Peerless 830875 in sealed box

ramiro77

Member
2010-06-07 3:09 am
Hello everyone. Recently, I built the enclosures for a pair of Peerless 830875, which are vented.
I was looking through the various threads of another web site, when I met a person who says these midwoofers Are Made for sealed box, and could provide a similar amount of bass than a vented box.
What do you think about that? The EBP for 830875 is 100, and I never saw it used in a sealed box.
I use subwoofers in my system, so I raise my doubts, since the ideal is to achieve the lowest group delay, but I also like the peerless deliver some bass...
 

infinia

Member
2005-05-15 9:51 am
SoCal
These drivers could be used for either, since its Qts is around 0.4. Remember using a passive crossover you must account for an increase in Q due to the resistive loss of a series inductor. Since you use a sub I would agree that a closed box mid bass allows easier integration with your sub response in a room, in turn giving more power handling for the mid bass with lower order filters. So in the end it comes down to the crossover design and final box tuning to acheive a given target response in your room.
 
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ramiro77

Member
2010-06-07 3:09 am
I use an active crossover. And I do not always use the subwoofers. So I wanted to know if they will deliver good bass despite achieving an F3 of around 80hz, but the slope is 12db, whereas in bass reflex is 24db...

Thank you for your prompt response. And happy holidays!
 

ramiro77

Member
2010-06-07 3:09 am
But with that you're referring to sealed or vented enclosures? I guess you're referring to vented. I wondered only if a sealed enclosure with an F3 of 80hz but with less roll off at low frequencies would give me good bass, even without using the subwoofer (you only have to be able to hear something from 55-60hz).
 

18Hurts

Member
2010-11-21 11:20 pm
Depends on what you define as "good bass"

For smallish woofers that will be driven full range, I prefer to use sealed since that helps prevent massive distortion under the tuned frequency. The roll off starts earlier but gently rolls down so can be "EQ'ed" a touch when used at low volumes.

Madisound has them listed as both--here is the sealed parameters:

Sealed box of 8 liters (0.28cf); F3 of 85Hz

A very small box for a 6.5 so if you are running a larger box, your F3 will continue to fall. The Fs for the Peerless is 48 Hz so pack that box with stuffing and see what happens. If you already have a ported box, plug the port and throw some acousti-stuff in the box and give it a listen.
 

ramiro77

Member
2010-06-07 3:09 am
With good bass I make reference to something that it accompanies. I do not looking for incredible low. Just something that allows me to enjoy, for example, a good jazz in a fairly decent way without an urgent need for a subwoofer. To me is enough that I can hear the range of 55-65Hz, but as I said before, without arriving at anything extreme. For something extreme, I have two 15 inch subwoofers in a sealed box.

In a sealed box of 8 liters, the F3 is 80hz, not 85hz. This is a detail, but everything counts :)
 
:snowman2: Hello,
I will jump in with an opinion.
Bass from a 6 ½ inch mid woofer will always be a compromise. Sealed has pros and cons.
Tuned reflex has pros and cons.
Just for grins here is a rule of thumb, tuned reflex tend to be double the size of sealed.
I prefer the cleaner sound of sealed. Add a real woofer if you want real bass.

Suggested box alignments:
Sealed box of 8 liters (0.28cf); F3 of 85Hz
Vented box of 12 liters (0.45cf); F3 of 53Hz; 2" port by 5.6" long.
From Madisound.com
DT
All just for fun!
 

ramiro77

Member
2010-06-07 3:09 am
@sreten: The enclosures I have now are bass reflex. I want to try a sealed enclosure for the reasons mentioned earlier, which left me very curious.

@DualTriode: I think the same way as you. I prefer the sound of sealed enclosures. And for that, I have two 15-inch subwoofers. But on the other hand, I like to use the Peerless, Without the Urgent Need for subs. As well I said before, I do not look good bass in them. Just looking for a bass that accompanies it. The only thing that interests me is that I can hear the range of 55-65Hz in a fairly decent way. It is not my intention to get more down in frequency with these monitors.
 
Hi,

F3 is not the issue, F6 and F10 matter far more in reality, and
optimising for these gives you a far better transient response.

This driver in small sealed will not have good bass, vented
done properly IMO will get down to 40Hz or so with a large
maximum SPL / lower distortion advantage, I cannot see
in this case sealed being preferable in any sensible sense.

rgds, sreten.

I've got nothing against sealed, but not these drivers without a sub.
Detuning your ports with a foam lining is by far IMO your best bet.
 
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@sreten: The enclosures I have now are bass reflex. I want to try a sealed enclosure for the reasons mentioned earlier, which left me very curious.

@DualTriode: I think the same way as you. I prefer the sound of sealed enclosures. And for that, I have two 15-inch subwoofers. But on the other hand, I like to use the Peerless, Without the Urgent Need for subs. As well I said before, I do not look good bass in them. Just looking for a bass that accompanies it. The only thing that interests me is that I can hear the range of 55-65Hz in a fairly decent way. It is not my intention to get more down in frequency with these monitors.

:snowman2: Hello,
I will jump in with more opinion.
It depends on time place and purpose. Mood music for the women in your life does not need chest pounding bass decibels.
Here is a thought: build the bass reflex boxes and provide the ability to blank off the ports for the times you may want to roll into the 15 inch bins.
Something you likely already have in mind is the “cabin effect”. Moderate to smallish rooms have the bass increase in real db’s due to the relationship between the wavelength and room size.
The Peerless may perform better than they appear on paper in the real space.
DT
All just for fun!
 

ramiro77

Member
2010-06-07 3:09 am
I like the idea of making a new bass reflex, with the possibility of plugging the ports. Could make about 13 liters, maybe a little less, to work well in both bass reflex and sealed when I plug in ports. To compensate for the decrease in size in bass reflex mode, I can try tuning the port at 50-53Hz. 40hz tune to me seems crazy, the group delay is very high.
 
I like the idea of making a new bass reflex, with the possibility of plugging the ports. Could make about 13 liters, maybe a little less, to work well in both bass reflex and sealed when I plug in ports. To compensate for the decrease in size in bass reflex mode, I can try tuning the port at 50-53Hz. 40hz tune to me seems crazy, the group delay is very high.

:snowman2: Hello,
The Madisound bass-reflex recommendation tuned to 53 Hz is 12 L.
I was thinking more of a cap (rather than a plug) with 2 to 4, ¼-20 cap screws with a T-nut like this pressed in the inside of the box.
T Nuts, Insert Nuts, Propell Nuts, Weld Nuts
DT
All just for fun!
 
With good bass I make reference to something that it accompanies. I do not looking for incredible low. Just something that allows me to enjoy, for example, a good jazz in a fairly decent way without an urgent need for a subwoofer. To me is enough that I can hear the range of 55-65Hz, but as I said before, without arriving at anything extreme. For something extreme, I have two 15 inch subwoofers in a sealed box.

In a sealed box of 8 liters, the F3 is 80hz, not 85hz. This is a detail, but everything counts :)

personally, i wouldnt be scared to use them in a sealed box. after many years of messing with both sealed and vented systems, i have come full circle and once again i prefer the small sacrifice in 'maximally flat' bass extension of a vented design to obtain the smoother, and transiently better response that a closed box will produce. room gain and the fact i listen within about 10ft mostly, means that often the result is better than the vented boxes i have. id even go as far to say that a low Qb (sub 0.707) sealed box can be even better, and ultimately flatter, when room gain is factored in. group delay on bass is noticable in many vented systems, and until recently i was sceptical about its audibilty. all these things combined with the fact you will sometimes be using a sub, makes me think that closed is definitly the way to go. ive often found jazzy drums and double bass sound far better, although less 'full' when i used the same driver in 'optimal' boxes both vented and sealed for comparison. and this is using the visaton AL130 which also has a very high EBP(pointing to a vented design) but the qts of 0.4ish means its a little more versatile. group delay in WinISD is cut from about 15ms to less than 6. ive also tried this with a old pair of audax ap130zo, with slightly less impressive results. the Fs of the audax is about 58hz thought, and the EBP way over 100 if i recall correctly.

i hope that maybe this is of some help
 
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40Hz tune to me seems crazy, the group delay is very high.

Hi,

Tuning it wrong for the wrong reasons IMO is not a good idea at all.
The tuning is perfectly sensible to me. The group delay is inevitable
and FWIW superior to the higher tuning interpreted correctly, as
are the other parameters except for maximum F3 bass extension.

rgds, sreten.

This driver IMO does not suit sealed well for full range, no subs.
Suggested alignment is quasi-first order rolloff for room matching.
 
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