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.

[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

[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.

[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.

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

[kiirojbl]

I like classical music, especially orchestras, so I like speakers that can make dynamic expressions in a wide range.
This Remodeling Altec System meets this demand with an 18 inch woofer and ALTEC MR94 Large Format Horn and 291-16K.

The 828B cabinet is divided into upper and lower chambers by a partition plate.
The lower chamber containing the PEAVEY LOMAX 18 inch woofer has a capacity of 8.0 cubic feet/225 L.
The enclosure volume recommended by PEAVEY are 4.0cf a small volume enclosure (44Hz/-3dB), 6.0cf a medium volume enclosure (37Hz/-3dB), 8.0cf a large volume enclosure (31Hz/-3dB).
Therefore, the volume of this lower chamber is ideal for this woofer unit.
The vent dimensions are 4.7inch/12cm x 5.5inch/14cm for the opening and 11inch/28cm for the length.

This Remodeling Altec System succeeded in efficiently storing an 18 inch killer woofer.
And this system with excellent space factor is a very compact system for me.



One of my other systems is Yellow Horn System which driven by 8 way multi amp system.



My other system is DIY Horn System which driven by 7 way multi amp system.



These systems are also controlled using Behringer DCX2496 and DEQ2496.



This Remodeling Altec System is a very small system compared to the Yellow Horn System and the DIY Horn System, but I like it because it sounds great despite being compact.

[Mr. Widget]

Pretty spectacular looking systems! Not sure they would fit in very many homes, but it looks like you’ve made them work.


Widget

[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:



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