Altec voix du Theatre A7/A5 anybody done this?

[hifiapart]

Hi,
Anybody done anything like this to "raise the lower bass output..."?

If so feedback would be appreciated.
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[Ruediger]

I do not understand what You gain.

ruediger

[Lee in Montreal]

I do not understand what You gain.

Me neither. And I don't understand what was the goal of this modification. I have listened to instrumental music (jazz and blues) on A7 speakers and they sound very natural. With the mods done as shown above, the volume for the the original drivers was reduced by at least 75%, and the volume for the added driver is most likely not enough. In both cases it has raised even more the Q of the cabinets. Raising the enclosure's frequency, which is what you were trying to lower...

My suggestion is to get back to the original design and simply use one proper driver. Be it an Altec or JBL. You'll get a tight bass. if you want deep, then simply buy two subwoofers.

[Altec Best]

Me neither. And I don't understand what was the goal of this modification. I have listened to instrumental music (jazz and blues) on A7 speakers and they sound very natural. With the mods done as shown above, the volume for the the original drivers was reduced by at least 75%, and the volume for the added driver is most likely not enough. In both cases it has raised even more the Q of the cabinets. Raising the enclosure's frequency, which is what you were trying to lower...

My suggestion is to get back to the original design and simply use one proper driver. Be it an Altec or JBL. You'll get a tight bass. if you want deep, then simply buy two subwoofers.

+2 , You should just built sub boxes for the 18"s I think you are trying to get as much output from the same area of floor space.There really is no Free Lunches so to speak in speaker design.Those cabinets need to be twice as big now that you have dual woofers.The woofers can't share the same amount of volume,they need their own,(double)minimum. ;)

I agree with Lee !!

[hifiapart]

Well i have not done this but was considering.....guess it seems like the wrong idea...

[Lee in Montreal]

Last winter I listened to some blues and african drums on a pair of A7 in a medium size room. Source was vinyl, powered by a lamp amp. A single horn for mids and high. Damn it sounded natural. Sure it didn't have the low end extension, but such extension never existed when these cabs, drivers and music were created.

The ideal set-up would be to have a set of A7 at the front, and two subs behind you. That will fill the room gently. Your will hear the tight contrabass strings and drum skins from the front, while your body will feel the infra bass from behind or "somewhere". The best of both worlds :D

[hifiapart]

Lee,
What recommendation for subs?
I have valve amps, 300hz horn (cut at 500hz) and tweeter.
Thanks for idea(s)
Tim

[Lee in Montreal]

Hi Tim

If you already have the A7, most likely you already know they don't have "much" below 50Hz. Perhaps you can build a pair of subs for the 20Hz-60Hz area. Basically, the subs will only add the physical enveloppe to the music. There are hundreds of off-the-shelf subs available out there. But if you have a set of A7, perhaps your intention is to "keep it in the family" by using JBL drivers... ;)

What about subs built around a set of 2245h? You can probably drive them with subwoofer amplifier plates with their own crossovers.

[hifiapart]

Lee,
Had vot boxes moved to omken 360 hread some vot boxes at a friends place, going back to vot......the onken goes lower but remains dry "mat" and in the end does not entertain the way the vot does.

But i moved from the vot because of bass.

Will look at some subs.....even if i like less is more!

Tim

[Altec Best]

If you already have the A7, most likely you already know they don't have "much" below 50Hz.

Yes due to the port being too big.In Movie Theaters that was fine.With a few tweaks you can get the A-7 down near the 30-35 Hz range with a pair of 416's in them.If your running 515's you can still get them lower but not as much.There is a thread at the Altec userboard that Panomaniac started.He made several tweaks to the crossovers & box and got his down a lot lower.For one the port is too big to acheive a lower tuning.His thread is " My A7-500s. A journey " , if you can get the A-7 down near 30-35 Hz no sub will be needed IMHO ! There isn't much music below that (30HZ) anyway except for the occasional pipe organ notes and stuff like that. ;)

Smaller ports and adding length of 3" to those ports a long with XO tweaks will acheive a lower tuning is what he did IIRC.

[Lee in Montreal]

Smaller ports and adding length of 3" to those ports a long with XO tweaks will acheive a lower tuning is what he did IIRC.

;););););););)

This empty pair has removeable front panels, and is for sale locally for $250/pair. I am tempted. I think it is the proper way to make an A7 go lower. Simply tune the BR port to according frequency.

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[hifiapart]

:applaud::applaud::applaud::applaud::applaud::appl aud:

Wow seems as if you are motivated.....at that price go for it if you have the drivers....

[Eaulive]

;););););););)

This empty pair has removeable front panels, and is for sale locally for $250/pair. I am tempted. I think it is the proper way to make an A7 go lower. Simply tune the BR port to according frequency.

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You went to see Joseph again?
Nope, not his floor :D

[Lee in Montreal]

You went to see Joseph again?
Nope, not his floor :D

Nop. That set of A7 is in Sherbrooke.

[Wardsweb]

Here is one of my old systems. The A7's are veneered in walnut with solid walnut bases. They are sitting on BassMaxx B1 sub horns fitted with 18" McCauley 6174 drivers. This system could literally vibrate your bones.

51003

[Lee in Montreal]

With all that bass, I am surpised the plants still have leaves on them... :eek:

[reVintage]

The idea is not all bad. Everyone knows the A7 has too big volume and also suffers from shelving as all hornreflexes do when forced to go low. But it is still recommended to keep it as hornreflex, now with correct volume and ports. Take a look at the 816 below that doesn´t play bad at all.

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The system needs to be biamped as the bass driver will have a lot lower sensitivity. The crossoverpoint should also be choosen above the point where shelving sets in.

[JBL 4645]

With all that bass, I am surpised the plants still have leaves on them... :eek:

It’s also a bad idea to put plants above electronics that need watering!

[Altec Best]

Everyone knows the A7 has too big volume


I disagree you can never have enough volume,it is the port that is too big.



Take a look at the 816 below that doesn´t play bad at all.




Agreed, But the 816 won't go below 80-100 Hz so it lacks the deep bass IMO.A couple 816's stacked 2 per side would be better. :bouncy:

[reVintage]

Agreed, But the 816 won't go below 80-100 Hz so it lacks the deep bass IMO.A couple 816's stacked 2 per side would be better. :bouncy:Hey, didn´you read the whole post/thread??

Once again: A smaller box, still hornreflex, on the horn(Yes, it is ment go 80-100Hz) and a biamped sub (BR?) below.

Unfortunately the A7 horn has a very uneven respons so it should also(easy fix;)) be reworked.



I disagree you can never have enough volume,it is the port that is too big.Unfortunately this isn´t true. The box is still to big but the smaller port helps a lot.

About choosing box volume, whether Vb in a horn, BR or closed, there are many good books out there to read.

About the shelving I mentioned before, it takes place at maybe 150-200Hz where the response below this will be 4-6dB lower. EQ?

The optimal volume for 416-8A in an Onken is 220dm3. With a port length of 2cm(3/4") the portarea will be 100cm2.

But 515 is probably more appropiate here.

[theophile]

It’s also a bad idea to put plants above electronics that need watering!

Thus,if your electronics don't need watering,the plants will be fine where they are? ;)

[DjSoundMan]

I'm not shure about a kind of project to add an other speaker in A5/A7 cabinets, first because the magnets are not in the same axe and can cause delay between each drivers. This is only for the reach of more power but bass doesn't work only by adding speakers..

when drivers are not in the same axe and alligned with others, the delay is not good for the quality of reproduction and also can cancel bass frenquencies

--- I have a A7 pair for sale, they are not perfect, comes with JBL drivers (i don't know wich model) but realy clean, they are few littles differences between both but it's sounds realy good and perfect for a project. I don't have horn, only de boxes.. 150$ for the boxes and 300$ with JBL drivers. Montreal Canada ---

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[eso]

I've had my old A5s for over 10 years now and after many early attempts to improve them I realized they are at their best with just a few modifications to tighten up the cabinet.

The components are all early '50s vintage: 515b, 288b, 1005A (Original tar-filled). I found this on the old Altec users board and pretty much followed what is says:

http://dl.dropbox.com/u/4500648/Audio/smallVOT.pdf.

I did block off the midbass horn flares and sand-filled them: lots of added weight but really clearing up the 100-500Hz range. That volume is not needed for the bass response and the flimsy construction of the horn has always been a source of noise.

Gluing and screwing a bunch of 2X4 and 2x2 bracing to the inside of the cabinets does wonders to tighten up the bass they do produce. Resizing the vent to 100 sq/in and making sure the front panel there is sufficiently stiffened up will give crisp response to 40-45Hz with the 515.

They live in my shop and spend most of their time being fed by my iPod or streams through my iPhone:

http://dl.dropbox.com/u/4500648/Shop/Flying%20A5s.jpg

While they will never be the last word in inner detail or frequency extension, they are one of the most relaxed and natural sounding systems ever.

eso