Apogee Diva with Infinite Baffle

[rugyboogie]

Have been building our retirement home on an Island that is off grid and boat access only.
Background on build.
The home will be powered by PV and MH. Heat is hydronic via Solar and a Wood Burning Gasification fireplace with a water jacket. No fossil fuels required for our home.
The home has a dedicated music room which has the following dimensions W16'x H10' x L24'.
Learned from experience after building my existing home music room that I build 18 years ago and also from ones that I have build for my clients. I'm a GC.
Retirement home music room walls are 8" cast concrete, floor is suspended concrete 8" and also sog . Ceiling is 5" x12" fir beams with solid 3" t&g fir timber. Will be purchasing a pair of Apogee Diva's from True Sound Works.
Want to help out the the lower end of the Divas with an infinite baffle subwoofer.
The Divas will probably be 3-5 ft from the front wall, three comfy chairs for listening.
So my questions are :
1. Is an infinite baffle a good fit with the Divas ?
2. With an infinite baffle should the opening be near my sitting position ?
3. In front or behind me ?
4. Forget about IB and go for a different sub, Funk, JL, Seaton, Paradign.....
Opinions thoughts and comments are welcomed.

 

[christoph]

Hi rugyboogie

Your project sounds like heaven to me

I also like your dimensions (4.9m x 3m x 7.3m) for the dedicated Audio room, not too big and not too small, and with a very nice room hight. IMHO just right.

Are you sure you will need subwoofers with the big Apogee?
The big Apogees go easily down into the very low 20Hz. I rather see integration problems with the Subs to the Apogees, apart from my opinion that big Apogees don't need subwoofers anyways

3ft out is rather too close to the front wall, while 5ft are a good starting point. You will have to find the sweet spot trying.

I would start without any Subs at all and see if you really miss something.
I'm very confident you won't miss deep bass from the Apogees alone.

Is the Diva set in stone or can you also imagine a pair of Apogee FullRanges or Scintillas?
With what amplification do you plan to drive the Apogees?

Let the discussion begin

 

[bonzo75]

Nice. In your place subs are the last thing I would worry about for now. The two main things are:

1. Placement. Three feet sounds too less, minimum 5, but you also need to try that strategy of putting them 33 to 40 percent in, documented by that Texas apogee full range dude Gallantdiva and also linked to and clarified on by thekong in my apogee full range thread.

2. Amps. You will get varying recommendations. You will need to seriously amp roll to get this right. I would biamp with powerful SS amps

Your analog with kodo beat, Garrard, etc is great

You should consult thekong as well as he has full ranges in a similar, slightly bigger room

 

[tmallin]

Several things:

1. If it's not too late to change your construction specs, you should do away with the plans for concrete walls and floor and stiff timber ceiling. I struggled for 20 years in a basement "concrete bunker" room. What many (including me at the time I built it) don't realize is that even with the "right" dimensions, making the room surfaces "stiff" accents the room's bass modes, creating large-in-magnitude sharp (high Q) peaks and dips in the bass response. Even with dipole speakers like the Apogee, you likely will need electronic equalization to tame the peaks and dips in such a room. Certainly the range covered by the subs will need equalization.

What you want is actually a "bass leaky" room, one with surfaces which flex a good bit in response to bass. Think thin drywall, wood paneling sheets, and suspended hardwood floors which have noticeable "give" to them. This will spread out (i.e., lower the Q) of the the peaks and dips in the bass response, as well as decrease the magnitude of the peaks and dips. Smoother bass, in other words.

2. For dipole speakers, if your room is large enough, there should be a minimum of seven feet between the back of the speaker and the wall behind the speakers. You need that much distance to delay hearing the back wave of the speakers enough to have the back wave just add spaciousness to the sound rather than cause smearing of the direct sound. This is a common error of those who use dipole speakers. It is the #1 reason why most dipoles are said to require a lot of space around them. Proximity to side walls is not an issue, but proximity to the wall behind the speaker is a huge issue in terms of getting the to sound maximally pleasing and open. Your 24-foot dimension is large enough; I suggest starting with the speakers 8 feet from the wall behind them, you sitting 8 feet in front of them, and having 8 feet behind you to the wall behind the listening seat. The Rule of Thirds makes a lot of sense with dipole speakers because this arrangement puts the backwave in phase with the front wave as heard from the listening seat.

3. An infinite baffle subwoofer has no opening in the box. It is a large sealed box which exerts minimal back pressure on the interior side of the bass driver. Historically, for example, the KLH Model 12 speaker was an infinite baffle, while the AR-3a, having much smaller sealed boxes creating significant back-pressure against the interior side of the bass driver, was classified as acoustic suspension.

 

[Zero000]

I've always thought a suspended hardwood floor is a massive no, and having lived with one for ten years, they just end up acting as an uncontrolled subwoofer. Dreadful, I thought, really, even with substantial carpet and underlay on top of it.

The floor was one inch thick solid hardwood made in 1928, on huge super thick and deep rafters. They don't make them like they used to.

I would be very wary of the crossovers, and work with Rich to make sure they work in your room. Use a test mic and find out the frequency response at the listening position. Use digital PEQ to trial out various FRs you think you might like, and make crossover mods to try and get close to it using a software crossover simulator if you or Rich can.

This is not a quick process. You have to make sure it is acceptable over a wide range of music. This is a tough call, as Apogees sound very different depending on the source you feed it with. What sounds too bright with one track will sound too dull with another etc. You need to find that happy compromise.

Whilst doing this, use cheap crossover parts. When you think you have it right, use very expensive ones

Getting the crossover right in room is more important than the room itself. Don't let anyone kid you otherwise. Unless the room is an absolute disaster.

 

[spiritofmusic]

Tmallin, that's fascinating. My dedicated room is within the roof space of an 1861 Victorian chapel, with a certain level of flex in the original timber floor w new ply overlay, overall span 50x35, and a certain amount of give in the eaves. Indeed the only structures that are inert are the 2" steels, 7 of them at 7' centres.

 

[rugyboogie]

Being on an Island and not having any form of a fire response we elected to build entirely out of concrete. Walls, floors, roof along with roof overhangs, stairs etc all concrete.
This year here in BC we had 566 wildfires and over 25000 people were evacuated.
Our Island has 110 people, low priority.
So concrete it was. Also no maintenance equals more time to do the things that I want to do, music, travel, explore and spending time with family & friends.

The concrete interior wall which have hydronic heat in them have been cast.
The floors haven't been poured but shoring, rebar and knock outs are in place.
Drywall is no go because of potential mold issue if the heating system should fail.
Have isolated the front sog from the walls and the suspended slab in order to isolate it from the rest of the slabs.


Not needing a subwoofer would be ideal, but.
If I were to install an infinite baffle I would use 4 x 15 or 18" drivers. Install in the crawl space and have the opening / vent in the concrete floor.
Otherwise install in the vent and speakers in the ceiling. That is why I ask re position of the vent for the IB.
Thank you all for giving me an idea of placement of speakers from front wall.
This allows me to figure out lighting better.

User 211
Great idea on the crossovers using lesser parts to get me close. Will be speaking to Rich on this on Monday.

Tmallin Thanks for your informative input. Good to know about the rule of thirds to get me started.

In music rooms that we have build for clients when using wood frame we always stiffened the walls by using 3/4" t&g plywood and gluing and screwing to the studs.
Then when installing the drywall we would always make sure that the four wall would have different thickness of drywall. This way the walls don't all vibrate at the same frequency
Eg
front 2x 5/8",
back 5/8"+1/2 "
Left wall 2x1/2"
Right wall 5/8"+1/4"
Ceiling 5/8"
Have the drywall boarder apply drywall mud with a v notch trowel over the whole wall before applying the second sheet. Then use rubber mallet to hammer against a 2x4 to ensure proper bond between layers, no air pockets.
This has worked extremely well and clients have always been satisfied.


Bonzo
Have reached out to thekong as per your suggestion. He shared really informative info. Lot's of reading ahead for me.

Christoph
Amplifiers that I'm contemplating are
Pass, Lamm, Ayre, Coda, Krell, Boulder, Accuphase...
Will also consider a D amp. Haven't heard any yet

Thanks to all for your help.

Mike

 

[BruceD]

I have a friend about to take delivery of a fully rebuilt pair of Divas--he will be using the big 400W AYON Monos--I'll report how they fare--upon my summons to his inner sanctum

BruceD

 

[bonzo75]

Already tried those big Ayon Orthos XS (I bought them and shipped them to Justin to try on his Duettas). While they had more tone than Parasound, the Parasound clrearly woke up the Duettas more. Also heard the AR 250SE with Divas. These kind of things just don't work. Get a good, class A SS

 

[Zero000]

Already tried those big Ayon Orthos XS (I bought them and shipped them to Justin to try on his Duettas). While they had more tone than Parasound, the Parasound clrearly woke up the Duettas more. Also heard the AR 250SE with Divas. These kind of things just don't work. Get a good, class A SS

This is true and the cheap Parasound is amazing with a valve pre in terms of what it can do for the money.

But I disagree, really. I think a good solid state and a good valve option is really worth having to just flick between at will. What one will do the other won't and vice versa.

 

[bonzo75]

This is true and the cheap Parasound is amazing with a valve pre in terms of what it can do for the money.

But I disagree, really. I think a good solid state and a good valve option is really worth having to just flick between at will. What one will do the other won't and vice versa.

My point was to get a good SS that will do both. These push pull valves are alright but having heard Aaron and AR 250SE not really made for apogees.

 

[rugyboogie]

Have always enjoyed SS amps with a tube pre.
Had the ML 33 and 33h with my Cat SL-1.
Good to hear that Parasound could work. Are you talking about the JC-1 ?

 

[Zero000]

No the A21. JC1 monos would probably be better, I would be surprised if not.

I sold my A21 and actually use 211 based valve monoblocks. I also have some powerful Accuphase monoblocks but I have tried many solid state amps at various price points and I always end up using those 211 based monoblocks more than any other amp(s).

It is easy to understand Ked's viewpoint but he hasn't lived with Apogees for years on end. He has heard a lot more Apogee models in short listening sessions than I ever will, though.

Just try a few options s and see what you like best. No better way.

 

[bonzo75]

Sorry, those accuphase and those para sound are not good enough SS. The point with living with only one's system and not listening to others is the issue here. You had a chance to listen to one quality apogee yesterday and you blew that. You have to have good quality SS. Not para sound, not 50 year old accuphase that you get for 2k today.

 

[christoph]

You had a chance to listen to one quality apogee yesterday

Please elaborate...

 

[bonzo75]

Please elaborate...

He was in Amsterdam

 

[christoph]

He was in Amsterdam

Pity

 

[Zero000]

Sorry, those accuphase and those para sound are not good enough SS. The point with living with only one's system and not listening to others is the issue here. You had a chance to listen to one quality apogee yesterday and you blew that. You have to have good quality SS. Not para sound, not 50 year old accuphase that you get for 2k today.

Oh FFS Kedar how many times do we need to have this BS conversation?

I have had £30K worth of Rowlands on them. Not better than the 211s.

Your £20K Ayons. Nice. Not better than the 211s.

Countless other amps. Many documented on the web. Not better than the 211s.

Are you spotting a theme between your bullshit?

Find me a decent solid state amp.

£12K Merrill monos. Dreadful. Need I go on?

 

[Zero000]

A.Luxman might be better than most. Anyone wanna bring one round?

 

[spiritofmusic]

Justin, as you know I heard yr 211 amps on the Duettas. They truly sang. Now, whether they would in another room, esp a larger one, maybe, maybe not. But in yr personal situation, the sound wanted for v little.