Best midrange for intelligibility of voice - Page 18 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 26th April 2005, 05:04 AM   #171
azrix is offline azrix  United States
diyAudio Member
 
Join Date: Oct 2004
Quote:
Originally posted by ucla88

Well, I happen to live in one of those houses you describe. A rather large family room, ~33x25 with high ceilings, open to other rooms with vaulted ceilings, lots of glass.

Nonetheless, the RT60 in my room is pretty average. I can't recall the exact number offhand, but it was fairly typical.

The reality is reverb is not usually a problem. The rooms just aren't that big. It doesn't matter how reflective the walls, celing and floor is, the echos just won't be delayed enough.

Now floor bounce and room modes may be a problem, but just a little bit, since these will start to be less of an issue over 400 hz.

The best thing to do is to measure RT60. If it's average for a small to medium room, then the room is fine as far as voice intelligibility goes. If the room is a bit live, sure, some overstuffed chairs, pillows, throw rugs etc.
Well, it's the wood flooring that's the issue here. Every room like yours that I've been in that has wood floors has problems with speech intelligibility above or below a narrow volume level, from a person or a stereo or TV. Normal carpet, in particular the padding under the carpet, does a lot to help with this problem. It's when you have every surface in your room that's reflecting sound that there's a problem. Your reverb time in the midrange goes way up and you begin to have masking effects. Sound diffusion can help some, but that usually has about the same size/space requirements as absorbtion. Also, with wood flooring, any extra noise inside the room can also play havoc on intelligibility, such as someone just walking through the room (sound from foot falls and the wood creaking underneath) or central heat/air. Rugs will not help with all of this as much as just carpeting the room but they can help. Not to say that carpeting is a fix-all, just that I think, for most homes, it fixes the most problems with the least effort/invasiveness.

Quote:
Originally posted by rick57
> it seems control of the lower frequencies provides the best results

Other than in the crossover, is there anything you do to the room?
Rigid fiberglass absorbers are the most efficient here. Owens Corning 703 and 705 (or equivalent) covered in fabric works wonders. The 703 will also work great as a mid/high absorber. http://www.ethanwiner.com/acoustics.html is a great article about all of this, though it's more focused on studio and not home acoustics. That site also has plans for absorbers using rigid fiberglass.

Quote:
Originally posted by rick57
But this problem: your suggestions have clarified that it’s not the room.
Well, it could still be the room. My suggestions were just the easiest and most aesthetically pleasing ones I could think of. Based on what you had written previously, the room sounded like the most likely culprit for your problem. If you could talk your SO into cloth covered panels, which can be made to match your decor, you can have much better acoustics by building some fiberglass absorbers that I mentioned above and placing them in the right spots. If your new speaker doesn't fix your problem, then you might give them a shot.

Quote:
Originally posted by rick57 I'm keen to get a new speaker, in fact the Jordan 92 is calling me like a siren. If it doesn't help I can find a good home for it.
Well, far be it from me to keep anyone away from new toys.

Ben.
  Reply With Quote
Old 26th April 2005, 05:19 AM   #172
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by azrix
Well, it's the wood flooring that's the issue here. Every room like yours that I've been in that has wood floors has problems with speech intelligibility
My room must be a counter example -- douglas fir -- no carpets (due to dust mite allergies). The room is a bit bright but mo intelligibility problems -- and further ther is a parade of speakers thru here (Dynaco A50s at the moment, but back to the $7 open baffles as soon as i can get the next round of tweaks done.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 26th April 2005, 09:48 AM   #173
rjb is offline rjb  New Zealand
diyAudio Member
 
Join Date: Jun 2004
Location: Piha
Default Room effects

Rick- The room treatment suggested in various posts above, such as full and heavy pile carpeting with thick underlay, absorbent panels on walls and ceiling etc certainly work in some situations- as will breaking up the room by freestanding walls. This is what I meant by extreme modification.

The other point I did not make clear was that our room is effectively sealed. Any significant opening will change results noticably. It is not just a matter of reflective surfaces bouncing the sound around, (although this can be noticeable in some situations too). We can open a full third of one long wall, and the intelligability improves considerably. This still leaves the floor-ceiling effect though, (with a significant boost around 150 hz) and is not a full cure.

Size of room also changes things. my wife has just been in a smaller but similarly constructed room, about two thirds the volume, and intelligability was worse. Rooms much smaller do seem better however, probably because the furnishings typically form a larger percentage of absorbent surfaces and volume.

Treating a room for best sound requires individual tayloring, and trial and error. Various textbooks can only give a general guide. Other living priorities made this approach unaccepatable for us. However, despite my earlier comment that scattering a few rugs around is virtually useless, we will be doing a little of that.

Re headphones, the cordless type are convenient, (we use cheap RF FM), but the quality is not adequate for serious listening to music. But as discussed music seems to survive much better than speech.

Re speakers, I have done considerable experimentation, with various size/type of cones, even hauling out some old Jordan Watts. As a result I am doing much as you propose, ribbon tweeter, dual Seas L12s, both mounted at ear level in very thin towers. Seperate twin Al sealed subs, probably Dayton 7 inchers. Active, with adjustable filters on both mid and bass. I expect to have to experiment a lot for best results, In particular the subs may have to be fixed in location, and the electronics adjusted to suit. (If they move, the compensation would then be all wrong.). The towers are more flexible in location.

All the electronics will be internal to the speakers.

I have some reservations re chip amps, although my Linn Klassic seems OK with the current speakers on it. I tend to agree with some of the ideas expressed by Graham Mainyard that amplifier measurement is not the full story, and "first-cycle" and speaker loading effects can be significant. I would like to use all LJH type amps, but heat would certainly be a major problem, and power insufficient for the bass I suspect. Hence my interest in trying class D, but those I have heard so far in commercial gear have not been up to the standard of best convenional amps.

As a result of work by Zaph and others (including MarkMk), I was temped to try 4 Aura 3"s or BS3's in an even thinner tower, but could not get as good a simulation with the particular external appearance I was aiming for.
  Reply With Quote
Old 26th April 2005, 11:37 AM   #174
diyAudio Member
 
Join Date: Dec 2002
Location: dry ol Melbourne Australia
Rob

> speech clarity requires lower reverberation times than music

Ah, haah I see.

> How does the off axis drop of a full range compare with a horn ?

I thought a horn gave more concentrated ie more sound within its flare range eg 90* 40, but less outside that. Is that incorrect?

DSP_Geek

> Hearing loss tends to occur on a band centered around 4 kHz, not surprising since the ear is most sensitive there, and that's where most transient energy lives.

Hearing loss Hz is different to the most critical Hz for discerning consonants ie voice intelligibility.

ucla88

> measure RT60.

I believe I’d need to buy & use eg ETF US $ 150.

> If it's average . . then the room is fine as far as voice intelligibility goes

Then the only avenues are better speakers/ headphones/ better amp/ HT processor.

Ben

> Owens Corning 703 and 705 (or equivalent) covered in fabric works wonders.

In the table at http://www.ethanwiner.com/acoustics.html, “Typical Acoustic foam” performs similar to the 703 from 1000 – 4000 Hz! I’d have to check that the right spots acoustically are also acceptable to the resident décor expert.

Dave

> My room must be a counter example

to every “rule” there is an exception . . or maybe you have golden ears

rjb

> Any significant opening will change results noticably. . . We can open a full third of one long wall, and the intelligability improves considerably. This still leaves the floor-ceiling effect though.

My room is 75% open on side, which further emphasises that the room is probably not the main culprit.

You weren’t suggesting that cordless headphones are adequate for speech?

> Re speakers . . adjustable filters on both mid and bass.

Great idea!

> I expect to have to experiment a lot for best results

. . the way of the world

> amplifier measurement is not the full story, and "first-cycle" and speaker loading effects can be significant.

Agree.

> work by Zaph and others (including MarkMk) . . 4 Aura 3"s or BS3's

I’ll have to check it out Preliminary HIVI B3S design

Cheers!
  Reply With Quote
Old 26th April 2005, 06:17 PM   #175
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by rick57
> My room must be a counter example

to every “rule” there is an exception . . or maybe you have golden ears
not golden, but trained... which should make things worse. The room thou was designed with hifi in mind, and sounds pretty good.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 26th April 2005, 07:52 PM   #176
diyAudio Member
 
RobWells's Avatar
 
Join Date: Aug 2002
Location: UK
Rick,

Chapter 3 of the sound system design manual here:

http://www.jblpro.com/pages/tech_lib.htm

Will give you more info than I ever can.

Also theres a couple of papers on speech intelligibility there aswell ( haven't read them yet)

Cheers,

Rob
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Single Voice Coil Vs Double Voice Coil Subwoofer Workhorse Car Audio 6 12th April 2007 06:36 AM
Driver (speaker) for voice intelligibility mefistofelez Multi-Way 3 16th August 2006 06:22 PM
Where can I buy mission 782 midrange voice coil ? ANALOG GUY Multi-Way 3 30th July 2006 10:17 PM
Want to buy mission 782 midrange voice coil ANALOG GUY Swap Meet 0 30th July 2006 05:40 AM


New To Site? Need Help?

All times are GMT. The time now is 11:11 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2