Researching surround speakers

JoshK · « **on:** 19 Nov 2010, 02:30 pm »

Its been nearly a decade since I last had surround sound. I am now thinking ahead to when I finish my Abbey clones (boxes are all done and bondo is 98% done, awaiting paint job). Next up is finishing the subs. I did the big rips for the subs already so I just need to do a few cuts and glue them up.

My plan is to set up a 2.x HT system (x because its either 3 or 4 subs, depends on what works) using the Abbeys and then add surrounds. My priority is concert DVDs, as I still feel surround for movies is more of a gee-whiz factor, but it comes as a freebie.

With that in mind, I am leaning towards a direct radiating constant directivity/coverage surround, matching the philosophy of the mains. I am mostly looking at the pro side of audio as they seem to have this down much better. I am not adverse to building something, but that may mean its a lot further out as I am going to be working on my horn system before that.

So far, I've uncovered a few speakers that look interesting based on priorities, size (my location can't hold huge speakers) and price.

EV EVID 6.2
http://www.electrovoice.com/product.php?id=128

QSC AD-S52
http://www.bhphotovideo.com/c/product/397532-REG/QSC_AD_S52_WH_ADS52_5_25_2_Way_Loudspeaker.html

JBL AC15
http://www.jblpro.com/catalog/General/Product.aspx?PId=228&MId=2

In the more extreme example... Krix Mega Phonix (although this is getting large)
http://www.krix.com/Product/Detail.aspx?p=97&id=78
The Phonix is more sanely sized...
http://www.krix.com/Product/Detail.aspx?p=97&id=77

Any other good ideas that I should look at? What are the rest of you guys using, particularly the ones with Geddes or similar concept mains?

raindance · « **Reply #1 on:** 19 Nov 2010, 02:42 pm »

Those speakers in your list are quite inefficient. Look at the EV SX80 or SX100+ depending on coverage pattern you need. Probably the 100+...

If you want small, JBL Control 28 is just OK. What about Klipsch or Hsu?

JoshK · « **Reply #2 on:** 19 Nov 2010, 02:52 pm »

The EVID 6.2 is 94db/w. That isn't all that inefficient. The other two are far less efficient.

raindance · « **Reply #3 on:** 19 Nov 2010, 03:13 pm »

Right, but the EVID series has the least controlled directivity.

dwk · « **Reply #4 on:** 19 Nov 2010, 07:47 pm »

Interesting - those Evid 6.2's look like up-sized versions of the JBL Control Now that I have in our TV room. An interesting design actually, and does pretty well in terms of uniform coverage if corner-mounted horizontally. I don't think the Now's have the output to keep up with Abbeys (or probably the quality either, although they're not bad)

raindance · « **Reply #5 on:** 19 Nov 2010, 08:31 pm »

See the teeny tiny waveguide in the EVID? It can only control very high frequencies. so doesn't qualify in my book as controlled dispersion.

The other option to look at is Tannoy or KEF dual concentrics. They have very well controlled directivity and image like champs. Tannoy Di8 is a great sounding pro sound speaker. I have KEF IQ3's in my HT and they are great for that and quite efficient.

poseidonsvoice · « **Reply #6 on:** 19 Nov 2010, 08:40 pm »

Quote from: JoshK on 19 Nov 2010, 02:30 pm

What are the rest of you guys using, particularly the ones with Geddes or similar concept mains?

The latest research has shown that in addition to your mains, controlled directivity is also recommended for the surrounds (Toole, Geddes, etc...).

Josh if you could swing the bucks you will also consider Geddes' Harpers which is what I'll be using in my system (4 of them actually). If you want to control dispersion down to a low enough frequency that is audible, you need larger waveguides. Tiny waveguides, that are a bit bigger than a 1 inch tweeter, imho, are just a marketing tool. Good luck! You might want to also look at Hsu's HB-1 MkII. It's small and cheap. When your venue and budget gets bigger, spring for the Harpers.

Anand.

raindance · « **Reply #7 on:** 19 Nov 2010, 08:51 pm »

I second the Hsu idea, it will sound better than most of the pro speakers as the pro speakers require a fair bit of EQ to get them flattish.

Of course, if these will be going in corners or close to wall/ceiling junction they'll need EQ anyway.

JoshK · « **Reply #8 on:** 22 Nov 2010, 03:03 pm »

Quote from: poseidonsvoice on 19 Nov 2010, 08:40 pm

The latest research has shown that in addition to your mains, controlled directivity is also recommended for the surrounds (Toole, Geddes, etc...).

Josh if you could swing the bucks you will also consider Geddes' Harpers which is what I'll be using in my system (4 of them actually). If you want to control dispersion down to a low enough frequency that is audible, you need larger waveguides. Tiny waveguides, that are a bit bigger than a 1 inch tweeter, imho, are just a marketing tool. Good luck! You might want to also look at Hsu's HB-1 MkII. It's small and cheap. When your venue and budget gets bigger, spring for the Harpers.

Anand.

I have considered the Harpers. Unfortunately, the prices keep going up. That is more than I would like to spend on surrounds. I could DIY a pair of something similar but I have too many projects already.

JoshK · « **Reply #9 on:** 22 Nov 2010, 03:04 pm »

Quote from: raindance on 19 Nov 2010, 08:51 pm

I second the Hsu idea, it will sound better than most of the pro speakers as the pro speakers require a fair bit of EQ to get them flattish.

I don't necessarily believe that all pro speakers need EQ. I think that is an old myth.

raindance · « **Reply #10 on:** 22 Nov 2010, 03:20 pm »

You are welcome to believe whatever you choose to. I use pro speakers EVERY day and have a pretty good idea of what is what. For example, Tannoy Di8, one of my favorites, has a bump up in the vocal region to ensure high intelligibility for speech. Not necessarily desirable for hifi.

Charles Xavier · « **Reply #11 on:** 22 Nov 2010, 03:35 pm »

Abbey clone!Time for you to have another Rave!

JoshK · « **Reply #12 on:** 23 Nov 2010, 01:39 pm »

Quote from: Charles Xavier on 22 Nov 2010, 03:35 pm

Abbey clone!Time for you to have another Rave!

They need to be painted (no big deal) and they need for me to develope the crossover. I am probably going to start on the XO before the paint job. I am in need of a 4 channel amp actually.

JoshK · « **Reply #13 on:** 23 Nov 2010, 01:43 pm »

Actually, just remembered that my Onkyo receiver should work for a multi-channel amp.

JoshK · « **Reply #14 on:** 23 Nov 2010, 01:58 pm »

I've been playing around with box modeling, and I think I can make these small enough with sealed alignment to serve my purposes. Depth is a key dimension for me, so even some bookshelf monitors are too bulky there.

I have half the parts already, so its cost effective from that perspective. I just have to make the boxes. That isn't too bad as its the XO work that takes time.

Letitroll98 · « **Reply #15 on:** 24 Nov 2010, 04:57 am »

How about a quick word describing the aforementioned CD philosophy regarding multi-channel audio for an old guy who grew up with wide dispersion theory for muti-channel. I have a rudimentary understanding of CD theory for two channel audio, you could go from there. You don't have to explain every minute detail, I can surf for that, just the general idea. Thanx.

JoshK · « **Reply #16 on:** 24 Nov 2010, 02:08 pm »

Well, it basically evolves from the work of Toole (see his book) and Geddes. The idea is that the sound one hears is a lot more than just the directly radiated sound. The spectrum of all the reflections greatly influences the tonal balance.

It is not enough to have flat on axis response and actually that is less important. Its about the power response, or frequency response over the entire radiating angle of the speaker that matters since that is what is influencing all the in room sound.

One way to go about an even power response is omni-directional speakers. However, Toole and Geddes both argue against such. The reason is all the early reflections are destructive to the way we hear. Our hearing is quite apt at seperating late reflections from direct sound but not so well at seperating direct from early reflections. So the idea is to narrow the radiating angle and keep the power response smooth in that angle.

JoshK · « **Reply #17 on:** 24 Nov 2010, 02:18 pm »

Interestingly enough, Siegfried Linkwitz's Orions possess many of the same features albeit from a completely different design objective. Even the rear facing tweeter is an effort to balance the in room spectral balance of reflections.

JohnR · « **Reply #18 on:** 24 Nov 2010, 02:37 pm »

Linkwitz makes an interesting observation on dipole vs monopole - he listens to the monopoles closer, in order to get the same ratio of direct to reverberant sound: http://linkwitzlab.com/Pluto/intro.htm (diagram about halfway down).

Anyway - Josh, I don't think you specifically said, but will the surrounds be wall-mounted? (Mostly just curious)

JoshK · « **Reply #19 on:** 24 Nov 2010, 02:50 pm »

Yeah, I am looking to wall mount these speakers or atleast very near the walls with stands. So BSC will need to be modified accordingly.