Seas Prestige 3 way all metal Project

[saevox]

I have a 3 way SEAS Prestige line speakers. They are H1208, H1141, and H1212. Built these as my first speakers back in 2008 and looking to rebuild them with better cabinets and get the tweeters at a more ideal height. I was considering expanding into a MTM arrangement with another H1141 mid range driver, and adding another H1208 to the low end for a WW MTM setup. I was wondering if this would be worth my while to even rebuild these or expand them to the WWMTM. I went into this project blind on the advice of a sales rep from MadiSound. I have attached the crossover and leap modeling used to make these speakers.
I am looking for feedback from experienced and more knowledgeable builders than myself on this design and if I should pursue it or just go in another direction. I do not want to sink more money into these if they are not that great of a design.
Also if I expand the number of drivers what modifications should I make to the crossover or should I start over with a whole new design.
I have the ability to build the cabinets and more than enough tools to get them done correctly.

Attached are the LEAP and Crossover

[PeteMcK]

you haven't said why you're considering this...
(It's usually easier to start from scratch)

[saevox]

I am looking to build the cabinets better, get the tweeters ear level, flush mount the drivers. Also I would like feed back on driver alignment and the cross over from experienced eyes. Plus maybe add more drivers for future use in laeger rooms.

[oldmanaudio]

The crossover design would have to be trashed if you add a mid. If the speakers are not flush mounted just doing that will help smooth them out. I would only add more woofers if your not happy with bass. And if you are not happy with the bass adding a powered sub would be the best way to intergrate it into yor system. I would build better cabs taller to get the tweeters up to ear level and flush mount the drivers. You may want to upgrade crossover caps and coils.

[saevox]

Thanks for the responses. I just want to make sure i am not sinking money and time into somthing that maybe one of you can see an obvious flaw in. Like the mid is over extended etc. As it is now x over points are ~300 and ~2800 from what i can tell. I was considering using the rjbaudio alpheus xover design on the woofer as it is measured vs program designed and xover at 300 as well. Can I do this while leaving the remaining mid/tweet xover alone?

[navin]

Originally Posted by saevox

I was considering expanding into a MTM arrangement with another H1141 mid range driver, and adding another H1208 to the low end for a WW MTM setup.

Also if I expand the number of drivers what modifications should I make to the crossover or should I start over with a whole new design.

Originally Posted by saevox

I was considering using the rjbaudio alpheus xover design on the woofer as it is measured vs program designed and xover at 300 as well. Can I do this while leaving the remaining mid/tweet xover alone?

It is best to design the crossover from scratch.

How big is your room? According to madisound the L22 woofer is capable of 40Hz in about 25 liters but given that is is only 8" and limited Xmax it might be SPL limited so adding a second woofer should help raise the overall SPL capability of the entire system
SEAS Prestige L22RN4X/P (H1208) 8" Aluminum Cone: Madisound Speaker Store

The L22 is below 85db below 300Hz and if you are doubling up on this you would need to double up on the 1141 as well to retain the sensitivity. The other options would be to dump the 1141 (for a later project) and get the 1224 instead and build a WW MT.

H1208-08 L22RN4X/P

H1224-08 L18RNX/P

[saevox]

The room is 15' by 20', and open to the rest of the first floor, the room only has 3 walls, so about 1000 sq feet on the first floor and then upstairs......My reason for doubling drivers would be for the spl and to get more overhead.

The rjb audio xover would only be for the woofer if I kept the speaker as is with only the one woofer, his design is very similar to the leap I have for the woofer section, but his has been measured, and I feel it should be more accurate. I would keep the mid adn tweet xover as is. Is there any major flaw is this method of thought?

I saw your suggestion on the 1224, and I actually have 2 of those doing duty as my surrouds in the ZAPH SEAS L18 / SEAS 27tbfcg design....those boxes have to be redone as well....

I do not have the skills to design a 3 way x over form scratch as i have never done so, so going that route would be me having madisound leap one for me.

I guess I am on the fence right now about either rebuilding these and trying to improve them quite a bit, or buying a set of speakers like the revel F12.

Even if I do rebuild the mains and get them working, I will also have to re-do my surrounds and center as well. All I can say is I read way too little b4 building these speakers the first time and it is coming back now.

[saevox]

Was just thinking about this and I could be way off, but could I take the zaph L18 2 way and add the 1208 to it using zaph design xover for the L18/ tweeter and the rjbaudio audio woofer xover for the woofer or is there alot more to in the xover?

[saevox]

Was just thinking about this and I could be way off, but could I take the zaph L18 2 way and add the 1208 to it using zaph design xover for the L18/ tweeter and the rjbaudio audio woofer xover for the woofer or is there alot more to in the xover?

[saevox]

I was doing some more reading on this and I think I could use the Zaph L18 build http://zaphaudio.com/audio-speaker17.html. Add the L22 as a base box like RBJaudio does http://rjbaudio.com/Astorius/astorius.html. I have my mains setup to bi amp as it is and I could use the rbj audio low pass filter for the L22 and have the top end handled by the zaph l18 build.
Does this seem like a plan or am I missing something?
Also would I have to bi-amp or could I tie both sets of xovers (l18 zaph, L22 RBJ) into the same set of terminal plugs?
Then I could get 2 more L18 to handle the surround duty since I already have the tweeters.

If this all works out I will have to come up with some sort of center channel as currently I run 2 Seas L16 4 ohms and the the 27T tweeter in a vented enclosure mtm horizontal. Any suggestions on a center? I will have the 2 Seas L15 if I do the towers as described above...