A first design thoughts/recomendations.

[ahaik]

I have been lurking here fo a couple of years now and would like to learn to design too. PE has some peerless and Vifa drivers on sale and I have been reading good things about them over at the PE board. In general I know that poly and paper cones are easier to work with due to the self damping properties of the cone.
I don't have any measurement equipment yet, but planning to purchase in the future.
My plan is for a 2 way system.
Would like to get some opinions about these:

Woofers:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-127

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-250

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-252

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-126

I tend towards the 6.5" HDS.

Tweeters:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-578%20%20%20%20%20%20%20%20&FTR=dx25&CFID=7847773&CFTOKEN=85706323

http://www.parts-express.com/wizards/searchResults.cfm?FTR=vifa+tweeter&search_type=main&WebPage_ID=3&searchFilter=vifa+tweeter

http://www.parts-express.com/wizards/searchResults.cfm?searchFilter=VIFA+TWEETER&srchExt=&perPage=9&sortBy=1&layout=grid&page=2&srchPrice=&srchCat=&srchMfg=&srchPromo=

Questions/help:
I would like to design an MTM, would an MT be much easier?
Any input/suggestions on driver selection would be great.

This will be a slow process for me (since my life is very bussy at the moment), but I rather do it slowly then delay it for a couple of years.

Thanks,
Asi.

[ThomasW]

Use the 830875 midwoofers (get them quickly before they sell out) then buy Seas 27TBFCG tweeters, no the tweeters aren't on sale nor are they sold by PE

MTM or MT depends on the room and how loud/low you want the system to play

[Face]

Peerless 830875 HDS 6.5" Woofer
Sku 299-127: Out of Stock -
Awaiting updated due date

[HareBrained]

The 873 (HDS 5.25") will play as low as the 6.5", which is to say "not very", is cheaper, likes a much smaller box, and are in stock. The BC25 tweeters are an excellent value. They're the soft dome version of the DQ25 tweeter Zaph used in the ZMV5 and I used in my MTM. There are better tweeters but they'll be at least 5x the price and the difference may not be more than marginal. The XT25 is a nice choice. I don't see an advantage to the DX25. The aforementioned Seas is nice too. You just need to decide if the extra cost is worth it.

[ahaik]

Use the 830875 midwoofers (get them quickly before they sell out) then buy Seas 27TBFCG tweeters, no the tweeters aren't on sale nor are they sold by PE

MTM or MT depends on the room and how loud/low you want the system to play

These are nice, I have the soft dome version in my Modula MT and my brothers Modula MTM are using them.
And I just remembered that I have a a pair of 27TFFNC/G in storage. I remember a discussion about them a while back, CJD was thinking of a design using them.

The 873 (HDS 5.25") will play as low as the 6.5", which is to say "not very", is cheaper, likes a much smaller box, and are in stock. The BC25 tweeters are an excellent value. They're the soft dome version of the DQ25 tweeter Zaph used in the ZMV5 and I used in my MTM. There are better tweeters but they'll be at least 5x the price and the difference may not be more than marginal. The XT25 is a nice choice. I don't see an advantage to the DX25. The aforementioned Seas is nice too. You just need to decide if the extra cost is worth it.

It will also be nice to have higher sensitivity since I'm using an F5 Pass clone (27 Watts @ 8ohms). Using one of these tweeters and the peerless woofers in an MTM configuration I should be able to get 90+, correct?
I would like to have the extra cone surface, will model both woofers to get an idea of box size needed.

Peerless 830875 HDS 6.5" Woofer
Sku 299-127: Out of Stock -
Awaiting updated due date

I was hoping to get them before they run out. I'll give PE a call later to see how long untill they have them back in stock.

Edit: I called PE and the 6.5" HDS woofers should be comming in any day.

Thanks everyone,
Asi.

[ThomasW]

Edit: I called PE and the 6.5" HDS woofers should be comming in any day.

I think that's in error. When I spoke with them the beginning of last week I was told what they had in stock was it, there would be no more...

If you look at the link now it says "No longer available"

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-127

[ahaik]

I think that's in error. When I spoke with them the beginning of last week I was told what they had in stock was it, there would be no more...

If you look at the link now it says "No longer available"
http://www.parts-express.com/pe/show...number=299-127

I called again and it was an error, they are no longer available. They do have plenty of the 5.25" though.

[HareBrained]

I called again and it was an error, they are no longer available. They do have plenty of the 5.25" though.

90db should be possible with this driver in the MTM as well.

You know, considering a TM was an option, a TMM 2.5-way may be better if these are going to be placed away from everything else. The pt5 woofer is used for BSC and you don't have any of the lobing issues of an MTM. Just a thought that hadn't been voiced yet.

[ahaik]

90db should be possible with this driver in the MTM as well.

You know, considering a TM was an option, a TMM 2.5-way may be better if these are going to be placed away from everything else. The pt5 woofer is used for BSC and you don't have any of the lobing issues of an MTM. Just a thought that hadn't been voiced yet.

A TMM 2.5 sounds interesting, definitly an option.
Looking at the data sheet of the SEAS, H1396 I think it can be crossed pretty low.
Also if I design them to be smooth of axis (and have them not toed in) it will flatten the rising response from 7K to 16K right?

I modeled two 5.25 HDS woofers in WinISD, F3 of ~60Hz is a little higher then what I expected. Does it look right?

I aslo have a pair of RS150-4 that I am not using, not sure how much harder it will be to tame the cone breakup, they should also play much lower.

[Curt C]

How about the $24 Vifa TP16WJ-06-08?

I’ve not played with these, but if you can look past the ugly flange and the high Le, they appear intriguing:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-277

They model with an f3 of 40 Hz in 28 ltrs. tuned to 32 Hz, but they will run out of Xmax quickly. A pair should net about 102 dB max SPL, however.

I’m thinking a trim floorstander TMM with a removable front baffle. Rear mount these woofers for a clean look. I.e.: The Harbeth monitor series.

C

[ThomasW]

The 5" HDS drivers have excellent sonics. Unfortunately they're handicapped not only by their small diameter, but the 3.5mm Xmax. So you might want to consider a TMW or MTMW or MTMWW using them as the mid.

Curt's suggestion regarding the close out Vifa is a good one if there are cost limits for the project.

[ahaik]

I’ve not played with these, but if you can look past the ugly flange and the high Le, they appear intriguing:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-277

They model with an f3 of 40 Hz in 28 ltrs. tuned to 32 Hz, but they will run out of Xmax quickly. A pair should net about 102 dB max SPL, however.

I’m thinking a trim floorstander TMM with a removable front baffle. Rear mount these woofers for a clean look. I.e.: The Harbeth monitor series.

C

I actually looked at those, I modeled them too, in a 38 ltrs box tuned to ~35 Hz they showed F3 of about 33 Hz. You tuned them a little lower in a smaller box getting a more gradual roll off and a higher F3. I am trying to understand the reason, will having them roll off sooner allow them to run out of xmax 'later' resulting in higher maximum SPL? Is there a different reason?
That is a strange flange I wonder why design such a flange.

The 5" HDS drivers have excellent sonics. Unfortunately they're handicapped not only by their small diameter, but the 3.5mm Xmax. So you might want to consider a TMW or MTMW or MTMWW using them as the mid.

Curt's suggestion regarding the close out Vifa is a good one if there are cost limits for the project.

I don't have a budget in mind, my main goal here is to learn, if I get a nice sounding speaker it would be a great bonus and a motivaor.
Out of all loudspeakers I had a chance to listen too, the highs in the Statements are my favorite, they give an extra dimension that didin't exist in the others. If I choose a 3 way design, the Fountek NeoCd1.0 looks apealing to me. With the peerless HDS woofers as mids and a pair of RS180-8 in an MTMWW.
I just don't feel confident with a 3 way as a first design, on the other hand maybe I should just jump in water and learn how to swim.

[Curt C]

I actually looked at those, I modeled them too, in a 38 ltrs box tuned to ~35 Hz they showed F3 of about 33 Hz. You tuned them a little lower in a smaller box getting a more gradual roll off and a higher F3. I am trying to understand the reason, will having them roll off sooner allow them to run out of xmax 'later' resulting in higher maximum SPL? Is there a different reason?

It's just personal preference ahaik. I like to tune vented designs to emulate a sealed box rolloff down to f10 or so, if possible. I feel the lower Q of the transfer function provides tigher bass than a QB3 or other traditional vented alignments. And yes, they typically eck out an extra dB or so of SPL, but my main aim is to mitigate the 'woolyness' some vented designs have.
Here's one of my 'dubious veracity' articles that goes into a bit more detail:

http://www.geocities.com/cc00541/Sealed_v_Vented.html

That is a strange flange I wonder why design such a flange.

This is so it will fit into every car ever made. -except yours... :rofl:

I don't have a budget in mind, my main goal here is to learn, if I get a nice sounding speaker it would be a great bonus and a motivaor.
Out of all loudspeakers I had a chance to listen too, the highs in the Statements are my favorite, they give an extra dimension that didin't exist in the others. If I choose a 3 way design, the Fountek NeoCd1.0 looks apealing to me. With the peerless HDS woofers as mids and a pair of RS180-8 in an MTMWW.
I just don't feel confident with a 3 way as a first design, on the other hand maybe I should just jump in water and learn how to swim.

I'd suggest starting with a 2 way. -Plenty of information to assimilate, yet not so much that a good design cannot be created. 3 ways on the other hand add several more levels of complexity and can be overwhelming to the uninitiated.

C

[ThomasW]

With the peerless HDS woofers as mids and a pair of RS180-8 in an MTMWW.
I just don't feel confident with a 3 way as a first design, on the other hand maybe I should just jump in water and learn how to swim.

You could start with the MTM as a separate box then later add a bass module. Consider using dual 8"-10"s in the bass module

[Face]

This would make a nice build:

ScanSpeak D2904/7100-02

http://www.madisound.com/catalog/product_info.php?manufacturers_id=148&products_id=1349

Accuton C90-T6-89

http://www.madisound.com/catalog/product_info.php?cPath=45_228_254&products_id=1036

And two of Seas L26ROY 10" Subwoofer

http://www.madisound.com/catalog/product_info.php?products_id=8535

When or if overtime picks up again, this will probably be my next project.

[ahaik]

It's just personal preference ahaik. I like to tune vented designs to emulate a sealed box rolloff down to f10 or so, if possible. I feel the lower Q of the transfer function provides tigher bass than a QB3 or other traditional vented alignments. And yes, they typically eck out an extra dB or so of SPL, but my main aim is to mitigate the 'woolyness' some vented designs have.
Here's one of my 'dubious veracity' articles that goes into a bit more detail:

http://www.geocities.com/cc00541/Sealed_v_Vented.html

Thanks, thats a great explanation, now I understand. I also read Jon's post: http://www.htguide.com/forum/showthread.php4?t=33457 (second post).

This is so it will fit into every car ever made. -except yours... :rofl:

Heh... must be sold by HomeDepot then :roll:

I'd suggest starting with a 2 way. -Plenty of information to assimilate, yet not so much that a good design cannot be created. 3 ways on the other hand add several more levels of complexity and can be overwhelming to the uninitiated.

C

You could start with the MTM as a separate box then later add a bass module. Consider using dual 8"-10"s in the bass module

In general I rather compromise the low end extension and get cleaner midrange midbass. So maybe the Peerless would be a better choice for me. If sometime in the future I can add bass bins, that could be a great solution.
My question is, would the bass bins have to crossed very low (ie sub) or can I incorporate a HP filter to the mids without having to change the mids LP filter and the tweeter's HP (assuming I use woofers with adequate sensitivity), crossed somewhere in the area of 300-600 Hz?

This would make a nice build:

ScanSpeak D2904/7100-02

http://www.madisound.com/catalog/pr...roducts_id=1349

Accuton C90-T6-89

http://www.madisound.com/catalog/pr...roducts_id=1036

And two of Seas L26ROY 10" Subwoofer

http://www.madisound.com/catalog/pr...roducts_id=8535

When or if overtime picks up again, this will probably be my next project.

These are nice drivers....

Asi.

[ThomasW]

My question is, would the bass bins have to crossed very low (ie sub) or can I incorporate a HP filter to the mids without having to change the mids LP filter and the tweeter's HP (assuming I use woofers with adequate sensitivity), crossed somewhere in the area of 300-600 Hz?

To have a 'reasonable' amount of output with small midwoofers like the 5" Nomex and their 3.5mm Xmax, bass bins should probably be woofers, not subwoofers. The crossover to the bass bins can be active or passive.

[Curt C]

My question is, would the bass bins have to crossed very low (ie sub) or can I incorporate a HP filter to the mids without having to change the mids LP filter and the tweeter's HP (assuming I use woofers with adequate sensitivity), crossed somewhere in the area of 300-600 Hz? Asi.

That assumption is the main concern. IF the woofers are 'just right' then a simple series cap can potentially turn the 2 way mid/woofer crossover network into a 3 way midrange network. Often however, the mid will need to be attenuated to match the woofers, and that attenuation generally will necessitate revisiting the entire mid crossover. -At least in my experience. -But if you biamp the woofers and mid/tweet you can sidestep the sensitivity issue, perhaps even using active or line level passive crossover networks for the woofer LP and the mid HP. This will gain one of the big advantages of bi-amping: The increase in amplifier 'headroom'.

C

[ahaik]

I decided to use the Vifa woofers and keep it simple (it didn't really take me a week to decide, its just been a very bussy week).
I'm thinking an MTM with the pair of Seas Neo's that I already have, but when I did a final lookup at PE I noticed they have the Vifa D26NC-67-06 on a buyout. I'm not sure if these are the same tweeters or have the same performance as the D26 Jed uses in his lineups, I know they are considered great tweeters for the price, so $20 should be even greater, I would also like to have the opportunity to listen to those tweeters.
Any thoughts before I make my order would be appreciated.
Thanks,
Asi