either tempest or shivas). After reading an article at Harmon International on multiple subs and their placement... the dual mid-wall sub set-up has intrigued me for its balanced compromises. Has anyone experimented with this? Since I was already planning building speaker stands for my rear channels and they are placed almost mid wall... what would you think of combining the two (kinda like Eric Jones did for his mains at http://www.nwlink.com/~ericj/emjspeakers/ss.html). Unfortunately this would limit optimization of either of their placements... is it still worth it? What would be the recommended height of the tweeter for the rear channels considering I'm also using them for DVDA?

Another option I've been considering is just one SVS PCi 20-39 sub and making standard DIY stands. Has anyone tested (measured) a DIY Vented Adire versus a SVS unit? Is there a web page where we can find response curves and max SPL for both under the same test conditions? I realise that it's very enclosure dependant... I'm just trying to get a general idea on how they compare... Although the SVS is more expensive initially (esp with duty and brokerage fees), it does have a much better resale value when I eventually upgrade.

Thanks...
Rob

 

[Stephen Hopkins]

Either way you go, dual shiva's or a single tempest, chances are you'll get much better performance than a single SVS unless you get into the much more expensive Plus and Ultra series. I have a single EBS Shiva and couldn't ask for more performance, especially for the under $250 i have invested in the driver, enclosure, and PE Amp. The great thing about DIY is you can build it/them almost any way you'd like.

I would be careful using 2 subs as speaker stands because putting subs on opposite sides of the room in line with your listening position could create some nasty comb-filtering and destructive interference at the listening position. For dual subs I would stick with the split front wall placement, or simply stack them. If you went with a single Tempest, you could use it as a stand for one speaker and make a conventional stand for the other, or make it into an end table and make a matching non-sub entable for the other side. Like I said, options are almost limitless when it comes to DIY.

One more comment... since you're looking at 65% music listening, it seems to me that your listening habits would push you in the direction of sealed enclosures. You may lose some extension, but you'll get the kind of accurate and responsive bass that music demands. Take a look at the reccomended sealed enclosures for the Shiva and Tempest, and also give the Stryke AV-12 and AV-15 a look.

Hope this helps

 

[Rob Formica]

I’ve seen a lot of positive things about the Stryke woofers... and I will look further into them to see if they are worth the extra expense... the reason I initially mentioned Adire is that they are readily available in Canada duty and brokerage free (www.creativesound.ca) (±410$cnd for the AV15 versus 255$cnd for Tempest shipped and taxed ) But you are probably right about the better value being DIY, pour resale value included. I’ve seen the “theoretical” SPL plots (I’m using WinISD) but I’m really curious if anyone has measured it especially compared to a commercially available sub. (SVS, Paradigm servo-15, velo HGS-18, etc...) I did read the reviews at http://www.hometheaterhifi.com/volum...s-12-2001.html as well as their test of the Adire Rava. SPL may seem un-audiophile of me, but I’m using Klipsch heritage speakers on all channels and my current Energy sub can’t keep up! I’m looking into a pro amp... if the deal is right, I’ll go DIY.

I didn’t have my links when I typed up my last post but for the dual subwoofer placement... the article which describes the mid wall placement is “Subwoofers: Optimum Number and Locations 10.30.2002” at http://www.harman.com/wp/index.jsp?articleId=1003 . The placement does seem quite critical so keeping the stand / subs separate might not be a bad move. I guess I’m trying to cover too many possibilities and future upgrades in one design. With a pro amp (hopefully stable to 2 ohms) I can always build one sub, and later add a second one. If the ideal position works out to be under my rear channel speakers (which is a slim chance), I’ll rebuild the boxes / stands.

Thanks...
Rob.

 

[ThomasW]

It's unlikely that you'll find a sub to match the efficiency (high 90's -low 100's) of the Klipsch speakers. But using multiple drivers and amps of relatively high power, you would be able to reach the same output levels. FWIW it would take 4 Tempests to get an baseline efficiency of ~95dB @/1 watt/1 meter

The budget also needs to be realistic. I doubt that you got any of the Klipsch Heritage speakers at bargain basement prices. And you aren't going to get a sub with similar output for cheap.

You ask about a single DIY Adire Tempest or SVS PCi 20-39 then talk about them in comparison to $1500+USD subs. This isn't a fair comparison. If you want to compare $1500+USD subs to DIY then you need to be seriously considering a Tumult or dual AV-15's

BTW the Harman article is a good reference, but it isn't gospel. There are other approaches to sub placement that provide good performance.

 

[David Lorenzo]

Rob,

I gathered some numbers that were posted various places. These were from reviews done by Tom Nousaine. I think they were both done in the same room also.

SVS16-46PC($649)~~31hz/113...20hz/102dB(107dB w/some air rushing thru grille noise).
SVS25-31PCi($549)~~31hz/112...20hz/96(25hz tuned)) 98(22hz tuned)

And here are the stats for the Dharman.

Average SPL 25-62 Hz: 107.9 dB
Average SPL 20-62 Hz: 105.9 dB
Bass Extension: 20 Hz @ 96 dB SPL
Maximum Output: 114.6 dB SPL @ 32 Hz

Hope this helps.

 

[Rob Formica]

Thomas: I agree with you that I wasn’t being fair comparing one of these DIY’s or SVS’s to a 1500$US sub... but I chose these models simply because they are highly regarded and have many reviews online. I can also easily audition a Servo-15 locally, which I can’t with either of solutions I’m looking at. I could have chosen to compare to a Paradigm PW2200 as well.... I guess I’m trying to get a real world feel for it.

Even though the Klipsch Heritage have a very good efficiency (96 and 98 @ 1W/m in my case) I never drive them to clipping with a 100W SS amp... and my in-room RS-SPL C-weight reading are around 110db (which is quite loud for me)... I guess I’m aiming this range for the moment. My current (12’x18’ x8’ non rectangular) and future (12’x16’ x 6’8”) room aren’t very large either. If I go DIY, I was looking at a JBL MPC-200 (225Wx2 @ 8ohms or >550Wx1 @ 4ohms) which I’m hopping will push a Tempest near it’s max. I haven’t ruled out the AV15 either... just more of a hassle.

David: Thanks for the numbers... and I’ll look further into Tom Nousaine... J

Thanks again...
Rob

 

[Chris Tsutsui]

If you can go DIY, then I'd get a tempest and the 280W PE amplifier and have a finished product for less than $400.

Not only did you save $200+ but it should also beat the Dharman and SVS models posted above.

 

[ThomasW]

Rob

You might consider the Maelstrom. It's efficient almost 93dB @1watt/m, and has ~50% more swept volume than a Tempest. The price has been lowered 25% in the US (now $225). That should translate to a lower price in Canada as well

 

[Dustin B]

David, those numbers are from different reviewers with different measuring technics and in different rooms. There was no strick THD limit on those SVS numbers, the reviewer just decided by ear when the distortion was too much. Nousaine did the Dharman review in a larger room with a strick measured 10% THD limit.

The only SVS sub I'm aware of Nousaine testing was an original SVS 20-39CS.

 

[David Lorenzo]

Oops. The SVS tests were done by Ferstler. My bad. Well it still gives a general idea of their respective performance.

I wonder why Ferstler goes by ear only. It seems that it would give inaccurate resuts.

 

[Jack Gilvey]

Comparing Nousaine and Ferstler numbers is, at best, useless and certainly misleading.

 

[Rob Formica]

I just wanted to thank all you guys for steering me in the right direction... I think I'm going to try the DIY solution...

Dustin: thanks for the heads up... I checked around and the Nousaine testing for the original SVS 20-39Cs for $ensible $ound at 10%THD and a 300W amp seems to have been done in the same room (7500ft3) and should be somewhat similar to the Dharman testing setup.

SVS 20-39Cs 10% SPL tests:

Average SPL 25-62 Hz: 109.5 dB
Average SPL 20-62 Hz: 106.4 dB
Bass Extension: 20 Hz @ 91dB SPL
Maximum Output: 114.9 dB SPL @ 32 Hz

Dharman 10% SPL tests (Shiva Mark ?):

Average SPL 25-62 Hz: 107.9 dB
Average SPL 20-62 Hz: 105.9 dB
Bass Extension: 20 Hz @ 96 dB SPL
Maximum Output: 114.6 dB SPL @ 32 Hz

That is mighty close !! I can see how the tempest can easily surpass it with 2.5l of displacement.

Thomas: I must agree that the Maelstrom is very efficient and looks nice too. Why does it seem to be the black sheep (few people seem to use it) of the adire lineup? The only thing I can see is its cost / performance ($/displacement ?) or the lack of reference designs? The 22" sealed cubed adire mention sounds nice but isn't even in their own white papers... hmmmm...

 

[Bryan Michael]

dual av15 can push past 125db with no problem.....

 

[ThomasW]

Rob

I think the lack of popularity for the Maelstrom is a couple of things. A modest Xmax, it wasn't cheap, and it isn't a mondo woofer like the old BP-1803 which was introduced at virtually the same time.

People tend go fixate on certain aspects of driver construction such as huge Xmax, alu cones, massive magnets, etc. So speakers that don't have these fall in the cracks.

Also many 15"s have as much displacement as the Maelstrom, but none are as efficient.

For your needs I think that it might be a good solution. I know for a fact that DanW and company will assist you in designing a custom enclosure for your install.

 

[Matt Tucker]

I had the same dilema... SV sub or DIY. I chose DIY with a Tempest in a sealed sonotube. I am very happy. I agree with Stephen, the sealed will treat you right for your 65% music listening. Don't think you will lose out in movies though, she will pick you up and shake you.
Matt

 

[Rob Formica]

I had decided to go for the DIY route after finding an interesting JBL pro amplifier on liquidation... which may interest some of you as well. It’s a 225W x 2 @ 4ohms (20-20k) ... 750W x 1 @ 4ohms (1k x 10%thd) manufactured by QSC for JBL... and the beauty is that it is less than 150$US. It should give 500W realistically into one 4ohm channel. Two problems...

1)it’s 220V but I think there is an easy solution to that...
2)unfortunately I need a US address, and I’m in Eastern Canada. A postal box won’t do!!! :frowning:

Have any of you Canadians run into similar problems?